Measurement of Bystander Dermal Exposure Resulting from Drift after Drone Application under Three Crop Treatment Scenarios

The use of drones for plant protection product (PPP) applications is increasing; however, field data are lacking for drift exposure to bystanders and residents, allowing one to compare different exposure scenarios. We determined the dermal exposure of bystanders from spray drift after drone application to bare soil, soybean crops, and peach tree orchards. Dermal exposure was increased in orchard crops at higher wind speeds and lower when mannequins were placed further away from the application site. Approximately 90% of the total spray drift was deposited on mannequins within 5 m from the field edge. Drift exposure after drone spraying was lower than predicted values for ground boom applications compared to predictions using knapsacks. In conclusion, our study confirms the operator and bystander exposure-related benefits of the use of drones for applying PPPs to field and orchard crops.