Carbon monoxide is released by the burning of carbon-based fuels such as wood, coal, natural gas, gasoline, kerosene and oil. Heating devices that burn these substances use oxygen and give off carbon monoxide, Barber said.
"Something that does not burn completely is the most dangerous, such as charcoal briquettes," he said. "They smolder. CO is produced in large amounts when there is incomplete combustion. When it's cold, some people who are worried about their heating bill will bring a little grill into the house and burn some briquettes. This is so dangerous. Never use briquettes indoors."
Carbon monoxide is odorless, tasteless and colorless, and can only be detected by a carbon monoxide detector, something Barber recommends all homes have.
The detectors are accurate, Barber said, and do not have to be wired or hooked up, just plugged into an outlet.
Forty to 50 parts per million of carbon monoxide, the level found in most homes, is safe, according to the EPA and federal government, Barber said. Eight hundred PPM is toxic.
"A lot (of CO poisoning victims) come in with a headache of unknown origin, and doctors pick it up that way," Barber said. But some cases go undetected until it's too late.
CO poisoning is insidious.
"Lower levels of CO affect the body." Barber said.
CO replaces oxygen in the blood, and this displacement can occur at many levels, he said.
"Someone who smokes two packs of cigarettes a day may have a CO level that is close to toxic," Barber said. "With long-term exposure, such as a leaky stove in the house or a poor muffler in a car, the body adjusts by making more blood so that more oxygen can be carried. This results in higher blood pressure and other health problems."
In an acute case of CO poisoning, such as when a heating system backs up, a person might experience a frontal headache, then a throbbing headache, nausea, confusion and shakiness caused by the lack of oxygen. But, Barber said, the flu and other conditions also cause those symptoms, so a series of tests is done to narrow the cause.
A patient with acute CO poisoning is given large volumes of oxygen until the CO level in the blood drops, he said.
CO poisoning that happens quickly has a profound effect, but it can be turned around.
"If there is brain damage, it can take awhile to recover," said Barber, who has worked in the respiratory field since 1973. He has been at Chambersburg Hospital since March 2005.
Barber said carbon monoxide problems can be caused when a bird's or squirrel's nest blocks a chimney, causing a backup of CO into the house. A stovepipe or flue could otherwise be obstructed. Heating equipment that is not properly maintained is dangerous, as are space heaters if they are in an unvented area, he said.
A car is a very rich source of CO, he added.
"Lack of maintenance to the engine, undercarriage or muffler may cause CO to be gathered in your car, especially in the winter when the windows are kept closed," Barber said.
Starting a car in a garage attached to the house and leaving it running for several minutes to warm up is a mistake, Barber added.
"Even with the garage door open, there is a sizable risk of increasing the CO in the house. A baby sleeping upstairs is the recipient of that," he said.
Barber is especially concerned about children and pets riding in the back of pickup trucks with caps on the back.
"There is no good seal between the bed of the truck and the cap," he said, and anyone in the back is exposed to carbon monoxide.
He cited a case he saw when working in West Virginia. Parents driving home from a Christmas celebration allowed their three children to ride in the back of the pickup. When they arrived home, all three children were dead.