Dermal exposure of bystanders and residents to direct spray drift in low crops during pesticide application

A database was compiled with field measurement studies which were conducted by CropLife Europe (CLE) member companies between 2011 and 2019 to refine product-specific bystander and resident risk assessments and studies previously used to develop and test BREAM and BROWSE models. Bayesian analysis of the database suggests that the most important variables influencing drift are drift reduction, boom height, wind speed, mannequin height, distance downwind, crop class and formulation class. A comparison between BREAM 2 predictions and field measurements of potential bystander exposure have shown that the level of conservatism in the model is satisfactory and is therefore the most appropriate model currently available for risk assessment for bystanders and residents. Comparing spray drift values as median, 75th and 95th percentiles derived from the CLE data show that current EFSA guidance values significantly overestimate bystander/resident exposure. • Bayesian analysis shows that higher potential dermal exposure is positively correlated with higher boom height above the crop, wind speed and mannequin size. • A comparison between BREAM 2 predictions and field measurements of potential bystander exposure have shown a satisfactory level of conservatism in the model. • Comparing empirically derived spray drift values from the CLE data show that current EFSA guidance values significantly overestimate bystander/resident exposure.