The Safety Net

Indoor Air Quality and Health

Indoor air pollution can have significant harmful effects on health. According to studies by the U.S. Environmental Protection Agency, exposure to indoor air pollutants may be much higher (25 - 100 times higher) than exposure to outdoor levels. Given that most people spend as much as 90% of their time indoors, air quality concerns are an important issue to consider with respect to all indoor environments where people live, work, and enjoy leisure pursuits. Additionally, some consumers may spend more time indoors and may have existing health conditions that make them more susceptible to the harmful effects of indoor air pollutants.

Exposure to indoor air pollutants is believed to have increased due to several factors that include:

• construction of more tightly sealed homes and buildings that minimize the amount of outdoor air ventilation;
• use of organic chemicals in personal care products, household cleaners, and pesticides; and
• use of synthetic building materials and furnishings.

Causes of Indoor Air Problems: Indoor air problems may be caused by a variety of pollution sources and inadequate ventilation. Indoor pollution sources release gases or particles into the air that affect air quality. Inadequate ventilation increases indoor pollutant levels because there is insufficient outdoor air brought inside. If too little outdoor air enters a home or building, pollutants within the air are not diluted or carried outside and can accumulate to levels that pose health problems.

There are a number of factors that impact the extent to which a pollution source may cause health problems. This includes:

• the nature of the pollutant, how much is emitted, and how hazardous the emissions are;
• the age of some pollution sources;
• whether the pollutant is emitted continuously or intermittently;
• the combination of certain pollutants that can amplify effects; and
• each person’s individual circumstances such as age, genetic predispositions, and existing health problems, especially respiratory and cardiovascular conditions.

Sources of Indoor Pollution: There are numerous sources of indoor pollution in any home or building. Indoor pollution sources include the following:

• Asbestos: deteriorating, damaged, or disturbed insulation, fireproofing, acoustical materials, and floor tiles containing asbestos.
• Biological pollutants: mold, mildew, bacteria, pollen, dust mites, pet dander, and cockroaches.
• Carbon monoxide: un-vented kerosene and gas space heathers; leaking chimneys and furnaces; back-drafting from furnaces, gas water heaters, wood stoves, and fireplaces; gas stoves; generators and other gasoline powered equipment; automobile exhaust from attached garages; and tobacco smoke.
• Environmental tobacco smoke: secondhand smoke.
• Formaldehyde: Pressed wood products (hardwood plywood wall paneling, particle board, fiber board) and furniture made with pressed wood products; combustion sources and environmental tobacco smoke; durable press drapes and clothing.
• Household products: paints, paint strippers, and other solvents; wood preservatives; aerosol sprays; cleansers and disinfectants; moth repellents and air fresheners; stored fuels and automotive products; hobby supplies; dry-cleaned clothing.
• Lead: lead-based paint; contaminated soil, dust, and drinking water.
• Nitrogen dioxide: kerosene heaters, un-vented gas stoves and heaters; environmental tobacco smoke.
• Pesticides: insecticides and disinfectants used to kill household pests; products used on lawns and gardens that drift or are tracked inside the house.
• Radon: gas from uranium in the soil or rock beneath a home or building.
• Respirable particles: fireplaces, wood stoves, kerosene heaters; environmental tobacco smoke.

Health Effects: Indoor air pollutants can cause immediate and long-term health effects. Numerous health problems may result from or be worsened by exposure to these hazards. While many of these health problems are respiratory, there are other signs and symptoms. Effects may be short-term and treatable or may be long-term, debilitating, and even fatal. It is often difficult to detect exposure to indoor air pollutants because many of the substances give no warning and produce vague or similar symptoms that are difficult to pinpoint to a specific cause. Further, they can produce symptoms years later when it is even more difficult to identify the source.

• Long-term Effects: Long-term effects may appear years after exposure has occurred or after long or repeated exposures. Long term effects are associated with radon, asbestos, and environmental tobacco smoke and include lung cancer and other respiratory diseases.
• Immediate Effects: These effects appear soon after a single exposure or repeated exposures and can include irritation of the eyes, nose and throat, headaches, dizziness, and fatigue. Often these immediate effects are similar to symptoms of colds and other viral diseases making accurate diagnosis difficult. Biological pollutants can trigger symptoms of some diseases such as asthma, as well as symptoms of hypersensitivity, pneumonitis, and fever soon after exposure. Pollutants such as carbon monoxide can cause flu-like symptoms that clear up after leaving the home, or at very high concentrations may be fatal.

It is important to consider if air quality problems may be impacting the health of consumers. The first step is to consider the potential sources and ensure that appropriate preventative and corrective measures have been taken. Identification, consideration, and planning regarding environmental risk factors in a consumer’s residence, day program, school, or other service locations can help to keep consumers safe and healthy. For information on preventative measures, see this month's article for Service Providers.