Where All That Household Dust Really Comes From—The Truth May Surprise You

Outdoor Particles

People are typically familiar with the main sources of dust inside a home: dead skin cells, pet dander, pet hair, dust mite matter, and dirt from shoes. “What people don’t always focus on are particles from the outdoors that can waft into the home whenever a door or window is opened,” says Mary Gagliardi, in-house scientist and cleaning expert at Clorox.

Pollen is one common type of external dust particle, as is combustion exhaust. This can come from a local manufacturing facility or cars and trucks on a nearby freeway. “These black particulates that settle on windowsills outside the home can also travel by air into the home,” Gagliardi says. 

Soot and ash—particulate matter generated from burning wood—can also accumulate during the winter when people are using their fireplaces. Having your chimney professionally cleaned annually will ensure the flue operates properly, drawing smoke up the chimney instead of billowing into your home. “When your fireplace is not in use, close the damper to stop air from blowing through the chimney into the home,” adds Gagliardi.

Mold

When mold growth occurs, it releases microscopic spores and byproducts into the surrounding area. “These will attach to dust and settle on horizontal surfaces, adding to that visible layer of matter,” explains Michael Rubino, council-certified mold remediator and founder of HomeCleanse. “The longer the colony is present inside, the more particles it will release, increasing the dust inside and polluting the indoor environment.”

Fabric Shedding

Textiles break down over time, and fibers are released into the air every time you sit on a sofa or get into bed. “These tiny fibers settle on surfaces and are a major contributor to the dust that returns quickly after cleaning,” says Petya Holevich, house cleaning expert and supervisor at Fantastic Services, a UK-based company of experts. 

To reduce impact, Holevich recommends washing bedding weekly, vacuuming upholstered furniture once a week, regularly cleaning pillows, throws, and rugs, and washing or steam cleaning curtains every few months. These items shed fibers, so consistent washing removes a major source of airborne dust.

Carpeting

Thanks to the fibrous nature of its material, carpet traps small particles over time, including mold spores, bacteria, pesticides, organic matter, dirt, pollen, and dust. “Even with regular cleaning, dust and other matter build up within the fibers and padding over time,” Rubino says. “Every time this surface is disturbed—by walking or the HVAC system kicking on—some of those particles will become suspended in the air for a short period of time, lowering the indoor air quality in the home.” 

If possible, opt for hard surfaces throughout the home since they’re typically easier to thoroughly clean. “As an alternative, choose rugs or other soft materials,” Rubino advises. “These can be thrown into the washing machine with a botanical laundry additive to get clean, and they are easier to replace.”

Vacuuming is most effective when it’s done with a vacuum cleaner that has a HEPA filter, adds Holevich. “Vacuum the carpets, rugs, and upholstery at least once a week, and don’t skip the areas under the furniture,” she says. “This will stop the dust from becoming airborne when you walk through the room.”

Knick-Knacks

“Knick-knacks are notorious for holding onto dust,” says Dr. Megan McCarty, allergist at Lehigh Valley Health Network. “This includes books, wall hangings, and figurines, and the first step is to declutter—which is easier said than done.” 

What you can't declutter, make sure you clean with a microfiber cloth—not a feather duster—at least once per week. "You want to make sure you are trapping the dust in the cleaning item and not kicking it up into the air where it can stay suspended for days to weeks," explains Dr. McCarty. Lightly dampening the cloth makes dust pickup even more effective and reduces airborne movement.

Dust Mites

When it comes to bedding and furniture, another contributor to increased dust levels in the home is microscopic dust mites. “Avoid upholstered furniture in favor of leather or vinyl,” McCarty advises. “Additionally, invest in allergy-proof casings for your mattresses and pillows, as they help trap the particles inside and keep them out of your nose.” 

To further prevent dust and dust mites, McCarty also recommends the following.

• Limit stuffed animals: Have just one stuffed animal in the bed that takes a vacation in the freezer or hot dryer once per week to reduce levels. 
• Add air filters: Consider adding HEPA air filters in the bedroom to reduce the amount in the air.
• Vacuum frequently: Use a vacuum with double-ply bags. 
• Avoid horizontal blinds: Instead, choose pull-down shades or vertical blinds. 
• Turn off the humidifier: Dust mites need moisture in the air to survive, so while it is tempting to run a humidifier in the winter, this can actually increase the amount of dust in the home.