Evaluation of an in vitro hsp70 induction test for toxicity assessment of complex mixtures: comparison with chemical analyses and ecotoxicity tests

The aim of this study was to assess the potential of a human cell line containing the hsp70 promoter linked to the chloramphenicol acetyltransferase reporter gene in evaluating the toxic potential of complex mixtures. Cells were exposed to eluates of industrial wastes and the cellular responses were compared with the metal contents of the samples and with standardized aquatic (microalgal growth inhibition, daphnia Immobilization, bacterial luminescence inhibition, Ceriodaphnia dubia reproduction inhibition) and terrestrial (earthworm lethality, plant growth inhibition) tests. The hsp70 promoter was significantly induced by 11 of 14 samples, with different dose–response patterns. Significant correlations of in vitro induction potency with aquatic ecotoxicity, especially with chronic tests, and with the metal contents of the samples were observed. Our study provides new information on the relevance of hsp70 gene induction as a criterion of toxicity and suggests its usefulness for the detection of toxicity associated with metallic pollution in complex mixtures.