Questions arise about whether chemicals played a role in oil tank deaths

Petroleum poisoning in oil fields is a growing concern that has led to several deaths and left many medical professionals baffled or unwilling to place the blame on chemicals, Mike Soraghan reports for Environment and Energy Publishing. (Soraghan photo: Marathon's Buffalo 34-12H well pad near Killdeer, N.D.)

Robert Harrison, an occupational medicine specialist at the University of California, San Francisco, Medical Center who has investigated fatal chemical exposures in the workplace, "said authorities such as coroners and medical examiners may be missing the signs of petroleum poisoning in oil field death cases," Soraghan writes. Harrison told him, "That's certainly something we should be checking into further and doing additional investigations on whenever deaths occur suspiciously like this in the oil fields. And I'd say dying alone in the middle of the night in North Dakota is a pretty unusual circumstance."

In a sworn statement to the attorney of the family of a worker who died of "hydrocarbon poisoning due to inhalation of petroleum vapors," environmental engineer Fred Bremseth said, "With that excessive gas, you get lightheaded. It would be just like carbon monoxide. You're gonna doze off, and Katy bar the doors, man—you're dead."

Confusion and a "look-the-other-way" attitude have hampered investigations, Soraghan writes. Trent Vigus's death certificate states his cause of death as "hypertensive and atherosclerotic heart disease"—hardening of the arteries, Soraghan writes. "Essentially, it says he died of hardening of the arteries and a sudden cardiac 'event' from an undiagnosed heart condition. But some of the postmortem results contradict that and suggest Vigus' exposure to chemicals may have contributed to his death."

"Laboratory tests turned up small amounts of propane and butane in Vigus' blood. Both these chemicals are found in Bakken crude," Soraghan writes. The pathologist who did the autopsy, Thomas Bennett, "wrote only that the toxicology test found caffeine and nicotine, ignoring the propane and butane results. Bennett wrote that Vigus died from a 'sudden cardiac event, most probably due to his underlying enlarged heart from hypertensive cardiovascular disease.'"

"But Bennett didn't find any hardening of the arteries in Vigus' 30-year-old body," Soraghan writes. "He wrote in his description of the heart that there were 'no gross atheromatous narrowings' of the arteries. That would usually mean there is no atherosclerotic heart disease."

Another instance involved a Marathon health, environment and safety specialist, who said when he was interviewed, the only question he was asked was "Can you keep your mouth shut?" Soraghan writes. "The problem turned out to be not what he said, but what he wrote," according to the attorney for the family of Dustin Bergsing, whose autopsy said he died of "hydrocarbon poisoning due to inhalation of petroleum vapors."

"Marathon managers were upset that he put his questions and concerns in writing in emails," Soraghan writes. "Unlike a spoken conversation, those could turn up as exhibits in a lawsuit." The employee was fired not long after Bergsing's death. (Read more)