The application of QSARs, extrapolation and equilibrium partitioning in aquatic effects assessment for narcotic pollutants.

QSAR estimates of toxicity of relatively unreactive organic chemicals for 19 species of bacteria, algae, fungi, protozoans, coelenterates, rotifers, molluscs, crustaceans, insects, fish and amphibians were used to predict 'no-effect-levels' (NELs) at the ecosystem level by means of a recently developed extrapolation model. Equilibrium-partitioning theory for sediment and water was used to derive NELs for aquatic sediments. A simple table is given from which NELs for water and sediments can be predicted on the basis of only the octanol-water partition coefficient and molecular weight.