Pesticide Exposure of Residents Living Close to Agricultural Fields in the Netherlands: Protocol for an Observational Study

Abstract
Journal of Medical Internet Research - International Scientific Journal for Medical Research, Information and Communication on the Internet #Preprint #PeerReviewMe: Warning: This is a unreviewed preprint. Readers are warned that the document has not been peer-reviewed by expert/patient reviewers or an academic editor, may contain misleading claims, and is likely to undergo changes before final publication, if accepted, or may have been rejected/withdrawn. Readers with interest and expertise are encouraged to sign up as peer-reviewer, if the paper is within an open peer-review period. Please cite this preprint only for review purposes or for grant applications and CVs (if you are the author). Background: Application of pesticides in the vicinity of homes has caused concern regarding possible health effects in residents living close by. However, the high spatiotemporal variation of pesticide levels and lack of knowledge regarding contribution of exposure routes greatly complicates exposure assessment approaches. Objective: To describe the study protocol of a large exposure survey in The Netherlands assessing pesticide exposure of residents living close (< 250 meters) to agricultural fields, to better understand possible routes of exposure, to develop an integrative exposure model for residential exposure, and to describe lessons learnt. Methods: We performed an observational study involving residents living in the vicinity of agricultural fields and residents living more than 500 meters away from any agricultural fields (controls). Residential exposures were measured both during pesticide use period (UP) after a specific application, and non-use period (NP), during 7 and 2 days, respectively. We collected environmental samples, outdoor and indoor air, dust, soil (garden, field), and personal samples (urine, hand wipes). We also collected data on spraying applications, as well as on home characteristics, participant’s demographics and food habits via questionnaires and diaries. Environmental samples were analyzed for 46 prioritized pesticides. Urine samples were measured for biomarkers of a subset of five pesticides. Alongside the field study, and by taking spray events and environmental data into account, we developed a modelling framework to estimate environmental exposure of residents to pesticides. Results: Our study was conducted between 2016 and 2019. We assessed 96 homes and 192 participants, including seven farmers and 28 controls. We followed 14 applications, applying 20 active ingredients. We collected ~5000 samples: 1018 air, 445 dust (224 vacuumed floor, 221 doormat), 265 soil (238 garden, 27 fields), 2485 urines samples, 112 handwipes, 91 tank mixtures. Conclusions: To our knowledge, this is the first study on resident’s exposure to pesticides addressing all major non-dietary exposure sources and routes (air, soil, dust). Our protocol provides insights on used sampling techniques, the wealth of data collected, developed methods, modelling framework and lessons learnt. Resources and data are open for future collaborations on this important topic.