Dust is sort of like cookies. It’s made up of whatever ingredients are in the air or whatever happens to be floating around in the environment. Most household dust is composed of human skin flakes, animal fur, dust mites, decomposing insects, food debris, fibers from clothes, bedding, rugs, and other fabrics, plant fibers, paint particles, bacteria, tracked-in soil, mold spores, pollen, soot, particulate matter from smoking and cooking, and even lead, arsenic, flame retardants, heavy metals, and pesticides. Of course vehicle exhaust, construction sites, home remodeling and the outdoors can produce other types of dust.
Dust mites which feed on human skin flakes and humidity, produce allergens that are known triggers for people suffering from asthma. Allergies, asthma, itchy eyes, coughing and runny noses are typical reactions to dust but many other health effects, including reproductive issues, brain development problems, and cancer as in the well known asbestos cases, can be caused by dust, depending on which contaminants are present. City air pollution has been linked to increases in heart attacks.
It’s enough to make us want to live in a bubble but, as foreboding as it seems, dust may not be as much of a demon in our lives as some believe. Although some particles can be absorbed through the skin, our respiratory tract is equipped to handle much of the dust we breathe in. The respiratory tract is coated with a thin layer of mucous which traps foreign particles. Tiny hairs, called cilia, move back and forth pushing these trapped particles back toward the nostrils or the throat, where they are sneezed or coughed out. Sometimes we clear our throats and swallow these particles which are then digested and passed out of the body.
Dust itself also has a positive side. According to an article in The Globe and Mail a couple of years ago, one study found that human skin flakes in household dust actually neutralized harmful ozone which, when present in the air we breathe, can cause lung damage. Researchers from the American Chemical Society found that dust containing high amounts of squalene, a component in human skin, can reduce up to 15 per cent of ozone in the air.
And, according to results of a study conducted by scientists at the Johns Hopkins Children’s Center and other institutions, babies exposed to household germs, pet and rodent dander and roach allergens during their first year of life appear to have lower risk of developing asthma and allergies. The findings are consistent with the hygiene hypothesis, which holds that children who grow up in too-clean environments may develop hypersensitive immune systems that make them prone to allergies.
So, before you become a slave to daily dusting and vacuuming, consider that perhaps, as in most things, moderation and common sense is the key.