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TRANSFORMATION AND TRANSPORT OF SEMI-VOLATILE ORGANIC COMPOUNDS FROM SOIL: MEASURING DICARBOXIMIDES IN A CHAMBER
Citation:
Vallero, D A. TRANSFORMATION AND TRANSPORT OF SEMI-VOLATILE ORGANIC COMPOUNDS FROM SOIL: MEASURING DICARBOXIMIDES IN A CHAMBER. Presented at American Institute of Hydrology International Conference 2000, Research Triangle Park, NC, November 5-8, 2000.
Impact/Purpose:
The overall objectives of CTEPP were to measure the aggregate exposures of approximately 260 preschool children and their adult caregivers to low levels of a suite of pesticides and organic pollutants that the children may encounter in their everyday environments, and to apportion the routes of exposure and estimate the relative contributions of each route.
Description:
A laboratory chamber was used to determine transport of a suspected anti-androgenic dicarboximide fungicide, vinclozolin (3,5-dichlorophenyl)-5-methyl-5-vinyl-oxzoli-dine-2,4-dione) and three degradation products from a North Carolina Piedmont aquic hapludult soil following a spray application of fungicides. Results suggest that pH, rain events, and method of application were the primary factors influencing vinclozolin's post-application transformation into three degradation products. Other factors such as the presence of clay and soil organic matter, moisture and microbes were investigated for their potential role in vinclozolin's degradation and fate. One metabolite, 2-[(3,5-dichlorophenyl)-carbamoyl]oxy-2-methyl-3-butenoic acid ("M1"), appears to be formed by base-catalyzed hydrolysis mediated by soild particle surfaces and microbial enzymes. The greatest M1 production appears to increase with higher soil pore fluid pH levels and when the fungicide incorporated into the soil. Reduction and acid-catalytic reactions also appear to play a role in dicarboximide degradation in the soil at lower pore fluid pH levels. The three degradation processes were not found to be mutually exclusive. Non-equilibrium partitioning coefficients and deposition velocities of the dicarboximides determined from the chamber results will also be presented.
This abstract has been reviewed in accordance with the Unites States Environmental Protection Agency peer and administrative review policies and approved for presentation and publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.