Agricultural Pesticide Use Near Public Schools in California

BACKGROUND: Agricultural production frequently relies on the applications of pesticides that, under some circumstances, can be hazardous to human health. There is little known about the types and magnitude of agricultural pesticides applied near schools. Because of the potential public health risks to children, we examined the use of selected agricultural pesticides near public schools.

METHODS: The California Environmental Health Tracking Program (CEHTP) assessed the use of agricultural pesticides near 2,511 public schools, attended by over 1.4 million students, from the top 15 agricultural counties in California for 2010. The accuracy and resolution of school parcel data were enhanced using geographic information systems (GIS) and satellite imagery. Enhanced school location data were linked with refined field-level pesticide application data to estimate agricultural pesticide use within ¼-mile of each school. Pesticides included in this study were selected for their public health relevance and categorized based on their known health effects or regulatory status.

RESULTS: The majority of schools in this study (64%) did not have any pesticides of public health concern applied within 1/4-mile. The top three pesticides used near schools, by pounds applied, were chloropicrin, 1-3-dichloropropene, and methyl bromide. Of the top ten pesticides used near schools, by pounds applied, eight have a chemical persistence of more than one week. Hispanic children were 46% more likely than White children to attend schools with any pesticides of public health concern applied nearby, and 91% more likely to attend schools in the highest quartile of use.

CONCLUSIONS: We found that the data and technology exist to accurately assess pesticide use near sensitive populations with a high degree of geographic resolution. The results from our study could inform future epidemiological research activities and investigation efforts, as well as inform the planning and evaluation of policies that minimize potential pesticide exposures near schools.