QSAR studies of comparative toxicity in aquatic organisms.

This study investigated the relationships between the toxicities of common organic pollutants to the fathead minnow (Pimephales promelas), to Daphnia magna, to Tetrahymena pyriformis and in the Microtox test, which uses the luminescent bacterium Photobacterium phosphoreum. The toxicity data were compiled from the literature, with the exception of 40 experimentally determined Microtox data. Encouraging correlations are seen, indicating significant relationships between fish toxicities and those to lower organisms. When the toxicities of individual chemical classes are studied, further improvement is often seen in the correlations. Analysis of significant outliers from the inter-species relationships has led to the suggestion that the fathead minnow may be more susceptible to chemicals that are metabolised to reactive intermediates (such as the aldehydes). The fish may, however, be less susceptible to other chemical classes such as ketones and alcohols.