Extended Abstract
Esther Pembele Wumba
Abstract
Humans are continuously exposed to mixtures of chemicals. However, historically the risks are assessed for the each compound individually. Regulation requires sometimes the characterization of the effects of mixtures, but this is not the general case. But, this remains a major concern for regulators or the general population. This study is a state of the art on the health and environmental effects of mixtures. It also presents the different available methodologies to assess health and environmental risks. Their feasibility was examined through different case studies on waste or effluent. The main results indicate that the effects of mixtures are mainly additive or antagonist. Cases of synergy are unfrequent. This is especially true as the number of substances in the mixture is important. In terms of risk assessment, methods on the mixture itself should be preferred. However, in the absence of data on the mixture, and in accordance with the recommendations of major international or national agencies, substance by substance approaches (doses/concentrations additivity or responses additivity) are appropriateand generally protective. However, the quality of the substance by substance methods depends directly on the completeness and sensitivity of the analytical methods used to characterize the mixture. It should also be mentionned that many complementary methods are on development (QSAR, “Omics” ...). In the next future, associated with screening tests on the mixture itself, they will be useful tools for better risks assessments and then for a better consideration of the effects of mixtures.