Environmental

Concern grows over effects of oil dispersants in the Gulf

In recent days a lot of media attention has shifted from the oil that gushed into the Gulf of Mexico for weeks to the chemical dispersants BP used to break the sludge down into smaller particles. But many scientists are now saying that Corexit, the primary chemical BP dumped into the Gulf to disperse the oil, and similar chemicals are much more toxic than the oil itself.

BP has sprayed the Gulf waters with more than a million gallons of Corexit and it has shot an undetermined amount of the chemical into the cloud of crude that gushed uncontrollably from the broken wellhead. (The oil giant’s use of the chemical is estimated to be nearly 2 million gallons.) Broken down into finer particles, much of the dispersed oil hovers somewhere between the seabed and the surface in enormous plumes.

The goal in using Corexit, at least ostensibly, is to break the oil into particles small enough that they can be consumed by microorganisms and to keep the sticky sludge from reaching vulnerable coastal environments. Now it’s looking more and more like the genuine aim was to hide the actual size of the spill from the public.

Why? Because oil dispersants don’t actually remedy anything. While they may change the appearance of an oil spill and make it appear less threatening, they are known to make matters worse.

On the most fundamental level, oil is energy. And energy never disappears or dies. It merely goes somewhere else or transforms into something else.

Marine toxicologist Dr. Susan Shaw, one of the few scientists who dove in the Gulf after the Deepwater Horizon sank to witness the oil spill’s effects firsthand, told ABC News that the dispersants aren’t just killing marine life, they’re hindering cleanup and containment efforts.

“The only way to get at an oil spill safely is to get it off the surface while it is still all in one mass,” she told ABC.

The oil that BP released deep beneath the surface is now a thin cloud cloud of congealed oil and there is no way to collect it. Had it risen to the surface, it could have been skimmed and pumped onto containment ships.

Unfortunately, BP used Corexit in unprecedented amounts, and so no data exists to indicate what its effects will be immediately or years in the future. EPA Director Lisa Jackson called BP’s unrestrained use of Corexit  “uncharted water.”

The Environmental Protection Agency said in June that it measured the toxicity of the Corexit types used in the Gulf and found them to be less toxic than oil. But Dr. Shaw said those tests were pointless.

“We already know that dispersants are less toxic than oil,” she told ABC. “But nobody in the Gulf is encountering Corexit on its own — it’s Corexit combined with oil they need to be testing.”

Indeed, studies have revealed the combination to be more toxic than Corexit or oil alone. Coral has a 98 percent fertilization rate in the presence of oil alone, but when exposed to a Corexit and oil combination, it has a zero percent fertilization.

The Corexit and oil combination also makes it easy for marine mammals to ingest, and the petroleum solvents that cut through the oil also cut through cell membranes, leading to internal bleeding and causing the animals to bleed to death.

According to the Corexit manufacturer’s safety sheet, the dispersed oil actually becomes more toxic once it’s been eaten, a process known as ‘bioaccumulation’. That toxicity then travels up the food chain, to larger fish like tuna and other predators.

According to an environmental report in the Huffington Post, “scientists have already found signs of an oil-and-dispersant mix under the shells of tiny blue crab larvae in the Gulf of Mexico, the first clear indication that the unprecedented use of dispersants in the BP oil spill has broken up the oil into toxic droplets so tiny that they can easily enter the food chain.”

While scientists are certain that the oil and chemicals are now present in the smallest forms of marine life, nobody knows what effects they will have on animals further up the food chain and on human health.

On Tuesday, Beasley Allen filed a lawsuit on behalf of individuals who claim they have sustained personal injury as a result of exposure to toxic chemical dispersants used in the oil spill cleanup.

Sources:

http://www.huffingtonpost.com/2010/07/29/scientists-find-evidence_n_664298.html

http://www.abc.net.au/news/stories/2010/07/29/2967160.htm?site=thedrum