There are many substances that cause indoor air pollution. They include gases from heating equipment, fibers from carpets and fabric, dust, and allergens carried inside a building on hair, clothing, or shoes. Even cleaning products can add odorous pollutants to the air people breathe. In addition to such substances, indoor environments are often polluted with biological contaminants, such as mold spores and airborne viruses.
One of the main categories of indoor air pollutants consists of particles that find their way into the air. Among these particles is pollen brought in from outdoors, often on shoes, on the skin, and in the hair. Other types of particles that may contaminate an indoor air environment are dust, dirt, and fibers that come from rugs and upholstered furniture. Fibers from insulation and pet dander contribute to indoor air pollution as well.
Gases and odors make up another category of indoor air pollution. Gases can be released into the indoor environment through ordinary tasks like cleaning with aerosol sprays and liquid cleaning products. Painting, varnishing, and using air fresheners expel gases and noxious fumes as well. Even stoves and heaters can cause chemical vapors to pollute the air. Pesticides, perfume products, and cigarette and cigar smoke contribute to indoor air pollution as well.
Some types of indoor air pollutants fit in the biological-contaminant category. This pollutant category includes mold spores, yeast, fungi, and numerous types of bacteria and viruses. Even dust mites are among the most common types of biological contaminants that are found indoors. Typically, biological contaminants are found in places that are both warm and humid. For example, dust mites like to take up residence in people’s beds, as they are typically both moist and warm, especially when people are sleeping in them.
Many indoor air pollutants cause health problems. For example, some contribute to asthma and other types of breathing problems. An asthmatic individual who sleeps in a bed with a high population of dust mites, for instance, may experience more asthma attacks. Additionally, both particle and biological contaminants often contribute to headaches and allergy symptoms, including itchy eyes, coughing, and sneezing.
Besides asthma and allergy symptoms, indoor air pollutants can cause such issues as fatigue and nausea; this is particularly true of gases. Some pollutants even contribute to the development of upper respiratory infections. Tobacco smoke pollution can contribute to the development of lung cancer.