Carbon monoxide

Carbon monoxide gas is the leading cause of accidental poisoning deaths in the United States. Adding to the danger of this killer is that it is invisible, colorless, odorless and tasteless; it's virtually undetectable without special equipment. Could you or your family be at risk for carbon monoxide poisoning?

The statistics

Carbon monoxide poisoning causes an average of more than 500 unintentional, non-fire related deaths in this country annually, and more than 2,000 more use carbon monoxide to commit suicide by intentionally poisoning themselves each year. More than half of the accidental deaths are attributed to auto exhaust and the remaining cases were related to other appliances. Most deaths caused by appliances were associated with heating systems, but other culprits include charcoal grills, gas water heaters, gas ranges and ovens, and fuel-burning space heaters and camping equipment.

In addition to the deaths attributed to carbon monoxide, the number of people seeking medical attention annually because of carbon monoxide exposure reaches into the tens of thousands. It is difficult to estimate the exact number of cases because exposure at low levels is often misdiagnosed. While the effects of exposure are often temporary, severe poisonings may leave permanent damage.

Why is carbon monoxide

so dangerous to humans?

Everyone knows that humans must breathe to live. Our bodies require oxygen to keep our organs alive and functioning properly. After inhaling, oxygen passes from our lungs into the bloodstream where it binds to a substance called hemoglobin on our red blood cells. This enables the oxygen to be carried throughout our bodies via the circulatory system where it is available to all of our organs and tissues.

Carbon monoxide poisoning inhibits the blood's ability to carry oxygen throughout the body, including to vital organs such as the heart and brain. When carbon monoxide is inhaled, it takes the place of oxygen on the hemoglobin molecule. Hemoglobin "prefers" binding with carbon monoxide so the more there is in the blood, the less hemoglobin that is available to bind with oxygen.

How quickly the carbon monoxide level in the blood (referred to as carboxyhemoglobin) builds up is a factor of both the concentration of the gas being inhaled and the duration of the exposure. In other words, a concentration of carbon monoxide that causes only minor symptoms after 30 minutes may be life threatening after several hours. In addition, it takes much longer for carbon monoxide to leave the body than to enter it. Once exposure is terminated many hours, even days, may be required for it to be eliminated from the body unassisted. During this time, further damage may occur.

The health effects

The effects of exposure to carbon monoxide vary depending on the concentration of the gas in the air and the blood, the length of exposure and individual differences of victims. Among individuals, traits such as age and general health make a difference in how severely the person may be affected. Infants, children, pregnant women, and people with existing heart and lung problems are especially vulnerable. People who smoke already have carbon monoxide in their body and will reach dangerous levels more quickly than nonsmokers.

Mild exposure to carbon monoxide results in symptoms that mimic the flu - headache, nausea, dizziness and fatigue. As exposure increases symptoms may include a throbbing headache, drowsiness, confusion, vomiting and an increased heart rate. Extreme exposures can lead to convulsions, unconsciousness, organ failure, brain damage and death.

Carbon monoxide sources

Any fuel-burning appliance or equipment can be a potential source of hazardous or fatal carbon monoxide levels. Some fuels such as wood, coal and gasoline always produce this gas when they are burned. Others produce it only when the fuel is incompletely burned because of a lack of oxygen needed for combustion. In properly installed and maintained appliances gas burns cleanly producing only a small amount of carbon monoxide. Many of these appliances should be vented to carry gas to the outside where it can disperse.

Examples of appliances and equipment that can produce carbon monoxide are:

Gas, propane or kerosene furnaces and space heaters

Gas water heaters

Fireplaces and woodburning ovens

Gas stoves

Gas dryers

Charcoal grills and gas lanterns

Generators

Lawn mowers, snowblowers, chain saws and other gas-burning equipment

Cars, trucks, motorcycles and mopeds

Even if appliances such as furnaces, water heaters and fireplaces are vented to the outside, if they are installed incorrectly, if the vent or chimney is undersized or blocked by debris, or if they are deteriorating, vent failure can cause the carbon monoxide to spill into the house.

What should you do if you suspect carbon monoxide poisoning?

Carbon monoxide poisoning is a serious situation, yet the symptoms can be difficult to distinguish from many other common maladies.

It is important to consider this as a possibility, especially if symptoms go away when you leave home and then reappear when you return, multiple people in the home or building are experiencing symptoms, and you are using any fuel-burning appliances in your home and they have not been inspected recently.

If you or someone near you experiences symptoms that you think could be caused by carbon monoxide poisoning, GET TO FRESH AIR IMMEDIATELY.

Open windows and doors, turn off fuel-burning appliances if possible, and leave the building.

Call for medical assistance.

Most importantly, DO NOT ignore suspicious symptoms, particularly if more than one person is experiencing them. You could lose consciousness and die if you do nothing.

Prevention is the key to avoiding exposure

There are steps you can take to minimize your risk of carbon monoxide poisoning. Things that you SHOULD do include:

Install a carbon monoxide detector.

Have appliances such as your furnace and fireplace installed by a trained professional and inspected yearly to make sure the vents and chimneys are connected properly, in good condition, and not blocked.

Choose appliances that vent their fumes to the outside whenever possible and have them professionally installed. Perform appropriate maintenance such as cleaning and adjusting stove burners properly and removing lint from gas dryer vents so that airflow is not restricted.

Read and follow all of the instructions that accompany any fuel-burning device.

Use unvented appliances and equipment only in well-ventilated areas.

Be aware of problems that could indicate improper appliance operation such as unfamiliar or burning odors, soot buildup on appliances, furnace running constantly and not keeping the house warm, or a decreasing hot water supply.

If you live in a multi-family dwelling or have an attached garage, be aware that carbon monoxide can enter your home underneath doors and through cracks or floorboards.

Things you SHOULD NOT do include:

Never leave cars or other vehicles running in a garage or other enclosed area, even if you leave the door open.

Never operate a gas or charcoal grill or camp stove inside your home, garage, tent or other enclosed area.

Never use a gas oven or range to heat your home, cabin or camper - even for a short time.

Never use any gasoline-powered engines, generators or space heaters in an enclosed room.

While many causes can be prevented, others can not and may occur unpredictably such as malfunctioning appliances. Being aware of the symptoms and taking these easy precautions could help you avoid a serious threat of carbon monoxide poisoning.

Don't let this silent killer sneak up on you.