What causes indoor air pollution?

Indoor air pollution comes in 3 basic variations:

• Particulates (35%): Particulates include: pet dander, dust, dust mites, asbestos dust, pesticides, pollen, post-fire ash, spray mist from aerosol products and more.
• Gases (31%): Gases include: tobacco, paints, welding fumes, chemicals, varnishes, correction fluids, paint strippers, household cleaning products and more.
• Germs (34%): Germs, mold, bacteria and viruses breed in consistently moist and / or unclean environments. They’re introduced into your home with water damage or when people enter your home.

There are many sources of indoor air pollution in any home. These include combustion sources such as oil, gas, kerosene, coal, wood, and tobacco products; building materials and furnishings as diverse as deteriorated, asbestos-containing insulation, wet or damp carpet, and cabinetry or furniture made of certain pressed wood products; products for household cleaning and maintenance, personal care, or hobbies; central heating and cooling systems and humidification devices; and outdoor sources such as radon, pesticides, and outdoor air pollution.

Some sources, such as building materials, furnishings, and household products like air fresheners, release pollutants more or less continuously. Other sources, related to activities carried out in the home, release pollutants intermittently. These include smoking, the use of unvented or malfunctioning stoves, furnaces, or space heaters, the use of solvents in cleaning and hobby activities, the use of paint strippers in redecorating activities, and the use of cleaning products and pesticides in housekeeping. High pollutant concentrations can remain in the air for long periods after some of these activities.