By Jane Tierney

A Berkeley scientist who is advising British Petroleum is cautioning against the use of too many detergents to clean up the vast oil spill in the gulf.

Terry Hazen, a microbial ecologist at Lawrence Berkeley National Laboratory (Berkeley Lab) and a leading bioremediation expert, is advising authorities that using detergents to clean up oil-contaminated sites may make matters worse. They might cause their own environmental problems.

Instead, Hazen suggests that biomediation, a process that uses microorganisms, enzymes, fungi or green plants to repair a natural environment compromised by contaminants, might be a better approach.

“It is important to remember that oil is a biological product and can be degraded by microbes, both on and beneath the surface of the water,” said Hazen. “Some of the detergents that are typically used to clean-up spill sites are more toxic than the oil itself, in which case it would be better to leave the site alone and allow microbes to do what they do best.”

Hazen, the head of the ecology department at Berkeley Lab, is advising BP on behalf of the Department of Energy.

Hazen is also managing two research vessels in the gulf, staffed by international scientific crews from Canada, Australia and the U.S. They are sampling the gulf beaches and deep water for toxicity and levels of contamination.

Hazen has also appeared widely in the news, including an appearance on KQED’s Forum with Michael Krasny. Hazen will be on NBC Nightly News tonight.

Experts estimate that 29 million gallons of oil have leaked out of the broken BP underwater well, making the spill the largest in U.S. history. In attempts to contain the spreading oil slick and protect the fragile ecosystems of the gulf region, clean up crews have resorted to an array of oil skimmers, booms and chemical dispersants, as well as burning off the surface oil. Such extreme clean up measures are rife with unintended consequences, said Hazen.

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“There are newer dispersants, such as the Correctix 9500 that have not been tested by EPA, and can have toxic effects on specific marine life,” said Hazen.

In 1978, 227,000 tons of crude oil leaked off the coast of Normandy, France, affecting nearly 200 miles of coastline. In that catastrophe, known as Amoco Cadiz spill, only areas of greatest economic impact were treated with detergents, said Hazen. Large remote areas were left untreated.

“The untreated coastal areas were fully recovered within five years of the Amoco Cadiz spill,” said Hazen. “As for the treated areas, ecological studies show that 30 years later, those areas still have not recovered.”

The Exxon Valdez, the oil supertanker, spilled 11 million gallons of crude oil into the Prince William Sound in Alaska in March 1989, and impacted some 1,300 miles of US coastline. Until now, it was the largest US oil spill. A combination of detergents and bioremediation were used in the clean up. The detergents added phosphorous and nitrogen compounds to the environment. In addition, as part of the bioremediation effort, fertilizers were also used to promote microbial growth.

After the first year, the treated areas were dramatically cleaner, Hazen says, but after the second year no improvements were observed. Long-term prospects for the treated Alaskan areas remain grim. Hazen believes this experience should inform current strategies.

While improvements to detergent dispersants have been made, including some degree of biodegradability, they remain rich in nutrients and in some cases are more toxic to the environment than crude oil. They also upset the ecological balance of the treated locations for years to come.

“From a clean-up standpoint, right now we should be using sorbents to take up as much of the oil as possible,” Hazen said. “Then we need to gauge how quickly and completely this oil can be degraded without human intervention.”

A public lecture by Terry Hazen entitled “Bioremediation: The Hope and the Hype for Environmental Cleanup” can be viewed on the Berkeley Lab YouTube site.