5. Conclusions

The results described in this article show that industrial effluents from the surface treatment sector, while complying with current regulations, are characterized by metal polycontamination, which is highly variable over time. The toxicity of these discharges towards the bio-indicators Daphnia magna and Lactuca sativa depends on the chemistry of each discharge. The results also show that a reduction in the pollutant load of the discharges results in a concomitant reduction in the toxicity of the discharges, thus demonstrating the existence of a relationship between "chemical efficiency" and "reduction of environmental impacts". It therefore makes sense to combine the two different but complementary approaches of chemical analysis and ecotoxicology.