A Multi-Pathway Approach to Pesticide Exposure in Agricultural Communities: Protocol for an Observational Study

BACKGROUND: The widespread use of pesticides in agriculture raises concerns about exposure among populations living near treated fields. Environmental contamination may lead to prolonged pesticide exposure, with potential health effects, yet significant knowledge gaps remain regarding exposure levels and pathways in agricultural communities. OBJECTIVE: The Exposure to Pesticides Used in Regions of Agriculture (EPURA) study aims to characterize pesticide exposure patterns and identify their key sources and determinants through an integrated approach combining biological and environmental measurements. METHODS: We recruited 400 participants from agricultural communities living within 1500 meters of vegetable production fields in Quebec, Canada, throughout the 2 years of data collection. Over 4 summer months and 3 winter months, participants provided monthly urine samples and floor wipes and completed questionnaires on diet, water consumption, household characteristics, pesticide use, and lifestyles. Summer and winter urine samples were pooled for each participant, and summer and winter wipe samples were pooled for each household. At the end of the summer, we collected additional samples, including indoor dust, yard soil, and tap water. Environmental and biological samples will be analyzed for 51 pesticides and their metabolites. Pesticide applications near residences will be estimated using agricultural land use data integrated into a geographic information system. Pesticide intake from food and water will be assessed by combining consumption data with pesticide residues measured in water and in food monitoring programs. Residential contamination will be estimated by measuring pesticides in indoor dust and yard soil. Urinary pesticide concentrations will be used to estimate exposure doses. Urinary concentrations will be compared across population subgroups and seasons and with available Canadian biomonitoring data. Associations between exposure doses and dietary and water intake, indoor and outdoor contamination, proximity to treated fields, and household-level determinants will be examined using mixed models. Variable selection will be performed using high-dimensional methods. RESULTS: As of June 1, 2026, participant recruitment and data collection are complete. A total of 173 households (372 participants) were included in the study, with 1049 wipe samples, 170 sealed petri dishes, 157 water samples, 170 yard soil samples, and 2257 urine samples collected. Completion of all laboratory analyses is expected in 2027, after which the statistical analyses will be conducted in accordance with the study objectives. CONCLUSIONS: This study will generate crucial data on pesticide exposure in agricultural communities. Its findings will help identify major determinants of household contamination and key risk factors contributing to residents' pesticide exposure. Ultimately, the EPURA study will support the development of targeted strategies to reduce pesticide-related health risks and inform public health policies. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/94740.