Melissa R. Winters

Project title: The Washington Aerial Spray Drift Study: A Comparison of Children's Inhalation Exposures to Methamidophos Estimated Using Diary and Personalized Global Positioning System Data

Degree: MS | Program: Environmental Health (EH) | Project type: Thesis/Dissertation
Completed in: 2008


As residential areas grow and expand into once solely agricultural areas, pesticide application practices that result in pesticide drift or the deposition of a pesticide off taret are causing concern over the health of those living in nearby communities, particularly high risk populations like children. In July 2002, University of Washington researchers conducted an extensive children's exposure assessment in Eastern Washington. Before, during, and after an aerial application of the organophosphate pesticide mathamidophos to potato crops, eight children living in the community surrounding the fields wore portable global position system (GPS) instruments to record their time-location and researchers performed environmental monitoring, including collecting air samples. Physical drift and volatilization were modeled for the community area. The children's GPS time-locations were matched with modeled air concentrations to produce an inhaled mass estimate. Diary proxies were created from the GPS data, and diary entries were matched with air sampler results to estimate inhaled mass. The GPS method resulted in consistently higher inhaled mass estimates than the diary method. These results suggest that the GPS method is a valuable new tool for exposure assessments and warrants further attention.