ON THE DESIGN AND SELECTION OF POLYCHLORINATED-BIPHENYLS FOR USE IN BIOLOGICAL TEST SYSTEMS

The polychlorinated biphenyls (PCBs) consist of a large number of indi vidual congeners with varying degree of chlorination and possible subs titution patterns. No single congener can be used as a representative congener for the whole class of compounds. Multivariate chemical chara cterisation (principal component analysis) in combination with factori al design provide tools by which small sets of structurally representa tive congeners can be determined. These tools are suggested to be used in the design of biological experiments in order to introduce systema tic structural variation in the congeners to be tested and to make it possible to construct quantitative structure-activity relationships (Q SARs). A QSAR based on bioaccumulation factors (BAFs) in fish for 20 s ystematically selected PCBs made it possible to pi edict BAFs for all 134 non-tested tetra-through hepta-chlorinated congeners. The use of t hese systematic and balanced sets of congeners in the experimental pro tocol will provide increased knowledge of the environmental behaviour of the PCBs. (C) 1998 Elsevier Science Ltd. All rights reserved.