Pesticides which do not evaporate so quickly are spread as droplets of various sizes, as in rain, mist or fog. The finer the spray, the further it drifts. Most aerially sprayed pesticide is applied at Ultra Low Volume, with very fine spray. The best equipment produces droplets of fairly uniform size and ostensibly predictable survival and drift. Actual practice can be far from ideal, especially when there is no rigorous training or inspection of operators.
Many rural communities have evidence of pesticide drifting over their crops or homes.
Few agricultural areas would have conditions as predictable and controllable as the broad flat cotton fields. In Tasmania 3,000 petitioners asked for a 2 km buffer zone, and achieved a nominal 100m. There are no buffer zones in Queensland. In NSW it is illegal to spray pesticide within 150m of the boundary of a dwelling or public premises without written consent of the occupiers. Subdivision of rural land in horticultural districts brings spray right up to suburban gardens and some rural Councils have attempted to impose 500m buffer zones around development sites, without much success so far.