CHIRAL PESTICIDES AS TRACERS OF AIR-SURFACE EXCHANGE

The enantiomers of chiral pesticides are selectively broken down in so il and water to yield residues and metabolites, which are non-racemic. The distinctive enantiomer signatures of residues are preserved upon volatilization, providing site-specific tracers for air-soil and air-w ater exchange. Applications of enantiomeric tracers include distinguis hing the atmospheric transport of freshly applied pesticides from thos e which are 'recycled' from lakes, oceans and soil, and investigating biotic vs abiotic degradation pathways. Examples are given of using pe sticide enantiomers to follow volatilization from the Great Lakes and arctic waters and as indicators of pesticide emissions from agricultur al soils. (C) 1998 Published by Elsevier Science Ltd. All rights reser ved.