Title: Cancer Among Agricultural Populations in Argentina

Issue:

Cancer is a general name for a group of diseases associated with the rapid creation of quickly developing abnormal cells which grow beyond regularity.¹ Loss of human productivity, quality of life, and money directly spent on treatment costs are a few economic and social burdens attributable to the disease which make it a significant public health issue.² According to the World Health Organization (WHO), cancer was the cause of 8.8 million deaths globally in 2015.¹ It is currently a leading cause of death in the world, and the number of new cases in the world is expected to rise by approximately 70 percent in the next twenty years.¹ Cancer is caused by a combination of genetic factors and environmentally-introduced carcinogens (substances or agents causing cancer³). A full list and classification of carcinogens are kept by the International Agency for Research on Cancer (IARC).¹

Early detection of cancer through diagnosis at early stages and screening for the disease generally lowers cancer mortality and makes treatment less expensive. Diagnosis of the disease is extremely important because different treatments, such as surgery or chemotherapy, are required for the various types of cancer. When detected early, certain types of cancer, such as breast cancer and cervical cancer, have high cure rates. In other cases, the goal is to improve quality of life through palliative care.¹

Important risk factors for cancer include tobacco and alcohol use, poor diet and exercise habits, and certain chronic infections. Aging is also a significant factor for developing cancer since the various risk factors can accumulate over time.¹ Prevention is currently thought to be the most effective method to control cancer, and it is estimated that between 30 and 50 percent of cases are preventable.¹ It should be the goal of national and global programs to reduce human exposure to known risk factors and carcinogens. While there are many risk factors for cancer, the focus of this paper will be on occupational carcinogens as they relate to pesticide use in Argentina’s agricultural industry.

Burden on health:

Argentina’s age-standardized cancer rate for men and women combined was estimated to be 216.7 per 100,000 capita in 2012, which ranked as the 49^th highest worldwide.⁴ Furthermore, it is estimated that over the next two decades, the incidence of new cancer cases and cancer-related mortality will increase by approximately 43 percent and 48 percent, respectively.⁵ In Argentina, breast, colorectal, lung, and prostate cancers are diagnosed most frequently and account for the most cases of cancer-related mortality.⁵ According to the WHO, it is estimated that the burden of cancer (for all cancers other than lung cancer) in Argentina is 2.2 disability-adjusted life years (DALYs) per 1,000 capita per year.⁶ The world’s lowest country rate is 0.3 DALYs per 1000 capita per year, and the world’s highest county rate is 4.1 DALYs per 1000 capita per year.⁶

Attention has been drawn to pesticide use in Argentina largely due to two agricultural regions in which adverse health outcomes have been reported to be abnormally high. For the purposes and scope of this paper, cancer in Argentina’s Córdoba region will be the focus. According to a report prepared by the Provincial Tumour Registry and the Department of Statistics and Census titled Report on Cancer in Córdoba 2004-2009, rates of deaths from cancerous tumors in areas where pesticides were used and genetically modified crops were grown were twice that of the national average.⁷ A region referred to as pampa gringa occupies the eastern portion of the Córdoba province and is known for its agricultural production. According to this report, the cancer mortality rates (per 100,000 capita in 2012) in four Córdoba departments in pampa gringa were as follows: 229.8 (in Marcos Juárez), 228.4 (in Presidente Roque Sáenz Peña), 217.4 (in Union), and 216.8 (in San Justo). The average provincial cancer death rate in Argentina was 158 deaths per 100,000 capita in 2012.7

Several studies have also determined that inhabitants of Córdoba who have been exposed to pesticides have genetic damage, which is notable since DNA damage following carcinogen exposure can be a precursor to cancer.7,8 Glyphosate, for example, is an herbicide applied to plants to control weeds and is used frequently in Argentina’s soybean industry. The chemical has been detected in lakes, soils, and rainwater in the Córdoba province and been found to alter early stages of morphogenesis in vertebrate embryos.⁹ In 2015, the World Health Organization’s IARC declared glyphosate to be a “probable human carcinogen.”¹⁰ Despite this information, the link between cancer in humans and agrochemical use is still debated.

Country context:

Argentina is South America’s second-largest country, covers approximately 2,780,400 square kilometers, and has a population of approximately 41,446,000.11 The republic government is led by an elected president, and as of 2016, 35.8 percent of the seats in the national parliament were held by women.11  As of 2015, the average life expectancy at birth was 79.8 years for females and 72.2 years for males, and the infant mortality rate was 14 per 1,000 live births.11 In 2015, approximately 96.2 percent of the urban population and 98.3 percent of the rural population were using improved sanitation facilities, and 99.0 percent of the urban and 100.0 percent of the rural populations were using improved drinking water sources.11 In 2013, there were 3.9 physicians per 1,000 people11 and approximately 8.2 percent of the GDP was spent on health care11, which is less than the United States, but comparable to other wealthy nations.

Argentina is one of the largest economies in Latin America (Gross Domestic Product (GDP) over $550 million USD), of which approximately 6 percent is invested in education.¹² Argentina’s World Bank income classification is upper-middleclass; however, the country historically has gone through periods of economic and political instability.¹³ Russian and Brazilian financial market collapses in the late 1990’s caused a major economic depression in Argentina between 1998 and 2002. Although the country’s economy rapidly recovered from this crisis, the instability and rapid recovery may have contributed to the wide and unregulated use of pesticides in the past two decades.

In 2009, the incidence of poverty was 13 percent, and the incidence of extreme poverty was 3.5 percent. This was a dramatic reduction compared to 54 percent and 27.7 percent, respectively, in 2003.¹⁴ Similarly, the proportion of employed individuals living on less than 1 United States Dollar (USD) per day dropped from 12.9 percent in 2002 to 0.5 percent in 2009. In 2014, the government reported that 12.7 percent of Argentina’s population was living in poverty, which was defined as living on less than 4 USD per day¹⁴. Later, the government released new definitions of poverty and declared that approximately 32% of the country was living in poverty, defined as living on under approximately 8 USD per day in 2016.¹⁵

These definitions of poverty came after a long absence of published national statistics. Many economic reforms were implemented after Argentina’s presidential elections in 2015, including reform of the national statistics system. These changes in the national statistics system and periods lacking standardized published data may contribute to why there is insufficient evidence to make conclusions about the associations between cancer rates and pesticide exposure in areas like pampa gringa.

Argentina has a diverse climate, fertile land, and many natural resources. As such, Argentina has big export agriculture and livestock industries, which have grown particularly fast in the past 50 years. Approximately 34,700 hectares of land were used for soybeans in 1970, compared to an estimated 18 million hectares of land in 2015.16 With this expansion came the use of pesticides to support the fast and efficient growth of crops. Between 1995 and 2012, Argentina’s pesticide market grew from 155 million pounds to 700 million pounds.16 It is possible that the lack of published research, governance, and compliance to regulations regarding pesticide use are products of this rapid growth, and have contributed to the increase in cancer rates in areas where agrochemicals are heavily used.

Solutions:

An obvious potential solution to reduce cancer rates in these agricultural regions is to ban the use of the pesticides that are suspected of causing cancer; however, several factors make this difficult to implement. Short term exposure to certain types of pesticides is known to be toxic, but long-term effects are more variable and depend on many factors.¹⁷ Pesticides have been proven to increase crop yields and produce crops of better quality which can lead to direct and indirect benefits for humans18; however, many studies have also shown associations of low-level pesticide exposure and cancer; neurological, immune, and reproductive disorders; fertility issues; birth defects16,19-21; and DNA damage among agricultural workers⁸. Despite these studies, rural agricultural workers in Argentina are still being exposed to high levels of pesticides¹⁶.

In Argentina’s case, soy is an important source of export-tax revenue. In 1996, Monsanto Co. introduced genetically modified soybeans resistant to glyphosate to Argentina and has a large stock in Argentina’s soybean industry today.22 In a statement put out by the Industry Task Force on Glyphosate, it is claimed that glyphosate is not a carcinogen or a mutagen, and that associating an increase in cancer rates to a single chemical (glyphosate, for example) is “highly implausible.”23 While this may be the case, there remains a lack of evidence that there is no association.

In a 2010 lawsuit brought by residents of the Santa Fe province in Argentina, the regional court banned the spraying of agrochemicals near populated areas. This set the precedent that the government and agrochemical countries had to prove that spraying chemicals is safe, rather than residents proving it is harmful.22,24 Today, Argentina has some restrictions on the use of agrochemicals (mainly glyphosate), but grants certain permissions for the “unconfined planting of GM crops.”25 Furthermore, general compliance to restrictions is perfect across provinces.

Another potential solution is to collect better data and determine what exactly is the cause of the higher cancer rates in the agricultural regions, since some sources argue that cancer rates were not higher in the aforementioned regions in the first place.26 Changing of the national statistics system and lack of historical statistics present challenges, but there needs to be comprehensive studies which measure pesticide exposure of individuals and cancer rates. Unfortunately, such studies will likely take a long time and potentially put people exposed to pesticides at risk of adverse health outcomes.

Globally, pesticide use data are sparse.²⁷ With what is known about the effects of the agrochemicals in controlled settings, stopping use of potentially dangerous agrochemicals would be the safest solution; however, this is likely not an option due to conflicting interests of involved parties. In the meantime, since so little is known about pesticides and their effects over an individual’s entire life, measures must be taken to educate and train workers about the safe and cautious use of pesticides. A viable temporary solution that been proposed is to develop health education packages for workers and community members in order to minimize their exposure to pesticides.18

Conclusion:

While Argentina’s age-standardized cancer rate for men and women does not stand out as particularly good or bad in a global context (216.7 cases per 100,000 capita in 2012, which ranked 49^th worldwide in terms of frequency⁴), its agricultural regions with abnormally high cancer death rates are problematic. Argentina’s unstable political and economic history followed by a period of rapid ecomic growth (which includes the growth of the soy industry) in the past twenty years are possible explanations for the wide use and poor regulation of potentially-harmful agrochemicals, such as glyphosate. A lack of general information on cancer rates and pesticide use makes implementing solutions to lower cancer rates difficult. Pesticide use and the associated health effects are fairly unknown, but are likely to be important issues in the future. While banning the use of pesticides in the country and specifically in areas with elevated cancer rates may be best solution, it may not be feasible for economic and political reasons. As such, the promotion of data collection and safe working practices is extremely important moving forward.

References:

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2. Cancer and Public Health. NIH: National Cancer Institute; 2015. https://www.cancer.gov/research/areas/public-health. Accessed April 3.

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12. 2016; http://www.worldbank.org/en/country/argentina/overview. Accessed March 22, 2017.

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22. Argentina Court Blocks Agrochemical Spraying Near Rural Town. Monsanto Company (NYSE); 2010.

23. Position on recent claims arising in Argentina.  http://www.glyphosate.eu/position-recent-claims-arising-argentina. Accessed April 3, 2017.

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25. Restrictions on Genetically Modified Organisms: Argentina. 2015. https://www.loc.gov/law/help/restrictions-on-gmos/argentina.php. Accessed April 3, 2017.

26. Porterfield A. Despite activists’ claims about glyphosate dangers, there’s no cancer spike in Argentina. 2016. https://www.geneticliteracyproject.org/2016/03/28/despite-activists-claims-glyphosate-dangers-theres-no-cancer-spike-argentina/. Accessed April 3, 2017.

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