Gas Appliances Can Be a Source of Unhealthy Indoor Air

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Gas Appliances Can Be a Source of Unhealthy Indoor Air

Guest Blogger

Saturday, August 28, 2010

Becky Gillette:

Many parents ban cigarette smoke in their homes to protect their children. They may not realize, however, that some household appliances can emit the same pollutants found in cigarette smoke.

In fact, gas stoves and other fuel-burning appliances, including space heaters, clothes dryers, water heaters and furnaces, can create serious indoor air pollution problems if they aren’t properly installed, maintained and operated.

Most of us recognize the smell of gas when a burner on the stove has not been properly turned off. Gas companies deliberately add an odorant to natural gas to alert people of a gas leak, which can prove fatal if not detected quickly. But when fuels like natural gas, kerosene and gasoline are burned, or combusted, in gas appliances, they can also produce and release harmful byproducts – fumes and particles that aren’t necessarily visible or strong smelling.

Children and fetuses are especially vulnerable to these air pollutants because their small body sizes and underdeveloped organs make them more susceptible to pollution than adults. Children breathe at a faster rate than adults do, which means that they inhale more air and whatever is in it. And children generally spend more time indoors, where pollutants can concentrate to levels higher than outdoors. As a result, children living in homes with gas appliances have higher rates of respiratory infections, such as colds, studies show.

The Elusive Culprits

When used to operate a heater or stove, burning fuels can form two dangerous and invisible gases: carbon monoxide (CO) and nitrogen dioxide (NO2).

Carbon monoxide is easily absorbed into the bloodstream and starves it of oxygen. High levels of this gas can cause death–CO poisoning causes hundreds of deaths every year. Even breathing low levels of this gas is harmful, causing fatigue and chest pain. When levels rise, carbon monoxide can impair vision and coordination, and cause headaches, dizziness, nausea, vomiting, memory loss, and flu-like symptoms. Because carbon monoxide is invisible to all senses, a monitor is required to detect its presence (see How To Reduce Gas Pollution In The Home).

Fuel-burning appliances leak more CO, and consequently cause more CO poisonings, than has previously been recognized, says George Tsongas, Ph.D., a professor emeritus of mechanical engineering at Portland State University in Oregon. Concentrations in the kitchen are often greater than nine parts per million, the maximum exposure limit recommended by the U.S. Environmental Protection Agency (EPA) for an eight-hour period.

"Testing indicates unacceptably high carbon monoxide levels are created with the [oven] door open," Tsongas reports. Gas ovens are used for heating during winter’s chill in about half of the low-income homes in the United States. Even when used for cooking with an exhaust fan running, fumes are still released into the kitchen. Carbon monoxide can also leak from space heaters, furnaces and barbecue grills used indoors.

Nitrogen dioxide, a sharp smelling gas, is a deep lung irritant. It can irritate nose, eyes, throat and lungs, trigger asthma attacks, and can cause headaches, coughing and nausea. Often, however, the effects of nitrogen dioxide exposure are not immediately apparent. Symptoms can appear as long as 72 hours after the gas has been inhaled. Long-term exposures can permanently damage the lungs, causing chronic bronchitis and emphysema.

Soot may contain irritating and even cancer-causing particulates, such as polcyclic aromatic hydrocarbons (PAHs). One PAH, benzo(a)pyrene, is a potent carcinogen.

Particles that are emitted by gas appliances can sink into carpets and cling to dust, remaining in the home and within the reach of children.

Safer Use of Gas Appliances

Properly operating gas appliances produce less pollution, burning cleaner and more efficiently. Problems arise when appliances aren’t adjusted properly or when the pollutants created from burning gas aren’t vented. Venting is a means of channeling the exhaust from gas appliances to outside the home. Regular inspections and cleaning of gas appliances ensure that the units are working at peak efficiency–saving fuel and reducing pollution.

Gas ovens in residential homes are usually not vented. Many homes, however, are equipped with exhaust fans above the stove’s burners. Exhaust fans can pull the pollutants outdoors, and, therefore, should always be used when the stove or oven is in operation. If you do not have an exhaust fan, open your kitchen window while you’re cooking.

"It would be prudent for anyone to make sure gas appliances are working properly," says David W. Cugell, M.D., Bazley professor of pulmonary diseases at the Northwestern University Medical School, Chicago. "One, you save money, and two, you avoid any bad effects that might occur from the release of carbon monoxide or other emissions."

For more information:

image courtesy of stevendepolo / CC BY-SA 2.0

The opinions expressed here are solely those of the author and not necessarily those of
Healthy Child Healthy World.