Healthy Home
Indoor
Air Quality
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.
Indoor Air Quality Concerns
In the last several years, a
growing body of scientific evidence has indicated that the air within homes and
other buildings can be more seriously polluted than the outdoor air in even the
largest and most industrialized cities. Other research indicates that people
spend approximately 90 percent of their time indoors. Thus, for many people,
the risks to health may be greater due to exposure to air pollution indoors
than outdoors.
In addition, people who may be exposed to indoor air
pollutants for the longest periods of time are often those most susceptible to
the effects of indoor air pollution. Such groups include the young, the
elderly, and the chronically ill, especially those suffering from respiratory
or cardiovascular disease.
Indoor Air Quality
in Your Home
What
Causes Indoor Air Problems?
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 can also increase concentrations of some
pollutants.
Pollutant Sources
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.
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.
Amount of Ventilation
If too little outdoor air enters a home, pollutants can accumulate to levels that can pose health and comfort problems. Unless they are built with special mechanical means of ventilation, homes that are designed and constructed to minimize the amount of outdoor air that can "leak" into and out of the home may have higher pollutant levels than other homes. However, because some weather conditions can drastically reduce the amount of outdoor air that enters a home, pollutants can build up even in homes that are normally considered "leaky."
Powered by EPA Document # 402-K-93-007, April 1995