Proximity to agricultural fields as proxy for environmental exposure to pesticides among children : The PIAMA birth cohort

BACKGROUND: Agricultural pesticides are frequently used for crop protection. Residents living in close proximity to treated fields may be exposed to these pesticides. There is some indication that children living near agricultural fields have an increased risk of developing asthma and decreased lung function. OBJECTIVES: The aim of this study was to assess the proximity of participants' homes to fields likely treated with pesticides as proxy for environmental exposure to agricultural pesticides among participants of a Dutch birth cohort study, and to combine acreage of fields with farmer-reported pesticide use. METHODS: Potential pesticide exposure at the home address at the time of the 14-year follow-up was estimated for 2291 participants of the Dutch PIAMA birth cohort study. We used spatial data on the presence of crops during the year 2012 to calculate the surface area of specific crops relevant for pesticide use in The Netherlands cultivated within 50, 100, 500 and 1000m of the study homes. Farmer-reported pesticides use on specific crops from a national survey performed in 2012 was used to estimate the amount of all pesticides and pesticides with known irritant properties for the respiratory system applied within the aforementioned distances of the study homes. RESULTS: For 3%, 7%, 40%, and 65% of the homes, any relevant crops were present within 50, 100, 500 and 1000m, respectively. Among these, the most frequent crops were corn, cereals, and potatoes. For almost the same percentages of homes, it was estimated that pesticides with known irritant properties for the respiratory system were potentially applied within these distances. CONCLUSIONS: We observed that a small proportion of the study participants lived in close proximity (<50 or