Low-Level Carbon Monoxide Dangers

On a wintry day two weeks ago, Domenic DiOrio, 73, feared his genes had caught up with him. With every step he took, jolts of pain stabbed his chest. His breathing slowed. His words slurred. His head throbbed. "I thought it was a heart attack coming on," he recalls, the very thing that killed both his father, and his sister. "I thought I was dying."

And he very well might have. But he was lucky enough to seek help at an emergency room in Providence, R.I., that gives every patient an unusual test: a simple measurement of blood-gas levels through the finger to determine whether they have carbon monoxide poisoning. Turns out, DiOrio did have dangerous amounts of carbon monoxide in his body, and the toxic gas—not his heart—caused his episode that day. "I was stunned and confused," he says. "I was loaded with carbon monoxide."

DiOrio's experience isn't unique, according to a yearlong study at Rhode Island Hospital, an institution in the same Providence network whose results spurred the testing that helped him. That research indicates that an estimated 11,000 cases of carbon monoxide poisoning could be going undetected every year in the United States. "There are people walking around who don't have [apparent] signs or symptoms of carbon monoxide poisoning that actually have significant carbon monoxide poisoning," says study leader Selim Suner, director of emergency preparedness and disaster medicine at Rhode Island Hospital's department of emergency medicine, whose findings were published online last month in the Journal of Emergency Medicine. "These cases are abundant. We're just not picking them up."

That's because symptoms—such as headache, dizziness, chest pain, nausea, and vomiting—aren't specific, and often masquerade as other illnesses, like the flu. Unless suspected, physicians are likely to overlook carbon monoxide as the source of a patient's woes, blaming a virus instead, says Allison Stock, a carbon monoxide expert at the National Center for Environmental Health. It's known that the gas causes some 500 accidental deaths and between 15,000 and 40,000 ER visits each year, according to the Centers for Disease Control and Prevention. At high levels, it can kill in minutes.

It's critical that victims like DiOrio be identified and treated with high-dose oxygen, says Suner, and that the source of their exposure is located. In DiOrio's case, the culprit was an unused but faulty chimney. Otherwise they and others will continue to be at risk. Moreover, accumulating evidence indicates that overexposure to CO can inflict lingering, even permanent, bodily harm. One study, published in the Journal of the American Medical Association in 2006, found that poisoned patients who'd suffered heart muscle damage as a consequence of CO toxicity were much more likely to die in years following than poisoned patients with no such damage. Other known complications can include delayed neurological effects—like vertigo; incontinence; and memory, speech, and movement problems—or psychiatric troubles, like depression. All of these, Suner says, could "last a lifetime."

"I feel lucky that I had symptoms of a heart attack, because otherwise I wouldn't have gone to the ER," DiOrio says. He was told that, had he not sought help that day, he'd be dead. "I hope I'm an example for all people to go out and buy a detector immediately."