It's the season for a blazing fire, for goodies baking in the oven and bubbling on the stove top, for a crackling fire in the
wood stove, and for the space heater and the furnace roaring around the clock.
It's also the season for carbon monoxide poisoning.
The Consumer Product Safety Commission (CPSC) attributes 200 deaths to carbon monoxide poisoning from home combustion appliances -- those very ones named above -- in the U.ited States every year. Hundreds more people suffer from milder cases of poisoning from fumes given off by their improperly functioning fuel-burning appliances.
What are the symptoms of low levels of carbon monoxide (CO) exposure? According to the American Lung Association, at moderate levels, carbon monoxide can cause headaches, dizziness, nausea, fatigue, hearing loss, heart palpitations, loss of appetite and vomiting. Older people, pregnant women, infants and people with a history of heart disease are particularly sensitive to CO. At high levels, CO causes asphyxiation and death.
Carbon monoxide is odorless, but its associated gases may have a telltale sour, stale smell. If you suspect you are being subjected to CO poisoning, get fresh air immediately. Call your doctor and tell him or her you suspect CO poisoning. A blood test can verify your suspicions.
Many homes in the United States use fuel-burning, or combustion, appliances. These appliances include oil- and gas-fired water heaters and furnaces, gas clothes dryers and gas stoves, wood- and coal-burning stoves and kerosene heaters. They fall into two categories: vented and unvented.
Vented appliances are those that have chimneys or flues through which the emissions -- fumes -- escape to the outside. Furnaces fall into this category, as do wood stoves, water heaters and gas clothes dryers. Gas cooking stoves supposedly fall into this category, too, but they are vented only if you remember to flick on the hood fan every single time you turn on the gas.
Unvented appliances are fuel-burning appliances that don't have chimney or flue, whose fumes simply become part of the air around you. A space heater that burns kerosene is an example of an unvented appliance.
Unvented appliances vent their fumes right into the room they are heating. If you are shopping around for ways to heat a room in your house, look for alternatives to fuel-burning space heaters.
If you do use an unvented heater, always run the heater exactly as the owner's manual recommends. The wick height is particularly important. Keep a window open in the room you are heating to make sure the flames are getting enough oxygen to burn properly. CPSC recommends that you keep doors open to the rest of the house from the room you are heating as well. And never leave it on overnight or in a room where you are sleeping.
Vented appliances, properly installed and maintained, should not emit harmful fumes into your home. But they can have problems. Here are the biggies:
* Improper installation. Vented fuel-burning appliances must get adequate fresh air. Too little air, and your furnace can produce dangerous amounts of carbon monoxide. Too little air, and these dangerous fumes can "backdraft" -- blow down your chimney into your basement or living space.
* Cracks or gaps in your chimney or duct work. Fumes will readily escape through any openings.
* Clogged chimney or flue, causing the furnace to vent into the house. According to the CPSC, this can be a problem, under certain circumstances, if you have converted from oil to gas without cleaning your chimney or lining it with metal. Burning oil produces soot, which deposits inside your chimney. Emissions from a high-efficiency gas furnace are cooler and more moist. They can wet the soot, causing it to fall in and clog your chimney. If you are converting to natural gas from oil, make sure you take care of this problem in advance. Call the local energy hot-line for advice. If you have already converted to gas from oil without cleaning or lining a masonry flue, have your chimney inspected by a reputable firm right away.
* Insufficient maintenance. Have your furnace serviced every year, preferably in the late summer, before the big rush. If you are a do-it-yourselfer, learn how to check the system, look into the clean-out cap and vacuum or replace the filter.
What clues will you have if something has gone awry? Dorothy Bracken, spokeswoman for Washington Natural Gas in Seattle, says warm, moist air escaping from the front of your furnace is a good reason to call a service person right away. Natural gas gives off a warn ing stench, so you'll know if you have a gas leak. Again, call the gas company immediately.
The symptoms of chronic, low-level exposure to these combustion pollutants are similar to flu symptoms and they can be hard to diagnose. Keeping track of whether you feel better after being away from the house for some time is one helpful diagnostic method. For other suggestions, write the Consumer Product Safety Commission, Washington, D.C. 20207, and ask for a copy of its free booklet, "What You Should Know About Combustion Appliances." And call your local branch of the American Lung Association to ask for fact sheet No. 1182, "Combustion Pollutants."