Enzymes from an oil dispersant used after the Deepwater Horizon spill in the Gulf of Mexico are harmful to both humans and marine animals, a new study suggests.
After the Deepwater Horizon oil rig caught fire off the coast of Louisiana in 2010, it unleashed 210 million gallons of oil over the course of 87 days. It remains the largest oil spill in U.S. history and continues to damage the region’s ecosystem and economy to this day. Corexit EC9500A, an oil dispersant agent, was liberally used in the cleanup operations; some 1.84 million gallons of it was sprayed on the water or just below the surface to break up the oil.
In a study published last week in the journal PLOS ONE, researchers from the University of Alabama at Birmingham found that exposure to Corexit correlates with damage to epithelium cells in the lungs of humans and the gills of marine animals.
Epithelium cells line the airways of lungs and some marine species and provide a critical barrier to harmful inhalants. When inflamed, these cells can swell and constrict the airway. When they break down, the body loses an essential line of defense. The UAB study suggests that Corexit exposure to human lungs and marine gills cause oxidative stress that damages the cells and can even cause their death.
“There were some 48,000 workers involved in the cleanup operations,” the paper’s senior author, Professor Veena Antony, said in a press release, “and it is possible that workers were exposed to Corexit via inhalation. Cough, shortness of breath and sputum production were among symptoms expressed by workers.”
Interestingly, researchers also found that Corexit exposure leads to an increase in the production of enzymes that protect against inflammation and cell death.
“[O]ur results indicate that respiratory epithelial surfaces across phylogenetic species are sensitive to injury by Corexit,” said Antony. “However, the enzyme HO-1 protects against inflammation and cell death induced by Corexit.”
With the likelihood of another oil spill high, the researchers “propose that upregulating HO-1 may offer a novel therapeutic approach for treating dispersant-induced injury and apoptosis by enhancing the antioxidant and anti-apoptotic ability of the epithelium.”