Stirring up dust and a health risk

Simply walking around the house and then plopping into a chair kicks up more lung-irritating dust than other everyday activities -- and releases half as many air-polluting particles as smoking a cigarette.

Such particles can aggravate asthma and allergies, so people prone to respiratory problems are advised to be careful while dusting and vacuuming. But researchers have found that ordinary household movement can rival cleaning in generating indoor air pollution.

For instance, dancing on a rug can release the same volume of particles as dusting, while walking on a rug can churn up almost as much as vacuuming.

The measurements come from a newly released study in which Andrea R. Ferro, now an assistant engineering professor at Clarkson University in Potsdam, N.Y., set out to quantify the amount of air pollution created by housecleaning and other activity that stirs up dust that has settled on floors, furniture and other surfaces.

Although scientists have measured particles from direct sources like smoking and cooking, there had been scant attention paid to re-floated dust.

As a doctoral student at Stanford University, she and her colleagues placed particle detectors in the house of an allergy-suffering colleague who had wooden floors and thin area rugs (rather than dust-collecting carpeting) and no cloth-upholstered furnishings except beds and pillows. Over five days, Ferro and a colleague went about daily chores (folding blankets and laundry, cleaning and making beds) and engaged in a little recreation (kicking up their heels on the rug).

Most of the particles detected were bigger than 5 microns, which are considered a lesser health threat than smaller particles. But the researchers detected a substantial amount less than 5 microns, fine enough to lodge deep in the lungs, where they can decrease lung function and exacerbate asthma. The study appears in the March 15 issue of Environmental Science & Technology.