Feasibility study to assess the ecotoxicological and toxicological impact on sediments as a result of the July 2021 flood in the transition from the low mountain range to the lowlands.
Geotechnics, Hydraulic Engineering
Physical Geography
Final Report Abstract
25 sediment samples, which were taken after the flood event of July 2021 in the inundated area of the rivers Rur, Inde, Vicht, Ahr and Erft, were analysed using a battery of standardized bioassays for their basic toxic, mutagenic, dioxin-like and endocrine activity as well as for the oxidative stress response. This should clarify the research questions as to whether (eco-)toxicologically active organic pollutants were introduced and mobilized and what effects occur in the sediments. The investigated sediments from the flooded areas of the rivers showed a complex profile of effects with sometimes extreme levels of activity, especially with regard to mutagenic and dioxin-like effects. In addition, the samples from the Inde and Vicht showed a very high basic toxicity, anti-estrogenic and anti-androgenic activities and a high level of oxidative stress. The findings not only show that highly contaminated sediments and soils were mobilized by the floods and deposited in the floodplains of the rivers, but that these deposits also pose significant risks to human health and the aquatic ecosystems as well as to the floodplain biocenoses of the rivers.
