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Scientists and Doctors Sound Alarm Over Health Dangers of Oil Spill Dispersants

Some are questioning whether the EPA’s proposed changes to chemical dispersants standards are enough to prevent harm.

"Dispersed" oil oxidizes and clumps on the surface of the Gulf of Mexico after the BP oil spill. (Photo: NWFblogs / Flickr)

Part of the Series

Last week, the US Environmental Protection Agency (EPA) proposed a series of changes to its standards governing the use of toxic chemical dispersants during oil spills, like the 1.9 million gallons of dispersants used during BP’s Gulf of Mexico disaster.

The EPA claims their new rules will incorporate part of what officials learned during BP’s Deepwater Horizon disaster, including toxicity testing requirements, information that manufacturers must provide the EPA and the public, and how toxicity must be monitored while the chemicals are used on future spills.

Mathy Stanislaus, who oversees the EPA’s emergency response policies, stated: “Our proposed amendments incorporate scientific advances and lessons learned from the application of spill-mitigating substances in response to oil discharges and will help ensure that the emergency planners and responders are well-equipped to protect human health and the environment.”

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But several scientists and doctors took issue with the EPA’s claims, stating that the agency has not gone nearly far enough in protecting people, wildlife and the environment from dispersants that they described as “deadly,” “cancer-causing,” “extremely toxic,” and that “wreak havoc on people’s bodies.”

Human Health Impacts

During a January 14 webinar co-hosted by the Government Accountability Project (GAP) and A Locally Empowered Response Team (ALERT), experts in several areas painted a grim picture of the profound effects of the dispersants on the environment, wildlife and humans, as well as their ongoing human health and environmental impacts in the Gulf of Mexico since the BP crisis.

Robert Mathis, an M.D. and doctor of environmental medicine in Santa Barbara, California, described how several of the chemical ingredients of the dispersants that are regularly used on oil spills remain unknown because they are “trade secrets,” but that even the known chemicals in the dispersant cocktails are extremely dangerous to humans; they contain an “emulsifier that allows chemicals deeper penetration into tissues and cells.”

“Dispersants disrupt both bacterial and human cell membranes,” Mathis explained. “Damage disrupts cell functions, leading to cell failure, and may cause cancers and death. All living things are damaged, including groundwater.”

Mathis described in detail how, by using the toxic dispersants, oil companies and cleanup crews “give the chemicals access to cellular machinery by breaking down the lipid cell membrane.”

“Human health impacts for decades are a certainty, especially among sensitive portions of the population like pregnant women, the elderly and people with disabilities.”

Dr. Susan Shaw, founder and president of the Marine and Environmental Research Institute and School of Public Health at the State University of New York, Albany, also spoke to the human health consequences of dispersant use.

“There is no safe level of exposure to the carcinogenic and mutagenic chemicals in oil,” said Shaw, who also served on the Department of the Interior’s Strategic Sciences Working Group – a team of 14 scientists charged with assessing consequences of the oil spill and recommending policy actions in the Gulf. “Corexit [dispersant used during the BP disaster] multiplies the toxicity of oil and forms a reservoir of ongoing toxicity in the sea.”

Shaw, who has been studying the health effects of chemical exposure for more than 30 years, explained that even BP’s Material Safety Data Sheets for Corexit, which were widely available throughout the oil industry well in advance of the BP disaster, warned that the dispersant posed high and immediate human health hazards, but the company, of course, used it anyway.

“Human health impacts for decades are a certainty, especially among sensitive portions of the population like pregnant women, the elderly and people with disabilities.”

Like Mathis, Shaw emphasized that dispersants allow “oil to enter the skin and organs more easily.”

“Oil and dispersants damage the same organ systems in the body’s nervous system, respiratory system and immune system,” she explained. “Toxic compounds in oil, like polycyclic aromatic hydrocarbons, benzene, naphthalene, ethylene, propylene and many others are all toxic ingredients in Corexit 9527 and 9500 [the dispersants used on the BP spill], and another of them, 2-butoxyethanol, is known to cause internal bleeding.”

“BP told the public that Corexit was ‘as harmless as Dawn dishwashing liquid.'”

In an earlier interview with Truthout, Shaw accused both BP and the EPA of knowingly placing people in harm’s way, since they both had prior knowledge of the damaging effects of the oil and dispersants.

“BP told the public that Corexit was ‘as harmless as Dawn dishwashing liquid,'” she said. “But BP and the EPA clearly knew about the toxicity of the Corexit dispersants long before this spill.”

According to Shaw, the massive human health crisis that continues in the Gulf today was wholly predictable.

“Five of the Corexit ingredients are linked to cancer, 33 are associated with skin irritation from rashes to burns, 33 are linked to eye irritation, 11 are or are suspected of being potential respiratory toxins or irritants, and 10 are suspected kidney toxins,” she said.

A 2013 study in the American Journal of Medicine sheds more light on the potential health repercussions for the more than 170,000 people who worked in some capacity to clean up the 2010 disaster.

The study shows that people hired to clean up Gulf of Mexico beaches and marshes during the 2010 oil spill have significantly altered blood profiles that, just as Shaw and other toxicologists warned, put them at increased risk of developing liver cancer, leukemia and other disorders.

According to Shaw, thousands of people in the Gulf – cleanup workers, fishermen and residents – have reported multiple severe symptoms related to chemical exposure from the spill.

“What ties them together as a group is their spill-related health problems, which are also typical of the health problems reported from previous oil spills,” she said. “Some of these include blood in urine, heart palpitations, kidney damage, liver damage, migraines, multiple chemical sensitivity, neurological damage, memory loss, rapid weight loss, respiratory system damage, skin lesions, muscle spasms, seizures and temporary paralysis.”

Several scientific studies have confirmed this, like “Health Consequences among subjects involved in gulf oil spill clean-up activities,” published in 2013. The conclusion of the study: “Clean-up workers exposed to the oil spill and dispersant experienced significantly altered blood profiles, liver enzymes, and somatic symptoms.”

Shaw also cited the National Institutes of Health Gulf cleanup worker study, which she feels is “compromised by a lack of exposure measure in the studies’ subjects” since the health agency was prohibited from entering the spill area until 2011. She also drew attention to the fact that since the study is long-term (the study began just after the spill and will last at least 10 years), there is “no medical care for subjects, even those who were highly exposed.”

Shaw concluded by recommending that in order to protect public health, “we must use the precautionary principle to regulate dispersant chemicals. Their ongoing use is of very high risk to human and nature’s health.”

The precautionary principle, as summarized by the Science and Environmental Health Network, states that whenever an activity could threaten to harm either the environment or human health, precautionary measures ought to be taken, even if a direct cause and effect relationship has not yet been fully established.

Wildlife Impacts

Dr. Samantha Joye of the University of Georgia’s Department of Marine Sciences became internationally famous during the BP oil disaster for having first identified the massive subsea oil plumes that formed as a result of the use of dispersants.

“Where do dispersants go? The earth is a closed ecosystem; there is nowhere to go. Nothing leaves the planet. Once they are sprayed, they don’t go away.”

In a lecture delivered during the webinar by Dr. Sairah Malkin, a member of Joye’s research group, Joye noted how the effects of dispersants on microbial communities and their rates of degradation are clear. The group’s research showed that dispersed oil is not more readily bioavailable to microorganisms. This flies in the face of claims by BP, the EPA and other organizations that claimed that dispersing the oil would help break it down faster by causing it to become bioavailable for microbes to ingest.

“The research is conflicting,” Malkin said. “There is no clear answer as to if dispersants alter microbial community composition in ways that enhance biodegradation.”

She mentioned the need for additional and ongoing studies of the impacts of dispersants.

Regardless of conflicting research, Shaw reiterated that the precautionary principle must come into play concerning the use of dispersants – especially given ample existing evidence of their injurious effects. She cited a 2011 study by the National Oceanic and Atmospheric Administration that linked dolphin illnesses in the oil impact zone directly to BP’s disaster. The study revealed a 50 percent spike in dolphin mortalities. Similarly, a 2013 study led by Lori Schwacke for NOAA states:

Dolphins sampled in Barataria Bay showed evidence . . . consistent with adrenal toxicity as previously reported for laboratory mammals exposed to oil. Barataria Bay dolphins were 5 times more likely to have moderate-severe lung disease, generally characterized by significant alveolar interstitial syndrome, lung masses, and pulmonary consolidation. Of 29 dolphins evaluated from Barataria Bay, 48% were given a guarded or worse prognosis, and 17% were considered poor or grave, indicating that they were not expected to survive. Disease conditions in Barataria Bay dolphins were significantly greater in prevalence and severity than those in Sarasota Bay dolphins, as well as those previously reported in other wild dolphin populations. Many disease conditions observed in Barataria Bay dolphins are uncommon but consistent with petroleum hydrocarbon exposure and toxicity.

Beyond the immediate and near-term health impacts of the dispersants, the scientists emphasized the dangers that come with their lingering presence. Mathis noted that once the toxic dispersants are introduced to the environment, they do not go away.

“Where do they go?” he asked. “The earth is a closed ecosystem; there is nowhere to go. Nothing leaves the planet. Once they are sprayed, they don’t go away.”

To underscore his point, Mathis pointed out the fact that umbilical cord blood from newborn babies “contains more than 207 chemicals” because “we breathe them [chemicals] in, drink them, wear them, eat them, wash with them and cook with them.”

Mathis also pointed out how several of the chemicals in both crude oil and dispersants are “toxic to plants, animals, birds, marine and human life.”

Like Shaw, Mathis also stated that many of these chemicals, when mixed together like the dispersants and oil were during BP’s disaster, “are many times more toxic than the individual chemicals are by themselves.”

Use and Effectiveness of Dispersants

In order to understand the impacts of dispersants, it’s necessary to look closer at the ways in which they react with water and oil, when delivered onto spills. Dr. Ira Leifer, an atmospheric and oceanic scientist with the University of California, Santa Barbara, delved into these interactions during the webinar.

“Dispersants are surfactants that reduce oil-water interfacial tension, which helps waves break the oil into small droplets,” Leifer explained. “The purpose of dispersants [is] to break the oil into small droplets that are easier to disperse throughout a water volume, and small droplets may be more readily biodegraded by microbes.”

Ninety-five percent of the people interviewed “continued to experience spill-related health problems in 2013.”

Leifer explained that during the BP disaster the decision to use dispersants was based on trade-offs, and that since oil is toxic on the surface, using dispersants to remove it from the surface, move it into the water column and expose aquatic life to dispersed oil was, at the time, seen as the better move.

While a large amount of the dispersants were applied to BP’s oil via airplanes spraying it, Leifer argued that it was not a good way to apply it because so much dispersant used in this way does not even go into the oil.

He added that just the amount of dispersants alone released during the BP disaster would have made it one of the top 10 oil spills in US history because of the chemicals in the dispersants.

Speaking to how BP injected large amounts of dispersants into the oil erupting from the ruptured piping at 5,000 feet beneath the surface, Leifer said, “Most of the plume was not being impacted by the dispersants, because there is only seven to nine seconds it was actually even touching the oil.”

Leifer concluded by saying, “Given the realities that the real world is not a beaker in a lab, applying dispersants as specified by the manufacturer is an unrealistic assumption. There are enormous challenges that are insurmountable to real world applications.”

Overall and Continuing Impacts

As we begin to grasp the widespread and long-ranging effects of the dispersants used by BP, it becomes clear that we are dealing with an ongoing crisis that requires both continued study and strong action. On April 20, 2015, the fifth anniversary of the BP disaster, GAP will release a report on that disaster’s overall and continuing impacts – and according to Shanna Devine, a GAP investigator, “Our findings are, in some cases, more severe than they had previously found.”

According to Devine, the study incorporates interviews with more than 30 whistleblowers, “including divers, scientists, coastal residents, cleanup workers, doctors and industry leaders.”

It also makes use of Freedom of Information Act requests and off-the-record interviews with government officials. Devine stated that GAP’s findings “are starkly at odds with BP and federal claims about dispersant use being safe.”

Regarding the EPA’s recent announcement about dispersants, Devine said, “We welcome the EPA’s role in regulating their use, but it is unclear if [the agency] will ban their use, and that is the real indicator we must watch.”

GAP’s current studies, according to Devine, show that 95 percent of the people interviewed “continued to experience spill-related health problems in 2013, and 50 percent of those living in impacted areas report their children’s or grandchildren’s health had been impacted.”

GAP’s findings on human health impacts include “heart palpitations, memory loss, IQ drops, seizures, vomiting, paralysis, skin irritation, burning and lesions.”

Devine added, “We are already seeing signs of reproductive damage and cancer.”

The study also looked at what types of protective measures BP took to shield cleanup workers from dispersant-related harm. According to Devine:

– 47 percent of workers reported that their employers told them Corexit [dispersants] did not pose a health risk.
– 85 percent of workers were never informed of or made aware of any available safety literature on the job site.
– 87 percent of workers had contact with Corexit while on the job.
– 57 percent of witnesses reported they, or someone in their family, was exposed to Corexit outside of the cleanup zone.
– More than 46 percent of workers were threatened with termination when they tried to wear respirators or additional safety equipment on the job.

“BP and [the] federal government have denied any significant human exposure to Corexit occurred,” Devine said. “But 100 percent of witnesses that took blood tests for us tested positive for high levels of chemicals found in both Corexit and oil. Independent air monitoring by the Louisiana Environmental Action Network found that chemical concentrations exceeded the physical health symptom concentrations by 100 to 120 times.”

Devine added that more than 60 percent of the cleanup workers and coastal residents GAP interviewed reported evidence of oil or oiled debris in areas where cleanup operations were deemed “complete” by BP and the US Coast Guard. More than 70 percent of witnesses cited evidence that dispersants had been used “after BP and the EPA claimed they were no longer being used.”

“Nearly 80 percent of the fishermen GAP interviewed have reported seafood deformities,” she said.

“The federal government has a responsibility to effectively regulate the use of dispersants and has effectively failed in protecting the public,” Devine concluded. “We are finding that none of the health impacts are lessening, and in fact all kinds of cancers are increasing.”


Dr. Riki Ott, a toxicologist, marine biologist and founder of ALERT, was on scene for the Exxon Valdez oil disaster in Alaska in 1989.

Ott has been working to have dispersants banned for many years, and said that while BP’s disaster “triggered more regulations, many things remains unaddressed.”

“Rules are being broken and the laws have not kept up with the science. Congressional action is needed.”

“Post BP, the EPA has proposed to make products more transparent, but dispersants still have some ingredients that are trade secrets and not available for public knowledge,” Ott told Truthout. “There is no EPA process for delisting the product. Furthermore, dispersants contain sinking agents, and the EPA proposes to allow products that sink oil to the bottom.”

According to Ott, the EPA’s current toxicity tests are 40 years out of date, and it is the EPA’s responsibility to monitor the long-term health impacts from the dispersants, as well as to track their impact on nature.

Ott concluded by stating that the EPA “can only make a bad situation a little better. Rules are being broken and the laws have not kept up with the science. Congressional action is needed. In lieu of congressional action, we on this panel are all committed to work for stronger regulations.”

During an interview with Truthout in 2012, US Coast Guard Capt. Jonathan Burton, who at the time was the federal on-scene coordinator for the region of the Gulf of Mexico that included the area where BP’s disaster took place, said that dispersants remain one of the “primary tools” in the toolkit used in response to future oil spills. The other two tools are skimming and burning the oil.

On January 20, the third phase of the BP oil disaster civil trial will resume in federal court in New Orleans, Louisiana. The result of this trial will determine how much BP and other responsible parties will pay in Clean Water Act fines for the 2010 drilling disaster that released at least 3.19 million barrels of oil into the Gulf of Mexico. Estimates for the amount of BP’s fines range from $5 to $13.7 billion.

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