Researcher: Pesticide Exposure Is "Universal" in Farmworker Communities; Urges Biomonitoring

Ana Maria Mora, an environmental epidemiologist at the University of California, Berkeley, summarized findings from the CHAMACOS birth cohort and said exposure to pesticides begins in utero. "Exposure to pesticides is universal, and it begins before birth," she told lawmakers, describing detection of pesticide breakdown products in nearly all urine and breast‑milk samples collected in her study.

Mora said the study — begun in 1999 and following several hundred mothers and children into young adulthood — documents shorter pregnancies, poorer lung function, and neurodevelopmental differences tied to higher prenatal exposures. She emphasized that harms were greatest among children facing social adversity: "prenatal exposure to organophosphates was linked to a 2.5 drop in IQ in children with lower... adversity homes, compared to an 8 point drop of IQ in the kids... living with higher adversity."

Recommendations Mora offered included building sustained biomonitoring programs in agricultural communities, linking pesticide-use reporting to health and birth‑outcome data, and evaluating chemicals as classes and mixtures rather than one-by-one. "I would urge the state to build ongoing biomonitor... in agricultural communities so we can track exposure in something closer to real time," she said.

She closed by stressing equity and independent community‑based research to inform regulation, and offered to answer technical questions from the committee.