Where Does Dust Come From? Here’s the Dirt

Ever wonder where does dust come from in an empty house or a closed room? If dust is made out of dead skin and insects, how can it form so fast when there is almost nothing to build on? Despite your best effort of cleaning it, why is there still be dust gathering at every corner? Don't' fret as all of your questions shall be answered below. If you are hyperallergic to dust, knowing the sources of dust can make big differences in your neverending struggle. So read on to know the root cause plus tips on how to reduce dust in your home sweet home.
Short answer
60% of household dust comes from outdoors.


You And Your Pets

Indoor dust comprises a lot of skin flakes, fur, and hair. Pets shed on a daily basis and the tiny flecks of pet dander that can be very sticky to carpet and upholstery. Like an animal, we humans shed skin every day too. Dead skin will be replaced every 4-5 weeks and left scattered on our pillow, mattress, sofa, and floor. Not only that, we ourselves do shed a good amount of hair dandruff, eyelashes, eyebrows, and fingernail chips. It will eventually break down into smaller particles that can be easily airborne when disturbed. The flakes of dust will then travel around the house, settled down and slowly snowball into dust bunnies.

Soil, Pollen, Mold And Particulate Matter

60% of indoor dust comes from outside and mostly made up of the above components. Outdoor dust pollutants will travel inside via the wind or from our shoes, clothes, and hair before settling down. Soil, pollen are fine particles that are especially prevalent during the spring season. Mold spores are allergens that will travel through soil, decaying plants, and airborne in a high humidity environment. Outdoor pollutants AKA black dust are the combustion of fossil fuels by industrial plants and vehicles. Common sources include PM2.5, CO, SO2, NOx, and hydrocarbons.

Furnishing Fibers/ Lints

Carpets, rugs, furniture, bedding, upholstery will release fibers as they slowly wear down. As for the bathroom, towel dust is the main culprit that easily breaks off fibers with constant wiping. Fibers that get loose will become airborne and eventually stick to the wall, bathroom tiles, cabinet, floor to becomes part of the dust group. That’s why the bedroom is always the dustiest due to the high number of fibers shed from the bedding. If you have a stuffy nose when you go to bed, dust may be the problem.

Heating And Cooling Air Systems

The number one route for outdoor dust especially on the older one with cracks and leaks air duct. A furnace or HVAC system requires routine check-ups to maintain its efficiency. If you have no idea how to perform extensive cleaning, there are plenty of HVAC or air vent specialist to be hired.

Dust Mites And Insect

The more dust you have, the more dust mites you will find. When you talk about indoor dust, dust mites and insects are always in the picture. The dead body parts and fecal matter will form into a clump of dust and aggravate allergic reactions. Mites, silverfish, fleas, cockroaches thrive on warm and humid conditions and feed on dead skin cells. A home is a perfect environment for the microscopic pest to breed and prosper. You will find dust mites hiding mostly in your bedding, mattress, sofa, and carpets.

Household Stuffs

Dust happens because there are just too many places for the contaminants to settle down. Our home is filled with things that we need, we want, and we have no use of. For example, fan (oscillating, box, or ceiling) attracts a fair bit of dust and helps distribute it around. Lighting, windows ridge, top cabinets all collect specks of dust that are out of sight. Electronic devices like TV, computers all will have dust accumulating all the back of the sensors and circulate board. Even food crumbs create quite a bit of debris and food source for pests.

How To Stop Indoor Dust From Causing A Scene

There are 2 ways of reducing incoming dust: prevention and filtration. If you notice some places are dustier than others, it’s good to acknowledge that and find out what is causing it. Below are a couple of ways you can tackle the high dust accumulation in a home.

  • Make sure all air ducts are in excellent condition – Air ducts seal may be damaged or worn out over the years. A hole in an air duct may suck in dust from crawlspace, attic, between walls or basement and blow the dirty air to other parts of your home. Hire a heating specialist to repair any damaged air duct.
  • Clean thoroughly starting from top to bottom – That way we can vacuum out the dust that has fallen to the ground. Focus on hard to reach places like ceiling fan, lighting, top shelf, back of the electronic, bottom of a cabinet. For furniture and floors, go with a HEPA vacuum cleaner that can capture microscopic particles that normal vacuum couldn’t. For places that are hard to reach, use a damp rag or cloth and wipe out all the settled dust. Finish it up by mopping the floor. No matter which method you go for, avoid using feather dust as it pushes settled dust from one place to another. Wear a mask if you are hyperallergic to dust.
  • Place an air purifier on the dustiest roomAir purifier can prevent airborne dust from settling down and forming into a bigger clump of dust. You will need to leave the dust air purifier on 24×7 though as dust will continuously flow by. By pulling the air in, the pre-filter and HEPA filter will trap all dust contaminants into its filtration leaving only purified air out.
  • Get a dehumidifier/ humidifierKeep home humidity level between 30-50%. This will discourage the growth of dust mites, insects, and other allergens. Parasite’s carcass and droppings are what most indoor dust is made of.
  • Regularly clean or replace the air filter – Basically, anything that uses filter must be clean to avoid the spreading of dust across the home. This includes HVAC, air purifier, and dehumidifier.
  • Keep yourself and your pet clean – This includes cats, dogs or any exotic animals you have. Any home occupants that travel back from outside will bring in dust, germs, skin flakes, pet dander, and so forth. While there is no need for curfew, we want to keep out as many dust as we can. So always change your clothes, shower yourself after an outing. Same goes with your pet, groom and bathe them to reduce the amount of pet dander in the air.
  • Replace Venetian blinds – Notorious for collecting dust and difficult to clean. This is due to the horizontal alignment and high placement. Switch to roller shades or curtains that are much easier to clean.
  • Do not wear outside shoes inside – Your shoes might have been in touch with mud, dirt, and germs on the road. You can also reduce dust tracked into the house by using doormats.
  • Keep everything inside – Cluttered objects like toys, clothes will attract dust when it is left in the open. Store it in drawers, plastics bin, or storage box instead.
  • Don’t smoke indoor – Not even with an ashtray or an air purifier. The toxin emitted from tobacco smoke is very harmful to our body and will leave a trail of tiny dust ashes. If you do have to smoke, smoke outside and make sure the wind does not blow back in the smoke particles.
  • Change bedding regularly– It will indirectly reduce the number of dust in your home. This includes fiber, dust mites, silverfish, skin flakes, and pet dander if you have a pet at home. We would wash the bedsheet every 3-4 weeks but you could do it every week if you choose to.
  • Groom your pets daily – Cat or dogs are notorious for their contribution in shedding pet dander and germs. If possible, leave your pet outside as they would bring it a good amount of dust particles indoor.

Dust may not be as harmless as one would assume. Most people would associate dust as an annoying sight that causes allergy reactions and deteriorate air quality. Many people forgot that dust is also the ideal breeding ground for insects and allergens. Exposing to high concentration level household dust can be a health concern for you and your family. According to c&en, 10 compounds of chemicals are found in 90-100% of U.S. dust samples. Phthalate BBP and flame retardants TDCIPP, TCIPP, TCEP are top carcinogen substances capable of causing cancer in living tissue. These chemicals can get into our body through inhalation or ingestion.

Where Does Dust Come From?

Most people associate dust with dirt, sand, dead skin, and dead insects. It is more than that. Dust is the composition of all the finest, smallest particles roaming on the face of the earth. As there is constant moving airflow, outside dust often travels in through air conditioners, ducts, vents, windows, and doors. Tiny particles can also sneak in through tiny gaps from ceiling, wall, crawlspace, and floor. Holes and electrical outlets, switches, and windows ridges are another way of attracting dust. The location and weather also play a big factor in the share of dust flowing in. For example, industrial areas will be plague with particulate matter pollutants. Close to nature, dry and windy weather will pull in more pollen white dust than an urban area. Another pathway of dust getting inside is through us especially those that wear outdoor shoes indoors. If your pets are free to travel in and out of the house, they are too part of the dust transporter. Sources of outdoor dust include dirt, sand, insects, plants (pollen), feces, and pollution. For indoor, typical sources include skin flakes, hair cells, dust mites, carcasses, droppings, food wastes, fibers/ lint from worn down clothing and furniture.

In short, most indoor dust comes from outdoors. Let's break down some of the most common sources of indoor dust.

Max Fernandez

A loving father and a dedicated reviewer for airfuji.com with more than 1000 air purifiers under his belt. Max Fernandez is also one of the million patients currently suffering from asthma. Feel free to nudge him if you have any questions.