The good chemical and ecological status of water bodies as defined by the EU Water Framework Directive is unlikely to be attained in Germany by 2015. This is the conclusion of a study in which data from the four largest rivers in northern Germany - the Elbe, Weser, Aller and Ems - were analysed over ten years. The study was carried out by the University of Koblenz-Landau, the Helmholtz Centre for Environmental Research - UFZ and Freiberg University of Mining and Technology, and published in the international scientific journal Environmental Science & Technology.
"This study is the biggest of its kind anywhere in the world," stated Ralf B. Schäfer, an assistant professor at the Institute for Environmental Sciences at the University of Koblenz-Landau. River monitoring data spanning from 1994 until 2004 were analysed. The study was only recently made possible by a new technique enabling the prediction of the toxicity of previously untested substances. Explaining the cut-off date, Prof Schäfer added that data after 2004 weren’t available to the extent required owing to the closure of Lower Saxony’s Department of Environment.
The occurence and possible toxic effects of 331 organic pollutants were examined in order to evaluate the quality of the rivers. A total of 257 of these compounds were detected in the rivers - sometimes in concentrations likely to have acute toxic effects on river organisms. Yet despite being potentially harmful to aquatic organisms, many of these compounds are not among the priority substances defined by the European Union and used to assess the chemical status of surface water under the Water Framework Directive. In fact just two of the 33 priority substances were found to exceed the recommended limits. Banned pesticides were also frequently detected in the river water raising the question of origin.
Even though the detection frequency for most compounds decreased significantly over the ten years , still the pollution caused by pesticides and industrial chemicals was found to be so high that flora and fauna will almost certainly suffer toxic impacts. "These results cast doubt on the assumption that rivers aren’t significantly impaired because the chemicals in them are diluted," said Peter von der Ohe from the Helmholtz Centre for Environmental Research. The scientists agree that if this pollution in the major rivers remains unchanged, it will be difficult to meet the ecological objectives of the EU’s Water Framework Directive.
To assess the concentrations of chemicals in river water, the scientists compared data from official monitoring with laboratory results from standard tests involving water fleas, fish and algae. "In some cases we found worrying concentrations of substances at levels which under laboratory conditions would kill 50 per cent of water fleas and could lead to the significant decline of the algae population," explained Prof Schäfer. Dr von der Ohe pointed out that the monitoring data were collected using point water grab sampling, although pesticides occur episodically, meaning that pollution levels are likely to be even higher at times.He added that official river monitoring is currently only carried out at a few times a year and in order to cut costs the number of measured chemicals has been reduced focusing on the 33 priority substances - hardly any of which were found to play a role in water pollution in the rivers investigated. Instead, the greatest risks were caused by other substances, according to the researchers. They advocate that future water monitoring should pay more attention to these substances and identify their exact sources. In addition to point sampling, integrated and event-driven sampling methods should be used.
Andreas Staak | UFZ News
Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung
Scientists reveal source of human heartbeat in 3-D
07.08.2017 | University of Manchester
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
17.08.2017 | Earth Sciences
17.08.2017 | Life Sciences
17.08.2017 | Materials Sciences