Influence of Molecular Weight and Molecular Volume on Dietary Absorption Efficiency of Chemicals by Fishes

Abstract

Rainbow trout (Salmo gairdneri) were exposed to 17 halogenated organic chemicals to examine the influence of molecular weight (MW) and molecular volume (MV) on dietary absorption efficiency. The results of this and other studies indicated that organic chemicals with MWs greater than 600 were poorly absorbed although some chemicals with lower MWs were also poorly absorbed. A better trend was suggested when efficiences were examined in relation to MV where chemicals with MVs over 0.3 nm3were poorly absorbed. Neither index provided a relationship that would consistently estimate the absorption efficiency of chemicals that were moderately to well absorbed by salmonids.