Preliminary Toxicological Evaluation of the River Danube Using in Vitro Bioassays

Abstract

Abstract:The Joint Danube Survey 3, carried out in 2013 was the world's biggest river research expedition of its kind. The course of the second largest river of Europe passes large cities like Vienna, Budapest and Belgrade and is fed from many tributaries like Inn, Thisza, Drava, Prut, Siret and Argeș. During the 6 weeks of shipping the 2375 km downstream the River Danube from Germany to the Black Sea an enormous number of water samples were analyzed and collected. A wide spectrum of scientific disciplines cooperated in analyzing the River Danube waters. For toxicological analysis, water samples were collected on the left, in the middle, and on the right side of the river at 68 JDS3 sampling points and frozen until the end of the Danube survey. All samples were analyzed with two in vitro bioassays tests (umuC and MTS). water samples came up with toxic signals on two stretches, when activated with S9 enzymes. The override of the limiting value of the umuC investigation with prior S9 activation started downstream Vienna (Austria) and was prolonged until Dunaföldvar (Hungary). This stretch of the River Danube passes a region that is highly industrialized, intensively used for agricultural purposes and also highly populated (Vienna, Bratislava and Budapest). The elevated values may indicate these influences.

Evaluation of Genotoxic Pressure along the Sava River

“…We have assumed that the assay would provide preliminary screening of genotoxic potential, but the induction ratio has not exceeded value 1.5 (threshold value) in any of the investigated samples. Similarly, in the study of Kittinger et al [ 30 ] performed on the water samples of the Danube River, only four sites out of 68 investigated within the JDS3 showed mutagenic potential, indicating either to low sensitivity of the assay or low genotoxic potential of water.…”

“…When constructing the battery of bioassays we were focused on types of assays which have already been employed earlier in ecogenotoxicological studies of the Sava River [ 8 – 14 , 27 ]. Also, we have used experience gained during the Joint Danube Survey 3 –JDS3 [ 22 , 28 , 29 , 30 ] for updating the assay list as usage of the same methodology would enable comparison of water quality of the Sava and Danube in further research. As the assays employed in the study showed different sensitivity in detection of the stressors at investigated sites we have finally employed IBR approach to identify the most critical spots on the river but also to recommend which site has potential to be a reference site for Sava River.…”

Linking in Vitro Effects and Detected Organic Micropollutants in Surface Water Using Mixture-Toxicity Modeling

“…Although most samples did have a response in the assays, the effects were relatively low, with the EC values for the oxidative stress and AhR assays similar to previously benchmarked EC values for surface water . Kittinger et al also only detected minimal effects in Danube River samples when assessing genotoxicity. Furthermore, ER activation, when expressed as BEQ bio (0.02–1.1 pM), was lower than generally observed in wastewater effluent due to dilution in the river, although one contaminated site, JDS 41 (BEQ bio 4.7 pM), was identified by this assay.…”

The role of effect-based methods to address water quality monitoring in South Africa: a developing country’s struggle

“…For this reason, Brack et al ( 2019 ) suggested EBMs that would allow for detecting the combined effects of mixtures. This suggestion in fact, had been done in New Zealand, Australia, and Canada (Brunner et al 2020 ; Kittinger et al 2015 ).…”