13
May
Prenatal, Childhood Exposure to Toxic Pesticides Linked to Neurodevelopment Issues
(Beyond Pesticides, May 13, 2024) A study published in Environmental Research finds that “early life organophosphate pesticide exposure has been linked with poorer neurodevelopment from infancy to adolescence.” Researchers in this study acknowledge that there is still much more to be done in furthering understanding of “neural mechanisms underlying these associations,” and yet there is “notable consistency” in their Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) birth cohort study. This study’s findings are consistent with decades of substantial, peer-reviewed scientific literature documenting the adverse health impacts of organophosphate pesticides on public and ecological health. Organic advocates believe that a transition away from chemical-intensive agriculture and land management is the most viable solution to avoid adverse health impacts and end reliance on toxic chemicals in households and communities.
The researchers for this study are based at the University of California, Berkley (Center for Environmental Research and Community Health as well as Center for Interdisciplinary Brain Sciences Research), Department of Public Health at University of California, Merced, and Stanford University (Departments of Radiology and Pediatrics in the School of Medicine). “We have reported associations of prenatal [organophosphate] exposure with poorer cognitive function and executive function, and more attention and behavior problems from birth through age 18 years,” according to the researchers.
The researchers arrived at this conclusion through a multi-pronged approach, including a pesticide exposure assessment, infrared spectroscopy (fNIRS), covariate assessment, and subsequent statistical analysis of the data.
Over the course of this 18-year study time horizon, 317 youth from the original cohort of pregnant women recruited in 1999 and 2000 made up the study population with a note “that the youth in this analysis are separate from the subset of 95 youth who completed fNIRS at age 16 years.” In the end, 291 CHAMCOS youth and their respective families were included in this analysis. Most mothers were born in Mexico (90.4 percent) and were living “at or below the poverty line at the 18-year visit (41.6%).” Pesticide exposure was measured two times during the pregnancy (13- and 26-week gestation) and at 6-month, 1-year-, 2-year, 3.5-year, and 5-year appointments.
The researchers measured the concentration of 6 dialkyl phosphate metabolites – three dimethyl phosphate metabolites (dimethylphosphate, dimethylthiophosphate, dimethyldithiophosphate) and three diethyl phosphate metabolites (diethylphosphate, diethylthiophosphate, and diethyldithiophosphate)—using gas chromatography-tandem mass spectrometry. From there, the researchers estimated neurodevelopment changes through fNIRS to measure “cortical activation in the frontal, temporal, and parietal regions of the brain during tasks of executive function and semantic language.” Data was gathered from the mother-youth pair participants “at approximately biennial visits (twice during pregnancy, shortly following delivery, and when youth were 6 months and 1, 2, 3.5, 5, 7, 9, 10.5, 12, 14, 16, and 18 years of age).”
Various organophosphates, most notoriously the insecticide chlorpyrifos, are linked to adverse health effects in vulnerable individuals, including children, mothers, farmworkers, and frontline workers in the agricultural and pest management sectors. Although advocates for public and environmental health initially prevailed when in 2021 a three-judge panel of the Ninth Circuit of Appeals ordered EPA to promulgate a rule eliminating chlorpyrifos use in agriculture after its ban on golf courses in 2001, the Eighth Circuit Court of Appeals ruled in favor of industry by vacating this prohibition.
In terms of the scientific literature, there are numerous studies that document the public health hazards caused by organophosphate pesticides. For example, a 2023 meta-analysis of organophosphates published in Toxics found that current pesticides that fall in this class of chemicals, including chlorpyrifos and malathion, induce oxidative stress, as well as DNA and cellular damage in the cardiovascular system. In addition, organophosphates can disrupt the homeostasis of proinflammatory and anti-inflammatory responses of cytokine proteins responsible for immune protection. Thus, exposure can exacerbate vulnerability to deadly diseases, including cardiovascular disease. A 2024 study published in Environmental Sciences Europe builds on this linkage, finding that some organophosphate pesticides—including metabolites of organophosphates (oxypyrimidine [diazinon], paranitrophenol [parathion], and dichloroynl-dimeth prop carboacid [dichlorvos]) can increase cancer risk while simultaneously elevating inflammation biomarkers that indicate damage to organs (e.g., liver) via oxidative stress. Different cancers are associated with different pesticides; consequently, cancer risk changes with exposure concentration and pattern.
Organophosphates also pose a threat to reproductive health based on studies published in Environmental Health Perspectives, F1000 Research, and additional peer-reviewed journals. For example, men exposed to organophosphate (e.g., glyphosate and malathion) insecticides have lower sperm concentrations than the general population, with an even greater degree found in men exposed through professional settings such as factories. To learn more about the adverse, long-term health impacts onset by organophosphate pesticides, see its section in the Daily News Blog and search details on specific organophosphates in the Gateway on Pesticide Hazards and Safe Pest Management.
Dependency on individual toxic pesticides and families of pesticides are symptomatic of chemical-intensive land management practices. According to Beyond Pesticides, campaigns to ban individual pesticides can be important in elevating public understanding of the scope of the problem, but insufficient in galvanizing transformational change of food systems resulting in public, worker, and environmental exposure. Toxic pesticides do not have a place in certified organic products, nor should they have a place in any food products consumed by the public. Organic advocates have long decried the use of toxic pesticides in mainstream, industrial agriculture and land management and call for systems-change transformation that is achievable through organic agriculture and land management principles. This sentiment is aligned with Beyond Pesticides’ mission to eliminate use of toxic petrochemical pesticides by 2032 to address the compounding crises of public health, biodiversity collapse, and climate change.
See Organic Agriculture, including sections on Why Organic? and Keeping Organic Strong, to view an array of resources, guides, and research on the ecological, public health, and environmental justice implications of a wholesale organic food system. See Eating With a Conscience to learn about which organophosphates, neonicotinoids, and other class of chemicals are most commonly sprayed on everyday produce and vegetables to inform your next trip to the grocery store. And finally, see Tools for Change to learn about organizing strategies to transition your community toward organic lawncare management programs.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: Environmental Research
