The first time Charles Kihnel was poisoned, he didn't know it.
His symptoms surfaced when he was working on his car in his garage on a cold day in winter. After a couple of hours, his head started throbbing; he couldn't concentrate. He went inside and took medication for the headache, but couldn't shake the splitting pain. Late in the evening, his head still pounded and he felt like he was in a fog.
It took a day or two for the headache to go away completely, but the following Saturday, when he was back in the garage, it happened again. It was then he realized what was happening.
It was carbon monoxide.
"I had a bad heater in my garage," says Kihnel, a technician and manager with General Heating and Air Conditioning, which has offices across the New Orleans area. "It's like no headache you've ever had before. It depletes the oxygen to your brain."
Approximately 480 people die in the United States every year — about five of them in Louisiana — from carbon monoxide poisoning: a heater malfunctions, a generator isn't ventilated properly, and the gas kills its victims in their sleep. Thousands of others are sickened by carbon monoxide poisoning but don't die. The Centers for Disease Control (CDC) estimates more than 20,000 people visit emergency rooms annually because of carbon monoxide.
No one is sure exactly how many people get sick from carbon monoxide exposure in Louisiana, but that is about to change. In November, the Louisiana Department of Health and Hospitals (DHH) announced that health care workers must report all cases of carbon monoxide poisoning, not just those resulting in death. Nationally, carbon monoxide poisoning spikes in January when people are most likely to bring a fuel-burning heater inside or turn on an oven to heat up a room. While this pattern holds in Louisiana, there are questions about what other risk factors there may be here.
"We want to know what are the circumstances where we have carbon monoxide poisoning," says state epidemiologist Dr. Raoult Ratard, one of the researchers who will analyze the information. He already knows that power outages during hurricane season mean increased carbon monoxide poisoning for Louisianans who turn on generators inside or too close to a house. "Once you try to understand who gets carbon monoxide poisoning and what are the circumstances, we may find out a better way to prevent it," he says.
Carbon monoxide is a gas byproduct from the incomplete combustion of fossil fuels. Common sources of acute and often lethal carbon monoxide poisoning include generators whose fumes to enter a house; kerosene heaters being used indoors; charcoal being burned inside a house; and cars left running in a garage, even with the door open.
Exposure to the toxic gas is less obvious when a gas heater or stove is not working properly, or when a fuel-burning appliance is not burning clean. In those cases, enough carbon monoxide can leak to cause chronic poisoning, but not severe, acute poisoning.
"What is so misleading is that it's a colorless, odorless, tasteless gas, but to get pure carbon monoxide poisoning is almost impossible," says Dr. Paul Harch, a professor of emergency medicine at Louisiana State University Health Sciences Center (LSUHSC). "(Because it is just one byproduct of incomplete combustion), in almost every instance, you will smell the smell of unburnt fuel," he says. "But especially in work settings, where there is unburnt fuel from a car tailpipe or a leaf-blower, for instance, patients lose sensitivity to the smell. They may go home at the end of the day feeling achy, lethargic and tired without realizing they've been exposed to carbon monoxide."
Harch, a specialist in hyperbaric medicine, has been studying the use of hyperbaric oxygen therapy for patients poisoned with carbon monoxide. In acute cases, the high-pressure oxygen is extremely helpful. Harch also finds the therapy helps alleviate and reverse many of the lingering effects of carbon monoxide poisoning in people who have suffered chronic exposure. Diagnosing that kind of exposure, however, if often difficult, he says.
"It is one of the great imitators of flu," Harch says. "It's malaise and headache, achiness, fatigue, diziness, nausea." It doesn't help that flu season and the time of year when carbon monoxide poisoning is most prevalent overlap, he adds.
Part of what makes carbon monoxide so dangerous is that its molecule has a shape similar to an oxygen molecule. When you breathe under normal conditions, oxygen molecules from the air pass across your lungs and into your bloodstream. Those molecules bind to red blood cells, which then distribute the oxygen all over your body.
When carbon monoxide is pulled into the lungs, it enters the bloodstream and binds to the red blood cells just like oxygen would, but it is more efficient at binding than oxygen; it clings to the red blood cells tighter and longer, essentially elbowing out the oxygen and blocking it from needy cells. Carbon monoxide not only starves cells of oxygen, but it also degrades the protective coating on connections between neurons in the brain, leaving them exposed like stripped wires. This causes the flu-like symptoms that make carbon monoxide poisoning so difficult to diagnose.
"The symptoms of it are like so many other things — that's the rub," says one carbon monoxide survivor and Tulane medical student who asked not to be identified because of litigation issues stemming from his exposure. During the colder months, he developed symptoms including dizzy spells, severe headaches and sleeplessness that worsened when he was in his apartment, located above a restaurant kitchen. Over the course of the winter, his diagnosis ran from flu to vertigo. It took several doctors and significant personal research to figure out he was suffering from carbon monoxide exposure. The symptoms stopped when he moved out of the apartment.
The CDC and the Consumer Product Safety Commission advocate servicing fuel-burning appliances and heating systems annually to prevent poisoning. A carbon monoxide detector will sound an alarm when gas levels are high enough to cause sickness or death. But one detector in the bedroom may not pick up a chronic, low-grade leak on the other side of the house, which is why it's important to have a heating-ventilation and air-conditioning (HVAC) professional inspect your home.
"Almost anywhere you go, you do get some carbon monoxide," says Kihnel. On the job, he has seen plenty of leaks — an open stove flame, anything that's not vented properly, old-style open heaters. But he points to the age of New Orleans' architecture as part of the reason his customers often don't know they're being exposed. "Mostly your old houses have enough air leaks that it's not critical," he says. The carbon monoxide dissipates, but not enough to prevent symptoms entirely.
"I'm in this business and I didn't realize what was going on with me," he says. "A lot of people are aware of carbon monoxide, but they don't realize how common it is."