Uptake and Photodegradation of 2,3,7,8-Tetrachlorodibenzo-p-dioxin Sorbed to Grass Foliage

摘要

Plant uptake rates were determined for airborne 2,3,7,8-TCDD using grass foliage. The primary elimination mechanisms for 2,3,7,8-TCDD from grass, photodegradation and volatility, were measured in natural sunlight, filtered sunlight which reduced UV-B radiation, and in the dark. Rapid sorption of 2,3,7,8-TCDD vapor to grass resulted in an initial uptake rate constant of 1750/h(-1). Photodegradation of 2,3,7,8-TCDD and volatility of 2,3,7,8-TCDD from the foliage back into the air were both significant elimination mechanisms. The rapid photodegradation of 2,3,7,8-TCDD sorbed to grass indicates this elimination mechanism should be considered when estimating plant contamination from 2,3,7,8-TCDD. (Copyright (c) 1993 by the American Chemical Society.)