How to Protect Yourself Against Indoor Air Pollution

The first step in protecting yourself from air pollution in your home is awareness. You may not even know you have a problem. Once you’ve identified a problem exists, there are actions you can take to improve the air quality in each room of your home.

To protect yourself going forward, you need to understand how outdoor air enters, the signs and symptoms that it’s impacting your health, and how to take the right precautions.

How Does Outdoor Air Enter a Home?

There are three ways that outdoor air enters and leaves a home:

Infiltration. This is when the outdoor air flows into the house through openings, joints and cracks in walls, floors and ceilings, and around windows and doors.
Natural ventilation. Air moves through opened windows and doors. Air movement associated with infiltration and natural ventilation is caused by air-temperature differences between the indoors and outdoors, and by wind.
Mechanical ventilation. There are a number of mechanical ventilation devices, from outdoor-vented fans that intermittently remove air from a single room, such as the bathroom and kitchen, to air-handling systems that use fans and ductwork to continuously remove indoor air and distribute filtered and conditioned outdoor air to strategic points throughout the house.

The rate at which outdoor air replaces indoor air is described as the air-exchange rate. When there is little infiltration, natural ventilation or mechanical ventilation, the air-exchange rate is low and pollutant levels can increase.

More About Ventilation

If too little outdoor air enters a home, pollutants can accumulate to levels that can pose health and comfort problems.

Unless a home is built with a 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.”

Indoor Air Pollution and Health

The air in your home can have adverse effects on your health both in the short term and in the long term.

Immediate effects show up after single or multiple exposures, and can include:

Irritation of the eyes, nose and throat
Headaches
Dizziness
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.

How fast someone reacts to the indoor air pollutants depends on several factors:

Age
Pre-existing medical conditions
Individual sensitivity

Some people can become sensitized to biological and chemical pollutants after repeated exposures.

Some immediate effects are similar to those from colds and 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 that symptoms occur. If the symptoms fade or go away when a person is away from home, for example, an effort should be made to identify indoor air sources that may be possible causes.

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 years after exposure has occurred, or only after long or repeated periods of exposure.

Respiratory diseases
Heart disease
Cancer

These effects 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.

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 over short periods of time.