All of us face a variety of risks to our health as we go about our day-to-day lives. Driving in cars, flying in planes, engaging in recreational activities, and being exposed to environmental pollutants all pose varying degrees of risk. Some risks are simply unavoidable. Some we choose to accept because to do otherwise would restrict our ability to lead our lives the way we want. And some are risks we might decide to avoid if we had the opportunity to make informed choices. Indoor air pollution is one risk that you can do something about.
Scientific evidence indicates the air within buildings can be more seriously polluted than outdoor air in even the largest and most industrialized cities. According to NADCA, “Studies conducted by the U.S. Government Environmental Protection Agency (EPA), the National Institute for Occupational Safety and Health (NIOSH), and others, show indoor pollutant levels may be 10 to 100 times higher than outdoor concentrations”. This is of particular concern because it is estimated people spend upwards of 90% of their time indoors. Recently, comparative risk studies performed by the EPA and its Science Advisory Board (SAB) have consistently ranked indoor air pollution among the top five environmental risks to public health. The American Medical Association (AMA) states 94% of all respiratory ailments are caused by polluted air, and also reported that one-third of our national health bill is for causes directly attributable to indoor air pollution.
Indoor pollution sources that release gases or particles into the air are the primary cause of indoor air quality problems in homes. Inadequate ventilation can increase indoor pollutant levels by not bringing in enough outdoor air to dilute emissions from indoor sources and by not carrying indoor air pollutants out of the home. High temperature and humidity levels also increase concentrations of some pollutants.
Sources of indoor air pollutants include combustion materials such as oil, gas, kerosene, coal, wood, and tobacco products; building materials and furnishings as diverse as deteriorated or 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 pesticides, and general outdoor air pollution.
The relative importance of any single source depends on how much of a given pollutant it emits and how hazardous those emissions are. In some cases, factors such as how old the source is and whether it is properly maintained are significant. For example, an improperly adjusted gas stove can emit significantly more carbon monoxide than one that is properly adjusted.
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 are concluded.