Flood water: Toxins from the riverbed

Date:
August 2, 2021
Source:
Goethe University Frankfurt
Summary:
A long-term hazard from flood water is often underestimated: The
raging rivers swirl up pollutants out of their sediments that stem
from environmental pollution decades or centuries ago. Such harmful
substances can not only cause ecological damage in the river. They
can also deposit themselves on flooded areas and affect crops,
grazing livestock and humans.



FULL STORY ========================================================================== Sediments are regarded as a river's long-term memory. They mainly comprise particles that are eroded from the ground, ending up at some point
in river deltas or the sea. However, sediments can also remain stable
for a relatively long time -- and bind pollutants which, for example,
have entered the rivers through mining or industrial wastewater. As a consequence, many old river sediments contain pollutants as "chemical
time bombs," such as heavy metals or dioxins and dioxin-like compounds
that are not easily degradable.


========================================================================== During flood events in the more industrial regions of Europe, North
America and Asia, old sediments can be churned up as a result of the high speeds at which the water is flowing. In the process, the pollutants
bound in them are regularly released in one go and contaminate flooded
areas. An interdisciplinary team of researchers from Goethe University,
RWTH Aachen University and the University of Saskatchewan in Canada,
along with other partners, has compiled a review of previous scientific
studies on this topic.

In it, the researchers, headed by junior research group leader Dr Sarah Crawford in Frankfurt and Canadian researcher Professor Markus Brinkmann,
show, for example, which pollutant loads were measured after various
flood events, which test systems were developed for different pollutants
and how different sediments behave when water flows at high speeds. It describes the risks for drinking water production, the influence of
temperature on pollutant intake by fish and methods for assessing the
economic costs associated with the remobilisation of pollutants.

Despite the many years of research on this subject, Henner Hollert,
professor of environmental toxicology at Goethe University and senior
author of the publication in hand, is greatly concerned: "I have the
impression that the problem of pollutants from old sediments is greatly underestimated in Germany and also in Europe as a whole. One reason
for this could also be that to date there have been practically no
studies at all on the economic consequences of this problem, as we've
been able to show. However, contaminated sediments are a ticking time
bomb that can explode each time there's a flood. What we need now is
good river management across the board that not only looks at immediate
hazards for humans, animals and infrastructure but also at the long-term consequences resulting from pollutants in the riverbeds. It's imperative,
for example, that we examine flooded areas used agriculturally for river-specific pollutants so that these do not end up on our plates in
the form of meat and dairy products." In an interdisciplinary approach, researchers from Goethe University Frankfurt, in collaboration with
RWTH Aachen University, the University of Saskatchewan in Canada, the
Helmholtz Centre for Environmental Research in Leipzig, the Institute for Social-Ecological Research (ISOE), the Senckenberg Institute, the LOEWE
Centre for Translational Biodiversity Genomics and many other partners,
are also studying the recent extreme flood events in Rhineland-Palatinate
and North Rhine-Westphalia in terms of hydraulic engineering and the biological, ecotoxicological, ecological, geoscientific but also the social-ecological and economic consequences. These studies are embedded
in the new research cluster RobustNature at Goethe University, which
is examining the robustness and resilience of nature-society systems
in the changing Anthropocene and aims to contribute to knowledge-based transformation research using the examples of biodiversity and water --
that is, from knowledge to action.

========================================================================== Story Source: Materials provided by Goethe_University_Frankfurt. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Sarah E. Crawford, Markus Brinkmann, Jacob D. Ouellet, Frank
Lehmkuhl,
Klaus Reicherter, Jan Schwarzbauer, Piero Bellanova, Peter
Letmathe, Lars M. Blank, Roland Weber, Werner Brack, Joost
T. van Dongen, Lucas Menzel, Markus Hecker, Holger Schu"ttrumpf,
Henner Hollert. Remobilization of pollutants during extreme
flood events poses severe risks to human and environmental
health. Journal of Hazardous Materials, 2022; 421: 126691 DOI:
10.1016/j.jhazmat.2021.126691 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/08/210802140140.htm

--- up 12 weeks, 3 days, 22 hours, 45 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)