Featured Research

from universities, journals, and other organizations

Bioavailable Contaminants Come From Exxon Valdez Oil Catastrophe; Natural Coal Deposits Not Source Of Environmental Pollution, Study Finds

Date:
September 1, 2009
Source:
Helmholtz Association of German Research Centres
Summary:
Contaminants from natural coal deposits in the Gulf of Alaska are not easily bioavailable, unlike the crude oil from the Exxon Valdez tanker catastrophe, according to a new study. The findings challenge the theory that natural coal deposits were the cause of observed environmental damage.

When the Exxon Valdez spilled its load on a reef in March 1989, about 40,000 tons 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 kilometers of coast were polluted with oil.
Credit: Photo by E. Gundlach

Contaminants from natural coal deposits in the Gulf of Alaska are not easily bioavailable, unlike the crude oil from the Exxon Valdez tanker catastrophe, according to a new study. The findings challenge the theory that natural coal deposits were the cause of observed environmental damage.

Related Articles


Polycyclic aromatic hydrocarbons (PAH) pollutants were blamed for the continuing degradation of the ecosystem off the coast of Alaska. Then a scientific dispute erupted over the origins of these pollutants. According to an international team of researchers writing in the 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 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.


Story Source:

The above story is based on materials provided by Helmholtz Association of German Research Centres. Note: Materials may be edited for content and length.


Journal Reference:

  1. Deepthike, H. U., Tecon, R., van Kooten, G., van der Meer, J. R., Harms, H., Wells, M., Short, J. Unlike PAHs from Exxon Valdez Crude Oil, PAHs from Gulf of Alaska Coals are not Readily Bioavailable. Environmental Science & Technology, 2009; 43 (15): 5864 DOI: 10.1021/es900734k

Cite This Page:

Helmholtz Association of German Research Centres. "Bioavailable Contaminants Come From Exxon Valdez Oil Catastrophe; Natural Coal Deposits Not Source Of Environmental Pollution, Study Finds." ScienceDaily. ScienceDaily, 1 September 2009. <www.sciencedaily.com/releases/2009/08/090831130709.htm>.
Helmholtz Association of German Research Centres. (2009, September 1). Bioavailable Contaminants Come From Exxon Valdez Oil Catastrophe; Natural Coal Deposits Not Source Of Environmental Pollution, Study Finds. ScienceDaily. Retrieved October 31, 2014 from www.sciencedaily.com/releases/2009/08/090831130709.htm
Helmholtz Association of German Research Centres. "Bioavailable Contaminants Come From Exxon Valdez Oil Catastrophe; Natural Coal Deposits Not Source Of Environmental Pollution, Study Finds." ScienceDaily. www.sciencedaily.com/releases/2009/08/090831130709.htm (accessed October 31, 2014).

Share This



More Earth & Climate News

Friday, October 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How A Chorus Led Scientists To A New Frog Species

How A Chorus Led Scientists To A New Frog Species

Newsy (Oct. 30, 2014) A frog noticed by a conservationist on New York's Staten Island has been confirmed as a new species after extensive study and genetic testing. Video provided by Newsy
Powered by NewsLook.com
Raw: Hawaii Lava Inches Closer

Raw: Hawaii Lava Inches Closer

AP (Oct. 30, 2014) Aerial video shows the path lava has carved across a portion of Hawaii's big island, threatening homes in the town of Pahoa. Officials say the flow was just over 230 yards from a roadway Thursday morning. (Oct. 30) Video provided by AP
Powered by NewsLook.com
Raw: Hawaii Lava Approaching Village Road

Raw: Hawaii Lava Approaching Village Road

AP (Oct. 30, 2014) The lava flow on the Big Island of Hawaii was 225 yards from Pahoa Village Road on Wednesday night. The lava is slowing down but still approaching the village. (Oct. 30) Video provided by AP
Powered by NewsLook.com
Endangered Carpathian Ponies Are Making a Comeback in Poland

Endangered Carpathian Ponies Are Making a Comeback in Poland

AFP (Oct. 29, 2014) At the foot of the rugged Carpathian mountains near the Polish-Ukrainian border, ranchers and scientists are trying to protect the Carpathian pony, known as the Hucul in Polish. Duration: 02:17 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins