Research from UC Davis Health found that a significant portion of adults and children in California’s San Joaquin Valley were breathing detectable levels of pesticides, including chlorpyrifos, which is no longer permitted in California. The new findings, published in the Journal of Exposure Science and Environmental Epidemiology, highlight the ongoing exposure to pesticides and herbicides in agricultural regions of the San Joaquin Valley, despite efforts to reduce their use. The study, led by Professor Deborah H. Bennett, emphasizes the need for continued monitoring and research to evaluate potential health effects on individuals in these communities.
California, as a heavily agricultural state, uses millions of pounds of chemical pesticides each year. Data from the California Department of Pesticide Regulation revealed that in 2022, the top counties in terms of pesticide use were concentrated in the San Joaquin Valley. Fresno, Kern, Tulare, San Joaquin, and Madera counties were among the highest users of pesticides in the state. This reliance on pesticides raises concerns about the impact on the health of residents, particularly children, who are more vulnerable to the potential adverse effects of these chemicals.
The researchers conducted the study by recruiting 31 adults and 11 children from three small agricultural towns in the San Joaquin Valley. Participants were given backpacks with special air-collection tubes to sample the air they were breathing. The backpacks were worn for 1-3 days, eight to 14 hours per day, totaling 92 days of combined air sampling. Analysis of the samples revealed that 22% of adult participants and one school-aged child were exposed to detectable levels of at least one pesticide, including chlorpyrifos, pyrimethanil, and trifluralin.
The pesticides detected in the air samples, such as 1,3-dichloropropene, chlorpyrifos, and penthiopyrad, are commonly used in agricultural practices. Chlorpyrifos, in particular, has been linked to neurologic damage in children and sensitive populations. While the toxicity of some compounds is well-known, others, like penthiopyrad, are less studied in mammals, leaving uncertainty about their potential effects on human health. The study underscores the importance of expanding monitoring and research efforts to better understand the risks associated with pesticide exposure in agricultural communities.
Participants in the study served as citizen scientists, wearing the backpacks to collect air samples as they went about their daily activities. Jane Sellen from Californians for Pesticide Reform, a co-author of the study, highlighted the concerns of many individuals in agricultural communities about pesticide exposure and their willingness to participate in collecting data. The results, while alarming, were not surprising given the prevalence of pesticide use in these areas. The study was funded by the California Air Resources Board Community Air Grant and the National Institute of Environmental Health Sciences.
Overall, the research conducted by UC Davis Health sheds light on the ongoing exposure of adults and children in the San Joaquin Valley to pesticides, despite efforts to reduce their use. The study emphasizes the need for continued monitoring and research to assess the potential health risks associated with pesticide exposure in agricultural communities. By engaging community members as citizen scientists, the study provides important data that can inform future efforts to protect the health of individuals living in areas with high pesticide use.