What about upwind buffer zones for aerial applications?

Buffer zones are areas set adjacent to areas sprayed with pesticides in which spray drift can deposit without consequence. It has been suggested that buffer zones should totally surround areas to be sprayed. We reviewed the scientific literature and employed a recently developed mechanistic model of spray drift to assess the magnitude of upwind spray drift and the consequent need for upwind buffer zones. Neither the scientific literature nor the AgDRIFT model support the need for upwind buffer zones for typical aerial spray applications.