Predictors of pesticide levels in carpet dust collected from child care centers in Northern California, USA

Background: Young children may be exposed to pesticides in child care centers, yet determinants of contamination are not well characterized. Objective: To characterize pesticide contamination in early care and education (ECE) centers and identify predictors of pesticide concentrations and loadings in carpet dust. Methods: Carpet dust from 51 licensed child care centers in Northern California was analyzed for 14 structural and agricultural pesticides. Center characteristics were obtained via director interviews, observational surveys, and an integrated pest management (IPM) inspection. Structural pesticide applications and nearby agricultural pesticide use during the prior year were obtained from California Department of Pesticide Regulation (DPR) records. Results: The most frequently detected pesticides were cis-permethrin (98%), trans-permethrin (98%), bifenthrin (94%), fipronil (94%), and chlorpyrifos (88%). Higher bifenthrin levels correlated with agricultural applications within 3 km, and higher fipronil levels correlated with professional pesticide applications in the prior year. In multivariable models, higher IPM Checklist scores were associated with lower chlorpyrifos and permethrin loadings. Placement of the sampled area carpet predicted chlorpyrifos loading. The strongest predictor of higher pesticide loading for frequently detected pesticides was location in the San Joaquin Valley. Significance: Pesticides are ubiquitous in children's environments. Some determinants (e.g., IPM practices) are potentially modifiable by ECE directors, while others (e.g., geographic location) are not. IPM may reduce pesticide exposures in ECE settings, including legacy pesticides no longer in use. Impact: Over one million California children under six attend child care programs where they may spend up to 40 hours per week. Identifying behavioral and environmental predictors of pesticide contamination can inform providers, consumers, and policymakers to reduce exposures and promote health.