Environmental pesticide concentrations in air and pregnant women’s urinary pesticide metabolites in the Infants’ Environmental Health Study (ISA)

Abstract

BACKGROUND AND AIM: We evaluated associations between environmental pesticide concentrations in air and specific urinary pesticide metabolites among pregnant women from the Infants' Environmental Health Study (ISA) in Matina County, Costa Rica. METHODS: We used a Bayesian spatiotemporal model to extrapolate concentrations of the fungicide pyrimethanil and the insecticide chlorpyrifos measured with polyurethane foam passive air samplers (n=48, from 12 schools) across space and time. Using mixed models, we compared them with urinary specific-gravity corrected pesticide metabolite concentrations: 4-hydroxypyrimethanil (OHP, metabolite of pyrimethanil) and 3,5,6-trichloro-2-pyridinol (TCPy, metabolite of chlorpyrifos), repeatedly obtained among 451 pregnant women from the ISA Study (n=951). Pyrimethanil in air, OHP, and TCPy were log-transformed prior to statistical analysis to normalize residuals of models. We considered several covariables. RESULTS:Median (p10-p90) concentrations were: pyrimethanil = 1.33 (0.27-17.0) ng/m3, chlorpyrifos = 15.62 (4.38 - 24.19) ng/m3, OHP = 0.39 (0.06- 2.75) ug/L, and TCPy = 1.63 (0.75-4.27) µg/L. A 10% increase in pyrimethanil in air was associated with a 5.7% (95% CI 4.6, 6.8) increase in urinary OHP (μg/L), women who lived near banana plantations had higher OHP, whilst frequent consumption of rice and beans was associated with lower OHP. In addition, each 1 ng/m3 increase in chlorpyrifos in air was associated with a 1.5% increase in TCPy (μg/L), and women who worked in agriculture tended to have higher TCPy. CONCLUSIONS:Despite the limitations of having limited data on pesticide air concentrations in space and time, and biomonitoring of pesticides with short half-lives, the results of this study indicate environmental air concentrations of pyrimethanil and chlorpyrifos explained to some extent internal pesticide metabolite concentrations in pregnant women. Our results suggest that inhalation of these pesticides is one of the pathways of environmental exposure. Passive air sampling of current-use pesticides seems a promising method to monitor environmental pesticide exposure. KEYWORDS: passive air sampling, pesticides, environmental exposure, biomonitoring