October is Children’s Environmental Health Month in California, and there’s no better time to face a hard truth: Here in the heart of the San Joaquin Valley, in counties like Fresno and Tulare, children are among the most pesticide-exposed in California. They inhale drifting pesticide sprays from fields next to homes and schools, and many risk exposure on campus because the Fresno Unified School District (FUSD) still reserves the right to use highly hazardous pesticides—including products other countries have already rejected for safety.
A new peer-reviewed study from the Public Health Institute’s Tracking California and UC Berkeley’s Center for Environmental Research and Children’s Health (CERCH) analyzed more than 390,000 California births and pesticide applications statewide, finding that 7.5% of all pregnant women lived within one kilometer (about 0.6 miles) of organophosphate (OP) pesticide use during their pregnancy.
Researchers found that 23% of pregnant women in Tulare County and 6%–10% of pregnant women in Fresno County lived within one kilometer of hazardous OP pesticide spraying during pregnancy.
Extensive research reveals that pregnant women living near farm fields where OP pesticides are applied face higher risks of harm to their developing babies—including lower IQ, learning and attention problems, and lung damage. No amount of a brain-harming chemical is acceptable for a developing child.
The authors of the new study warn that these exposures fall hardest on Latino families.
Fresno and Tulare counties remain among the highest users of agricultural pesticides in California, with Fresno as the top pesticide user county (nearly 26.3 million pounds of pesticide active ingredients applied in 2023) and Tulare the third highest (nearly 16.8 million pounds of pesticide active ingredients applied in 2023).
In Fresno County, OP use remains substantial. In 2023, growers applied more than 174,000 pounds of OP pesticides on fields across the county—with heaviest use on crops like pistachio, tomatoes, cotton, oranges and alfalfa.
In Tulare County, growers applied approximately 57,040 pounds of OP pesticides, with heaviest use on crops like citrus and cotton. When the wind picks up (and in the Valley it always does), those sprays don’t stay put; they drift into neighborhoods, across schoolyards and other places where children play and sleep.
Organophosphates are not “normal” chemicals. Many were adapted from the same nerve-agent chemistry developed for warfare.
They kill by blocking acetylcholinesterase—the enzyme insects’ brains and our brains use to shut off nerve signals. When that shut-off switch is jammed, nerves fire uncontrollably: tremors, headaches, memory problems, seizures; in high doses, paralysis. For a fetus or a young child whose brain is wiring itself in real time, the damage can be permanent.
Children aren’t “little adults.” Pound for pound they breathe more air, drink more water and eat more food—so the same exposure delivers a bigger dose. They’re also closer to the ground, they crawl and touch surfaces, and they put their hands and objects in their mouths, which means more contact with pesticide residues in dust and on floors.
And for many farmworker families, exposure begins before birth and continues when residues come home on a parent’s clothes, shoes, skin and car seats; that dust collects in living rooms and bedrooms and becomes the backdrop of childhood.
“My kids can’t play outside when they’re spraying,” said Ofelia Ochoa, a mother in Fresno County. “The smell comes through the windows. We all feel it in our throats. But we can’t afford to move.”
This is environmental injustice in plain view. Latino families are more likely to live near fields where OPs are applied, to attend schools adjacent to agriculture and to experience multiple exposure routes at once—prenatal, drift, take-home and on-campus applications.
The new Tracking California/CERCH study underscores that reality: OP proximity during pregnancy is common enough statewide to be alarming, and it clusters in places where working families already shoulder the heaviest burden.
Unfortunately, it’s not just the fields. The FUSD, the third largest school district in the state, still authorizes a list of pesticides for use on school grounds that includes particularly hazardous pesticides, despite safer integrated pest management options.
According to the district’s own documents, the FUSD reserves the right to use more than two dozen pesticides that are banned in the European Union because of risks to children, workers or the environment.
“If these pesticides are too dangerous for Europe, why are they still being used around our children’s schools?” asked one Fresno parent.
California’s 2020 chlorpyrifos ban was a necessary step, but swapping one organophosphate for another is not a solution—especially when the health endpoint is the same: harm to the developing brain. Regulators know this.
The science is strong, the monitoring tools exist and the exposure routes in Fresno are well understood. What’s been missing is the political will to put children’s health ahead of chemical convenience.
Here’s what Fresno and Tulare counties can do right now.
First, establish stronger buffer zones where OP applications are prohibited near homes, schools, childcare centers, farmworker housing, parks and hospitals. Drift doesn’t respect property lines, and children don’t choose where the wind blows.
Second, phase out the remaining OPs, period. Other countries have already moved on; our families should not serve as the control group for chemical policy failure.
Third, ban synthetic pesticides on school grounds and require the district to adopt safer pest prevention—repair and sanitation, physical barriers, least-toxic products as a last resort and full transparency in plain language to families.
Fourth, provide exact location information as part of the California Department of Pesticide Regulation’s precedent-setting SprayDays notification system and stronger air monitoring in agricultural neighborhoods so families can better protect themselves and so health agencies can act on real exposure data rather than averages that hide local spikes.
Finally, prioritize protections where the burden is highest—pregnant people, infants and children, farmworkers and the elderly—so our policies match what the science and common sense already tell us.
Fresno’s and Tulare’s agricultural economies shouldn’t hinge on chemicals that can rewire a child’s brain. The workers who feed California should not have to sacrifice their own children’s futures to do it. It’s Children’s Environmental Health Month; if those words mean anything, they must mean that our counties choose our children over pesticides.
Fresno and Tulare counties can lead. The Department of Pesticide Regulation can act. And our largest area school district can decide that a playground and school room are no place for products that other countries have abandoned as too dangerous.
The continued use of organophosphate and other particularly hazardous pesticides around children is not an accident—it’s a policy choice.
Our children deserve clean air, safe schools and a chance to grow up without permanent chemical interference in their developing brains. The next generation is watching.
References:
Bouchard, M.F., Chevrier J., Harley, K.G., Kogut, K., Vedar, M., Calderon, N., Trujillo, C., Johnson, C., Bradman, A., Barr, D.B., & Eskenazi, B. (2011, August). Prenatal exposure to organophosphate pesticides and IQ in 7-year-old children. Environmental Health Perspectives, 119(8), 1189–1195. doi:10.1289/ehp.1003185. Epub 2011 Apr 21. PMID: 21507776; PMCID: PMC3237357. https://pmc.ncbi.nlm.nih.gov/articles/PMC3237357/
Marks, A.R., Harley, K., Bradman, A., Kogut, K., Barr, D.B., Johnson, C., Calderon, N., & Eskenazi, B. (2010, December). Organophosphate pesticide exposure and attention in young Mexican-American children: The CHAMACOS study. Environmental Health Perspectives, 118(12), 1768–1774. doi:10.1289/ehp.1002056. PMID: 21126939; PMCID: PMC3002198. https://pubmed.ncbi.nlm.nih.gov/21126939/
Raanan, R., Balmes, J.R., Harley, K.G., Gunier, R.B., Magzamen, S., Bradman, A., & Eskenazi, B.(2016, February). Decreased lung function in 7-year-old children with early-life organophosphate exposure. Thorax, 71(2), 148–153. doi:10.1136/thoraxjnl-2014-206622. Epub 2015 Dec 3. PMID: 26634937. https://pubmed.ncbi.nlm.nih.gov/26634937/
Sagiv, S.K., Baker, J.M., Rauch, S., Gao, Y., Gunier, R.B., Mora, A.M., Kogut, K., Bradman, A., Eskenazi, B., & Reiss, A.L. (2024, February). Prenatal and childhood exposure to organophosphate pesticides and functional brain imaging in young adults. Environmental Research, 242, 117756. doi:10.1016/j.envres.2023.117756. Epub 2023 Nov 26. PMID: 38016496; PMCID: PMC11298288. https://pmc.ncbi.nlm.nih.gov/articles/PMC11298288/
