John Wiley & Sons, Ltd.

Model predictions of toxaphene degradation in the atmosphere over North America

0
- By: ,

Courtesy of John Wiley & Sons, Ltd.

Technical toxaphene (TT), a broad‐spectrum pesticide mixture, degrades in the environment, resulting in potential changes in toxicity. The present study uses a multi‐media model that we developed to estimate toxaphene degradation in the atmosphere over North America. The predicted degradation has strong spatial and temporal variability determined by processes such as emission and transport of TT as well as the complex interactions among many species (e.g. toxaphene, OH radicals, and ozone). More toxaphene is degraded in warmer months due to higher concentrations of TT (primarily due to higher TT emissions in the southeastern US and transport to other regions) and OH radicals. In the model, OH radicals are primarily created through the reactions of water vapor with the excited oxygen atom, O(1D), generated by the photolysis of ozone, which is primarily produced by reactions of VOCs and NOx in the presence of sunlight. The higher OH concentrations in warmer months are primarily due to higher solar radiation and ozone concentrations. The spatial distribution of degradation depends on the distribution of TT soil residues as well as atmospheric transport and chemistry; significant chemical degradation occurs in the southeastern US where soils are most heavily contaminated by past applications of toxaphene. Environ Toxicol Chem © 2013 SETAC

Customer comments

No comments were found for Model predictions of toxaphene degradation in the atmosphere over North America. Be the first to comment!