after exposure or, possibly, years later.
Immediate effects may show up after a single exposure or repeated
exposures. These include irritation of the eyes, nose, and
throat, headaches, dizziness, and fatigue. Such immediate effects
are usually short term and treatable. Sometimes the treatment is
simply eliminating the person s exposure to the source of the
pollution, if it can be identified. Symptoms of some diseases,
including asthma, hypersensitivity pneumonitis, and humidifier
fever, may also show up soon after exposure to some indoor air
pollutants.
The likelihood of immediate reactions to indoor air pollutants
depends on several factors. Age and preexisting medical
conditions are two important influences. In other cases, whether
a person reacts to a pollutant depends on individual sensitivity,
which varies tremendously from person to person. Some people can
become sensitized to biological pollutants after repeated
exposures, and it appears that some people can become sensitized
to chemical pollutants as well.
Certain immediate effects are similar to those from colds or
other viral diseases, so it is often difficult to determine if
the symptoms are a result of exposure to indoor air pollution.
For this reason, it is important to pay attention to the time and
place the symptoms occur. If the symptoms fade or go away when a
person is away from the home and return when the person returns,
an effort should be made to identify indoor air sources that may
be possible causes. Some effects may be made worse by an
inadequate supply of outdoor air or from the heating, cooling, or
humidity conditions prevalent in the home.
Other health effects may show up either years after exposure has
occurred or only after long or repeated periods of exposure.
These effects, which include some respiratory diseases, heart
disease, and cancer, can be severely debilitating or fatal. It is
prudent to try to improve the indoor air quality in your home
even if symptoms are not noticeable. More information on
potential health effects from particular indoor air pollutants is
provided in the section, A Look at Source Specific Controls.
While pollutants commonly found in indoor air are responsible for
many harmful effects, there is considerable uncertainty about
what concentrations or periods of exposure are necessary to
produce specific health problems. People also react very
differently to exposure to indoor air pollutants. Further
research is needed to better understand which health effects
occur after exposure to the average pollutant concentrations
found in homes and which occur from the higher concentrations
that occur for short periods of time.
The health effects associated with some indoor air pollutants are
summarized in the chart in the middle of this booklet titled
Reference Guide to Major Indoor Air Pollutants in the H
