HR: 12:05h
AN: H42A-07    [Abstracts]
TI: Relations Among the Use, Occurrence, and Flux of Azoxystrobin, Propiconazole, and Other Fungicides in US Streams, 2005-06
AU: * Battaglin, W A
EM: wbattagl@usgs.gov
AF: U.S. Geological Survey Colorado Water Science Center, Box 25046, MS 415, DFC, Lakewood, CO 80225, United States
AU: Sandstrom, M W
EM: sandstro@usgs.gov
AF: U.S. Geological Survey National Water Quality Laboratory, Box 25046, MS 407, DFC, Lakewood, CO 80225, United States
AB: Fungicides account for 10 percent of global pesticide use (0.25 million metric tons per year), and 6 percent of US use (33 thousand metric tons per year). Some fungicides such as chlorothalonil have been in use for decades (first US registration in 1966), while others such as azoxystrobin were introduced in the last decade (first US sales in 1996). Fungicide fate and transport is not well understood, but recent investigations have detected fungicides in precipitation, groundwater, streams, and streambed sediment. The occurrence of Asian soybean rust in the Southern US is of concern because of the increase in fungicide use that would result if it spreads to the Central US during the growing season. In the Central US many growers have never used fungicides to protect soybeans. The purpose of this study is to collect baseline data on fungicide occurrence in streams prior to the spread of Asian rust to soybeans in the Central US and the anticipated increase in fungicide use to control the rust. These data are then used to investigate relations among the occurrence and flux of fungicides in US streams, and the use of those products within the associated drainage basins. Water samples from streams in the Southern and Central US were collected in 2005 (26 sites, 40 samples) and 2006 (16 sites, 41 samples), and analyzed for up to 11 fungicides. This is the first study to monitor for several of these fungicides in environmental samples from locations in this region of the US. Chlorothalonil was used in all study basins but only detected in one sample from 2006. Azoxystrobin was detected in one or more samples from 12 of 26 sites in 2005 and 10 of 16 sites in 2006. Estimated daily fluxes of azoxystrobin ranged from zero to 440 grams/day but were not significantly correlated (p value = 0.3) with estimated azoxystrobin use in the upstream watershed. Estimated daily fluxes of propiconizole ranged from zero to 360 grams/day and were correlated (p value = <0.0001) with estimated propiconizole use. Results indicate that fungicides can readily enter aquatic systems where they may have toxic effects, and that their occurrence and flux in streams may be correlated with regional patterns of fungicide use.
DE: 1803 Anthropogenic effects (4802, 4902)
DE: 1871 Surface water quality
SC: Hydrology [H]
MN: 2007 Joint Assembly