As it turns out, indoor dust is made from many different types of particles that include dirt tracked into the home, skin cells, and tiny particles that have been shed from the carpet. Depending upon where you live you may encounter coal dust or tiny dust particles from a desert. We see this often in Arizona. A similar thing happens with Saharan dust from Africa that can reach North America and Europe as it spreads by winds in the atmosphere.
A popular myth is that dust is made almost entirely of human skin. This, according to science writer Luis Villazon of Science Focus, is simply not true. Skin cells are shed, but most of them are washed away in the shower or the bathroom, not dispersed throughout the home.
For the most part, indoor dust is made from outdoor sources, mostly dirt. When you walk into the home, you carry dirt and other small particles on the bottom of your shoes, as well as on your clothes and skin. These particles are then released into the home, becoming common household dust. A large portion of dust will also be made of fibers from carpet that are released into the air and settle into various surfaces.
If you have pets in the home, you will likely have pet dander, which is essentially a form of dust, as well as a common allergen.
Essentially, dust is made of just about anything. There are even findings that dust may contain lingering chemicals, such as DDT (an insecticide that hasn’t been used in decades) and pesticides. If ingested, these chemicals have the potential to create significant health problems for people of all ages.
Of course, dust doesn’t just reside in your home. Dust is a strong contributor to particulate matter, which is microscopic solid particles floating in the air. Particulate matter is a strong contributor to outdoor air pollution, and is made of many different materials, including sulfate, black carbon, ammonia, and mineral dust.