The ravages of pesticides on human health

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Estimating the impacts of pesticides on human health is a challenge. The most authoritative study on the frequency of pesticides poisonings was published nearly thirty years ago, in 1990, by the World Health Organization WHO. Pesticides were then believed to cause 25 million acute poisonings every year, resulting in some 220,000 deaths worldwide, with suicides representing about two thirds of cases.

Approximately 99% of these deaths occurred in LMICs. These WHO figures are now outdated, and most likely reflect only a fraction of the real problem given the increase in pesticide use in LMICs, which has not been accompanied by the necessary safeguards to control how they are applied.

Long-term exposure to pesticides can also result in chronic health effects. Accurately estimating the number of such cases is even more challenging as symptoms may develop only years after exposure, diseases are often multi-causal, and people tend to be exposed to multiple harmful substances throughout their lifetime.

Studies show high rates of cancers and other chronic diseases linked to the massive use of pesticides

© Lunaé Parracho/Reuters

According to a scientific review published in 2013 in the Journal of Toxicology and Applied Pharmacology, “there is a huge body of evidence on the relation between exposure to pesticides and elevated rates of chronic diseases, such as different types of cancer, diabetes, neurodegenerative disorders like Parkinson, Alzheimer, and amyotrophic lateral sclerosis (ALS), birth defects and reproductive disorders”.

A recent review by the US National Institutes of Health (NIH) also concluded that “the spectrum of suspected pesticide – chronic human disease associations continues to grow”. Chronic low-dose exposure to pesticides is considered one of the significant risk factors for increased rates of cancer.  A landmark report by the U.S. President’s Cancer Panel in 2010 stated that exposure to pesticides “has been linked to brain/central nervous system (CNS), breast, colon, lung, ovarian (female spouses), pancreatic, kidney, testicular, and stomach cancers, as well as Hodgkin and non-Hodgkin lymphoma, multiple myeloma, and soft tissue sarcoma.” The report added that farmers have been found to have elevated rates of prostate can­cer, melanoma, other skin cancers, and cancer of the lip.

In addition to cancer, pesticides have also been linked to different forms of endocrine-related diseases. A 2012 report by the United Nations Environment Programme (UNEP) and the Food and Agriculture Organization (FAO) blamed the exposure to endocrine-disrupting pesticides and chemicals for the global rise in endocrine-related disorders, such as low semen quality, genital malformations, adverse pregnancy outcomes, neurobehavioural disorders, endocrine-related cancers, obesity and diabetes.

Researchers are particularly worried about exposure of children and pregnant women. UNICEF has warned that children face “exceptional risks” at critical stages in their early development when toxic exposure can cause lasting damage. In short: it is the future of the youngest and future generations that is at stake.

UN human rights experts recently warned that pesticides have catastrophic impacts on the environment, human health and society as a whole, calling them “a global human rights concern”. The situation is particularly worrying in LMICs, where the staggering increase in pesticide use has not been accompanied by the necessary safeguards to control how they are applied.

Baskut Tuncak, United Nations Special Rapporteur on human rights and toxics, believes the warnings must be taken seriously. “Everyone should enjoy the same human rights, regardless of age, gender or where they live. We must act urgently to prevent impacts on those most at risk from exposure to toxic pesticides”, he said.