This clearly disproves the theory that natural coal deposits were the cause of observed environmental damage.
PAH pollutants were blamed for the continuing degradation of the ecosystem off the coast of Alaska. Then a dispute erupted over the origins of these pollutants in science.
According to an international team of researchers writing in specialist journal "Environmental Science & Technology", the crude oil from the Exxon Valdez was the main source of the bioavailable PAH contaminants.
The scientists from Tennessee Technological University, the University of Lausanne, Calvin College and the Helmholtz Centre for Environmental Research (UFZ) compared polycyclic aromatic hydrocarbons (PAHs) in samples of tanker oil and from coal deposits. Their investigation with bacterial biosensors has now shown that only the PAHs from the tanker oil had any effect on organisms.
The scientists were able to prove this in the lab with the help of genetically engineered bacteria which react with the contaminants. "These biosensors are based on bacteria which feed on polycyclic aromatic hydrocarbons. If these bacteria come into contact with these substances, it flips a biological switch and the bacteria start to glow", explains Prof. Hauke Harms from the UFZ. "There are clear advantages to this new forensic application: there is no need to take the indirect route of costly chemical analysis to prove results." As the bacteria used give off a great deal of light, the scientists are able to study the processes at a high resolution - down to a microscopic level in individual organisms.
Polycyclic aromatic hydrocarbons are a natural component of coal and petroleum. Because of their longevity and toxicity, sixteen of these substances were classed as particularly hazardous environmental pollutants as far back as the 1980s by the American environmental agency EPA.
Adhesives containing coal tar were thus prohibited, as a health hazard. Some PAHs are unambiguously carcinogenic – as long as they are metabolised by the organism. Their bioavailability thus determines their toxicity. They are generally only bioavailable if the substances are water-soluble.When the Exxon Valdez spilled its load on a reef in March 1989, about 40,000 tonnes of crude oil escaped and polluted the Prince William Sound. It is estimated that of seabirds alone, more than a quarter of a million were killed in the spill. Two thousand kilometres of coast were polluted with oil, bringing an end to fishing, and thus the livelihoods of many people living on the coast. According to ExxonMobil, the owner of the tanker, in a statement on the 20th anniversary of the spill, the company has paid out more than 3.8 billion dollars in compensation, clearance work, out-of-court agreements and fines.
Despite a large-scale clean-up, there are still lingering effects on the environment. An estimated 80,000 litres of oil in the form of lumps of oil and tar are still said to pollute the coast of Alaska. The consequences are now no longer evident. But they cause, however, that marine organisms are damaged and the food chain no longer work as before. The main problem is that the polycyclic aromatic hydrocarbons in the oil only decompose slowly due to the low Arctic temperatures.Publication:
The Helmholtz Association helps solve major, pressing challenges facing society, science and the economy with top scientific achievements in six research areas: Energy, Earth and Environment, Health, Key Technologies, Structure of Matter, Transport and Space. With 28,000 employees in 15 research centres and an annual budget of around EUR 2.4 billion, the Helmholtz Association is Germany’s largest scientific organisation. Its work follows in the tradition of the great natural scientist Hermann von Helmholtz (1821-1894).
Tilo Arnhold | UFZ News
Further reports about: > Alaska > Environmental Research > Exxon Valdez > Gulf of Maine region > Helmholtz > UFZ > bioavailable PAH contaminants > crude oil > environmental change > environmental pollution > environmental risk > natural coal deposits > natural resource > polycyclic aromatic hydrocarbons > tanker catastrophe
Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
Understanding animal social networks can aid wildlife conservation
23.06.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
26.06.2017 | Life Sciences
26.06.2017 | Physics and Astronomy
26.06.2017 | Information Technology