Submitted to: IUPAC Congress
Publication Type: Proceedings
Publication Acceptance Date: July 16, 2005
Publication Date: May 3, 2006
Citation: Mcconnell, L.L., Rice, C., Hapeman, C.J., Goel, A., Torrents, A., Bialek Kalinski, K.M. 2006. Atmospheric transport and deposition of pesticides within the choptank river watershed and the role of riparian buffers in pesticide delivery to streams. IUPAC Congress. p. III-3-35B.
For non-fumigant pesticides, drift and volatilization are loss processes that are often ignored in environmental fate studies. In some cases, a large fraction of applied active ingredient can be emitted to the atmosphere. Immediate losses during application are referred to as pesticide drift or the massive off-site movement of spray droplets over a relatively short distance (10-100 m). After application, pesticide volatilization continues, generally with the largest fluxes occurring within the first 24-48 hours, followed by an exponential decline over the next 4-5 days. Pesticide residues may be deposited into a nearby tree canopy or may be transported longer distances from the point of application. Detailed measurements of air and rain concentrations of agricultural pesticides were carried out in the Choptank River Watershed over four years from 2000-2003 to discern the physical, chemical, agronomic and meteorological factors controlling the sources, fate and transport of these chemicals on a regional scale. A small watershed study was also carried out during the same time frame to evaluate the role of riparian systems in trapping and delivering pesticide residues to a first order stream during rain events. Initial results suggest that atmospheric sources should be considered when modeling the effectiveness of conservation practices such as buffers and riparian systems in protecting water quality.