Effect of Moisture Content and UV Irradiation on Degradation of Fenpropathrin on Soil Surfaces

Abstract

The effect of a moisture content and UV irradiation on the degradation of the pyrethroid insecticide fenpropathrin (I) on soil surfaces was examined using a xenon lamp (A >290 nm). I was rapidly degraded at a lower moisture content of soil via hydration of the a-cyano group and UV irradiation was found to slightly facilitate the degradation. As with an increase of moisture, the degradation pathways previously reported in aerobic and anaerobic soil metabolism became predominant on the soil surfaces. The marked change of a surface acidity of clay with a moisture content was likely to account for the moisture dependency of the degradation. © 1993, Pesticide Science Society of Japan. All rights reserved.