Pesticides and Lung Health: Pediatric Association between Agricultural Pesticide Use and Respiratory Health in Fresno, California

Abstract

Previous studies suggest that exposure to pesticides may be linked to increased risk of pediatric asthma; however, there is currently insufficient evidence to demonstrate a causal link. We investigated the association between exposure to agricultural pesticide application of three classes of pesticides (organophosphates (OP), carbamates (C), and methyl bromide (MeBr)) and lung function in a pediatric cohort in Fresno, CA, a community with intense agricultural pesticide use and high asthma prevalence. Study participants were members of the Fresno Asthmatic Children’s Environment Study (FACES), a cohort of racially and ethnically diverse children recruited from ages 6 – 11 with a physician diagnosis of asthma. We developed the “purexposure” package in R to pull publically available data from the California’s Department of Pesticide Regulation and calculate exposure to pesticide application. Exposure to three classes of pesticides was estimated by calculating the kilograms of relevant pesticides applied within a 3,000-meter buffer around each child’s home for the year prior to the baseline measure of FEV1. Study participants’ baseline measure of forced expiratory volume in the first second (FEV1) was the primary outcome for this analysis. The association between pesticide application and FEV1 was estimated by fitting a generalized linear model controlling for sex, age, height, and weight. Compared to participants in the lowest quartile of pesticide exposure, participants in the highest quartile of exposure demonstrated a positive association between FEV1 and exposure to OP (RR: 1.004, 95% CI: 1.004, 1.018), C (RR: 1.004, 95% CI: 1.004, 1.017), and MeBr (RR: 1.006, 95% CI: 1.007, 1.020). These results do not support our hypothesized harmful association between FEV1 and exposure to pesticides, and suggest that the association between pesticide application and lung function may be confounded by other environmental exposures such as air pollution.