Research Product

New methods for predicting chronic toxicity (lethality) from acute lethality data with fishes were developed and assessed. Typically, acute toxicity tests with aquatic organisms provide lethality estimates for a series of toxicant concentrations at 24, 48, 72, and 96 h of exposure. Statistical models (multiple regression) were developed that utilize acute toxicity data to establish the relation of lethality to toxicant concentration and exposure time for predicting chronic lethality. The models provide estimates of toxicant concentrations that result in a low probability of death as a function of extended exposure times. Results from 28 data sets having lethality data for both acute and chronic exposures were used to evaluate the method. It is posited that the proposed methods are highly accurate when acute lethality data meeting stated quality requirements are available.