18
Mar
Common Use Organophosphate Insecticides Pose a Greater Threat to Women’s Health
(Beyond Pesticides, March 18, 2021) A new study published in Environmental Toxicology and Pharmacology finds chronic (long-term) organophosphate (OP) pesticide exposure increases adverse health and cancer risk for U.S. women relative to men. Organophosphorus pesticides have a wide range of biological uses—from insecticides to flame retardants—that make these chemicals ubiquitous, significantly contributing to ecosystem contamination. Furthermore, while organophosphates have less bioaccumulation potential, residues are consistently present in human and animal blood, urine, tissues, and milk. Although research demonstrates that OPs are highly toxic, there remains an inadequate understanding of how OP exposure impacts the nonagricultural population in the U.S., especially women. Therefore, it is essential to investigate the sex-specific health effects chemical contaminants can produce to mitigate exposure among vulnerable populations. Study researchers note, “Given the higher burden of OP exposure and their significantly higher overall health risk, including cancer, reducing OP exposure in U.S. women needs to be prioritized.”
To examine the relationship between OP exposure and health risks, researchers investigated the presence of commonly detected OP metabolite concentrations in urine using participants from the U.S. National Health and Nutrition Examination Survey (NHANES). Urine samples measure OP metabolite as an indicator of OP exposure like previous agriculture-related population surveys. Study participants report health issues and frequency of prescription use for treatment for asthma and other pulmonary (lung) ailments, cardiovascular disease, cancer, and more.
Study results demonstrate that non-smoking women with higher concentrations of OP metabolites are at greater risk of developing cardiovascular disease, bronchitis, asthma, and total cancer, including breast cancer. OP exposure contributes most significantly to cardiovascular disease risk in women 60 to 85 years old. Increasing prescription drug use to treat pulmonary issues among women with higher OP concentrations indicates a relationship between exposure and health issues. Although breast cancer risk is highest among women overall, female smokers have a significantly higher risk of developing breast cancer in combination with OP exposure. Lastly, OP exposure among male smokers can increase rates of prostate cancer.
Organophosphate insecticide use is widespread, while industry promotes the chemicals as having greater efficiency and lesser environmental persistence. However, OPs originate from the same compounds as World War II nerve agents, producing adverse effects on the nervous system. Chemical exposure can cause a buildup of acetylcholine (a chemical neurotransmitter responsible for brain and muscle function) can lead to acute impacts, such as uncontrolled, rapid twitching of some muscles, paralyzed breathing, convulsions, and, in extreme cases, death. The compromise of nerve impulse transmission can have broad systemic impacts on the function of multiple body systems. In addition to being highly toxic to terrestrial and aquatic organisms, human exposure to organophosphates can induce endocrine disruption, reproductive dysfunction, fetal defects, neurotoxic damage, and kidney/liver damage. Exposure can increase vulnerability to deadly diseases, including COVID-19. Moreover, OPs are one of the leading causes of intentional poisoning globally as pesticide toxicity makes them potentially lethal substances.
Since the implementation of the Food Quality Protection Act of 1996, residential uses of organophosphate pesticides have been highly restricted by the U.S. Environmental Protection Agency (EPA). Although most OP uses in the U.S. are now agricultural, toxicity experts recommend a ban on all OPs for agricultural use. EPA and World Health Organization (WHO) consider over 40 OPs that are moderately or highly hazardous to human health. EPA classifies some commonly used OPs like malathion, a popular mosquito control, and tetrachlorvinphos, a common flea and tick killer in pet collars and shampoos, as probable carcinogens. States, including Hawaii, California, New York, and Maryland, plan to phase out chlorpyrifos use, to different degrees, in agriculture following evidence of neurotoxic effects on children. However, other OPs remain in use despite their notorious toxicity.
This study adds to the growing body of research assessing sex-specific disparities in chemical metabolization (breakdown) and elimination in the body. OPs exhibit endocrine-disrupting properties that may alter estrogen or testosterone activity and receptors, resulting in differences in the clearance rate and toxicity of OPs. For instance, a 2018 study finds female rats manifest airway hyperactivity—a characteristic symptom of asthma—at lower OP doses than males. A 2020 study reveals that exposure to acetylcholinesterase (AChE) inhibitors like OPs can cause sex-specific differences in depression symptoms among adolescent girls through endocrine disruption. Furthermore, this study is the first to demonstrate that, among the general population, OP exposure causes an increased risk of total cancer for female non-smokers, breast cancer for female smokers, and prostate cancer for male smokers from OP exposure. Researchers suggest that the same endocrine-disrupting properties that induce sex-specific effects also play a role in promoting hormonal-related cancer development like breast and prostate. The study infers that the most likely source of OP exposure is from diet, due to the cyclic presence of metabolites in urine throughout the years. Therefore, researchers conclude, “reducing the dietary exposure to OP insecticides needs to be prioritized.”
Policies should enforce stricter pesticide regulations and increase research on the long-term impacts of pesticide exposure. Beyond Pesticides tracks the most recent studies related to pesticide exposure through our Pesticide Induced Diseases Database (PIDD). This database supports the clear need for strategic action to shift away from pesticide dependency. For more information on the multiple harms pesticides can cause, see PIDD pages on endocrine disruption, cancer, asthma/respiratory effects, and other diseases. Learn more about how the lack of adequate pesticide use regulations, including organophosphates, can adversely affect human and environmental health; see Beyond Pesticides’ Pesticides and You article “Highly Destructive Pesticide Effects Unregulated.”
Beyond Pesticides advocates a precautionary approach to pest management in land management and agriculture by transiting to organic. Buying, growing, and supporting organic can help eliminate the extensive use of pesticides in the environment and from your diet. For more information on how organic is the right choice for both consumers and the farmworkers who grow our food, see Beyond Pesticides webpage, Health Benefits of Organic Agriculture.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
People, the environment, and wildlife in developing countries are more exposed to pesticides/ chemicals and biocides due to a lack of regulations and enforcement.
March 26th, 2021 at 1:46 am