As autumn arrives, many of us head indoors to warm by a wood stove or fire up the furnace to stave off the chill. But closing up our homes against the cold also marks the start of the prime season for accidental carbon monoxide (CO) poisoning.
According to the Centers for Disease Control and Prevention, there are more than 100,000 emergency room visits annually for unintentional CO poisoning, and in excess of 400 deaths. The vast majority of these exposures occur in the home, frequently caused by poorly maintained furnaces, outdated wood stoves, blocked chimneys, or the use of portable generators indoors during power outages. More than one-third of fatalities occur when the victim is asleep.
CO is a colorless, odorless gas produced when combustible fuels burn, like propane, wood, or gasoline. Because it is undetectable to human senses, CO can build up quickly in the bloodstream, and take fewer than five minutes to reach dangerously toxic levels.
Once inhaled, CO molecules bind to the blood’s hemoglobin, and prevent it from carrying oxygen throughout the body. With continued exposure, the brain, heart, and other organs are deprived of oxygen, resulting in loss of consciousness and potentially, death. Even with mild poisoning, one in five victims can develop long-term neurologic problems, including blindness, deafness, and cognitive impairment. That number triples if the poisoning is severe.
Know the symptoms
Household pets are usually the first to show symptoms, such as vomiting and extreme drowsiness. Birds — especially parakeets and canaries — are uniquely susceptible due to their rapid breathing rates and tiny bodies.
For humans, early warning signs of CO poisoning include mild headache, nausea, and shortness of breath. With higher levels of exposure, victims can experience chest pain, stomach upset, dizziness, and fainting. Even in mild cases, organ damage or inflammation may cause symptoms to linger for up to two weeks after exposure.
While life-threatening toxicity can turn the victim’s skin a distinct cherry red color due to the bright pink tint of the CO-hemoglobin molecule, it is rarely seen in living patients.
Those at highest risk for CO poisoning include infants, adults over 65, and individuals with anemia, respiratory conditions, or chronic heart disease.
If you have symptoms of CO poisoning, or if your home CO alarm continuously sounds, go outside immediately and contact 911. Don’t try to find the source of the gas, and don’t stay indoors to make the call. If you are unable to safely leave the house, stay by an open window until help arrives. A detector that beeps intermittently typically signals a low battery or malfunction: You can safely inspect the unit as long as you are completely symptom-free.
How to stay safe
- Prevent accidental poisoning by installing a CO detector alongside your fire alarm, or use a combination alarm. New York State law requires these detectors in all residential dwellings. For maximum protection, place them near sleeping areas and attached garages, and test them twice a year.
- Home fuel-burning appliances should be professionally installed and vented to the outdoors.
- Never operate gas-powered tools inside
- Never leave your car running in an attached garage.
- Have your chimney, flues, and heating system inspected annually.
- If you own a wood-burning stove, make sure it is well-sealed and clean the ash pan regularly; burn only seasoned, dry logs. Wet wood burns incompletely and can release high amounts of the toxic gas.
- Fire safety and public health agencies discourage banking a hearth or wood stove fire at night, as it can dramatically increase CO production, and cause a 10-fold jump in the concentration of the toxic gas per pound of wood burned, compared to a clean, flaming fire.
The American Red Cross supplies free smoke alarms and CO detectors. As part of its Home Fire Campaign, Red Cross-trained volunteers can visit your home to check for fire safety, and install both fire and CO alarms.
Dr. Mary Jenkins, a contributor to the Herald and member of its board of directors, retired after nearly 40 years as a family practice physician in New York state.