Wind tunnel investigation of the ability of drift-reducing nozzles to provide mitigation measures for bystander exposure to pesticides

Models recently developed for assessing the potential exposure of residents and by- standers to pesticides through spray drift have highlighted the need for mitigation stra- tegies to reduce exposure of members of the public. Drift-reducing equipment is readily available in many countries and is accepted as mitigation for the exposure of surface water to drifting pesticide sprays but there is concern that the drift-reduction measurement methods used to define the exposure of surface water might not be relevant to bystanders. Airborne spray is an important component in bystander exposure. Two wind tunnel ex- periments were undertaken to evaluate whether reductions in airborne spray are as great as the reductions in measured spray drift that occur using protocols designed to classify nozzles for protecting surface water.