Bacteria by-products in household dust can trigger asthma, scientists report.

The by-products are called endotoxins. Adults living in homes with high endotoxin levels were more likely to have asthma, write Peter Thorne, PhD, and colleagues. Thorne works at the University of Iowa’s Environmental Health Sciences Research Center.

Thorne’s team did a national dust test from homes across the U.S. The results are enough to make you want to swab the decks and rev up the vacuum cleaner.

The study appears in the American Journal of Respiratory and Critical Care Medicine.

How to Create a Dust-Free Bedroom

Asthma-Dust Connection

The researchers vacuumed more than 2,500 dust samples from more than 800 homes nationwide. They found endotoxins in dust from all over the house -- bedrooms, family rooms, kitchens, and bedding.

Dust in the bedroom was the biggest asthma trigger. Endotoxins from dust on bedroom floors and in bedding were most strongly linked to adult asthma, the study shows.

Endotoxins in dust affected adults without allergies and those with allergies, the researchers note.

Dust in ‘Clean’ Rooms

Dust mites are another well-known asthma trigger found in dust. That’s all the more reason to try to cut down on dust.

Dust can crop up in rooms that look tidy. You don’t have to have big “dust bunnies” under the bed. Dust can be much finer, sifting and settling on surfaces and furniture around the home.

Dust-Busting Tips

The American College of Allergy, Asthma & Immunology offers these tips to reduce dust:

Vacuum frequently. Use a vacuum that doesn’t raise a dust cloud as it cleans. Clean surfaces often with a damp or oiled cloth.

Wash all bedding (including pillows without the cases) in hot water every week to 10 days.

Consider removing carpets. Hard surfaces may be easier to clean. If carpeting is necessary, low-pile carpets or washable rugs may be better choices than shag carpeting.

Get special casings made of plastic or rubberized fabric that zip around mattresses, box springs, and pillows.

Place a filter made of cheesecloth in the bedroom’s heating vent to help prevent dust from circulating into the bedroom’s air. Change the cheesecloth filter frequently.

Get rid of stuffed animals or use washable ones.

Hang clothes in a closet and keep the door shut.

Use air conditioning during warm months to keep inside humidity low. That can slow the growth of dust and molds. Change or clean filters for air conditioners and furnaces often.

By Miranda Hitti, Reviewed by Brunilda Nazario, MD

SOURCES: Thorne, P. American Journal of Respiratory and Critical Care Medicine, Sept. 1, 2005; advance online edition. News release, National Institute of Environmental Health Sciences. American College of Allergy, Asthma & Immunology.