Occurrence of Azoxystrobin, Propiconazole, and Selected other Fungicides in US Streams, 2005-2006

Abstract/Summary

This study documents the occurrence of fungicides in select U.S. streams soon after the first documentation of soybean rust in the U.S. and prior to the corresponding increase in fungicide use to treat this problem. Water samples were collected from 29 streams in 13 States in 2005 and/or 2006, and analyzed for 12 target fungicides. Nine of the 12 fungicides were detected in at least one stream sample and at least one fungicide was detected in 20 of 29 streams. At least one fungicide was detected in 56% of the 103 samples, as many as 5 fungicides were detected in an individual sample, and mixtures of fungicides were common. Azoxystrobin was detected most frequently (45% of 103 samples) followed by metalaxyl (27%), propiconazole (17%), myclobutanil (9%), and tebuconazole (6%). Fungicide detections ranged from https://0.002 to https://1.15 ug/L. There was indication of a seasonal pattern to fungicide occurrence, with detections more common and concentrations higher in late summer and early fall than in spring. At a few sites, fungicides were detected in all samples collected suggesting the potential for season-long occurrence in some streams. Fungicide occurrence appears to be related to fungicide use in the associated drainage basins, however, current use information is generally lacking and more detailed occurrence data are needed to accurately quantify such a relation. Maximum concentrations of fungicides were typically one or more orders of magnitude less than current toxicity estimates for fresh-water aquatic organisms or humans however gaps in current toxicological understandings of the effects of fungicides in the environment limit these interpretations.

Publication details
Published Date: 2011-02-01
Outlet/Publisher: Water Air and Soil Pollution 218:307-322
Media Format: URL

ARMI Organizational Units:
Rocky Mountains - Water
Topics:
Stressors; Water
Place Names:
United States
Keywords:
agriculture; pesticides; stressors; surface water; water; water quality
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