PREVENTIVE STEPS AGAINST CARBON MONOXIDE THREAT

Minus the clues of color, odor or form, carbon monoxide is a health risk with stealthy characteristics.

At higher concentrations, it can overcome people before a problem is identified. Lower dose symptoms are often like those linked with food poisoning or flu.

Despite carbon monoxide's seemingly secretive ways, the poisonous gas most often can be readily avoided if simple precautions are used.

Carbon monoxide is a gas given off by sources that create heat through combustion, such as automobiles, furnaces, kerosene heaters and charcoal grills, explained Randy Maley, an environmental specialist with the state Department of Health.

"Any source of incomplete combustion gives off carbon monoxide," explained Maley, who works in the Bureau of Environmental Epidemiology. "You can't see it, smell it, taste it, but it's there and you need to be aware of it."

Health officials say this time of year is the most dangerous for carbon monoxide build-up due to the increased use of home and car heaters and because the flow of fresh air is minimized by closed and sealed windows.

According to Maley, carbon monoxide is harmful to the body because it binds with hemoglobin at least 200 times more readily than oxygen. Consequently, an elevated level of carbon monoxide (CO) in air takes the place of oxygen in the blood.

At least 600 deaths in the United States are blamed each year on unintentional carbon monoxide poisoning.

Simple precaution can make the difference, experts say.

"The key is to have ventilation and air exchange," said David Roth of Mead Environmental Associates. "You don't want to have anything going in your home on a continuous basis that is burning either gas or something like that which would be emitting a product such as carbon monoxide or carbon dioxide without having efficient air exchange."

Homeowners can start with proper installation of units such as hot water heaters, ranges, furnaces and ductwork.

"If the unit (gas appliance) is installed, operated and maintained per the manufacturer's instructions it should be safe, reliable and economical," said Ralph Maxton, gas district engineer with Union Electric. The same maxim could be applied to units powered by fuel oil or propane.

Maxton gave this rule of thumb: "If the flame on a hot water heater, gas furnace or stove is a nice, clear, blue flame, then the carbon monoxide is at a minimum."

Whether a unit is operating at peak performance involves many factors. That's why an annual maintenance check by qualified personnel is a sound practice, said Bill Borgfield, owner of A-1 Service Inc.

Danger can arise from such hard-to-find deficiencies as cracked heat exchangers to easier-to-spot clogged chimneys. Cracked or rusted flues and improper ventilation are other areas homeowners often overlook.

Borgfield, in business for some 27 years, gives this advice: "Make sure the flues are clean, make sure the vent from the furnace to the flue is in good repair and sloping upward and make sure the water heater vents are in good repair."

While autumn is a good time to get into the habit of having units checked, Maxton advised, "anytime during the heating season, if you suspect your furnace is not operating correctly, call a qualified person."

Safety measures that should be taken extend beyond the home's heating unit and even beyond interior walls of the home. "Don't limit yourself just to a furnace," Maley stressed.

Automobiles, for instance, should be operated with care. "Don't leave a car idling in the garage," Maley said. The fumes might make their way into the home. Care should be taken to make sure the exhaust systems are functioning correctly.

Carbon monoxide detectors, which work like smoke alarms, are tools that state health officials suggest people consider installing in their homes. Maley said, however, that such detectors may not protect the most sensitive people from long-term, low-level exposure.

Infants, unborn babies, the elderly, smokers and people with heart disease are particularly susceptible to carbon monoxide exposure, officials say.

"The first symptoms of carbon monoxide poisoning include headache, lightheadedness, dizziness and unexplained sleepiness," Maley said. Other symptoms may include an inability to concentrate, memory loss and loss of vision or muscular coordination.

With high concentration of carbon monoxide, however, the signs may not appear or they may occur so rapidly that there is no time to react, he said.

The Missouri Department of Health compiled this list of carbon monoxide related dos and don'ts.

* Make sure furnace and ductwork are properly installed and maintained.

* Annual checks of furnaces are recommended.

* Do not leave a vehicle idling in a garage, even with the door open, as wind may direct the exhaust into the home.

* If operating a kerosene or other portable heater in the home, first make sure there is adequate ventilation.

* Do not use charcoal grills indoors.

* Make sure the exhaust systems in vehicles are functioning properly. If trapped in a car for an extended time because of inclement weather, make sure the car's tailpipe is free of snow, and only run the engine and heater when necessary and only for short periods.

* Consider purchasing a carbon monoxide detector.