Millions of gallons of chemicals were sprayed onto the spill to disperse the oil into tiny droplets that have mixed into the Gulf of Mexico.
Scientists say the oil is slowly disappearing. But residents remain concerned about effects the dissipated oil and chemicals may have on local waters and seafood.
Susan Felio Price, a Chauvin resident, said she’s gone to oil-spill meetings to ask some basic questions.
“Would you feed your children Gulf shrimp? How often would you do it? Would you do it five times a week? Because bayou people live off seafood,” Felio Price said. “Nobody has really been transparent and straight-up honest with us.”
Ed Overton, professor emeritus of environmental sciences in LSU’s School of the Coast and Environment, said dispersants are basically cleaning solutions for oil, similar to what you might use to clean an engine block in a boat.
Dispersants are comprised of about seven different ingredients that are found in common household products, from medicines to nasal sprays, and their toxicity is low, said Ann Hayward Walker, a scientist contracting with BP.
Though oil is broken down naturally by microbes, when a large slick sits on top of the water, it can block the processes that allow these bacteria to flourish. Dispersants work by separating the oil into individual droplets the diameter of a piece of hair, Walker said, making it easier for the bacteria to consume.
Some people mistakenly believe the dispersants sink the oil below the surface so that it simply can’t be seen, but it actually causes it to mix with the water, she said. The oil droplets remain in the water for a month until they’re completely broken down.
None of the chemicals in these dispersants will persist in the environment; they break down quickly, Overton said.
“Everyone seems to be focused on dispersant use for some unknown reason. I find that to be curious because they should be focused on the oil. Oil is toxic. Dispersants are nontoxic compared to oil and degrade very fast,” said Kerry St. Pe’, director of the Thibodaux-based environmental-advocacy group the Barataria-Terrebonne National Estuary Program.
Wilma Subra, a Louisiana environmental chemist, has been working with the Louisiana Environmental Action Network and the Lower Mississippi Bayoukeepers to test bays and estuaries for dispersed oil and dispersant. She suspects the chemical dispersants do pose a health risk to spill workers and bayou residents who may have come in contact with the sprayed chemicals or dispersed oil.
She said one of the formulas of Corexit, the dispersant used on the spill, contains 2-butoxyethanol, pinpointed as the cause of lingering health problems experienced by cleanup workers after the 1989 Exxon Valdez oil spill.
Dispersants can have health impacts on people when they’re inhaled or come in contact with the eyes or skin, Subra said.
Short-term exposure can cause headaches, nausea, vomiting, abdominal pain, dizziness, chest pain, eye, nose, throat, and lung irritation, difficulty breathing, decreased lung function, allergic reaction, skin irritation or high blood pressure, she said.
Long-term exposure risks include liver and kidney damage, nervous system depression, genetic damage and mutation, reproductive complications, immune system damage or cardiovascular damage.
“If you believe the numbers, for every 93 gallons of crude released into the Gulf, one gallon of dispersant was used. That’s a huge amount,” Subra said.
By law, dispersants cannot be applied in shallow waters within three miles of the coast. The last time dispersants were sprayed on the spill was July 19.
But Subra said she and other environmental activists have heard reports that dispersants continue to be sprayed. Bayou residents might also have been exposed as oil sprayed with dispersants floated into coastal estuaries.
Walker said the dispersant chemicals can cause skin irritation but added that “no one should have been sprayed” by the chemicals.
“People have said they have been, and that’s something we can’t explain,” Walker said.
Subra said she and her teams are sampling along the coast — in the Atchafalaya, the Mississippi River, and below Houma — to see just what kind of chemicals remain in the water. Results should be complete this week.
“I’ve heard from a lot of people who were very sick and lots of complaints from people that these dispersants were applied in coastal areas,” she said. “These dispersants are very toxic.”
Walker said university and government scientists are taking water samples in both deep water and coastal areas to test for dispersants and oil. Testing of the toxicity of dispersants on sea life has been done in laboratories.
St. Pe’ argues locals should be more concerned about what effect the tiny droplets of oil might have had on deep Gulf environments. The use of dispersants does not alleviate the impacts of the oil on the environment, he said. It was only used to protect one habitat over another. In this case, the aim was to prevent oil from entering sensitive wetlands, where it would have a more-disastrous impact and would be harder to clean up.
“There’s no denying the offshore fisheries have been impacted,” St. Pe’ said.
The dispersed oil was suspended in the water column in areas fish like red drum were spawning and migrating, he said. That could lead to acute toxicity for the fish, reproductive challenges and genetic deformity. But it will take years of study to know exactly how serious their exposure was.
Walker had a more optimistic view of the dispersed oil’s effect on sea life.
“It dilutes and mixes very quickly,” Walker said. “We don’t expect there to be a problem with marine life, except for larvae or plankton directly beneath the slick.”
Felio Price said she recently saw a picture of President Barack Obama swimming with his children in a bay in Florida.
“It’s all about propaganda,” she said. “They’re sacrificing human health. Your little swim isn’t impressive. If you want to swim someplace, come swim in Grand Isle. Eat fish caught in Grand Isle.”
Nikki Buskey is a staff writer for the Houma Courier.