Careful Of Their Diet Biology Essay

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The Arctic is a place where little pollution is generated. However, it is highly contaminated due to the transfer of both one-hop contaminants and multi-hop contaminants through the atmosphere. These are generated at different sources elsewhere in the world, mainly from Europe and the eastern United States, exacerbating problems with contamination in the Arctic food chain. Contaminants can travel regionally and globally through physical processes through the atmosphere, ice, and ocean currents (such as the North Atlantic Current which flows into the Arctic Basin).

These contaminants can be sub-categorized into more defined groups:

One-hop contaminants consist mainly of - radionuclides, Sulphates, Nitrates, and non-volatile heavy metals (excluding mercury).

Multi-hop contaminants can be broken down into Persistent Organic Pollutants, volatile organics comprised of PCBs and PAHs, semi-volatile organics HCHs, and Mercury.

These contaminants are very persistent. Over time they build up and lead to a legacy of effects on the food chain. A major concern for the native population of the Arctic is bioaccumulation. This is the buildup within living organisms of these toxic substances existing in the environment, occurring through consumption. Biomagnification is also a major problem that involves increasing concentration of toxic substances within the tissues of organisms at successively higher level links in the food chain (AHSD, 2008). The process always begins with phytoplankton and chemical transfer stems from this stage in the food web onwards, to the top. This process makes species at the top of the food chain more susceptible to toxic poisoning as levels of contaminants in organs can be up to a million times higher than that of species lower down the food chain.

These toxic chemicals are having a sociological impact on Arctic culture as they depend on contaminated sea life for sustenance and social and cultural well-being. The bodies of both the native people and animals located in the Far North contain extremely high levels of toxic chemicals due to the food chain being much more attenuated. Fat is an important part of the diet for Inuit who traditionally consume large amounts of fish and marine mammals such as polar bear, seal, whale and cod. All of these animals carry several toxic chemicals but are all important sources of nutrients such as protein, vitamins, minerals, and omega-three fatty acids. Pregnant women, children and women are especially sensitive to increasing toxic chemical concentrations in the Arctic.

The Arctic Monitoring and Assessment Programme (AMAP) is a joint secretariat which, over the past decade, has been responsible for conducting research into environmental toxins and offering advice to ministers of all eight Arctic nations in the circumpolar region. A report published in September of 2002 states that mercury and PCB levels in some Arctic native people are high enough to affect children's development, causing disorders related to the immune system, brain development and reproduction.

A common characteristic of many of the chemicals occurring in the Arctic environment is that they have a long half-life, meaning that they break down very slowly. Persistent Organic Pollutants (POPs) is the general name used for this group of toxic chemicals which can cause life threatening health problems in particular they can increase the risk of cancer by mutating hereditary DNA material in cells which in turn causes the cell to lose control of growth. They were used extensively in the early to late 20th century for a wide variety of applications. The use of POPs has been banned across many major countries for forty years now in an attempt to eliminate them altogether, thus terminating the negative effects they have on health and the environment over time. Children are more susceptible to the effects of toxic pollutants as they are still developing. Studies have shown that children exposed to POPs during infancy score lower on tests devised to determine intelligence as their developing cells are sensitive to contaminants and exposure can lead to decreased brain development and cognitive function. The immune system also becomes more vulnerable with increased POPs, as they limit cell-meditated immunity which fights parasites and cancer cells in the body (Kelly, 2004).

PCBs (polychlorinated biphenyls) are also a major concern for Inuit. They are the most significant environmental toxin in the Arctic due to long half-lives of about 8-15 years (Mahan, 1998). Before it was banned worldwide 25 years ago, PCB was used in huge amounts as oil in transformers but biodegrades very slowly. It is still present in the environment in large quantities and people are still being affected by the chemical. Experiments have shown that presence of PCBs in the Arctic has doubled in the last 3-4 years. An article published in the New York Times stated that a 1987 study conducted at Laval University in Sainte-Foy, Quebec found "The fat in the milk of the Eskimo women showed an average PCB concentration of 3.59 parts per million, compared with 0.76 parts per million for the rest of the samples… Some Eskimo women had a concentration of 14.7." (New York Times, 1989). These figures show just how urgent the problem of dealing with such toxins is becoming. Not only will it affect the mother in many different ways, whether it be carcinogenic or neurological, but it will also affect infants when exposing them to contaminated transplacental and breast milk transmissions from the Inuit mother (Cone, 2005).

From the food the natives consume comes a very high dietary exposure to mercury which exists in many different chemical forms. Methylmercury is the most predominant form and the most toxic to living organisms. Mercury has now been found over more or less the entire Arctic area, threatening animals and their ecosystems as well as the indigenous people (who eat the animals by way of biomagnification as it passes up the food chain). A draft version of UNEP's 2013 Global Mercury Report suggests that "Arctic marine animals have a mercury concentration that is about 10-12 times higher than in preindustrial times" (UNEP, 2013). Concerns have been raised about the human health effects that mercury has with potential effects on brain development, such as autism and Alzheimer disease, along with effects on the cardiovascular and immune systems, and also the reproductive system by altering chemicals in hormones (El-Hayek, 2007). However, selenium has been found in large quantities in Greenland's large mammals. It is a chemical element that can bind to mercury making the mercury within animals and humans harmless.

DDT is a chlorinated pesticide which travels to the Arctic through long range atmospheric transport. It is readily metabolised into a stable and equally toxic compound and stored in fat tissues of both humans and animals. DDT has been linked to human reproductive abnormalities ranging from defects amongst children, still births and decreased fertility (GPA, 2000). Despite the use of DDT being banned in the US for over 20 years now, it is still found concentrated in environments due to its long half-life.

Radioactive contamination is also a concern in the Arctic. Contamination has been created in the arctic environment from atmospheric nuclear weapon testing, nuclear accidents such as Chernobyl, and from nuclear processing plants dumping waste. Radionuclides are toxic and accumulate in food chains.

However, these toxic contaminants have geographical differences and are more concentrated in some areas than others. Because of this, guidance regarding diet needs to be given locally as contamination varies. However that is only a short-term solution. Where pollution is greatest, advice is given to eat the animals lower down the food chain such as Baleen whales (which eat only shrimp and other plankton meaning that PCB contamination is low). Reducing the exposure to all of these contaminants in the Arctic is the only true long-term solution. This will depend on global action to reduce quantities of toxins entering the environmental reservoirs (AMAP, 2011). Several political actions can be taken in order to reduce human exposure to such toxic substances. Such as monitoring, regulating, funding research and banning the use of toxic chemicals where necessary.

There are numerous additional toxic chemicals which exist in the Arctic. Some have been studied for decades, with well-known health effects. Others are recently being researched for the first time and so the effects are less well-known and less documented. For most circumpolar regions of the Arctic, traditional food consumption has been decreasing. Consumption of shop-bought foods is higher than that of traditional foods. This is lessening the impact of toxic contaminants. However, the transmission from traditional foods to a more 'western' diet can expose Inuit to other health problems such as heart disease and obesity (Dewailly, 2006).

To conclude, the Inuit would have to relinquish their traditions, and stop hunting, in order to ensure that they are no longer consuming dangerous levels of toxic substances; otherwise there is a danger of demolishing their culture. However, this would also not be ideal as it would threaten their heritage. The achievement of lowering toxic chemical levels in the Arctic environment is imperative if the Inuit are to continue consuming traditional foods.