Fingerprinting the effects of individual micropollutants in a bioanalytical test battery developed for water quality monitoring
Résumé
There is increasing interest in applying bioassays for water quality monitoring. However, information about the effects of individual micropollutants in bioassays, such as pharmaceuticals, pesticides and industrial compounds, as well as their contribution to the overall mixture effect in a sample, is often limited. In the current study, a bioanalytical test battery with both cell-based and whole organism assays was applied to fingerprint the effects of 34 micropollutants, which were selected based on their environmental presence, hazard quotients and mode of action. The bioassays were selected to cover different steps of the cellular toxicity pathway, such as induction of xenobiotic metabolism and receptor-mediated effects, as well as both specific and apical effects in whole organisms. All studied chemicals were active in at least one assay, with the industrial compound bisphenol A active in 70% of the applied assays. While many more chemicals were active in assays indicative of apical effects, the chemicals that had a response in the specific assays typically triggered an effect at much lower concentrations. The generated effect data were applied to existing mixture toxicity modelling of water samples to determine if and how the studied chemicals contributed to the biological effect. A slight increase in the fraction of the effect could be explained by detected chemicals. However, the fraction explained was still less than 1% for some assays, which suggests that many more chemicals contribute to the effect than those that are typically monitored by chemical analysis. This emphasises the need for a complementary approach of chemical analysis and bioanalysis for water quality monitoring.