ABSTRACT
Local-scale studies include process and matrix distribution studies and field studies that monitor agricultural worker exposure, pesticide drift during application, and the volatilization and off-site drift of applied pesticides after application. In the local, regional, and long-range type studies, knowledge of the pesticide types and use patterns are important in designing the sampling and analytical strategy. Agricultural pesticide inputs to the atmosphere occur during the application process through evaporation and drift, and post-application through volatilization and wind erosion. Pesticide occurrences in rain, air, and fog often show seasonal trends, with the highest concentrations corresponding to local use and planting seasons. The potential contribution of pesticides from the atmosphere to a surface-water body depends on pesticide levels in atmospheric deposition and on how much of the water budget is derived from surface runoff and direct precipitation. Airborne pesticides and their transformation products are continuously deposited on every surface on the earth as dry deposition and in rain, snow, and fog.
