Air Pollution

What is air pollution?

Air pollution is made up of many kinds of gases, droplets and particles that reduce the quality of the air. Air can be polluted in both the city and the country.

In the city, cars, buses and airplanes, as well as industry and construction may cause air pollution. In the country, dust from tractors plowing fields, trucks and cars driving on dirt or gravel roads, rock quarries and smoke from wood and crop fires may cause air pollution.

Ground-level ozone is the major part of air pollution in most cities. Ground-level ozone is created when engine and fuel gases already released into the air interact when sunlight hits them. Ozone levels increase in cities when the air is still, the sun is bright and the temperature is warm. Ground-level ozone should not be confused with the "good" ozone that is miles up in the atmosphere and that protects us from the sun's harmful radiation.

What symptoms does air pollution cause?

Air pollution can irritate the eyes, throat and lungs. Burning eyes, cough and chest tightness are common with exposure to high levels of air pollution.

Different people can react very differently to air pollution. Some people may notice chest tightness or cough, while others may not notice any effects. Because exercise requires faster, deeper breathing, it may make the symptoms worse. People who have heart disease, such as angina (chest pain), or lung disease, such as asthma or emphysema, may be very sensitive to air pollution exposure, and may notice symptoms when others do not.

Is air pollution bad for my health?

Fortunately for most healthy people, the symptoms of air pollution exposure usually go away as soon as the air quality improves. However, certain groups of people are more sensitive to the effects of air pollution than others.

Children probably feel the effects of lower levels of pollution than adults. They also experience more illness, such as bronchitis and earaches, in areas of high pollution than in areas with cleaner air.

People with heart or lung disease also react more severely to polluted air. During times of heavy pollution, their condition may worsen to the point that they must limit their activities or even seek additional medical care. In the past, a number of deaths have been associated with severely polluted conditions. Pollution this bad is rare today in the United States.

The health effects of long-term exposure to low levels of air pollution are currently being studied.

Is there a group that keeps track of air pollution?

The Environmental Protection Agency (EPA) checks and reports on air quality in the United States. The EPA, in cooperation with local air-quality boards, measures the level of pollution in the air over many large cities and a number of rural areas. Because of the Agency's efforts, the nation's air quality has greatly improved over the last 20 years.

Newspapers, television and radio stations often give air-quality reports in areas where pollution is a problem. The Air Quality Index (AQI) is a scale of air quality that ranges from 0 to 500 and is used in many weather reports. An AQI score of over 100 indicates unhealthy air conditions.

What can I do to protect my family and myself?

Check the predicted AQI in your area. Be careful if the AQI is greater than 100. Also be careful if there are high-risk weather conditions, such as a hot, sunny day, and if you begin to develop symptoms like chest tightness, burning eyes or a cough.

You can protect yourself and your family from the effects of air pollution by doing the following:

  • Stay indoors as much as you can during days when pollution levels are high. Many pollutants have lower levels indoors than outdoors.
  • If you must go outside, limit outside activity to the early morning hours or wait until after sunset. This is important in high ozone conditions (such as in many large cities) because sunshine increases ozone levels.
  • Don't exercise or exert yourself outdoors when air-quality reports indicate unhealthy conditions. The faster you breathe, the more pollution you take into your lungs.

These steps will generally prevent symptoms in healthy adults and children. However, if you live or work close to a known pollution source, or if you have a chronic heart or lung problem, talk with your doctor about other ways to protect yourself from air pollution.

More Information

For more information talk to your doctor.


Written by editorial staff.

American Academy of Family Physicians

Reviewed/Updated: 04/08
Created: 05/94