Water damage, high humidity regions, and humid areas of homes, like bathrooms and basements; most common molds are Aspergillus, Stachybotrys, and Penicillium; Aspergillus is a primary food for dust mites.
Bioaerosols (Biocontaminants such as airborne bacteria, viruses, etc.)
Humans, pets, moist surfaces, humidifiers, ventilation systems, drip pans, cooling coils in air handling units (can cause Legionnaires' disease and "humidifier fever")
Combustion By-products (PAH, CO, CO2, NOx)
Unvented kerosene and gas heaters, gas appliances, fireplaces, chimneys and furnaces, tobacco smoke, automobile exhaust from attached garages
Tobacco Smoke (including second-hand smoke)
Cigarettes, cigars, pipes can release mixtures of over 4,000 compounds
Pressed wood products (hardwood, plywood, fiberboard, etc.), urea-formaldehyde foam insulation, mattresses, clothing, nail polish, permanent press textiles, glue and adhesives, stoves, fireplaces, automobile exhaust
Pressure-treated wood products used for decks and playground equipment are often treated with arsenic-containing pesticides
Other Volatile Organic Compounds (VOCs)
Paints, solvents, wood preservatives, aerosol sprays, cleaners and disinfectants, copy machines/printers/faxes, carpets, moth repellents, air fresheners, dry cleaned clothes, hobby supplies
Vinyl flooring, food packaging, shower curtains, wall coverings, adhesives, detergents, personal care products, toys, PVC pipe
Pest control poisons, garden and lawn chemicals
Deteriorating or damaged insulation, fireproofing, or acoustical materials
Heavy Metals (lead, mercury, cadmium, chromium, etc.)
Paints, cars, tobacco smoke, soil and dust; huge industrial pollutants
Radon (a radioactive gas that comes from uranium)
Building materials such as granite, well water, soil, outside air, smoke detectors, certain clocks and watches; radon is second leading cause of lung cancer in the U.S.
What Can We Do to Reduce Indoor Air Pollution?
"The answer is CLEAR!"
Carbon monoxide is another harmful indoor gas that is formed form the burning of fossil fuels through heating and cooking and from cars running in garages. Carbon monoxide interferes with the blood's ability to carry oxygen, thus making this gas fatal if exposed to high doses. Nitrogen oxide is another gas that is a respiratory irritant and this is produced in the homes the same way as carbon monoxide by the burning of fossil fuels.
The potential hazard in using PVC is the by-product it produces which is organochlorine. This by-product begins with the production of chlorine gas. Flexible vinyl products are found in many homes like roof tiles and vinyl wall coverings. The potential dangers are that it releases phthalates and it also promotes harmful mold growth. Because it is impermeable to moisture, toxic mold may grow beneath the vinyl causing severe health issues.
Not all mold growth comes from flexible vinyl. Mold falls under the category of microbiologicals. This also includes bacteria, mildew, viruses, animal dander, dust mites, and pollen from both indoor and outdoor plants. Moisture and humidity make for a nice setting for these microbiologicals room to thrive. These biologicals cause diseases and infections, exacerbate asthma, allergic reactions, and irritate eyes and respiratory tract.
Lead was used in paint because it covered surfaces well and wore well. As of 1978, lead was removed from paint, but any home or building built prior to 1978 may still have lead paint. Lead paint dust can be breathed in and it impairs the central nervous system. Lead particles inhaled by children can interfere with their cognitive ability.
Then there are respirable particles that enter our homes principally through the combustion of stoves, fireplaces, hot water heaters, and boilers. Cleaning stirs up these particles. Car exhaust and particles from power plants also enter indoors. These fine particles increase the incidence of asthma attacks, respiratory irritation and can lead to heart problems.
Besides the general health impacts outlined above, there are specific diseases that have been directly correlated to indoor air pollution. One such disease is Legionnaires' disease, which first broke out in 1976 and killed 39 American Legion members at a convention. Legionnaires' disease is a pneumonia caused by breathing in Legionella bacteria. This bacterium can come from contaminated water in ventilation systems, or any other moisture-producing system.
Another specific disease is hypersensitivity pneumonitis, which is a rare lung disease caused by bacteria and mold resulting from air conditioning and humidifying systems. The symptoms of this disease are very similar to viral and bacterial pneumonia. Still another specific disease is humidifier fever with symptoms such as fever, aches, and fatigue. It may be caused by toxic byproducts of bacteria.
Then there are two well-known syndromes associated with indoor air pollution and they are "sick building syndrome" and "multiple chemical sensitivity." Sick building syndrome symptoms are fatigue, lack of concentration, nausea, and respiratory irritation, dry or itchy skin and sensitivity to odors. Multiple chemical sensitivity is more controversial. Most medical associations don't believe it exist at all, but theorists speculate that since it occurs more in women than men, it could be a dysfunction in the immunological or neurological systems brought on by being expose to chemical spills, or low-dose exposures to chemicals from soaps, cosmetics, or newspaper inks. The symptoms are headaches, fatigue, asthma, depression, rashes and muscles and joint pain.