Dispersants Add to Gulf Spill's Toxic Threats

Dispersants Add to Gulf Spill's Toxic Threats

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 NEW ORLEANS -- The Obama Administration has started to rein in BP's use of dispersants to break up spilled oil while a toxic stew swirls off Louisiana's coast, threatening marine life and human health.

More than a month after BP's oil-rig explosion on April 20, over 800,000 gallons of dispersants had been applied to Gulf waters, including 100,000 gallons that were injected underwater. Helicopters distribute the chemical cleaners, or deodorized kerosene, on the ocean's surface, while robots dispense them deep in water.

After the spill, the Environmental Protection Agency let BP use dispersants because they were seen as "the lesser of two evils," said Ronald Kendall, director of The Institute of Environmental and Human Health (TIEHH) in Lubbock, Texas. Dispersants break oil into small droplets more quickly than ocean waves do, but they can also widen the area of the spill. Using them is "a tradeoff between, on the one hand attempting to keep oil from the shore by dispersing it, and on the other, injecting the ocean with chemicals," he said. Dispersants have never been applied in the quantities that BP is using them in the Gulf, he noted.

The EPA on May 10 authorized BP to use two dispersants-COREXIT 9500 and COREXIT EC9527A, distributed by the Tennessee and Texas units of Nalco Co. in Illinois. BP had already applied those products at the spill site for nearly two weeks. As concerns about COREXIT grew, however, the EPA asked BP on May 19 to find a less-toxic dispersant within 24 hours, and to start using its replacement in 72 hours. BP answered that it wanted to stick with COREXIT.

Frustrated EPA and Coast Guard officials said the company's response was inadequate, and told BP to start reducing its use of surface dispersants. But in a decision questioned by some scientists, officials said BP's subsea or underwater dispersant use, authorized in mid-May, could continue.

The EPA and the Coast Guard now say they will call the shots about BP's dispersant use and that COREXIT applications could be scaled back by as much as 50 percent to 80 percent. COREXIT is not the best possible choice for combating the Gulf spill, according to experts, who question why BP first selected and then asked to stick with the dispersant. Wenonah Hauter, executive director of advocacy group Food & Water Watch in Washington, DC, pointed to corporate ties between BP and Nalco as possibly contributing to the decision to use COREXIT. Nalco board member, Rodney Chase, worked for BP for 38 years.

For its part, BP continues to say that large quantities of COREXIT are readily available and that Nalco can deliver as much as 75,000 gallons per day indefinitely.

Coastal experts worried about the ecosystem have sifted through past evidence about COREXIT and other dispersants. After the 1989 Exxon Valdez spill, a version of COREXIT was used, but abandoned when weak wave action made it ineffective. And in the 1969 Santa Barbara spill, some dispersants were applied before hay turned out to be a better solution. Oil-coated clumps of hay spread by boat washed ashore, and were hauled away by dump trucks.

Weeks into BP's Gulf spill, scientists questioned the company's decision to use dispersants on a wide scale and in particular its choice of COREXIT. On its own, COREXIT 9500 can be four times as toxic as oil, according to product evaluations. And of 18 dispersants approved earlier by EPA, twelve were found to be more effective on southern Louisiana crude than COREXIT, EPA data show.

Kendall said he was very concerned that EPA hadn't assessed risks to the Gulf earlier from BP's massive dispersant use. And in contrast with EPA statements, he is particularly worried about underwater injections. "LC 50 studies have shown that COREXIT is toxic to young marine and other aquatic life," he noted. In toxicology language, a Lethal Concentration 50 rating means that a chemical can kill at least 50 percent of a sample population.

Marianne Cufone, fish program director at Food & Water Watch in Washington, DC, said "COREXIT in studies was shown to be twice as harmful to shrimp as an alternate dispersant called Dispersit," produced by Polychemical Corp. in New York. That's problematic for the huge Gulf shrimp industry, she noted. Meanwhile, according to test results compiled by the EPA, seven alternative dispersants are less toxic to shrimp than COREXIT and at least 14 alternatives are less toxic to fish.

Cufone noted that Dispersit is about twice as effective in breaking oil down as COREXIT and is also far less toxic.

If dispersants must be used in the Gulf spill, choosing the right one makes a big difference because "the dose makes the poison," Kendall said "We're watching the biggest ecological, toxicology experiment in our nation's history," he stated. "Underwater pools of oil have formed that are 20 miles long. And the mixture of chemicals-oil, dispersants and residue from setting oil on fire-presents new threats to the sea bottom, the shore, marshes and the air."

Randy Lanctot, executive director of the Louisiana Wildlife Fed?eration, worries that dispersants are being used too close to the coast. "Dispersants are not supposed to be applied from aircraft within three miles of land, according to Coast Guard protocol." But he said "I'm not sure that rule is being precisely followed with respect to the barrier islands that are havens for shore and seabirds. Because of the proximity of birds and other wildlife, dispersants should not, in my opinion, be applied landward of these barriers, and they shouldn't be applied within three miles seaward either." He added "wetting birds with dispersants may put their survival at risk."

Andy Nyman, associate professor of Wetland Wildlife Manage?ment at Louisiana State University, said marsh food chains, starting with micro organisms and moving up to herbivores and carnivores, are often altered by an influx of oil or oily dispersants. Oil and dispersed oil can pass under containment booms, he noted. While fishermen usually don't enter marsh grasses, fish larva and young marine organisms spend their first few months of life there, he noted.

Moreover, findings from Dr. Nyman's experiments appear to contradict BP's reasoning that it's better to use dispersants to protect the coast than to allow oil to break up on its own.

An experiment conducted in the late 1990's by Nyman and other LSU researchers on soil from many of the state's tidal freshwater marshes found that dispersants mixed with oil reaching marsh soils were more toxic to fish, crustaceans and benthic invertebrates than undispersed oil for months after arriving in the soil. Benthic invertebrates are small, growing organisms that live at the bottom of the marsh.

Nyman said "it appeared in our experiments that COREXIT 9500 was toxic to microbes in the marsh soil that eat the oil." And in another experiment with salt marsh soils, Dr. Nyman found that dispersed oil biodegrades, or was eaten by oil microbes, much more slowly than non-dispersed oil.

Based on recent reports likening them to dish detergent and shampoo, dispersants might be viewed as safe to handle. But Kendall warns "for humans, dispersants contain solvents, so you don't want to touch them." A solvent is a substance capable of dissolving another substance. Solvents can be carcinogens, and touching, much less ingesting them, threatens the central nervous system, along with the heart, liver and kidneys. Inhaling solvent vapors can irritate the eyes, nose and throat.

The mix of chemicals at the BP spill site explains why the company requires fishermen under its Vessels of Opportunity program and others employed for cleanup to have HazMat training.

A concoction of oil and dispersants is already hovering over corral beds, like the Pinnacles south of Louisiana. And Kendall said the mixture is getting into the Loop Current, which heads to south Florida-where ancient corral reefs could be devastated. With hurricane season approaching, the presence of chemicals in Gulf Coast waters frightens him. Winds from a big storm will push the dispersed oil mixture around, and that could be catastrophic for the salt-and-fresh or brackish-water balance of Lake Pontchartrain, he warned. The lake has only recently been judged safe again for swimming after industrial and farm waste was brought under control.

"Given the size of the Gulf spill, we need to try everything that's environmentally sound to get rid of the oil and the added chemicals," Kendall said. Texas Tech Univer?sity, he noted, developed Fibertect, a product with an activated, carbon core between layers of non-woven cotton that can be used in containment booms and to clean wildlife. He said a marketing firm has explained Fibertect's several applications to BP.

Lanctot said the use of "dispersants in the Gulf is a huge, unplanned and not very well-controlled experiment." He added that it's anybody's guess how dispersants will effect the Gulf ecosystem as it tries to recover after the oil well is plugged.

Meanwhile, the price of Nalco stock rallied in early May after BP said it was using two forms of COREXIT, Cufone noted. Shares swiftly retreated however, after the EPA expressed its concern about using the company's products in the Gulf.