On Day 35 of the Gulf oil spill, I traveled with the ABC News dive team in the Gulf of Mexico as the doctor on board, reporting on the Deepwater Horizon oil spill and BP's use of the dispersant Corexit.
Good Morning America weather anchor Sam Champion and Philippe Cousteau Jr., renowned environmentalist and oceanographer, dove into the Gulf for the first underwater look at what Corexit has done. BP has used this dispersant widely, despite safety concerns from the Environmental Protection Agency.
We had our own safety concerns as well. Just two weeks before his dangerous hazmat dive into the oil, Sam underwent Mohs micrographic surgery for a skin cancer on his left shoulder live on "Good Morning America." So part of my duties as I traveled with him were as a board-certified dermatologist and Mohs surgeon to assess his surgical wound before and immediately after his dives. This also meant extra precautions for Sam's dives; happily, despite strenuous and physically demanding conditions both above and underwater, Sam's surgical site was successfully protected from the oil, dispersant, and contaminated water throughout the day.
The same could not be said for the waters of the Gulf. With over 600,000 gallons of dispersant dumped in the gulf so far, no longer is oil confined to a slick sheen on the water's surface. Exclusive, underwater ABC News video shows oil on the surface is just that -- the surface of a growing cloud of countless underwater droplets of oil. In what amounts to be an environmental experiment, tiny oil droplets are now part of the ecosystem in the Gulf of Mexico, the lasting impact of which is simply unknown.
The oil leaking into the Gulf, composed of hydrocarbons -- some in the form of brown liquid oil and some in the form of volatile, toxic and flammable gases -- is harmful not only to marine life, but also potentially harmful to front line clean-up workers.
Indeed, on day 37 of the Gulf spill, ABC news reported that nine fisherman in the Gulf suffered from severe nausea, headaches and trouble breathing, requiring the entire fleet of 125 boats in the area to evacuate and return to shore for medical evaluation. Four fishermen were taken to local hospitals. Although the cause of these symptoms has not yet been verified, the symptoms are consistent with oil or volatile organic compound gas exposure, though they could also represent heat exhaustion from harsh conditions on the open seas.
In light of the potential hazards, special medical and safety precautions were in place to protect the entire dive team on the nearly 20-hour dive expedition given the toxic nature of both the oil and dispersant. To protect the dive team from skin exposure to oil droplets and dispersant, the divers and underwater cameramen donned 30-pound oil and waterproof vulcanized rubber hazmat dive suits and 30-pound hard metal helmets. In addition, divers were kept completely dry and insulated from oil and dispersant with a special neck apparatus as well as cuffed gloves.
Immediately after emerging from oil-contaminated waters, divers underwent standardized decontamination procedures outlined by the Association of Diving Contractors. Hazmat dry suits were scrubbed with degreasing products and removed immediately. Divers then quickly showered after the decontamination procedure to remove any oil residue.
However, we were also wary of dangers not restricted to the water. Benzene, a predominant liquid hydrocarbon of concern, is poorly soluble in water. Still, some of the benzene gushing out from the well may be washed out in the water on its 5,000-foot journey to the surface, limiting human exposure, but potentially harming aquatic life. Because of its high vapor pressure, any benzene that does reach the surface of the Gulf is vaporized as soon as it hits the surface and is quickly released into the atmosphere in dilute concentrations. But benzene gas is heavier than air and can accumulate close to the water surface, further increasing exposure risk to workers at sea.
According to the United States Occupational Safety and Health Administration (OSHA), benzene is known to cause cancer in humans, and toxic levels have been linked to an increased risk of leukemia and heart and nervous system problems. OSHA has set the benzene permissible exposure limit at 1 part per million and a short-term exposure limit at 5 parts per million for 15 minutes. The CDC reports that breathing benzene at high levels can lead to drowsiness, irregular heartbeats, headaches, and with continued exposure or very high levels could result in unconsciousness or even death.
Although unsafe benzene levels were not detected at any point during our expedition, personalized full-face respirator masks with highly sensitive and effective filters for hydrocarbons and volatile gases were available on our dive vessel in the event unsafe levels were detected.
Fisherman turned cleanup crew are part of BP's "Vessels of Opportunity Program" -- a program started after the Deepwater Horizon accident which hires displaced fisherman and boats to assist with clean-up and response efforts. According to BP, 1,300 people have gone through the Vessels of Opportunity program so far, each receiving four hours of oil spill and safety training.
Although the EPA reports coastal monitoring of ozone and volatile organic compound levels has not revealed dangerously elevated levels so far, little information is available about the air quality at sea, where clean-up crews are most vulnerable. The EPA has reported normal ozone and particulate levels on the Gulf coastline as of May 24, 2010. Real-time air monitoring tests with trace atmospheric gas analyzers has not revealed elevated benzene, toluene or xylene gas along the Gulf coast or in New Orleans, but the same may not be necessarily true of the conditions at sea.
Despite news of ill clean-up workers, Chris Robertson, director of Environmental Health and Safety at Technical Environmental Services and part of the safety team on board ABC's dive vessel, reports there have been no elevated benzene or volatile organic compound levels recorded on the Gulf so far. His company is actively monitoring benzene levels at several remote sites in the Gulf as close as 10 miles away from the Deepwater Horizon accident site.