It's Not Just Dust

Home Pollution Image - Masterfile

House dust and dust mites are two hard-to-see pollutants that can trigger allergies and respiratory distress. According to Raymond G. Slavin, M.D., professor of internal medicine and microbiology and past director of the division of allergy and immunology at Saint Louis University School of Medicine, "house dust may not cause an allergy, but it can act as a mechanical irritant." Dust mites, on the other hand, can cause a true allergic response.

"Recently we have been seeing a lot more dust mite sensitivity, and I think there are two reasons for it. One is that people are insulating their homes to prevent the loss of warm air to the outside, so less cold dry outside air is getting into the houses. The inside air is warm and humid, and dust mites need heat and humidity. The second is that Americans, particularly children, are spending too much time indoors."

Clean Up, Sneeze Less

Steam-vapor cleaning—not to be confused with steam cleaning—kills mites, fleas, book lice, silverfish and spiders in carpets, upholstery, curtains, bedding and mattresses without using chemicals, according to Jeffrey May, principal scientist at May Indoor Air Investigations in Tyngsborough, MA.

"Steam-vapor machines emit pure steam, while steam cleaners spray hot water," says May. "Steam cleaners soak the carpet or the upholstery and vacuum up the water, but sometimes everything ends up pretty saturated, and this can lead to microbial growth. The larger steam-vapor machines are basically kettles on wheels, with a wand tool of maybe three inches by eight inches—like the end of a vacuum cleaner. The steam comes out the way it would out of a steam iron, and as you draw the tool across the carpet, the steam instantly kills whatever is crawling around in there. You can also use steam vapor to kill dust mites in upholstery or bedbugs where you sleep. Using a steam-vapor machine instead of chemicals is a great way to be green."

[The Shark Steam Pocket Mop is a smaller version of such a product; the editors tested it and found it to be effective and easy to use. For information, go to]

Jar Candles

Most people are unaware that jar candles emit a concentration of particles and can be very harmful to your respiratory health. As May, author of Jeff May's Healthy Home Tips, points out, "people like jar candles because they flicker and have a fragrance, but there is a real problem. Jar candles emit many, many times more soot than a regular candle."

With a tapered candle, the air rises along the edges of the taper and reaches combustion above, where the flame burns evenly and very hot. "But in order for the flame in a jar candle to burn," says May, "it needs to pull air in and down from the outside. Then the air changes direction inside the jar before it rises, and this causes the candle to flicker. The flickering cools the flame slightly and causes incomplete combustion, which results in soot."

May measured the concentration of carbon soot particles in a room where two jar candles were burning. "There were over ten million particles of soot per cubic foot of air in the room—about fifty times higher than the number of particles in the outdoor air."

One reason that the carbon soot particles are a health hazard is that they are so very tiny. "Recent epidemiological studies have shown that when you have high exposure to particles less than two and a half microns in size—jar candles emit particles smaller than a micron—you have more heart disease and respiratory problems," cautions May. When inhaled, the smallest of these particles can actually penetrate the lungs and go right into the bloodstream. "You might as well have a diesel-car exhaust pipe pointing into the house," he says.

If you don’t believe May, just look at a jar candle after it has been burning for a while. You’ll see the rim is black with carbon soot. And that’s only a small fraction of the particles that have gone into the air.

Coiled & Spoiled

You’d be surprised at the quantity of dust and allergens that can collect in the coils on the bottom or back of a refrigerator. "There is only one tool that will get them clean," says environmental scientist Jeffrey May. "It’s called a thirty-six-inch vacuum crevice tool. It’s an attachment that has an adapter on the end so that it can fit any size vacuum hose. In two minutes you can clean out everything that is stuck on the coils. The same is true for radiators in old apartments. That crevice tool will go right in there and suck out the dust and dirt." The air, he says, seems much fresher when your hidden trove of dust and mites is gone.

Fresh Paint

Most wall paint contains volatile organic chemicals (VOCs), which, we are now told—after years of inhaling the fumes—are very bad for us. According to the Environmental Protection Agency, eye, nose and throat irritation, headaches, loss of coordination, nausea, and damage to the liver, kidneys and central nervous system are all possible side effects. Some organics are suspected of causing or known to cause cancer in humans. What can you do? Look for paint certified as being low or very low in VOCs (sometimes called zero VOCs). Major brands are now getting on board.

Exhaust Fumes

Here’s a surprising source of indoor air pollution: If you have an attached garage, you need to be careful when you warm up the car during the winter months. Opening up the door that connects your garage to your house after starting the car will allow exhaust fumes to enter the house.

"If you have a tight house and leave open a chimney flue or a second-floor bathroom window, that can create suction that will pull those fumes indoors, allowing carbon monoxide to circulate throughout your house," says May. Although the level of carbon monoxide isn’t usually high enough to be acutely dangerous, it’s not a good idea to breathe it in, and it may set off some carbon monoxide detectors. So, to make sure you’re safe, let the car idle outside the garage.

Publication Review By: the Editorial Staff at

Published: 24 Aug 2010

Last Modified: 22 Jan 2015