Quantitative Evaluation of the Adverse Effect of Nitrate on Human Health

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Quantitative Evaluation of the Adverse Effect of Nitrate on Human Health

Executive Summary

The research project is all about the quantitative research on the effect of the nitrate contamination of the human body, For the execution of the project, not only the adult human being but also the infants have been taken into consideration as they use to get affected by the adverse effect of the nitrate contamination through the intake of the drinking water and the dietary foods. The study of nitrate contamination on the other animals has been excluded from the research subject. The secondary quantitative data collection has been considered to get the detailed view of the adverse effects of the nitrate contamination. The key incident that take place after the excessive nitrate intake or taking the contaminated nitrate is the formation of methemoglobin. The adverse effects on health,discolouration of skin, gastro genetic problem , even the death , along with the occurrence of cancer have been explained in a detailed manner But , no research has been linked with the reduction of the reproduction capacity due to the contaminated nitrate intake.

Table of Contents

Chapter 1: Introduction

1.1 Introduction to the Study

1.2 Background of the Study

1.3     Rationale of the Study

1.4 Aims and Objectives

1.5 Research Questions

1.6 Hypothesis testing:

1.7 Method of the Study

1.8 Constraints and Limitations

1.9 Structure of the Study

Chapter 2: Literature Review

2.1 Introduction

2.2 Major uses and the source of nitrate in drinking water

2.3 Environmental effect due to nitrate

2.4 Environmental levels and exposure of human being to nitrate

Air:

Water:

Food:

Projected whole exposure with relative involvement of drinking-water:

2.5 Metabolism of nitrate in human body

Absorption, assimilation, and the eliminate of nitrate

Endogenous amalgamation of nitrate and its compounds

2.6 Impact of Nitrate on Reproductive and developmental toxicity

2.7 Effects of nitrate on Humans

Methaemoglobinaemia

Babies under 3 months of age

Adults and children above the age of 3 months

Carcinogenicity

Symptoms of Nitrate problems

Other effects

2.8 Practical aspects related with the nitrate impact on human bodies

Analytical methods

Treatment and control methods and technical performance

2.9 Guideline values

2.10 Biological effects of the ingested nitrate

2.11 Nitrates in medicines

2.12 Legislation on nitrate intake

2.13 controversy with importance of nitrate and adverse effects of nitrate

2.14 Diagnosis of the Nitrate toxicity

2.15 Preventive measures

2.16 Summary

Chapter 3: Research Methodology

1.10 Research Philosophy

1.11 Research Approach

3.3 Research Design

3.4 Research Choice

3.5 Research Strategy

3.6 Data collection

3.7 Sampling Method

3.8 Research Ethics

3.9 Research Limitations

3.10 Reliability:

3.11 Summary

Chapter 4: Data Analysis and Findings

4.1 Health outcomes of Excess nitrate

4.2 Causes of methemoglobin

4.3 Exposure – response relationship

4.4 Diet

4.5 Nitrate intake

4.6 Results for the Bacterial contaminated water

4.7 Methemoglobin levels

4.8 The risk factors for the developed MethB levels

4.9 Key effects of contamination through Nitrate in drinking water and food

4.9.1 Metheglominemia

4.9.2 Cancer

4.9.3 Reproductive toxicity

4.10 Treatment plan for Metheglominemia

4.11 Discussion

Chapter 5: Conclusion and Recommendations

Conclusion

Hypothesis testing

Research limitation:

Recommendations

Scope for further research

References

Chapter 1: Introduction

1.1   Introduction to the Study

The discussion of the paper is involved with the adverse effect of the nitrate intake on the health of a human being through different intake mediums. After the indigestion of nitrate in the body, it gets transformed into different forms. The transformation of nitrate into NaNO3 enhances the exercise tolerance, reduces the blood pressure, and lowers down the oxygen functionality in the human body in an adverse manner (Kim, et al., 2015). The absorption of nitrate through food and drinks cross the placenta results into fetal methaemoglobinaemia is human being along within other animals. It also reacts with the stomach with the nitrosatable compounds in order to form N – nitroso compounds and adverse notarisation takes place in an effective manner. The intake of excess nitrate also leads towards the infection and diarrhea to the human being in an adverse manner (Habermeyer, et al., 2015). Thus, it is required by the physicians as well as the health care providers to understand the intake level of the nitrate in the human body to avoid any infection, or hazardous effect (Weitzberg & Lundberg, 2013). The acute gained methaemoglobinaemia is the most important adverse effect due to the ingestion of inhalation of the nitrate in the human body. It is generally caused by the excessive intake of the nitrate. The similar effects are subjected to be faced by the human victim whether the nitrate compounds re inhaled, ingested, or is produced in the video from the nitrate substances (Kim, et al., 2015).

Nitrate is an inorganic chemical that use to get highly soluble in water. Thus, the major origin of the nitrate is the drinking water which includes the sewage, animal wastage, and fertilizers. These resources get mixed up with the blood of the human body and different hazardous effects take place in the body of the human being. Thus, the detailed quantitative analysis of the nitrate in terms of affected population in the global market and level of the presence of nitrate in the food and water level is required to be understood along with the exposure of the nitrate towards the adverse effect on the human being is required to get a detailed knowledge (Bryan & van Grinsven, 2013).Based on the all the discussion, the first chapter has discussed regarding the introduction to the dissertation with brief idea about the nitrate elements and its functionality , along with the background of the study , rationale as the importance to perform the dissertation, the aims and objectives of the study to be met , the establishment of the hypothesis to test the statement as the adverse effects of nitrate on human body, and method of the study as well as the limitations of the study to be performed.

1.2   Background of the Study

Nitrate is the most hazardous inorganic element as it gets converted into the nitrite (Bryan & van Grinsven, 2013). After the intake of nitrate through food or through drinks, it gets converted to nitrite and gets mixed up with the saliva of the people those are in taking the food or drinks. It also affects the gastrointestinal tract of the infants. The infants covert 10 percent of the consumed nitrate than the old or adults of 5 percent conversion rate those are consuming the nitrate through the different media (Erisman, et al., 2013).The World health organisation has estimated the daily mean dietary intake is form 43 to 141 mg. the vegetables we eat constitute a large amount of nitrates. It has been reported by the National academy of sciences that 87 percent of the dietary nitrate intake that the human being does come through the foods in terms of vegetables. There are several factors which are required to know for the accumulation of the nitrates in the vegetables and also can lead to the high level of concentration of the nitrate accumulation in an effective manner (Jamaludin, et al., 2013). There are various kinds of the adverse effects of the nitrate consumption, such as short term effect, long term effect, cancer causing effect, and reproductive effects. Thus, it is the serious concern to discuss regarding the exposure rate and the causes along with the preventive steps, so that the wider population of the global market can be kept away from the adverse effects of nitrate.

As the nitrate hazardous amount is getting increased day by day through the diet medium of the human being, it is crucial to get the clear idea about the most common sources of Nitrate in the people’s diet so that the adverse effects can be controlled (Hord, et al., 2011). At the same time, it is also important to measure the safety rate of drinking the water, the water test for nitrate, way to lowering down the amount if nitrate in the water source as well as in the other food medium source.

1.3 Rationale of the Study

The rationale of the research study has discussed regarding the importance of discussing the topic and make a dissertation on that. The purpose of this section is to understand the importance of the nitrate in the human body and the adverse effect of the excessive nitrate presence inside the body of the human being. The importance to understand the modes of the nitrate spread in the human body in terms of water and food to investigate the effect of the exposure of nitrates on the human body.As already discussed that methaemoglobinaemia is the most important effect of the nitrate intake (Khan, et al., 2013). Methaemoglobinaemia also is termed as the “Blue bay disease”. It so has some symptoms as below:

  • 3 – 15 percent slight discoloration of the skin.
  • 15 – 20 percent cyanosis
  • 25 – 50 a percent headache, weakness, palpitations, chest pain, and others (Kim, et al., 2015)

Apart from that, there are other effects as well in terms of Hematologic effects, cardiovascular effects, Reproductive effects, carcinogenicity, and others. Thus, it is with utmost importance to execute the study to get the detailed analysis of the amount of the nitrate intake requirement and the level of the nitrate intake to be considered as the excessive nitrate intake.

1.4  Aims and Objectives

The underlying study would be done highlighting the modes of nitrate transfer and the hazardous exposure of nitrate to the human being. Thus, it is important to establish certain aims and objectives to justify the work to be done based on the subject topic in an effective manner. The aims and objectives related to the important thesis paper to get the complete idea regarding the functionality of the nitrate in the human body as the hazardous effect of ingestion of the contaminated water by nitrate and contaminate foods are important to discuss. The aim of the research is as below:

“To evaluate the adverse effects of the nitrate on the human body quantitatively”. Based on the research aim, the research objectives have been framed into the small divisions.

The objectives of the research paper are as below:

  • To Identify the most predominant modes humans get exposed to nitrates
  • To investigate the effect of exposure to nitrate on humans
  • To determine specific health hazard associated with different levels of exposure

1.5  Research Questions

Research questions are important to set based on the research objectives to meet the research criteria in an effective manner.Based on the research aims and objectives, the research questions are as below:

  1. What are the most predominant modes humans get exposed to nitrates?
  2. What are the effects of exposure to nitrate on humans?
  3. What is the specific health hazard associated with different levels of exposure?

Based on the research questions, the entire thesis paper is about to get framed.

1.6  Hypothesis testing:

The set of the hypothesis for the research conduction is as below:

HO: there are adverse effects of nitrate intake on the human being

H1: there are no adverse effects of nitrate intake on the human being

Based on the hypothesis testing the research outcome will be concluded.

1.7  Method of the Study

As desired for the sake of the research study, some objectives have been formed for the requirement of the study to catch the predominant modes humans get exposed to nitrates. The secondary research has been undertaken based on the already established data regarding the effects of the nitrate intake in a human being and its hazardous effects in an effective manner. The research study would be directed focusing on the integrity of the subject matter at the most.It is for the most determined objective of the research study that it could be well associated with the method of the study of understanding the mode of the transferring the nitrate to the human body and getting affected of the human being with the hazardous effects of nitrates to create a hindrance in the normal flow of life of the human being. In favour of the study, the secondary data from the authenticated resources have been collected to get the aims and objectives set for the research to be met. The perfect evaluation of the research outcome has been done to make the project a successful one in an effective manner. Numerous resources have been verified to cross check the information received from one source with the similar information received from another source.

1.8  Constraints and Limitations

The purpose of the research study is to identify the mode of transfer of nitrate and the conversion of nitrate to nitrite to pose a threat to the human being by their hazardous effects. It has been decided to take the secondary resources as the due to the secondary qualitative and quantitative data collection method. The research study is only based on the human being. It could have better research paper, if the threat to the plant and agriculture due to the nitrate pollution would be done. Thus, the target population to identify the adverse effects of the nitrate is the key constraints by limiting the study on the human being. At the same time, the time as also the crucial limitation, otherwise more data could have been researched to get the better outcome of the research project. Thus, in a nutshell, it can be stated that the topic of the effects of nitrates and the time limitation are the two most important limitations for the perfect execution of the study.

1.9  Structure of the Study

The researcher to perform the research study efficiently required to prepare a definite structure for the dissertation. Based on that concept, he has come up with a definite structure which would assist in the process of study. The following dissertation structure has been offered to conduct the study in a complete and integrated way.

Chapter 1: Introduction

This is the introductory chapter. The researcher has taken the attempt to give the overview of the study to be done through the research background, introduction to the research to let the readers know regarding the subject to be discussed in the entire dissertation. At the same time, the aims and objectives also have been established by the researcher to meet the requirement of the study and to draw an outline regarding the topics to be discussed. Based on the aims an objectives, the research questions also have been set. The method of the research to be conducted also has been described by the researcher in this first chapter to get the overview regarding the process of execution. Further, the chapter has been commenced by drawing the obstacles and limitations in a proper manner.

Chapter 2 Literature review

This is the second chapter. In this chapter, the researcher has discussed regarding the theoretic aspects of the subject topic. The basic idea of nitrate and its functionality and good and bad effects have been discussed in this chapter with the help of the suitable formulation and diagram to highlight the theatrical aspects in an effective manner.

Chapter 3: Research Methodology

This is the third chapter of the dissertation. This chapter has been dealt with the research processes and methods with the help of that the entire research process has been executed. The research philosophy, research approach, research design, research choice, research strategy, sampling method, ethics related with the research process, limitations of the research have been discussed to give the overview of the process execution in a proper manner by the researcher.

Chapter 4: Findings and analysis

This is the fourth chapter done by the researcher and it is considered the most crucial chapter as it is directly associated with the outcome of the research prices. The accumulation of the required secondary data from the authentic sources, and the analysis and discuss of those data to meet the objectives set at the initial phase of the research are the process flow in this chapter.

Chapter 5: conclusion and recommendations

This is the last and fifth chapter of the dissertation. The summary of all the chapters in the form of the objective meet is executed in this chapter in an effective manner.Along with the conclusion, recommendations also are offered by the researchers to the previous research work done by others to get the better outcome of the process and process requirement.

Chapter 2: Literature Review

2.1 Introduction

A literature review is the specific section of the research project to highlight the theoretical aspects of the subject topic. It is also termed as the chapter with the detailed analysis of any subject topic. The present research aims at the identification of the adverse effects of nitrate on the human body. Thus, through the literature review, the indepth as well as the extensive background of the research topic has been discussed. The prevailing literature, journals, websites have been reviewed to bring to light all the related work done on the present issue and to make the research outcome more successful. Thus, with the help of this literature review, the following aspects have been covered:

  • Major uses and the source of nitrate in drinking water
  • Environmental effect due to nitrate
  • Environmental levels and exposure of human being to nitrate
  • Agricultural process for the minimization of the nitrate accumulation in vegetables
  • Projected whole exposure with relative involvement of drinking-water
  • Practical aspects related with the nitrate impact on human bodies
  • Treatment and control
  • Legislations related to the nitrate intake
  • Impact of Nitrate on Reproductive and developmental toxicity
  • Diagnosis of the Nitrate toxicity
  • Preventive measures

Lastly, the entire chapter has been summarised for the overall review of the literature review aspects.

2.2 Major uses and the source of nitrate in drinking water

The usage of Nitrate is based on the development of the inorganic fertilizers. The composition of nitrate is used as the oxidising agent and also is used for the development of explosives. Thus, during the preparation of those explosives, the harmful chemicals use to have a bad impact on the different organs of the human body due to its rate of poison toxic inside (Kumar & Puri, 2012). On the other hand, the purified potassium nitrate is used for the glass making, this compound of nitrate also is harmful to the human body. On the other hand, the sodium nitrate is used as the preservative for food, especially for the preservation of meats. Nitrates are spontaneously formed inside the plants. This is the basic nutrient that the plant required for their living. Nitrate and nitrite also form in mammals including the human being spontaneous. Through Saliva, the nitrate uses to get secreted and get formed into the nitrate compound by oral microflora (Cosgrove & Rijsberman, 2014).

During the agricultural activity, the nitrate use to reach both the surface water and the underground water. The natural nitrate from the plants and the additional nitrates through the fertilizer get mixed up with the water which is the transferred to the plants. Thus, the excess nitrate poses threat to the human body as there is some limitation for the intake of the nitrate for the human body. Nitrate also is formed by the waste water treatment of the animal excreta and also it formed chemically in the distribution pipe due to the Nitrosomonas bacteria from the stagnant and nitrate containing drinking water at the galvanized steel pipes. Thus, proper steps should be followed so that the nitrate level in water can be balanced and the level of nitrate intake required for the human body will be maintained in an effective manner. These are the key issues ad sources of nitrate in using the drinking water (Hurley, et al., 2012).

2.3 Environmental effect due to nitrate

The environmental effect of nitrate also poses threat to the human body as the environments factors have a deep effect on the functionality of human being. The fertilizers containing inorganic wastes and the nitrogen are decomposed in soil to for the ammonia. This formed ammonia is then gets converted into the nitrite and nitrates. These freshly formed nitrates are used by the plants for the execution of the synthesis for the purpose of their individual growth. The additional nitrate moves to the soil due to the no use (Westhoek, et al., 2014). But, the amount of the nitrate accumulation gets increased at down to the lower level of soil ground, no plant lives to take the excess nitrate for their living status, and it’s also cannot get formed to another form of chemical to be used for other purposes. Thus, the water at the lower level gets poisoned with the excess water which is the limit of the nitrate intake by human beings and other mammals.

Degradation occurs in soil to some small extent and rocks use to get degraded to the aquifer. There are also other factors those can control the amount of nitrate to get deposited in the soil. The low or high level of water tables, the amount of the water of rain, the existence of the different organic materials are the determinant facts of the amount of nitrate in soil (Velthof, et al., 2014).              The surface water also becomes nitrate and denitrated based on the temperature of the soil and the level of the PH in the oil. Apart from the soil and the water medium, nitrogen compound also gets generated in air form the industrial gas releases, and the gas releases from the vehicles. In the air the presence of the nitrates is usually in the form of the nitric acid, which is also not good for the different organ functionality of the human body. Thus, the presence of nitrate in soil, water, and air for the poisonous effects on the human body during the intake of the nitrate through this medium in an excess amount.

2.4 Environmental levels and exposure of human being to nitrate

The environment levels and the exposure of human being to the nitre can be determined by the nitrate presence in air, water, food. The detailed description is as below:

Air:

The concentration of the nitrate in atmosphere use to range from 0.1 to 4µg/m3. The lowest concentration of this nitrate amount in water has been observed in water of South Pacific. On the other hand, the highest amount in nitrate in air level is for 1 – 404µg/m3. In Netherlands, the contamination of the nitrate has been reported as 1 to 144µg/m3 (Purves, 2012).

Water:

In the industrial areas, the concentration of nitrate in the rain water has been observed at the high level. But, in compared with that the amount of the nitrate in rainwater at the rural place are lower due to the no presence of the industrial waste gasses presence. The high level of the nitrate accumulation in the industrial places in water has been reported as               5mg/1 (Boas, et al., 2012). The surface water’s nitrate concentration is generally low with the value of 0 – 18mg/1. But, this amount also may get increased due to the excess presence of the human and animal wastes. Thus, based on the amount of deposited waste through a different medium, the concentration of nitrate use to get increased. The amount of nitrates in water has increased by double amount during the past 20 years. In the UK as well, the amount of the nitrate presence in water get increased annually by 0.7mg/1, which is high in level. The concentration of the nitrate in ground water under the aerobic condition is only a few milligrams per liter and strongly the amount is based on the type of the soil and the geological situation in an effective manner.

The USA use to get affected by the amount of nitrate and nitrite at different levels. The country gets affected by the nitrate amount of 4 – 9 mg/1, and with nitrite of 0.3mg/1 (Erisman, et al., 2013). On the other hand, the high concentration of the nitrate presence has been reported for India with the amount of1500mg/1, which is excess in amount, Thus, the human population of nitrate is affected by the adverse effects of the excess nitrate in a great manner. Based on that some precautionary measures should be taken by the industrialists for the less mount of the nitrate and the nitrite deposition in water and air through their manufacturing process. In the USA, the presence of nitrates can be observed in the ground and the surface water at 20mg / 1 based on the below level 4mg/1. This increase can be considered as the 3 percent excess. On the other hand, for the ground water, the excess nitrate presence can be observed with 6 percent(Porteous, 2013). The progressive level of the nitrate in surface and the groundwater levels for the last 20 years are responsible for the excessive usage of the chemical fertilizers, and the disposal of the waste through the industries, through the farmers during application of the fertilisers, and also due to the human and other animal waste deposition.In maximum countries, the nitrate levels in the drinking water do not get exceeded of 10mg/1. But, in some countries, the amount of the deposition in higher due to the contamination through the sewage effluents and the industrial wastes. Out of the entire European countries, 15 countries are exposed to the contaminated water with the nitrate level above 50 mg /l, ranging from 0.5 percent to the 10 percent in level (Freeman III, et al., 2014). Through this incidence, 10 million people of these 15 Europe countries gets affected. In the industrial areas, due to the release of the industrial waste, the toxicity of the water get an increase above 50 mg /l. based on the level of the toxicities, the amount of the nitrate presence in Netherlands water has been reported as 0.1 mg/l. But, the maximum value of the nitrate in the drinking water has been reported as 0.21 mg/l in the year 1993 (Freeman III, et al., 2014). Thus, it can be stated that Netherlands is the country to control their industrial release and preventing to get the drinking water contaminated by the effect of the nitrate.

Apart from that discussion, it also can be mentioned that the Chloramination may result to the development of the nitrate presence in the distribution system. Based on the fact, the concentration of the amount of the nitrate gets raised as the water moves towards the central system. In this aspect, it is crucial to mention the fact that the Nitrification in the distribution systems can increase the levels of nitrate by 0.2 – 1.5 mg / l (Freeman III, et al., 2014).

Food:

Vegetables, meat, fish, and the dairy products are enriched with the nitrate as per the requirement of the human body. But, due to the usage of the fertilizers and the pesticides in the agricultural fields and also the usage of the chemicals in the water body for the growth of the fish, the vegetables, as well as the fishes and indirectly the meat and the dairy products are getting contaminated by the excess nitrate amount. The meat products contain less than 2.7 to 945mg of nitrate in one kilogram of the amount. On the other hand, the dairy products contain less the 3 to 27 mg nitrate per kilogram, and less than 0.2 – 1.7 mg of nitrite per kilogram (Fordyce, 2013). It also has been reported that there are many fruits which contain 20 – 25 mg of nitrate per kilogram. Thus, the direct effect of the nitrate presence in fertilizers can be observed in the fruits.There are also some vegetates like Beetroot, spinach, lettuce in which the presence of the nitrate amount is more than 2500 gm per kilogram (Erisman, et al., 2013). Thus, the extreme direct effect of the nitrate enriched fertilizers effects, the soil temperature and the intensity of the soil can be observed in the presence of their nitrate level. The amount of the nitrate level in those vegetables also get increased when they are specially cultivated under the greenhouse supervision.

This nitrate contamination comes from the different environment factors as mentioned below:

Contamination from soil

Nitrate use to move from the bulk amount of soil to the root of the surface water by the process of convection rather than the process of diffusion. Therefore, the storage of water is about to restrict the nitrate uptake. The excess water quantity in soil makes the nitrate diluted in the soil solution and also can convert it to the soil anoxic. It further restricts the growth of the crop. It also causes the loss of nitrate by the help of the process named Denitrification(Jamaludin, et al., 2013). On the other hand, studies also have revealed the fact that type of the soil, and the content of the mineral in the soil use to affect the accumulation of nitrate in an effective manner.

Contamination from the intensity of light

Along with the soil presence, the intensity of the light also controls the accumulation of nitrate in the vegetables. The perfect assimilation and the process of the photosynthetic transport of the electrons to the leafs highlight the fact that the light intensity is the key contributing factor to the nitrite accumulation in the leaves of the vegetation in a direct manner. The intensity of the sunlight varies from month to month. Based on the fact, the accumulation of nitrate in vegetable varies from one month to another month. The crops are sown in winter and highly enriched with the nitrate rather than the summer son corps due to the variation of the light intensity. Based on the intensity of the sunlight, the Northern Europe crops have higher nitrate leveled crops rather than the Southern crops (Bickel & Friedrich, 2013). The UK crop assurance protocols have suggested the agricultural developer avoid the sown of the lettuce crop during the dull condition of weather. The same thing happens when the crops are grown under the supervision of the glass house condition based on the intensity of light. This statement reflects the truth that the shading of crops should be avoided to get the better nitrate enriched vegetables.

Contamination through the specific nitrogen fertilizer

The components in the nitrogen fertilizers are nitrate, urea, ammonia, and also other forms nitrate. After the application of the nitrogen based fertilizers, the concentration of nitrate use to get increased in the xylem of the plants. But the accumulation of the nitrogen does not affect much on the phloem of the plants. Based on the occurrence, the lettuce, and cabbage have reflected the high concentration of nitrate accumulation as the repose to the nitrogen fertilizers (Wick, et al., 2012). But, on the other hand, the storage organs of the vegetation in terms of peas and beans usually are fed by the Phloem.

Agricultural process for the minimization of the nitrate accumulation in vegetables

A special scheme named GAP has been developed for the sake of the farmers to understand the rules and regulation based on the legislation about the nitrate amount in vegetates and also to make them alert regarding the less concentration of nitre and its related compounds in their full grown vegetation. This scheme was produced by each and every member state. Each and every GAP is stuffed with the current violable knowledge regarding the vegetation process, recommendations offerings based on the experiments done by addressing the agricultural, economic, socially sustainable, and environmental impacts in an effective manner (Maggio, et al., 2013) .

The different GAP schemes use to operate under the different climate condition as the light intensity impact on the nitrate accumulation in vegetables in great amount. The abiotic factor is the common factor for all the GAP schemes. As per the GAP scheme, it has been suggested to the agricultural develop not to offer any shed to the vegetation where the crops are grown under the glass shed and under the plastic shed. The GAP scheme also make the farmers alter regarding the “untimely nitrate”. This statement refers to the point to not offer the nitrogen based fertilisers when the soil is not required of the same. Different agricultural studs also have revealed the fact that the greater concentration of nitrogen can be observed at the outer layer of the lettuce leaves rather than the inner layer (Cannazza, 2014). Thus, it has been recommended to the farmers to take the approach of regular basis trimming of the outer and older labs so that the accumulation of nitrate and nitrogen will be balanced in an effective manner. Thus, it is recommended to the growers to that they should aim for the big head weights to get trimmed. On the other hand , as the second recommendation , the intre alia analysis of the growing medium , and the harvest gap so that the nitrogen will get time to regenerate themselves in the soil as per the requirement of the normal full grown vegetation. Thus, it can be stated that GAP scheme has supported the farmers to cultivate their crops to get the better outcome.

Projected whole exposure with relative involvement of drinking-water:

The pollution in air can be considered as the minor source of nitrate exposure. The maximum amount of the nitrate presence can be observed in the vegetables and then followed by the nitrate levels in the drinking water. The situation , when the amount of the nitrate get increased in drinking water with the exceeding level of 50mg/l, the drinking water will become the major source for nitrate intake , especially for the bottle infants , as the key medium in water based solutions and mother milk. In the region like Netherlands, average exposure of the population to the nitrate is 140mg of nitrate in a day. The drinking water nitre intake contribution in this aspect is less than 14 percent(Hrudey, et al., 2013).

It has been reported by WHO that the dietary intake nitrate presence is from 43 to 131mg of nitrate per day and also from 1.2 to 3mg of nitrate in a day. In UK, the total nitrate intake in a day ranges from 50 to 81 mg per person which varies for Denmark with 70 to 172 mg, for Germany 70 to 110mg per person (Hrudey, et al., 2013). The presence of the nitrate in the cured meat has been reported as the 70 percent of the intake of the dietary products. The amount of the nitrate amount from all the required sources of the human been is accounted for less than 0.1 to 8.7 mg per day per person. At the same time, it also has been indicated by EFCA in the year 2008, that the requirement of the average consumption of the nitrate for a full grown human body is from 91 to 141mg.

2.5 Metabolism of nitrate in human body

Absorption, assimilation, and the eliminate of nitrate

After the intake of nitrate and nitrate related compounds, it gets absorbed by the upper small intestine at the initial stage. The nitrate compound in the form of nitrite gets absorbed directly by the stomach and the upper small intestine. Before the absorption of the nitrate compound, part of the compound gets reacted with the gastric juice contents (Hammes, 2012). The 20 percent of the ingested nitrate gets mixed with saliva where the concentration of the nitrate is ten times stronger than in plasma. The responsible factors for this strength are bioconcentration in an effective manner. It has been proved by many researchers that the usage of the antibacterial mouthwash destroys the nitrate amount in saliva.

The distribution and the assimilation of the nitrate take place in a great manner through the tissues. The fact also has been highlighted that 25 percent of the nitrate gets secreted into saliva. Out of this 20 percent, only 20 percent of the amount gets converted to the nitrite due to the bacterial reaction in saliva. Further, the small amount the nitrate is swallowed and re entre through stomach and the upper small intestine. The bacterial reduction takes place in stomach due to the effects of the gastric acidity and due to the intake of the antacids (strong chemical compound) by the human body. After the absorption of the nitrite, it gets oxidized into the nitrate for to get mixed with the blood of the human body (Abubucker, et al., 2012). Through the oxidation of the hemoglobin to mathaemoglobin, the nitrate gets involved in a large amount. It also has been reported that the nitrite use to cross the placenta and cause the formation of fetalmathaemoglobin in other animals rather than the human body. This fetalmathaemoglobin use to react in the stomach with the nitrosatable compounds. This type of the notarisation also is valid for the human body in an effective manner. The WHO has declared the fact through their studies that the maximum amount of ingested nitrate use to get excreted through urine in the form of nitrate (Larsen, et al., 2014).

Endogenous amalgamation of nitrate and its compounds

The excess amount excretion of nitre has been observed just after the low amount of nitrite and the nitrate intake in the human body. This low amount of intake accounts for 1mmol/ day which is equivalent to the 62 mg of nitrate per day. This amount again is equivalent to 14 mg of nitrate – nitrogen in a day. On the other hand, the excretion of the nitrate gets increased due to the gastrointestinal infections in the human body. This incident results in the endogenous synthesis. The endogenous synthesis of nitrate and its compounds with induced infections has been observed in the human body (Pagliano, et al., 2012). In this aspect, it is also important to mention the fact that this endogenous infection result into diarrhoea.

The excretion of the nitrate due to the excess intake of the nitrate in a human being has been reported in the year 1916. But, this result has been canceled after the 1970s. This result has been derived after the examination just because of the potential involvement of nitrate in the endogenous synthesis process in the human body. The researchers also have derived the fact regarding the production of 1mmol nitrate per day in the human body. The most important media for the endogenous nitrate production is by the conversion of the arginine by the macrophages to nitric oxide in a positive manner. Along with the macrophages, there are also other cells in the human body those are responsible for the formation of nitrate by the arginine. On the other hand, under certain critical situations, the bacteria can be formed from the nitric oxide from the arginine. These process also can lead towards the nitrosation of the amines at the natural Ph Value in an effective manner (Erisman, et al., 2013).

The studies through Vitro and Vivo have reflected the fact that the amount of nitrate can be reduced by the effect of the nitrite. Due to the bacterial and the mammalian metabolic medium. In the human body, saliva is the great source of the formation of nitre automatically inside body along with the intake of the nitrate form the food, water and air sources. Out of the total amount, 5 percent of the nitrate gets into converted to the nitrite. During the nitrate intake, absorption, assimilation elimination form the body, the direct co-relation has been observed among the gastric PH, gastric nitrite concentration, and bacterial colonisation in an aggressive manner.

2.6 Impact of Nitrate on Reproductive and developmental toxicity

The impaired reproductive behaviour has been observed for guinea pig which is more or less similar that of the human body. The nitrite is more toxic than the nitrate in this aspect. The dose of the nitrate for the impacted reproductive behaviour is 30000mg of potassium nitrate per liter.But for the other mammals such as rabbit the dose for such impaired reproductive behaviour is 250 or 500 mg of nitrate per liter of water. Thus, it is required by the human being to control the intake of the nitrate and the nitrate related compounds so that they will be able to reduce down the impaired reproductive behaviour in an effective manner.

2.7 Effects of nitrate on Humans

This section has discussed the theoretical perspective regarding the adverse effects of the excess amount of nitrate in the human below in a descriptive manner.

Methaemoglobinaemia

By the effect of the reduction of the nitrite, the toxicity level of the nitrate in the human body uses to get reduced in an aggressive manner. The oxidation of normal Hb to metHb is the resultant fact for the biological effect of the nitrite in the human bodies. The formation of the metHb becomes the factor as the hindrance for the supply of the oxygen to the tissues. When the newly formed metHb concentration reaches the 10 percent of the concentration level of HB, then the rate of the oxygen transport to the tissues get decreased. This effect is called the Methaemoglobinaemia(Bradberry, 2012).As the normal metHb concentration level in human is less than 2 percent as well as in infant, the concentration level is less than 3 percent, Thus, the concentration level by reaching 10 percent of the Hb level is quite high to support the transport of the oxygen to the tissues to maintain the proper functionality of the human body due to the support of the oxygen (Martinez, et al., 2013).

The formation of metHb in the infants from the Hb is more vulnerable than the old adults. Thus, they use to get affected by the slow supply of the oxygen to the tissues in reduced form than the older one. The reduced amount of NADH (nicotinamide adenine dinucleotide) does not reach the reference level in the blood until the age of 4 months. This results in the reduction of the methB level to get back to the level of Hb. The net application of the doses of nitrite in the infant body causes the greater formation of metHb in the body of the infants to have the adverse effect of nitrate intake. Due to the high exposure of the nitrate dose application in the infants pose the higher reduction of the nitrate by the nitrite with the help of the gastric bacteria which is due to the result of the low production of the gastric acid. Apart from that, there are also the incidents of the infections of the gastrointestinal which again results in the methB formation through the pathway of the nitric oxide. Though the gastrointestinal infection is the greatest contributor to the formation of metHb, but on the other hand, the high nitrate concentration above 100mg / l also is the great contributor to the formation of metHb(Hmelak Gorenjak & Cencič, 2013). Based on the occurrences, it can be stated that the microbiological quantity maintenance in drinking water is important along with the maintenance of the proper hygiene to protect the health factors.

Babies under 3 months of age

The incidents of Methaemoglobinaemia for the lower level of the nitrate intake is restricted fort human bodies of an infant under the age of 3 months. The children those are below the age of 3 months, the conversion rate of nitrate to nitrite and the formation of methB is low then the children of older age. The toxic effects can be included in this case.As per the view of Pawełczyk (2012), it can be assumed that for 80 percent reduction of nitrate to nitrate for these small aged children, the doses of toxic are ranging from 1.5 to 2.7mg of nitrate per kilogram of the body weight.

Adults and children above the age of 3 months

Due to the excess amount of the nitrate intake the Methaemoglobinaemia use to take place in the human bodies. In this discussion, it is also important to discuss that the accidental human intoxications have reported as the adverse presence of nitrite in food materials. The lethal dose in the oral form has been reported as the 33 to 250mg of nitrite per kilogram of the human body. Further, the toxic doses result into the Methaemoglobinaemia ranging from 0.4 to 200mg per kilogram of the body weight in an effective manner. It is also important to discuss in this aspect that the nitrite toxicity in the human body uses to get raised due to the intake of the sodium nitrate as the medication application to the human body (Karr, 2012). The scientists have revealed the fact that the doses of 30 – 300mg per person do not cause the toxic effects of the nitrate intake in the human body of children with above 3 months of age. Though the intoxication depends upon the nitrate intake dose, but few cases of methaemoglobinaemia has been observed on few older children. A perfect correlation among the children of aged between 1 – 8 years have been established by the USA scientists. The scientists were unable to find out nay correlation between the 64 children consumed the high nitrate drinking water and among the 38 children consuming the low nitrate drinking water. The concentrations were between 100 – 150 and less than 44 mg nitrate per liter.

Carcinogenicity

It has been mentioned by Kapil, et al. (2014), that nitrate has been observed that its use to react with the nitrosatable compounds those are present in the human stomach. After reacting with the nitrosatable compounds in the stomach, they form into the N-nitroso compounds. The N-Nitroso compounds carcinogenic in the human body are also carcinogenic that means they may cause cancer to the human being. This type of the formation of N-Nitroso compounds also has been observed in different animals but is more prominent for the Human body. Based on the fact the perfect link between the cancer risk and the nitrosation has been established in an effective manner.The geographical correlations also have reflected the fact that there is a strong relation between the estimated nitrate intake and the gastric cancer risk. The United States National research council have mentioned some suggestions regarding the perfect association of high nitrate intake and Gastric cancer in the human body (Cannazza, 2014). But, a close link has been rejected by World health organisation due to the lack of the proper evidence and the regular occurrence of gastric cancer due to the excess intake of the nitrate and its compounds. In this aspect, it also has been stated by WHO that the nitrate source form vegetables, the concentration of nitrate in the drinking water, as well as nitrate exposure to dust have not shown any evidence for the occurrence of gastric cancer due to these facts. As a solution of the traditional concept regarding the exposure of nitrate on the occurrence of gastric cancer, the intake of the vegetables filled with vitamin E, C decreases the risk of gastric cancer in a human being (Bryan & van Grinsven, 2013).

Symptoms of Nitrate problems

There are many regular symptoms those are associated with the intake of the excess nitrate. The general symptoms are as below:

  • Poor appetite problem in a human being: due to the effects of the high-level nitrate intake, the human body use to suffer from the low appetite problem. Thus, the growth of the human body as per the requirement, use to get stopped, and the proper body functionality also uses to get imbalanced.
  • Weak claves: due to the presence of the excess amount of nitrate, the calves also born as weak to get a stand on their own feet due to the poisonous effects of the toxics.
  • Abortions in pregnant women: the high-level nitrate intake by the pregnant woman also pose a threat to them in terms of the increased level of the abortion rate (Münzel, et al., 2013).
  • Poor growth of kid or children: the excess nitrate intake or the lower nitrate intake also pose a threat to the kid or child from the proper growth. The growth in terms of height and the body weight get affected by the excess nitrate intake due to its toxic effect in an effective manner.

Apart from these, some chronic disease, the nutritional, or some managerial problems. Thus, it is required to come to the conclusion regarding the adverse effects of nitrate. Thus, based on the general and the chronic causes, it has been proved that it is of utmost importance to check the amount of nitrate in the water and in another food medium so that the chronic disease can be reduced in intensity.

Other effects

As other effects of the excessive nitrate exposure, the congenital malformations can be highlighted linked with the presence of the excess level nitrate in drinking water in Australia, but the observation based on Australian occurrences, the link cannot be confirmed. On the other hand, there is no strong evidence to prove this link. Apart from the gastric cancer risk, cardiovascular effects, the study based on the adverse effect of the excess nitrate intake on the thyroid. There were also the indications for the antithyroid effect of nitrate on the human body. In this aspect, it is most important to mention the point that if the dietary iodine is available through the food to a human being with the amount of 150 – 30µg per day, the effects of the nitrate use to get decreased at an alarming rate. It also tends to be to the zero amount(Bryan & van Grinsven, 2013). The effect of nitrate on the thyroid also may be posing as a strong impact if the deficiency of the iodine exists in a normal manner.

The high linkage between the high nitrate concentrations in the drinking water, and the goitre incidence in an effective manner has been highlighted by Bryan & van Grinsven (2013). The presence of the inorganic nitrate in the drinking water also is associated with the occurrence of endemic goitre. There are also various studies those have revealed the fact that the dose of nitrate in water is more strong on the occurrence of the adverse effects on the human body rather than the dose of nitrate in goods as nitrated s are more soluble in water medium to get mixed with the blood content of the human body and to have a strong impact in the body parts in a more faster rate. In contrary, there are several studied regarding the subject topic which was not able to find any direct relationship between the intake of nitrate and thyroid infection. As there are a large number of factors that may create a hindrance in the epidemiological studies, it is important to consider the studies as sufficiently understandable of nitrate intake as the most important factors but to maintain the level of the nitrate intake so that any adverse impact will not take place.

2.8 Practical aspects related with the nitrate impact on human bodies

Analytical methods

The spectrometric techniques are used for the identification of the nitrate intensity in water. The average rate of the nitrate presence in water is 0.01 mg / l to 1mg / l. for the detection of the nitrate presence in the potable water the molecular absorption spectrometric techniques are used by the scientists. The average limitation of the nitrate presence in the potable water is from 0.005 – 0.001mg / l. on the other hand, the nitrate and the nitrite dissolved in water also can be determined by the help of the chromatography (DiMaio, 2015). The level is down to the level of 0.1g / l for nitrate, and 0.05mg/l for nitrite.

Treatment and control methods and technical performance

As per the view of Rodgers, et al. (2016), the preservation of the contamination in the groundwater is the most effective way to control the amount of the nitrate in this water.This preservation of the contamination process also is defined as the best practice in the agricultural process in terms of careful siting of the latrines, septic tanks, management of the fertilizers in a proper manner. Sewage control, waste release to the water, and also the storage of the animal manures. Methemoglobinemia is closely associated with the private wells. It is required to make sure that the septic tanks, and latrines are not situated inform of the private well to prevent the incident of toxics and nitrates from the human waste and animals waste to get mixed with the groundwater and to enter into the human body in the form of the drinking water. At the same time, it is also required to manage the waste release of household manures and fertilizers in an effective manner to prevent the ground water from becoming contaminated. The well should be perfectly protected to prevent the runoff water to get mixed with the groundwater (Tille, 2015). The water collected for the ground water should be boiled or disinfected by some other means before consumption of the same. Thus, protection should be taken to prevent the well to get contaminated and also to consume the water free from nitrate and the microbiological contaminations to avoid the adverse effects on the human body.

The wells those are common in the rural areas, the proper attention awareness programs should be set for the mothers or expecting mothers as their target audiometer. They should be made aware regarding the requirement of safe water consumption and also should be made aware regarding the ways to remove the contamination from the water. For the pipe water, where the level of nitrate contamination is higher, the substitute drinking water is supplied to the area. If the contamination is again high, then the high contaminated water is made to be diluted with the lower concentration nitrate. If the process is not successful, then, the process to remove the contamination using the different processes is adopted. In this aspect, the disinfection is one of the processes, where the oxidized nitre water is transformed into the less nitrate water in order to minimize the pathogenic and non-pathogenic population of bacteria into the water. Along with the disinfection, the chloramination also is another important process to offer the residual infection to the distribution system (Bondonno, et al., 2014).

2.9 Guideline values

The referred value of nitrate in water is 5mg/ l. Nitrate is completely based on the epidemiological evidence for Methaemoglobinaemia among the infants which is caused by the direct short term exposure in an effective manner. This direct exposure also can cause the microbial contamination as well as the gastrological infection at the stomach of the human body. It is proved and hence recommended by the scientist that the water should not be used for the bottle fed infants where the amount if nitrate in water is above 100mg/l (Sadler, et al., 2016). The proper guideline for the human body has been recorded as 3mg/l. with the application of the lowest level nitrate range of 0.4 mg/kg is suitable for the 5kg infant in an effective manner. There is one equation which should be followed regarding the consumption of the drinking water as below:

CnitrateGVnitrate+ CnitriteGVnitrate≤1

Thus, the value from the above equation can be recognised as the benchmark for the amount of nitrate intake so that the proper body functionality can be maintained. Based on the entire discussion, it can be stated that maintaining the nitrate level in the water based on the guidelines are required to be followed to avoid the adverse effects of nitrate in a human being.

Further, the guideline values for the nitrate from the agricultural activities those are significant for health and are coming from the drinking water has been mentioned as below:

Figure 1: Guideline about nitrate amount

Chemical µg/L Mg/L Remarks
Non Pesticides 50000

3000

50

3

Short term exposure

Short term exposure a provisional guideline value for chronic infection of nitrate that was in the third edition has been suspended and under review to the significant uncertainty to endogenous effects of nitrate contamination.

Pesticides used in agriculture

Alachlor

Aldicarb

Aldrin and diedrin

Atrazine

Carbofuran

Chlordane

Chlorotoluron

20

10

0.03

100

7

0.2

30

0.02

0.01

0.0000

0.1

0.0007

0.0002

0.03

Applies to aldicarb sulfoxide and aldicarb sulfone for combined aldrin plus dieldrin.

Source: (Sadler, et al., 2016)

2.10 Biological effects of the ingested nitrate

There are three key primary processes by which the intake of the nitrate through the drinking water may have a strong impact on the health of human body. The processes in details have been mentioned as below:

  • The first stage of the process by which the methemoglobin is formed. It is then is influencing the oxygen carrying capacity of blood. Through the oral bacteria and the stomach bacteria for the infants, the nitrate and its compounds get converted to the nitrite compound in an effective manner. Thus, formed nitrite use to react with the oxygen and also binds the haemoglobin. In this manner, the proper oxygen flows through the blood use to get hampered (Coggan, et al., 2015).
  • The second process is involved with the formation of the N-Nitroso compounds which are important for the animal body study. The reduced form of nitrate in the form of nitrite use to react with the stomach full of acids in order to generate a new compound named different nitro sating agents. This nitro sating agents react with the amines and amides from proteins as well as from the other sources interns of different medications applied to the human in order to form the N – Nitroso compounds (Coggan, et al., 2015).
  • At the final stage, the high dosed nitrate can effectively reserve induced hypertrophic changes in the thyroid.

The very current study of the nitrate effect in Eastern Europe has found the higher degree of Thyroid abnormalities in children those have up taken the drinking water filled with the high level of nitrate component. The various studies also have revealed the fact that the key component causing cancer is N – Nitroso compound. On the other hand, the human biomonitoring studies performed by the scientists have demonstrated the fact that in taking the nitrate in the form of the drinking water use to enhance the level of the urination through the excretion of the Nitroso compounds in a tactic manner (Coggan, et al., 2015). The formation of the N-Nitroso is inhibited with the help of the dietary antioxidants which are found in vegetables and fruits as well. As oxidants form together with the nitrate compounds in most of the vegetables, the dietary nitrate intake may not form with the substantial N – Nitroso compounds formation. The adverse formation of N-nitroso compounds sources for the drinking water dies to the adverse contaminations discussed above, when get added with the exogenous sources that use to help the preservation of meats and fishes for many days. Though it is variable, but in is approximately estimated that 45 percent to 75 percent of the human exposure to N – nitroso compounds generate from the vivo formation (Bondonno, et al., 2016).

The review done on 2006 based on the evidence collection for the study of carcinogenicity of the up taken nitrate and its nitrite compounds performed by the International agency for research on Cancer has concluded the statement that the ingested nitrate or its nitrate associated compounds, and nitrites can cause to the endogenous cancer formation”. The distinguishable factors between nitrate and nitrite cannot be done as both leads to the formation of the NNitroso compounds and also are formed in the human stomach in a frequent manner (Bondonno, et al., 2016). Many N – Nitroso compounds formed endogenously in humans from the dietary products are considered to be the probable human carcinogens.

2.11 Nitrates in medicines

Apart from the presence of nitrate in the natural vegetation and the different natural organic food sources the presence of nitrate also can be expected in the form of in taking the medicines. There are many patients those use to take angina as the short duration nitrate medicine required to reduce the pain. On the other hand, there are also various medicines based on the nitrate and its compounds in the form of the regular dose. The nitrate medicines include glyceryl trinitrate ,isosorbide, and others under the different brand name. If these medicines are not taken without the permission of the doctor or the health care practitioner, these many also lead to the endogenous effects on the human body in an adverse manner (patient, 2016).But, up to taking these medicine in proper dose may work on the affected area in a positive manner to get relief from the pain. Nitrates and the nitrate related compounds use to make the blood vessels relaxed for the proper flow of blood and this prevents form the further heart attack and heat attack related pain.

The sources of nitrate and its other forms in foods and drinking water in UL and France have been mentioned as below:

Figure 2 contribution for sources of nitrate and nitrite in the UK and France

Source: (Münzel, et al., 2014)

If any human being is offered with the nitrate compounds then, the person may be suffered through the minor, or major side effects respectively. The side effects as dizziness, fatigue, nerve problem may also arise in an adverse manner.

After the discussion of the amount of nitre present in the food intake and drinking water, it is also required to discuss regarding the legislation discussion to control the amount of nitrate presence in food, and drinking water to remain prevented from the adverse effects of nitrate and its different forms of nitrites in the next section.

2.12 Legislation on nitrate intake

The highest level of the nitrate presence in vegetables was set by EU in the year 1997 with the effective support of Commission regulation (EC). Starting from then, the regulations set for the nitrate amount has been amended on a regular basis in the global market. The maximum level of the nitrate presence has been reported in Annex, section 1 of EC. The figure is as below:

Figure 3: Maximum levels for nitrate as laid down in Commission Regulation (EC) No

Foodstuff Maximum level(mg nitrate/kg)
Fresh spinach(Spinaciaoleracea Harvested 1 October to 31 march

Harvested 1 April to 30 September

3,000

2.500

Preserved, deep-frozen or frozen spinach 2,000
Fresh lettuce(Lactucasativa L.)

(protected and open-grown lettuce)

Excluding lettuce listed below

Harvested 1 October to 31 March:

Lettuce is grown under cover

Lettuce is grown in the open air

Harvested 1 April to 30 September

Lettuce is grown under cover

Lettuce is grown in the open air

4,500

4,000

3,500

2,500

Iceberg-type lettuce Lettuce is grown under cover

Lettuce is grown in the open air

2,500

2,000

Processed cereal-based foods and baby foods for infants and young children 200

Source: (Quijano, et al., 2017)

Based on the regulation, the limitation for nitrate has been applied for five food commodities as: fresh spinach, preserved spinach, frozen spinach, fresh lettuce, iceberg lettuce, and cereal based foods for babies and infants. Due to the varied climatic condition, method and the production, as well as the change in the eating habits based on the season, the maximum level of nitrate in those components are fixed in amount. Thus, considering this record, the nitrate and its other components intake can be easily determined by the general population, and also by the health care practitioner to maintain a perfect level of nitrate in the body.

2.13 controversy with importance of nitrate and adverse effects of nitrate

There is an important controversy regarding the subject that whether in taking the nitrate is good for health or bad for health. Both nitrate and nitrites are used as the food preservatives especially for meats, and fish. Thus, both the food elements are connected with the concept of Gastrointestinal and heart disease. In this aspect, the Environmental working group (EWG) has listed both nitrate and the nitrite preservatives as “Dirty Dozen:” due to their adverse effects. That is the reason, many food retailers promote their brand name by displaying the items as “Nitrate free” or nitrite free” o their packaging to attract the brand attention.

But, on the other hand, the new animal studies done by UK has revealed the fact that those diets are rich with nitrates are able to improve the cardiovascular health by making the blood contents thin and also by widening the blood vessels for the smooth flow of the blood to maintain the other body functions without any blockage (prevention, 2015). There are also various studies those have revealed the fact that those foods are enriched with the nitrate amount supports the reduction of the blood pressure. It also supports to improve the athletic performance of the human being. Nitrate and nitrite both are naturally occurring chemical compounds those are found in soil, plants, normal vegetation’s, drinking water as well as inside the body forming of their own to a small extent. The most common form of nitrate is sodium nitrate those are used for the preservation of meat. It uses to react with the meat a form the sodium nitrite. To keep the bacteria interaction not to take place , the manufacturers use to add the synthetic sodium nitrate to the cured meat.

As a positive side, it can be stated that nitrate helps the meet to retain their fat content within them. But, in the year of 1970s, researchers have discovered the fact that if the meat containing the normal salt in the form of sodium nitrate above 266 degree F, it use to develop the nitrosamines those can create cancer causing reason to the animals along with the human being in an adverse manner. This statement has triggered USDA to draw the limitation of the sodium nitrate application to be offered to the cured meat to prevent the incident of formation of nitrosamines (Bedale, et al., 2016). But, still, in 2010, World health organization has listed the in taking of nitrates and nitrites along with its different form of compounds as the adverse element and cancer causing element for the human body.

But, it is also obvious that the total intake of nitrate and nitrite through the meat is with 6 percent, the rest 80 percent of our nitrate and nitrite in taking comes from the vegetables, drinking water as well as from the fruits due to the application of the nitrate fertilizers and not allowing the vegetation to be in the sunlight effects.

As the positive sides, the absorption of nitrate by the human body through the intake of the vegetables and drinking water also is important to discuss. The nitrates from vegetables and fruits absorbed by our body help in relaxing the blood vessels to highlight the smooth flow of blood through the vessels. As per the view of Bradberry (2012), nitrates and its related compounds are very much essential for our body. If the body will not get their required nitrates, they start to form their own inside the body by the different body functions.Thus, some researchers have highlighted the positive sides of the nitrate and its compounds intake, where other researchers have highlighted the fact that nitrate intake may have the adviser effect on the human body in terms of the cancer incident.

Based on the entire discussion, it is really the matter to concern that where the nitrate absorption is boon or blight. The simple statement can be referred as that it is required by the human being to check their dietary elements to control their amount of nitrate to the absorbed by their body as per the guidelines so that the nitrate balance in the human body will be kept for the body functionally in an effective manner.

2.14 Diagnosis of the Nitrate toxicity

There are several ways that the toxicity of the nitrate level and the nitrate related compound can be diagnosed. The ways have been explained as below:

  • The observation of the nitrate effect through the clinical signs
  • To diagnose the possible exposure to the plants with toxics, water with nitrate toxics, and the feeds with nitrate and nitrite toxics.
  • The findings through the post mortem by the doctor
  • The diagnosis through the laboratory tests by the scientists in plants, and water(Furtado, et al., 2015)

The affected human being by the toxic materials should be treated as the emergency basis with the help of the intravenous injections of methylene blue. This specifically injected medicine will convert methaemoglobin into the normal healthy haemoglobin to maintain the functionality of blood to carry the oxygen tote different parts of the body in an effect manner. There are also some preventive measures from the poisonous impact of nitrate and its nitrate related compounds, which has been discussed in the next section.

2.15 Preventive measures

The risk of the poisonous toxicity of nitrate and nitrite can be prevented with the help of the below necessary approaches:

  • To analyse the level of nitrate and nitrite present in vegetables when in doubt to get rid out of the problem of toxicity of the nitrate.
  • Not overstocking the vegetables and the pasteurized milk to avoid the nitrate and nitrite formulation in these organic materials
  • Take the approach to prevent the growth of the high risk weeds around the needed vegetation to avoid the situation of excess accumulation of nitrate in soil and underground water and also to get polluted by the poison with nitrate.
  • To make ensure that the drinking water in not polluted with the toxicity of the nitrate and its related compounds (Bryan & van Grinsven, 2013).
  • Do not use the green chop that has been heated after cutting
  • Another solution also is offered as the risk of the nitrate poisoning to harvest and also feed the high nitrate forages as silage.
  • Harvesting close to the maturity also is the recommended suggestions to the farmer to decrease the level of the nitrate toxicity in an effective manner.
  • It is also required to cut the bigger leaves in the plants and vegetation and the maximum amount of nitrate use to get accumulated at the outer layer than the inner layer. Thus, trimming is the effective recommendation offered to the crop manufacturers and farmers.

2.16 Summary

From the entire discussion, it has been understood that Nitrate and its related compounds as nitrites, and others if use to get accumulated in plants, soil and human body, the human body along with the other animal use to get affected in an adverse manner with different side effects like disfunctionality of the organs, vomiting, less oxygen supply to the different body parts as the haemoglobin gets converted to eh methaemoglobin. It also has been observed that there are many sources through which the nitrate and it’s related compounds use to get into the body. The guideline values for the requirement of nitrate should be present at the human body at the different ages also have been mentioned in this aspect. The legislations, the rules and regulations to the nitrate intake limit for the human body along with the controversial discussion regarding the good and the bad effects of nitrate its compounds for the human body also have been discussed in this chapter. Base on this chapter, the discussions, and analysis through the research of different articles will be verified to highlight the hypothesis testing and to meet the objectives of the research as set in the first chapter. To move to the discussion and analysis, it is required to discuss regarding the process of the research progress in terms of the research methodology to highlight the detailed process along with the research study process in the next chapter to link the theoretical aspects with the discussion and analysis on the subject topic in a positive manner.

Chapter 3: Research Methodology

The structured methodology for the successful completion of the research process has been discussed in this section that has been executed by the researcher.The way to execute the research process by the researcher is based on certain parameters such as: Research philosophy, Research approach, Research design, Research choice, Research strategy, sampling method, research ethics, and limitations of the research process. Thus, this section has discussed all these dimensions of the research methodology in a detailed manner based on the requirement. The dominations of the research methodology have been illustrated with the help of the research onion as below:

Figure 4: Research Onion

Image result for research onion

Source: (Gravetter & Forzano, 2015)

This concept has been established in a good manner in order to explain the different phases for the purpose of completion of the research.

1.10          Research Philosophy

Research philosophy is required to highlight the thoughtful knowledge of the research in an effective manner. The perfect alignment with the research strategy as per the requirement of the research outcome is discussed in this section. There are three different types of the research philosophy present in the theoretical perspectives such as intrepretivism, positivism, and realism. As per the view of Saunders, et al. (2015), Positivism has the believe that the genuineness can be considered objectively like the natural sciences. In the Positivism, the researcher act as the social scientist. The emotional contents of the target audiences are preferred by the researcher to establish the correct outcome.

The Interpretivism philosophical value supports the explanation of the critical and complex facts in the most generalised way. It highlights the requirement of research to be done by the human being for the perfect interpretation of the happenings in the wider world. On the other hand, the realism philological approach is based on the mixture of both the characteristics of the mentioned philosophies. Based on the entre discussion by Saunders, et al.(2015), it can be stated that the interpretivism research philosophy should be applicable to explain the adverse effect of the excessive nitrate intake.

Justification:

In Positivism approach, the emotional contents re give preference by the researcher, but in the interpretivism approach, the complex fact like the adverse effect of nitrate on the human being can be explained in a most generalised way so that the reader will understand the underlying meaning. Based on these explanations, the interpretivism approach as the research philosophy can be justified for the current research study.

1.11          Research Approach

Research approach defines the way to progress the research either in the form of the constructive manner or the decretive manner. There is two broad categories of the research approaches as Inductive manner, and the deductive manner. As per the view of Clark & Ivankova(2015), the Inductive approach is defined as the movement of top down approach. Inductive approach is subjected to deal with the movement of research from a definite point to a general scenario. The statement is established based on the subject after the completion of the research as a conclusion with the help of the Inductive approach. On the other hand, the already established statement is verified by the hypothesis testing.For the purpose of the present research study, the deductive research approach would be suitable.

Justification:

With the help of the inductive approach, the statement is about to be established. But, as per the present case scenario, the statement already is established in the form of the adverse effects of nitrate on the human being. Thus, the deductive approach theoretical perceptions are matching with the case scenario by testing the null hypothesis as well as the alternate hypothesis to check that whether there are adverse effects of excessive nitrate on the human body or not. Based on the discussion, it can be stated that the deductive approach is the justified approach as per the requirement of the progression of the project work.

3.3 Research Design

The Research design of any research process is considered as the document of the research body. Research design helps to create a framework to reply to the research questions. There are three broad categories for the research design present in the theoretical concepts. They are: explanatory, exploratory, and the confirmatory. As per the view of Shelly & Rosenblatt(2011), through the confirmatory research design, the predictions of the research outcome can be done even before the initiation of the measurement phase. The exploratory research design based on the hypothesis testing procedure out of the collected set of data on the subject topic for seeking the potential varieties at the same time in an effective manner. On the other hand, the explanatory research design is based on the explanation seeking out from the research process based on the topic as the social scientist. Out of the three categories, the exploratory research design is the justified one.

Justification:

Using the explanatory research design, the ground reality will be established based on the general observations. Thus, using the critical thinking approach, and the proper judgments of the researchers, the truth of the subject topic will get revealed. But, as per the present scenario, the statement already has been established as the adverse effects of the nitrate on the human body. It just needs to be proved as truth base on the information collection and using the hypothesis testing which satisfies the requirement of the exploratory research design, Thus, based on the decision, the usage of the exploratory research design is justified.

3.4 Research Choice

Based on the theoretical background, there are basic three types of the research choices as quantitative research choice, qualitative research choice, and the mixed research choice. As per the view of Neelankavil(2015), the research choice makes the concept clear to the researcher as well as the reader the proper dimension of the research progression with the using the numeric value, descriptive value or with the help of both.The quantitative research choice is based on the collection of the numeric value only to describe the research outcome in quantity basis. The qualitative research choice is based on the concept of the core theoretical explanation. Mixed method is based on the collection and the analysis of both the qualitative method and the quantitative method in an effective manner. Based on the discussion, it can be stated that the Quantitative research choice is appropriate for the present study.

Justification:

The aim of the research is to perform the quantitative evaluation of the adverse effects of nitrate exposure to the human body. Thus, clearly, the quantitative research choice is justified method to meet the requirement of the aim of the research process.

3.5 Research Strategy

As per the view of Emmel (2013), the research strategy defines the techniques, methods to be applied by the researcher to meet the purpose of the research study in an effective manner. The research strategy should be perfectly aligned with the research purpose, the goal of the research aim and objectives to be a market. Based on the concepts, the different research strategies are: survey, interview, a collection of the secondary data from the authentic source, and peer reviews are the ways to collect the data as per the research topic to analyse to meet the research objectives. Based on the requirement of the subject topic, the collection of the secondary data from the peer reviews, and other authenticated sources are applicable.

Justification:

The survey and the interview sessions are not justified as the topic is based on the adverse impact of the nitrate on the human bodies expressed in the quantitative form. The survey and the interviews are used to get the first hand data collected form the responses of the human being. But, for the present case scenario, the survey or the interview will not fulfill the case requirement as they will not be able to reply regarding the scientific responses. Based on the situation, the data from the peer reviews, and the authenticated sources are applicable and justified.

3.6 Data collection

As per the view of Bock& Kricher(2013), there is three data collection method present in the theoretical aspects. They are; Primary data collection method, secondary data collection methods, and the nixed method.Using the primary data collection method, the researchers are about to collect the primary and the first hand data from the respondents or the target customers. On the other hand, the secondary data collection method is associated with the concept of collecting the second hand data. Apart from that the mixed data collection redirects to the method of collecting both the first hand and the second hand to cross check the collected data. Based on the requirement, the secondary data collection has been applied by the researcher.

Justification:

The first hand data from the respondents is not justified as it is not feasible to set the target audience to collect the first hand data to get the answer of the research aim in finding the adverse effects of the nitrate on human bodies. This answers can be accumulated form the secondary data sources gathered by the researcher. Thus, mixed data collection process also is not justified. Therefore, based on the discussion, the secondary data collection is not suited with the requirement of the research topic.

3.7 Sampling Method

The sampling method is the most important statistical tool to get the correct data from the target resources. There are various types of the sampling methods such as simple random sampling, stratified smoking, and others. As per the view of Bock & Kricher(2013), simple random sampling is to collect the data from all the dimensions of the target resources without the reflection of biasness in the collection of data. There is an advantage for the simple random sampling where all the source of information is equally liable to contribute in the research work with their information.On the other hand, the stratified random sampling is based on making the strata or category to collect the data. Thus, the biasness in the collection of data is involved. For the current study, the stratified simple random sampling to collect the wide range of data from the authenticated sources.Two definite samples have been chosen. One for the impact of nitrate on the adults, and another to reflect the impact of nitrate on the infants with the sample size of 714 from the secondary source to make a contrast between the intensity of eh two impacts.

Justification:

As the detailed explanation with the in depth analysis is required to get the in depth view of the research topic regarding the adverse effect of nitrate on the human body, the stratified simple random sampling has supported the researcher to get the perfect set of data without any bias based on the subject topic. Thus, the stratified simple random sampling is justified rather than the stratified random sampling, and others.

3.8 Research Ethics

Maintaining the ethical aspect is the most crucial dimension regarding the completion of the project wok.The ethical considerations highlight the genuinely of the work done by the researcher. It is required by the researcher t offer the great attention to take the permission from the supervisors to perform the task of the research thesis and also to work on the authenticated resource in the form of the data collection. As per the view of Lo (2012), research ethics is termed as the “oath of practice for businesses. As per the present scenario, the business is the research performance. Thus, the researcher should take the oath to not manipulating the collected data to set the example in this field of research so that others will get benefitted with the research outcome further.

3.9 Research Limitations

Research limitations are important to discuss so that the researchers will understand the obligations that the researcher has faced during the completion of the task. The limitations of the research can be stated as the indemnification of the adverse effects of nitrate and its compounds on the human body only (Shipman, 2014). It could have offered the better result, if the researcher would have reviewed the opportunity to discuss the adverse effects of nitrate and its compounds on the other animals so that the comparative analysis would have added the value to the research outcome, on the other hand, the time limitation also was the important constraint during the completion of the work regarding the limited exposure and opportunity to collect the secondary data.

3.10 Reliability:

The high degree of the reliability has been reflected by the researcher by collecting the data for the project completion from the authentic sources only in terms of journals, books, and the other authentic journals. Thus, the research can be treated as the most reliable prophet to be used by others as per the requirement (Shipman, 2014).

3.11 Summary

From the above entire discussion, it can be concluded that research methodology planned by the researcher in such a way that will be helpful for the completion of the research is a positive manner. The secondary data has been collected as per the requirement of the subject as to describe the adverse effects of nitrate on the human body. The deductive approach has been selected by finding the ground reality with the help of the exploratory research design. Also, the stratified simple random sampling has been used to collect the required data in random basis on the subject topic to get the in depth view. In this manner, the researcher has described the required processes and methods for the completion of the project in an effective manner.This chapter is closely linked with the findings of the research process as well as the discussion as with the help of the process mentioned in the research methodology, the project has been executed to collect the required data or further analysis.

Chapter 4: Data Analysis and Findings

4.1 Health outcomes of Excess nitrate

The excess nitrate in the human body causes the generation of more methemogloninemia in the human body which may cause the adverse effects. The signs and symptoms of methemogloninemia are as below:

Figure 5: Signs and symptoms of methemoglobinemia

MetHBconcentration(%) Clinical Findings
10-20 Central Cyanosis of limbs/trunk
20-45 Central nervous system depression(a headache, dizziness, fatigue, lethargy), dyspnea
45-55 Coma, arrhythmias, shock, convulsions
>60 High risk of mortality

Source: (Gilchrist, et al., 2010)

As per the view of Gilchrist, et al.(2010), nitrate is the naturally happening ion, which is the essential part of the nitrogen cycle. The naturally formed nitrate is the combination of nitrogen and oxygenated system. Chemically it is unreactive, but become reactive when it comes into the contact of the biological compounds. The most adverse effect that nitrate can pose to the human being at the different age limits is the formation of methemoglobin when the nitrate oxidized the iron of ferrous into the form of haemoglobin into the ferric form. This does not support the oxygen to carry with them. Thus results in the condition of methemoglobin which came does not bind the required oxygen with them.

Under the normal situation, less than 2 percent of the total haemoglobin circulates in the form of MetHb. But, when the concentration become more than 10 percent then the actual adverse function of methemoglobin starts (Hord, 2011). As the initial stage of the adverse effects of bluish gray and brownish gray skin of human body appears.In Infants, the excessive crying along with drowsiness, and lethargy. This effect can be diagnosed in a proper manner with the help of the chocolate coloured blood which determines the excess level of MetHb presence. It has been mentioned by Sobko, et al. (2010) that methemoglobin in infants was initially linked with the theoretical aspects in the USA in the year 1945 through the nitrate intake by drinking water by the research of Hunter Comly. His research has highlighted to important cases as below:

  • Occurrence of methemoglobin in infants after the ingestion of water high with the level of nitrates
  • Infants suffering through the gastrointestinal disturbance may also affect by the adverse effect of methemoglobin just after the drinking water with the minimum level of nitrate in it.

The occurrence of methemoglobin in the infants below the age of 4 months are more prominent due to the combination of the following factors:

  • The higher value of gastric pH. This allows the greater amount of the bacterial attack of the human baby stomach. This results in the conversion if intake nitrate into the nitrite.
  • The intake of the greater fluid relative to the weight of the body of the infants.
  • A high rate of the fetalHb
  • The presence of the lower NADH-dependent (Linda, et al., 2011)

In this aspect, it is of great importance to mention that fact that though gastric pH in infants may be slightly higher than the gastric pH levels of the adult, still, conversion of the nitrate to the nitrite is not the good occurrence to allow them to happen in an effective manner.

4.2 Causes of methemoglobin

There are several causes for the occurrence of methemoglobin. The exposure to nitrate and the nitrite in excess level through the drinking water is the key source of the methemoglobin occurrence in the human body at the different age stages. Therefore, the exposure of the methemoglobin occurrence is especially dependent on the concentration of nitrate and nitrite presence in the drinking water (Trapp & Will, 2010). The general causes of methemoglobin have been illustrated as below:

Figure 6: Causes of methemoglobinemia

Designation Examples
Hereditary NADH-Cytochrome b5 deficiency, MHb, unstable Hb
Drug/Chemical Acetaminophen, amyl nitrite, benzocaine, dapsone, nitroglycerin, nitroprusside, phenazopyridine (Pyridium), sulfanilamide.
Induced Aniline dyes, chlorates, nitrofurans, sulfones
Diet Induced Nitrites, nitrates

Source: (Trapp & Will, 2010)

The effective guidelines and the regulatory limits associated with the amount of the nitrate in taking dissolved in water as 10mg/L nitrate – nitrogen and 50mg / L nitrate. These nitrate levels in water has been established as the preventive level of the methemoglobin and it was established based on the survey conducted by American Public health Association. This survey conducted by APHA has reported more than 270 cases of methemoglobin among the infants of the United States. Among these reported 270 cases, 214 cases were reported based on the excess amount of the nitrate filled drinking water (cfpub, 2005). But, these cases has been claimed by APHA as the nitrate contaminated drinking water in an effective manner. Through this survey, no limit has been reported as less than 10mg/L nitrate – nitrogen .

On the other hand, the quality of the soil and the geology are the dependent factors of the natural levels of nitrate present in the groundwater. In the USA the level of the natural occurring nitrate is within the range between 4 mg – 9 mg / L. But, based on the condition of the agricultural activities, it may also increase to the level of 100 Mg/ L (cfpub, 2005), which is the obvious contamination resource for excess level of nitrate in the ground water level at that region. At the same time, the survey also has revealed the fact that the private well where the depth of the wells is less than 15 m, along with the association with the permeable soils, the high nitrate presence in the drinking water can be expected. For the small community of the water supply and the poor sanitation also are responsible for the high concentrated nitrate drinking water. This impacts effectively on the gastro genetic problems to the adults as well as infant human babies. Apart from the shallow wells with depth less than 15 mg, the municipal water supply also can be contaminated with the high concentration of nitrate those are not safe as the drinking water to consume (cfpub, 2005).

As per the view of Minana, et al.(1991) has reported the levels of nitrate in Spain as to exceed than the limitation set by the WHO guideline as 50mg/L in total 95 towns along with the reporting of 18 municipalities with the nitrate concentration level more than 150mg/L. At the same time, it also has been estimated that there are 15 million families those are receiving the high nitrate contaminated water from their private and shallow wells in the United States. Based on the survey report done by Minana, et al.(1991), 13 percent which is equivalent to 5500 wells are in nine Midwestern states and at the same time, 2 million are the household supplies has exceeded the nitrate level of 10mg/L (Rechetzki, et al., 2012). Thus, based on the contamination rate, it has been estimated from the survey result that the expected rate of the nitrate contamination is likely to occur among 40,000 human infants causing different symptoms. This 40,000 is not the small amount and requires the necessary intervention in an effective manner. Apart from the large area of United states, there are also small places where the calculation of the population is not possible and the high nitrate contamination in the drinking water is found in an effective manner.

4.3 Exposure – response relationship

The complex cofactor relationship does not support the establishment of the quantitative Exposure – response relationship based on the search on Huan effects due to nitrate thought intake of food and water and the formation of methemoglobine. There is two important factors that use to estimate the cases of methemoglobinemia among the human being from infants to adult. It has been mentioned by Mohorovic, et al. (2010),that methemolglobimenia is not the disease to notify clearly. At the same time, there are different definitions of this disease present in the literature in the different forms. In different places, the response rate has been reported in a different format.

As mentioned by Minana, et al.(1991), there are three countries in Romania where the mean incidence rates are between the range of 117 to 363 out of the effective 100,000 live births for the duration between ( 1990 and 1994). Further it also has been reported by Ayebo, et al.(1997), that the range of 117 to 363 out of the effective 100,000 live births is the decreased level of 13000 out of 100,000 live births. The cause of the sudden decrease has been reported based on the low availability of the nitrogen filled fertilizer usage in an effective manner for the agricultural process which use to contaminate the ground water and the soil and as well as have a strong impact on the health condition due to intake of contaminated nitrate resources in daily basis. At the same time, WHO also has reported the fact that in 1985, there were more than 1300 cases of methemoglobinemia taken place in Hungary(cfpub, 2005). Until the end of te year 1980s, the methemoglobinemia was the serious concern of the health related problems. But with the knowledge awareness regarding the methemoglobinemia and its preventive measures, the rate of the methemoglobinemia infection is in decreasing mode.

There are different symptoms that have been reported along with the fractional amount of methB pres neet in the blood. The details are as below:

  • 3 percent to 15 percent methemoglobin causes slight discoloration like pale, blue, gray coloured skin.
  • 15 percent to 20 percent methemoglobin causes cyanmnosis, but still, the patients may be slightly asymptomatic (Su, et al., 2012)
  • 25 percent to 50 percent methemoglobin causes headaches, weakness, palpitation, and confusion in a human being in an adverse manner.
  • 50 percent to 70 percent methemoglobin causes mental disorder, coma, deep acidosis, and abnormal cardiac problems in an effective manner (Su, et al., 2012).
  • If the presence of methemoglobin will exceed more than 70 percent, then the affected human being will come to death due to the high toxicity (emedicine, 2016).

In another study, the reasons for the nitrate contamination and its effects have been discussing. In this study, the sample size of the infants were 724 in number. The age wise variation is as below:

Figure 7: Age wise variation

Characteristic No %
Age(Months)
< 1 6 0.8
1 to < 2 126 17.4
2 to < 3 183 25.3
3 to < 4 142 19.6
4 to < 5 124 17.1
5 to < 6 107 14.8
6 to < 7 36 5.0

Source: (cfpub, 2005)

The ethnicity wise and the language spoken variation is as below:

Figure 8: Ethnicity and the language spoken wide division

Race/Ethnicity
Hispanic 300 41.4
White 235 32.5
Mexican 160 22.1
Native American 19 2.6
Other 6 0.8
Asian 2 0.3
African American 2 0.3
Language Spoken at Home
English 396 54.7
Spanish 322 44.5
Other 6 0.8

Source: (Su, et al., 2012)

After the evaluation of the after birth condition under the supervision of parents at home, it has been reported that 9.7 percent infant had vomiting fever. Out of this percentage, 66 infants had given the proper medication to get rid of the adverse effect of the contaminated water (cfpub, 2005). The illustration of illness along with the medication also has been reflected as below:

Figure 9: illness and medication

Current illness
Fever 10 1.5
Diarrhea 43 6.3
Fussy 84 12.3
Runny Nose 199 29.2
Earache 14 2.1
Vomiting 17 2.5
Cough 1 0.2
Fever, Diarrhea or Vomiting 66 9.7
Medication use (past 24 hours) Used any 66 9.7

Source: (Su, et al., 2012)

When the review has been done on the water quality, it has been observed that amount of nitrate, Chloride, copper, and the microbiological bacteria are the determinant factors of the water quality that has bee consumed by the infants.

Nitrates:

The measured nitrate level in the water consumed has been mentioned as below. The report has highlighted the fact that the amount of nitrate is high the tap water with the mean of 3.5mg/L. it also has been reported that 8.6 percent of the samples with the nitrate level is greater than 10mg/L.

Figure 10: Household water analysis

Chemical and source of water n mean P25 P50 P75 max
Nitrate(mg/L No3-N
Kitchen Faucel 711 3.5 0.4 1.5 4.6 35.6
Pitcher 17 4.6 0.4 0.9 7.9 26.4
Refrigerator lap 73 2.7 0.3 1.1 3.1 27.9
Filtered Faucel 97 2.6 0.3 0.6 2.9 29.4
Bottled Water 209 0.4 0.1 0.2 0.4 10.1
Large Bottle 82 0.4 0.1 0.2 0.3 4.9
Chloride(mg/L) 703 0.7 0.2 0.5 0.8 5.0
Copper(mg/L) 708 0.1 0.0 0.0 0.0 3.0

Source: (cfpub, 2005)

The survey also has highlighted the fact that half of the households were accommodated with private wells. 44 percent of the houses were supplied by the water systems. The source of the tap water to check the further contamination has been highlighted as below:

Figure 11: Tap water source

Source No %
Private Well 407 55.7
Small water System 193 26.4
Community Water System 131 17.9
Total 731 100.0

Source: (cfpub, 2005)

The report has mentioned that the amount of the Tap water use to vary from the amount of nitrate in private wells, and the supplied water. There was 10 percent of the private wells with nitrate level more than 10mg/L. Thus, it can be commented that the private well beside which many daily activities are done are getting contaminated by the effect of the nitrate and its associated compound. The Tap water nitrate levels have been mentioned as below:

Figure 12: Tap Water nitrate level

Source of Tap Water n mean P25 P50 P75 max
Private Well 399 4.6 0.8 2.3 5.9 35.6
Small water system 190 2.8 0.3 1.3 3.5 25.3
Community System 129 1.2 0.2 0.6 1.0 14.8

Source: (cfpub, 2005)

The perfect distribution of the Tapwater nitrate levels by the source of the Tap water also has been highlighted by the diagram representation as follows:

Figure 13: Tap water nitrate levels by source

https://cfpub.epa.gov/ncer_abstracts/images/fckimages/index.cfm?imgid=1092

Source:(cfpub, 2005)

In different countries, there are strict limitations regarding the concentration range of nitrate in drinking water and in foods as well. In EU, the limit for nitrate concentration is restricted till50mg of nitrate per Litre. In the USA , the milt is till 44 mg. These limits are in accordance with the limits of nitrate concentrations recommended by WHO with their strict regulations (cfpub, 2005). The limits set by WHO as well as by different countries are based on the analysis of the general health conditions of the human beings at the different age levels as well as by considering the incidences of the different toxicity levels in an effective manner.The nutrient enrichment, the presence of the surface water also are the important sections to be considered while limiting the nitrate contamination level in an effective manner. The linkage between the methemoglobin and nitrate contamination along with its adverse effects has been established by the USA based on the report in the year 1940s. The report has been established the fact that environment facts also impacts on the formation of excessive nitrates which may cause the need for the environment conservation in a proper manner so that the nitrate contamination can be protected (cfpub, 2005). There are also some arguments that the researchers have made regarding the adverse effects on human being only due to the nitrate toxicity impact and not only due to the other facts. But, overall, it has been established that along with the nitrate contamination, the bacterial contamination also plays an important role in the development of the adverse health condition.

As per the view of Sindelar & Milkowski (2012), the dietary exposure of nitrate is very low in an amount which is commonly less than 2 mg nitrate in a day and also usually less than 5 mg nitrate in a day. In an exceptional manner, higher levels of nitrate contamination can result from the microbial reduction of nitrates in the poor quality water. It also has been estimated by the scientists of USA that on an average 3.5 mg nitrate are formed in the human body each and every day. Therefore, it is required to have a proper control over the nitrate exposure and the usage of the drinking water socially where the nitrate contamination is high and will not exceed the normal range of nitrate suited with the human body at the different stages.

Chloride and Copper:

Apart from the contamination through nitrate presence, the amount of the excess chloride also is the great contributor of the contamination. The mean chloride level is 0.7mg/L. The samples those were collected by the private wells, Tap water, and other household water supply are contaminated with the excess chloride with the rate of 1mg/L.Maximum chloride presence has been reported as 5mg/L. Apart from that only 1 percent of the sample collected were observed with the maximum value of 3mg/L (Bondonno, et al., 2016).

Bactereologicl quality of water:

TC ( Total coliforms) were found in a large portion of the household water. The different frequency of the total bacteria present in different water bodies have been mentioned as below:

Figure 14Bacteria presence in different sources

Household Water Source  

No. Samples

Total Coliforms E.coli
#pos. % #pos. %
Kitchen Faucet 714 275 38.5 20 2.8
Bottled Water 199 79 39.7 1 0.5
Large Bottle 76 52 68.4 0 0.0
Refrigerator tap 65 8 1.2 0 0.0
Filtered faucet 87 28 32.2 2 2.3
Pitcher 15 6 40.0 15 0.0

Source:(Rao, 2011)

As a secondary source of information, it can be mentioned that the report also has mentioned the fact that Tap water was the least occasionally offered water source with 78.3 percent. The bottled water has been offered to 43.8 percent of the infants. the report also has revealed the fact that targeted infants, 54 percent population were given with tap water (Rao, 2011). They were not being offered with the bottled water. Also, the fact has been highlighted that 19.5 percent were typically given only the bottled water. Also out of all targeted population, only 15 respondents have mentioned that they did not give any water to their infants.

4.4 Diet

The diet offered to these infants was recorded based on 24 hours duration. The data has been collected based on the responses of 677 infants in a positive manner. Out of the infants, 23.9 percent were offered by the breastfeeding for the last 24 hours observations. Also, 30.6 percent infants were offered with breastfeeding along with some other foods may be with some solid foods or some medicated formula foods.

Figure 15: Foods offered to infants

 

Food Type

All (n=677) Had solid food(n=123)
No % No %
Had Any:
Formula 471 69.6 94 76.4
Water(incl. used for foods) 399 58.9 93 75.6
Breast-feeding 369 54.5 55 44.7
Solid foods 123 18.2 n/a n./a
Plain water 29 4.3 13 10.6
Other drink 22 3.2 6 4.9
Juice 20 3.0 14 11.4
Breast milk(not breastfeeding) 19 2.8 3 2.4
Carrots, squash, spinach 14 2.1 14 11.4
Pedialyte 3 0.4 1 0.8
Exclusively breastfed 162 23.9
The only formula fed 214 31.6

Source: (Rao, 2011)

From the diagram, it can be stated that 60 percent of the infants were offered with some solid food and water before 24 hours. Out of these 60 percent infants, half of the infants were offered with the tap water. 80 percent of the kids were offered with the formula foods those were mixed with the normal water. Out of these 4.2 percent were offered plain water (Rao, 2011), 31.5 percent were offered with the water from Tap, 26 percent were offered with the bottled water. Also, only 4 infants were offered with both the tap water and the bottled water.

Thus, the total water consumed have ranged from 0 to 2.3 liters. It also has been noted that 12.6 percent consumed more than 1 liter. The percentage of the foods consumed by the infants over 24 hours has ben illustrated as below:

Figure 16: Food consumed for last 24 hours

 

 

Food Type

Age in Months
1-<2

%

2-<3

%

3-<4

%

4-<5

%

5-<6

%

6-<7

%

Overall

%

Formula 65.3 71.3 68.9 76.1 65.7 68.6 69.6
Any water 52.1 58.6 59.1 63.7 59.8 65.7 58.9
Breast-feeding 68.6 55.2 48.5 50.4 50.0 51.4 54.5
Any Solid food 0.8 2.3 5.3 30.1 50.0 74.3 18.2
Plian water 1.7 4.6 3.0 1.8 11.8 2.9 4.3
Juice 0.0 0.6 2.3 2.7 9.8 8.6 3.0
Breast Milk 3.3 2.3 1.5 4.4 2.9 2.9 2.8
(other than breastfeeding)
Carrots 0.0 0.0 0.0 2.7 3.9 20.0 2.1
Pedialyte 0.0 0,0 1.5 0.9 0.0 0.0 0.4
Exclusive breastfeeding 31.4 28.2 26.5 15.0 17.6 14.3 23.9
Exclusively formula fed 29.8 37.9 41.7 31.9 18.6 5.7 31.6
Sample size 121 174 132 113 102 35 677

Source: (cfpub, 2005)

4.5 Nitrate intake

The nitrate intake by the infants has been measured by finding out the total amount of nitrate intake divided by the weight of the kids. Further the actual amount of nitrate intake has been measured as the amount of water consumed with each of the food that they have taken for 24 hours before the observation multiplied by the concentration of nitrate measured in the source of water as the household water source taken to prepare the food to be offered to these infants (cfpub, 2005).

The cancellation has highlighted the fact that over the half of the infants has taken less than 0.1 mg nitrate, 12 percent has intaken more than 1.0 mg nitrate during the observation time of 24 hours. Only 0.3 percent of the thestedinfant population has ingested more than 10mg of nitrate, which s very much harmful for survival in a healthy manner. The detailed observation has been mentioned as below:

Figure 17: Nitrate amount ingested

Age in Months
1-<2 2-<3 3-<4 4-<5 5-<6 6-<7 Overall
Amount of water consumed past 24 hours(L)
N 121 174 132 113 102 35 677
Mean 0.27 0.35 0.44 0.46 0.41 o.42 0.38
10th %-tile 0 0 0 0 0 0 0
Medium 0.05 0.13 0.25 0.38 0.09 0.16 0.13
90th %-tile 0.8 0.92 1.08 1.11 1.15 1.17 1.06
Max 1.38 1.53 2.32 2.01 1.81 1.41 2.32
Nitrate concentration(mg NO3-N/L)
N 121 174 132 113 102 35 677
Mean 0.4 0.6 0.5 0.6 0.4 0.6 0.5
10th %-tile 0 0 0 0 0 0 0
Medium 0 0.1 0.1 0.1 0.1 0.1 0.1
90th %-tile 1.4 1.1 1.2 1.9 1.2 2.2 1.4
Max 7.2 17.1 10.1 6.6 5.8 5.7 17.1
Amount of nitrate ingested(mg)
N 121 174 132 113 102 35 677
Mean 0.37 0.5 0.47 0.61 0.44 0.53 0.48
10th %-tile 0 0 0 0 0 0 0
Medium 0.01 0.04 0.08 0.09 0.07 0.04 0.05
90th %-tile 1.03 0.95 1.06 2.17 1.44 1.95 1.19
Max 8.16 10.32 12.43 6.89 10.48 5.74 12.43

Source: (cfpub, 2005)

Over 90 percent of the targeted infants has consumed more than 500 mL of water. In the graphical mode, the nitrate ingested by the infant group is as below:

Figure 18: Nitrate intake for 24 hours under observation

Source:(cfpub, 2005)

The illustrations have revealed the fact that high intake consumed less than 5 mg /L nitrate. Out of these 63. 6 percent were observed with water intake between 5mg/L and 10mg/L. 57.1 percent has been reported with more than 10mg/L those can be recognised as the high intake of the nitrate source. Apart from that report also has highlighted the important fact that only 22 infants those have consumed more than 100mL or more than 10mg/L were considered among the high nitrate intake group in an effective manner (cfpub, 2005). Apart from the nitrate contamination, it is also required to identify the rate of contamination through the other media such as bacterial contamination to draw a comparison between the adverse effects on infants due to the high contaminated water.

4.6 Results for the Bacterial contaminated water

The collection of the report has identified the fact that out of the 58.9 percent of the infants those were offered with the water, 43.8 percent of the infants were offered with water collected from the household sources. Thus, the expectation for the impact of TC bacteria was confirmed. In this manner, all the infants have consumed TC positive water and at the same time, 1 percent of these targeted infants were offered with EC positive water in an effective manner (Burton, et al., 2011). With the assumption of the fact that boiling the water purifies the bacteria from the water, the amount of the TC affected infants amount has been dropped to 19 percent in an effective manner.

4.7 Methemoglobin levels

The report also has been published the data of the identification of 558 infants affected with Methemoglobin. Among these 558 infants, 21 cases, the Methemoglobin was within the standard level, but, for the rest of the cases, 63.5 percent has the Metab level greater than 1 percent. 11.7 percent had the level with greater than 2 percent, and 2.6 per percent had the Metab level with more than 3 percent. The Meth levels along with the ages has been illustrated as below:

Figure 19: MethB level by age

Age in Months
1-<2 2-<3 3-<4 4-<5 5-<6 6-<7 Overall
Methemoglobin level(% MetHb):
N 97 148 98 87 78 29 537
Mean 1.6 1.3 1.1 1.1 1.0 1.2 1.2
10th %-tile 0.8 0.4 0.2 0.5 0.5 0.5 0.5
Medium 1.4 1.3 1.0 1.0 1.0 1.0 1.1
90th %-tile 2.5 2.0 2.2 1.8 1.6 2.1 2.1
Max 5.7 4.5 4.2 4.3 2.7 2.5 5.7
%>1% MetHb 84.5 66.9 56.1 54.0 51.3 62.1 63.5
N>1% 82 99 55 47 40 18 341
%>2% MetHb 24.7 10.1 12.2 8.0 2.6 10.3 11.7
N>2% 24 15 12 7 2 3 63
%>3% MetHb 5.2 3.4 3.1 1.1 0.0 0.0 2.6
N>3% 5 5 3 1 0 0 14

Source: (Skold, et al., 2011)

The distribution level of MethB also is shown as below:

Figure 20: Distribution of MethB

https://cfpub.epa.gov/ncer_abstracts/images/fckimages/index.cfm?imgid=1104

Source: (Skold, et al., 2011)

4.8 The risk factors for the developed MethB levels

The description of the risk factors have been mentioned as below:

Figure 21: Risk factors for elevated methb

Risk Factor Measure Variable
Exposure to nitrate from drinking water and/or foods Nitrate intake (mg/kg day) No3intake
Nitrate intake>0.5 mg/kg day(0/1) Intakegtp5
Fed carrots or squash previous 24  hours(0/1) Any carrots
Nitrate intake > 0.5 mg/kg day or fed carrots or squash previous 24 hours(0/1) Intakegtp5b
Nitrate intake>1.0 mg/kg day(0/1) Intakegt1
Endogenous production of nitrite Current diarrhea (0/1) direct
Current diarrhea, fever or vomiting (0/1) sickest
Bacteriological water contamination (risk factor for enteric disease) Presence of total coliforms in household source of water consumed (0/1) Anytc
Water was boiled before feeding (0/1) any boiled
Presence of total coliforms adjusted for boiling (i.e., =0 if boiled ) (0/1) anytc3
Presence of E.coli in household source of water consumed(0/1) anyec
Presence of E.coli adjusted for boiling (i.e. = 0 if boiled)(0/1) anyec3
Bacteriological contamination of food or water(risk water for enteric disease) Exclusive breastfeeding(0/1) Exclbf
Intake of anti-oxidant Consumed juice past 24 hours (0/1) anyjuice
Exposure to other MetHb-forming agents Had medication containing benzocaine in past 24 hours(0/1) metmeds
Intake of copper >0.01 mg/kg day (0/1) Cuintakegtp01
Methemoglobin reductase enzyme level for the conversion of MetHb to Hb age in months Agemos
age <3 Months(0/1) agelt3
Unobserved differences in biological processes and/or household exposure- related behaviors associated with race, ethnicity and or gender Child is male (0/1) Male
Child’s race/ ethnicity is white (0/1) White
Language predominantly spoken at home is English(0/1) English

Source: (Vineis, et al., 2011)

There is a strong co relation between many risk factors. It has been observed that the associated risk factors started to increase with age, as well as with the change in the diet plan, and the intake of the water from the different sources. The exposure of the bacterial infection was also was strongly associated. Out of the target infants, 60.7 percent infants were affected by the high nitrate intake as well as also was affected with the TC (Vineis, et al., 2011). On the other hand, in compared with the high fat, only 22.8 percent infants were not impacted by the high exposure of the nitrate. The basic reason is the pattern of the diet and intake of water. Thus, the issue is justified in a clear manner that the intake of nitrate tor8gh the different do men as well as through intake of water from the different resources the impact of high level of nitrate intake as well as the contamination through the TC also is visible. After the entire discussion, in a nutshell, the three distinct categorised disease for the nitrate effects have been discoed in the next section.

4.9 Key effects of contamination through Nitrate in drinking water and food

The dose response assessment based on the key aspects of nitrate intake through drinking water and the food can be mentioned in terms of the effect of metheglominemia, cancer, and reproductive toxicity. The detailed analysis has been described as below:

4.9.1 Metheglominemia

The nitrate concentration in the human body below 50mg/L, through the bacterial contamination, and also through the dietary food intake, for example, Spinach can be considered as the most effective medium for the occurring of Metheglominemia. The American public health Association for the experiment purpose has set the survey questionnaire to 48 states to check the infection rate of nitrate present in drinking water and foods (especially vegetables). The survey has represented the data with 278 infection cases and total 39 deaths (cfpub, 2005). The survey result also has conveyed the following occurrence report:

Number of cases Nitrate level and methemoglobin contamination
214 Infection with methemoglobin and with More than 50mg/L nitrate contamination.
81percent of 214 cases Infection with methemoglobin and with contamination concentration of 220mg/L(cfpub, 2005).
17 percent of 214 cases Infection with methemoglobin and with contamination concentration of 90 – 220mg/L.
2 percent of 214 cases Infection with methemoglobin and with contamination concentration of 50 -90mg/L

Thus, the high rate of the contamination at the different level has been highlighted through this report. In a very similar manner, the survey also has been reported for German. Through the survey total, 745 cases have been highlighted (ncbi, 2011). But, out of the 745 reported cases, the data exposure has been identified only for 249 cases. The data listed have been represented as below:

Number of cases Nitrate level and methemoglobin contamination
84 percent of 249 cases Nitrate concentration in water with more than 100mg/L (cfpub, 2005)
12 percent of 249 cases Nitrate concentration in water with between 50 – 100mg/L
4 percent of 249 cases Nitrate concentration in water with less than 50mg/L (cfpub, 2005)

Out of the report established, only 3 cases have been reported with the nitrate contamination in water with below than 20mg/L.On the other hand, the survey also has represented the data regarding the age wise contamination report, for total 306 cases, the age wise contamination has been identified. 98 percent exposure to the nitrate contamination has been reported in the infants with 3 months or below than that (cfpub, 2005). At the same time, 53 percent infants have been reported with chronic diarrhea which was also the indicator of the bacterial contamination.

4.9.2 Cancer

The cancer link also has been highlighted by the various studies due to the high rate of nitrate contamination. The dangerous nitrosamine contamination is directly linked with cancer causing parameters. The regular dietary intakes of nitrosatable amines, amides, and urea have been successfully estimated to the range of less than 1mg to hundreds and also thousands of milligram in an effective manner. At the same time, the intake level of the Dietary nitrate use to vary from 75 to 270mg in an effective manner (cfpub, 2005).

4.9.3 Reproductive toxicity

There is no adequate data to support the incidence of the nitrate and nitrite exposures with the loss in the reproductive capability of the human being in an adverse manner. Based on the fact, the dose – response assessment is not possible to be established in this case. Through the various studies, the Nitrate has not been reported to produce the essential reproductive effects in a human being.

Thus, from the above discussion, it can be stated that the nitrate and the nitrate contamination through the drinking water and foods are not responsible for the occurrence of the reproductive toxicity as per the recent status of the research findings. But m it has a direct relationship with the occurrence of cancer and other effects of the methemoglobin in an adverse manner (Mathur, et al., 2010).Thus, as per the recent status of the ingestion of the contaminated drinking water and foods to take place the nitrate intake, it is required to have a proper control over the treatment plan for the infection. In this manner, the treatment plan is required to be discussed in next section.

The tabular form of the effects of nitrate contamination on the human being at the different ages is as below:

Characteristic No
Age(Months) Number
< 1 6
1 to < 2 126
2 to < 3 183
3 to < 4 142
4 to < 5 124
5 to < 6 107
6 to < 7 36
>7 months 278 infection cases
>7 months 39 deaths
>7 months 81 percent of 214 cases with  Infection with methemoglobin  of 220mg/L nitrate contamination
>7 months 17 percent of 214 cases with methemoglobin and 90 – 220mg/L nitrate contamination level.
>7 months 2 percent of 214 cases  with methemoglobin and 50 – 90mg/L nitrate contamination
>7 months 84 percent of 249 cases with  Nitrate concentration in water with more than 100mg/L
>7 months  12 percent of 249 cases  with  Nitrate concentration in water between 50 – 100mg/L
>7 months 4 percent of 249 cases with Nitrate concentration in water with less than 50mg/L (cfpub, 2005).

4.10 Treatment plan for Metheglominemia

Before the application of the treatment plan to the affected patients, it is important to diagnose the disease in a proper manner through laboratory test to identify the actual intensity of the blood contamination by the effect of nitrate intake through the different sources (emedicine, 2016). The details of the laboratory diagnosis are as below:

  • Study to execute the hemolysis process. This process will include the complete blood count, reticulocyte counts, measurement of indirect bilirubin, measurement of lactate dehydrogenase, and also the measurement of haptoglobin.
  • The urine pregnancy test for the suspected pregnant women
  • The Heinz body preparation (emedicine, 2016)
  • Identification of the serum levels of nitrates in blood and also to identify the other contaminations in blood.
  • The studies regarding the organ failure, the coverall organ dysfunction, the liver function test, blood urea nitrogen tests are also done.
  • Apart from the test for methemoglobin, the test for the identification of color of the blood of the affected person on the white filter paper under the exposure of the room air with the supply of 100 percent oxygen is measured (emedicine, 2016).
  • The Arterial blood gas determination is done.
  • Pulse oximetry is done to measure the capacity of the blood regarding carrying the oxygen.
  • Potassium cyanide test in order to differentiate between the methemoglobin and sulfhemoglobin.
  • The CT scan of the head also is done to identify any brain haemorrhage (emedicine, 2016).
  • The chest radiography is done to understand the dysfunctionality of the lungs due to the excessive intake of nitrate as the adverse effect.
  • Echocardiography also is done in order to identify the presence of the congenital heart disease.

The treatment plan for the affected patients with metHb is required to be guided in a proper manner. For the patients where the diagnosis level of the methemoglobin is low, the treatment plan consists of removing the inducing agent which administers the high rate flow of oxygen. The acute observation also is required to control the effect of methemoglobin. When the causative agents are discontinued, then the fMethB get returns to the lower levels within the time duration of 36 hours. The perfect use of the supplementary oxygen increases the levels of Plasma in the blood cells in an effective manner to reduce the effect of the cause of the methemoglobin. Further, in the reduction of the rate of the methemoglobin, Methylene blue is required to be used to the affected person to avoid the adverse effect.

Apart from the general treatment plan, the management for the infection methemoglobin also can be done according to the symptoms.

  • The high intensity methemoglobin can pose a threat to life and will require the emergency help to support the adverse estuation (Domene, et al., 2010).
  • The chronic and low intensity methemoglobin may be required with the specific treatment plan support the situation.
  • There is no pharmacologic treated than can be offered to the patients affected with methemoglobin this use to come from heredity as it comes from genes (Domene, et al., 2010).

But, there is also some initial care plan that can be used control the situation mentioned as below:

  • The patients should be administered of additional oxygen.
  • The identification of the nitrate and other drug toxicity also should be measured in an effective manner.
  • It is also required to remove the offending oxidizing substance (Domene, et al., 2010).

After the acute exposure to the oxidizing agent, it is suggested to treat the patients with methemoglobin levels with 20 percent or more than that level.The treatment process would include:

Methylene blue – This is the most primary emergency treatment to be offered to the patients with a high rate of methemoglobin. As methemoglobin can be the cause of the adverse effects on the human body including the adults and the children. Then the emergency treatment to control the amount of methemoglobin in blood is required to be controlled (Saria, et al., 2012).

Exchange transfusion – the patients those do not respond to the methylene blue can be offered with the treatment pattern of exchange transfusion in proper manner to control the adverse effects methemoglobin.

Dietary measures– as already observed that the dietary measures as well as the food and water intake are the root cause to get themethemoglobin occurs in the human body. Thus, it is with utmost importance that all the human being including the infants as well should be offered with the proper diet to control the adverse effects of the methemoglobin(Saria, et al., 2012).

Other medications– apart from the application of Methyleneblue, the process application of exchange transfusion and also using the proper dietary foods, there are also some important medicines like ascorbic food, riboflavin, and cimetidine, and others to control the effect of methemoglobin in an effective manner.

4.11 Discussion

All the ethical considerations have been maintained in the completion of the project based on the quantitative research on the adverse effects on the human being. The adverse effects on the human being have been categorised into two separate sections as effects of contamination through nitrate on the infants and effects of contamination thorough nitrates on the adults’ human being.

There is huge controversy regarding the importance of nitrate and nitrate contaminated diseases through the drinking water as well as through the dietary food intake. The first argument is based on getting the good water contaminated due to the agricultural fertilizers usage. This applied nitrate in the fertilizers after oxidization use to get converted to the nitrite which is the real cause of the methemoglobinemia(Bradberry, 2012).

The data observed from the findings also have reflected the fact that the massive cases of methemoglobinemia are not so much often in the United States. The condition in the United States is brief which use to make it nearly not possible to conduct a particular survey where the sample size is very small to get a survey done in a proper manner to get the desired data in an effective manner. The findings also have reflected the fact that the aetiology of the particular disease is very much complex, and it is also multi factorial. The reason behind this is the entrance of nitrate in the body through the most general forms. The nitrate can get enter in the adult human body as well as in the infants through the bottle feeding as well as through the specific vegetables as vegetables are also highlight contaminated due to the application of the fertilisers on them as well as due to the effect of the groundwater which is absorbed by them for their living purpose. Thus, identification of the actual source of the nitrate and its contamination percentage from the different sources cannot be highlighted in a proper manner (Bondonno, et al., 2014).

Many correlation factors between the nitrate – nitrite exposure and the methemoglobin have been highlighted based on age, nutrition factor, the source of water, and others. The contamination through private well has been reported as 57 percent out of the other two types of contamination sources as a community system, and the small water system in an effective manner. Thus, the contamination for the families using the private well are affected by the effect of methemoglobin in an adverse manner. Further, by the age profile, it also can be highlighted from the findings, that the infants from age 4 months to 7 months are contaminated more than the infants with below 3 months age. The obvious reason behind this situation is the best feeding infant of having age below 3 months (Fordyce, 2013). When infants start to take formula drink apart from breastfeeding or with breastfeeding , then through the source of water nitrate – and the compounds of nitrate use to get ingested inside the infant body to occur methebmoglobin, the same thing occurs for the adult body as well. Apart from that, there are also many biological factors those can relate to the exposure of nitrate and the formation of methemoglobin. These factors again can be co related with the age group, and the location as well. At the same time, the formation of methemoglobin depends on the ingestion of nitrate in the body as well as already existed nitrate level in adult human as well as in the infant bodies. In this aspect, research has also highlighted that the percent of blood in infant Hb affects the nitrite amount in blood in an effective manner (Hrudey, et al., 2013). The occurrence of the methemoglobin also gets enhanced when the infant body, as well as the adult human body, has lesser capacity to break down metHb back to normal Hb through their immunity power. Assuming the fact that the survey has been done in a combination of the many risk factors, it can be stated that the effects of the relevant risk factors associated with the cause of methemoglobin depend on the level of the risk exposure. The study of the findings also has been highlighted that the percentage of the methemoglobin in blood form 3 percent to 70 percent yields at the different results. At the initial stage, the discoloration of the skin of the adults uses to take place. As much as the methemoglobin amount get increased in the blood, the adverse effects start to increase by levels. The maximum exposure of the methemoglobin in the blood can impact on the adult either in the form of coma or in the form of death of the person (Vineis, et al., 2011). Thus, the perfect blend between the adverse effects on adult due to the methemoglobin exposure and the on the infants have been highlighted in a clear format through the findings of the random study of the cases.

As a good part of the research report is to make a perfect contrast between the adverse effects of the methemoglobin in adults and also in infants. The limitation of the research report can be highlighted as the exposure of nitrate and the nitrite contamination effects on the human body at the different ages rather than the inclusion of the other sources of contamination in drinking water and foods in detail. Further, one of the good parts of the data collected for the infant infection was done 24 hours prior to contamination, and 24 hours after the contamination to check the contamination rate as the useful information to conclude the research report with the collected data. The metHblevels in infants has been measured with the help of the most accepted method in the form of the laboratory test. This laboratory test has been considered as the reliable source of information regarding the status of the infection in infants. Another limitation fact can be considered as the number of the respondents.

Through the results, it has been observed that very small amount of infants have been highlighted with the adverse effects of methemoglobin as 3 percent while the normal infant amount has been highlighted as 10 percent. 4 percent infants have been identified with the nitrate contamination of 0.5mg /L, which is one third of the amount of RfD(cfpub, 2005). On the other hand, only three infants have been identified with the nitrate contamination which is above the RfD amount. Thus, the very poor amount of infants were infected by the adverse effects of methemoglobin. Adults are the higher in number in this aspect to be contaminated through the effects of nitrate and nitrite. It also has been highlighted that there were 44 infants those nitrate level lied between 0.5 g to 10 mg/L which is under the normal range of nitrate presence in the body.

The physiological processes triggering the exposure to the raised metHb are not simple and also not linear. Therefore, the functional relation is not clear. To describe the complex and nonlinear relationship, their different models have been used. The risk factors variation associated with the methemoglobin has been established with the help of the linear regression analysis. Apart from the usage of the model, the variability of the methemoglobin levels, and the nonlinear relationship between the risk factors as well as the metHb normal levels may not be proved as clinically justified (ncbi, 2011). Along with the usage of the non-liner relationship, the logistic regression model has been used to make a perfect co-relationship between the risk factors associated with the adverse effects of methemoglobin.

The research also has highlighted the fact that age has the inverse relationship with the infection of Methemoglobin. With the increased age, with the incrassated immunity power, the infection of Methemoglobin use to get decreased.The correlation has been observed between the bacteria, and the nitrate contaminated water causing the infection and also impacting in an adverse manner on adult human being as well as in infants.The nitrate intake has been considered as the continuous variable for the metHb happening with greater than 3 percent. The primary fact regarding the ability of the infants to convert the methb to hb with the help of their immunity power to get rid put of the adverse effects was not disclosed (ncbi, 2011).

Through the findings, it also has been observed that unless and until the methemoglobin concentration is reaching to 10 percent, the serious clinical symptoms will not take place among the adults as well as among the infants. The high rate production level of nitrate and nitrite, in taking the nitrate contaminated foods and drinks triggers the fact of high concentration of methemoglobin presence in the blood causing several symptoms based on the concentration level. Thus, offering the protection to the infants from the high level exposure to the nitrate-contaminated drinking water is able to reduce the high rate methemoglobin development among the infants. Thus, it is suggested to control the level of nitrate and nitrite contamination in an effective manner to control the adverse effects in an effective manner (Minana, et al., 1991).

Thus, the entire discussion of the study findings is based on the nitrate and the nitrite contamination in infant and in adult human being. The discussion has revealed the fact that exposure to the high level of the nitrate in the drinking water is effectively and positively increases the level of the methemoglobin which form a strong obstacles to the haemoglobin to carry the oxygen and also get transformed to the metHb and also hampers the proper functioning of the different body parts to support the healthy living of the human being in an effective manner. It also has been highlighted that the risk associated with the intake of the nitrate above the level of 0.5 mg NO3 /Kg day is equivalent to one third of the value of RfD(Bradberry, 2012). This incident generally occurs for the infants from the age level 1 month to months. 4 percent exposure to this level infants has been identified through the study. The sample that has been choosing to identify the contamination level has been offered as more than 0.5mgN/Kg day. At the same time, it also has been focused that the adverse exposure of TC positive water was strongly associated with the higher level of methemoglobin, along with the probability of more than 2 percentmetHb. But, the occurrence of diarrhea was not associated with the adverse effects of methemoglobin level increment. Thus, the multifactorial characteristics of methemoglobin make it slightly difficult to do the proper assessment of risk linking with other risks in an effective manner. Thus, the low level of nitrate and the increased level of metHb relationship is not so much strong. The elevated level of metHb is directly associated with the high level of the occurrence and the adverse effects on a human being due to methemoglobinemia. Thus, the consumption of the nitrate-contaminated drinking water collected form the different resources and the ingestion of the nitrate-contaminated foods, especially the vegetables state the strong link with the increased rate of the metHb formation and the elevated level of methomoglobin contamination (ncbi, 2011). After the discussion of the root causes of the nitrate contamination of drinking water and food and the ingestion of the different level of nitrate in a human being at different stages, the rate of the adverse effects has been discussed based on the level of the nitrate intake in an effective manner. At this stage, it has become important to conclude the discussion with the perfect objective linking with the objectives at the beginning of the research process. At the same time, the hypothesis testing also is going to be justified with the outcome of the result in an effective manner in the next chapter named as Conclusion. Apart from that few recommendations also will be offered based on the outcome of the research process.

Based on the discussion, it is required to make a perfect conclusion of the research project along with the scope for further research by the researcher, the limitations of the research along with the recommendations in an effective manner in the next chapter.

Chapter 5: Conclusion and Recommendations

Conclusion

This chapter will conclude the research findings and discussion based on the subject topic and in the form of the objective linking as below:

To identify the most predominant modes humans get exposed to nitrates

From the entire study and findings by the different secondary research outcome, it has been proved that the most prominent mode through which the human being at the different ranges get exposed to nitrates are drinking water and food intake (especially vegetables). The drinking water coming from the different resources such as private well, community water supply, deep digging ground water, and others are contaminated with the different level of the nitrate concentration to have adverse effects on the human body at the different level. The study has proved that the nitrate contamination is high for the case of the Private well rather than the small water system, and the community water system in an effective manner. Out of the total water supply, 55.37 percent contaminated water by nitrate has been observed for Private well. Thus, the families those are engaged in the collecting their drinking water from private wells are getting affected by excessive nitrate in a quick manner(Bondonno, et al., 2016).

Apart from the tap water nitrate contamination, the human body also come into the contact of the nitrate contamination through the contaminated foods (vegetables). But, the ingestion of nitrate in the human body is lesser than the ingestion of nitrate in the human body through the water intake. At the same time, it also can be concluded that the microbial reduction of nitrates in poor quality water also is responsible for the maximum contamination of water though nitrate. Thus, three basic reasons such as: contamination of water by nitrate in the case of good water and the other water resources, the nitrate contamination through the food intake, and the fact of microbial reduction in poor quality water are responsible facts in an effective manner(Bondonno, et al., 2016).

Along with the statement, it also has been observed that the infants those were offered with some solid food with the supply of the tap water were found to be affected by the high nitrate contamination resulting to diarrhoea, dehydration problem based on levels of the nitrate intake assessing before the food and water intake and after food and water intake. The report also has conveyed the message that the pattern of the nitrate intake by the infants are high among them those are taking the tap water and food with nitrate ranging from 5mh /L to 10mg/L. The benchmark of the nitrate intake supporting the adverse health effects to occur is above 10mg/L. Thus, it is required to take care of the source of water rather that the direct private well, and highly contaminated foods grown in the agricultural field with a high rate of chemical fertilizers usage. Based on this discussion, it can be justified that the predominant modes of nitrate exposure to the human being at the different age levels are through the water intake, through the food intake grown in the agricultural field where the fertilizer usage is high(Bradberry, 2012). This objective has been linked from the contents of the literature review from the theoretical aspect rather than from the findings and discussion based on the quantitative measures.

To investigate the effect of exposure to nitrate on humans

After the discussion of the predominant nodes through which the human being get exposed to the nitrate contamination, it is also important to investigate the adverse effects on the infant human being as well as in the adult human being.  At the beginning of the discussion, it can be stated that the formation of the methemoglobin is the key resultant fact for the high nitrate intake through the contaminated water and food. The amount of nitrate intake in higher through water rather than food. From the report, the maximum number of infants have been found to be affected by the adverse effects of methemoglobin formation which hinders the proper oxygen flow in the body. Here, the metHb create strong obstacles to Hb in order not to support the oxygen carrying characteristics to work in an effective manner. it also has been reported that the presence of nitrate level in a human being with am9nt 50mg/L also has resulted in numerous death incidents due to the strong intervention of methemoglobin formation supporting the disfunctioning of the different body organs(Bondonno, et al., 2016). Along with that, there are also various arguments relating to the cancer causing an incident by the effects of the methemoglobin formation. But, no toxicity effects of nitrate contamination and occurrence of methemoglobin has been reported as cancer causing effects. Thus, it can be concluded that the key effect of the nitrate exposure to the human being at the different age levels is concentrated on the formation of methemoglobin and causing the incident of methemoglobinemia causing to disfunctioning of the different body organs due to eh less flow of oxygen by metHb. This objective has been linked from the contents of the literature review from the theoretical aspect rather than from the findings and discussion based on the quantitative measures(Bondonno, et al., 2016).

To determine specific health hazard associated with different levels of exposure

As per the guideline value offered by WHO, the nitrate level in a human infant should be limited to 0.4mg /kg for the infants’ up to 5kg of weight. The amount gets increased but it should not reach the level of 10mg/L for the adult human being to get rid out of the adverse effects of nitrate. The research has represented the fact that in different countries the source percentage of the nitrate contamination varies. The results also have reflected the fact that contamination through nitrate in adult human being with 3 percent to 15 percent methemoglobin is sufficient to cause the discoloration of skin with pale, blue, gray coloured skin. With the increment of the methemoglobin percentage in blood, from 15 percent to 20 percent, the symptoms of cyanosis can take place in adult human being in an effective manner(Bradberry, 2012). With the methemoglobin percentage in blood ranging from 25 percent to 50, the symptoms of headache, weakness, palpitation , and confusion in human being use to get prominent in an effective manner. 50 percent to 70 percent methemoglobin presence causes mental disorder, coma, deep acidosis, and abnormal cardiac problems in adult human being. The report also has reflected the fact that presence of methemoglobin exceeding more than 70 percent is likely to affect the human being to death due to the high toxicity level in blood which does not support the oxygen supply to the required cells, Thus, due to the effect of the oxygen supply obstacle, the adverse effects takes place in human being as well as in infants(Bondonno, et al., 2016).

The age wise variation of nitrate contamination also has been highlighted as maximum nitrate contamination from 2 to less than 3 months due to the drinking water as at this level the breastfeeding and the formula feeding is the key dietary supplements given to the infants. Thus, based on the above discussion, it can be mentioned that all the objectives set at the beginning of the research process has been met and described as well as also been justified.  This objective has been linked from the contents of the quantitative measures of the findings and discussion rather than using the theoretical content of the literature review in an effective manner(Bickel & Friedrich, 2013).

Hypothesis testing

Apart from the objective setting, there was also the provision for the hypothesis testing as the research was based on the deductive approach. The two hypothesis established for the research process are as below:

HO: There are adverse effects of nitrate intake on the human being.

H1: There are no adverse effects of nitrate intake on the human being.

Based on the discussion the hypothesis testing also can be justified as the proving the null hypothesis establishment as “HO: There are adverse effects of nitrate intake on the human being” as at different age levels the nitrate contamination through the different resources (specially drinking water and dietary foods) have highlighted the adverse effects occurrence as per the percentage of the contamination level from slight discolouration to death for adult human being as well as low immunity power to vomiting , diarrhoea and other symptoms for infants(Boas, et al., 2012). Thus, based on the fact, the null hypothesis regarding in the project process can be justified. Apart from that hypothesis testing, there were also some restrictions to make the research process more stringent, the research limitations have been highlighted next.

Research limitation:

The research limitation for the current study are as below:

  • The key limitation was the subject topic as the study of the adverse effects of nitrate contamination on a human being at the different age levels. The researcher would have received more exposure to the research findings if the nitrate contamination and its adverse effects could have been disused o the entire animal group.  Then the study report could have been devised on the more contrasting and information enriched in a proper manner to help the readers understand the detailed nitrate contamination effects on animals and its variations in effects.
  • The second limitation can be regarded as the time limitation. If the researcher could have received the additional time, then the researcher would have added some additional valued information through the research of more secondary information on the wider research to make the research stronger.
  • The third limitation can be referred as the focus on the quantitative findings, instead of the both the usage of qualitative findings and quantitative findings to give the overview of the subject topic in a detailed manner.

Recommendations

Few recommendations can be offered to the further researcher to develop the subject matter. The recommendations are as below:

  • It is recommended to the future researcher to have a detailed research on both the qualitative and the quantitative methods to get the detailed knowledge regarding the nitrate and its other chemical related contamination ingestion to the human bodies at eh different age limits.
  • Further, it is also recommended to the researcher to search more secondary information to get the in-depth view of the subject matter regarding the adverse effect of nitrate contamination in the human body.
  • Last but not the least, it is also recommended to the researcher to alot the time schedule in a proper manner for each and every article or authentic source of information, so that the project with a wide range of information will be completed within the allotted time frame.

Scope for further research

The research has highlighted the importance of findings the adverse effects of nitrate contamination on a human being. This is the primary concern that the research has focused. As a further research scope, the explanation some other chemical contamination sources of drinking water and dietary foods can be focused to give the research a new dimension regarding the detailed analysis. Apart from that along with the quantitative discussion, the qualitative discussion also should have given importance to get the detailed idea about the subject topic. With the help of the quantitative design, only the numeric details based on the different sample researchers and its impact in the community of the different countries have been derived.  But, with the help of the qualitative research, along with the numeric results, the descriptive results also are supposed to be gathered to make the research outcome as the stronger. The scope of the further research identifies the gap in the research process that has been used by the researcher as per the required and the best possible result that could have been derived by the researcher using the best possible method to accomplish the task in an effective manner.

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