Assessing the toxicity of PFAS and other PMT substances

In PROMISCES, the German Environment Agency (Umwelt Bundesamt – UBA) has the task of assessing the toxicity of PFAS and other PMT substances. This is important e.g. for the other PROMISCES partners for evaluating the successes of their water treatment in the case studies. For the toxicological assessment, the UBA has drawn up a list of relevant chemicals. In the end, 44 PFAS, 3 PFAS mixtures and 17 PMT substances were selected.

The assessment of these single substances was conducted with human-cell-based bioassays. The aim was to evaluate which health effects (i.e. genotoxicity, endocrine disruption, cytotoxicity, etc.) are most relevant and what bioassays are the most suitable and most sensitive to use. First results indicate that receptor-binding effects on the hormone system, especially on the thyroidal activity (TTR-TR), seem to be the most relevant.

Based on these results, UBA will now develop a testing strategy and  test real contaminated water samples to assess possible health hazards. In a second step, enhanced treatment processes will be applied to reduce the contaminations and the bioassays will be used to evaluate the desired improvement in water quality.

Furthermore, computer-based models will use the bioassay data to improve their calculations and predictions. This can be useful for more efficiently evaluating the large amount of different PFAS in the environment – there are more than 10.000.

Finally, regulatory values, e.g. health-related indicator values (HRIV), will be proposed, based on the toxicological data acquired in this project.