Preparation and validation of exposure and risk profiles for pestcide use in greenhouses

Background. Greenhouses are a peculiar indoor working environment, where mixtures of pesticides, variable according to crop and season, are used. Occupational exposure measurement is thus difficult and only seldom performed, thus making task-based semiquantitative estimates an attractive tool for exposure and health risk assessment. Objective. To provide a user-friendly, reliable description of risk through a minimum set of exposure indicators of work conditions and absorbed doses. Methods. a: indicators were chosen according to scientific and agronomic literature and task analysis. Different exposure conditions were ranked by attribution of scores (high, intermediate, low) and a semiquantitative algorithm was implemented to model individual exposure. b: Risk Profile was applied to literature exposure studies to compare the agreement of model calculations to risk assessed by field measurements. c: a targeted study was performed to evaluate the agreement of model estimates to measured exposure of greenhouse workers using chlorpyrifos-methyl. Results. greenhouse workers resulted exposed to airborne concentrations below established safety standards; dermal exposure ranged from GM 20 ng/cm2 outside clothing to GM 2ng/cm2 under clothing (Range: 0.2-4100 ng/cm2). Total Exposure Index was estimated: variables affecting pesticide exposure levels for each task were highlighted. These estimates are in line with published studies and with the measurements performed in the exposed workers. Conclusions: Exposure measurement, indirect assessment and derived Risk Profiles provide a reliable description of working conditions through a minimum set of indicators and with minimal use of expensive workplace or biological monitoring, thus qualifying as promising tools for pesticide risk evaluation in agricultural settings.