Lethal and sublethal toxicity of benzene derivatives to the fathead minnow, using a short-term test

Abstract

Abstract The lethal and sublethal effects of six monosubstituted derivatives of benzene (MBs) were measured by using the 7-d test with fathead minnow larvae. The LC50s for larvae were compared to those derived from the acute test. The larvae were more sensitive than juvenile fish, yet the toxicity order of MBs was the same for both life stages, that is, butylphenylether > benzophenone > toluene = benzene > nitrobenzene > aniline. The slopes of the concentration–mortality curves indicate a peculiar behavior for aniline. The no-observed-effect concentrations (NOECs) and the lowest-observed-effect concentrations (LOECs) for survival and growth, obtained from hypothesis test statistics, are reported together with the inhibition concentrations (ICs) for growth and biomass, calculated with a point estimation technique. The performance of the two different statistical approaches in providing adequate data for toxicity assessment is evaluated. Growth was a more or equally sensitive end point than survival, and for three chemicals biomass was more sensitive than growth. The results of the 7-d test are compared with those of the early life stage (ELS) test. The short-term test gave the same estimates of chronic toxicity as the ELS test for benzophenone, toluene, and benzene. The toxicity of aniline was underestimated, especially with respect to growth effects.