Prepared by: The Consumer Product Safety Commission (CPSC), and
The American Lung Association, The Christmas Seal People
What are Biological Pollutants?
The Scope of the Problem
Health Effects Of Biological Pollutants
Talking to Your Doctor
Coping with the Problem
Self-Inspection: A Walk Through Your Home
What You Can Do About Biological Pollutants
Maintain and Clean All Appliances that Contact Water
Before You Move
Where Biological Pollutants May be Found in the Home
Correcting Water Damage
Additional Sources of Information
This page will help you understand:
Outdoor air pollution in cities is a major health problem. Much effort and money continues to be spent cleaning up pollution in the outdoor air. But air pollution can be a problem where you least expect it, in the place you may have thought was safest--your home. Many ordinary activities such as cooking, heating, cooling, cleaning, and redecorating can cause the release and spread of indoor pollutants at home. Studies have shown that the air in our homes can be even more polluted than outdoor air.
Many Americans spend up to 90 percent of their time indoors, often at home. Therefore, breathing clean indoor air can have an important impact on health. People who are inside a great deal may be at greater risk of developing health problems, or having problems made worse by indoor air pollutants. These people include infants, young children, the elderly, and those with chronic illnesses.
Biological pollutants are or were living organisms. They promote poor indoor air quality and may be a major cause of days lost from work or school, and of doctor and hospital visits. Some can even damage surfaces inside and outside your house. Biological pollutants can travel through the air and are often invisible.
Some common indoor biological pollutants are:
Some of these substances are in every home. It is impossible to get rid of them all. Even a spotless home may permit the growth of biological pollutants. Two conditions are essential to support biological growth: nutrients and moisture. These conditions can be found in many locations, such as bathrooms, damp or flooded basements, wet appliances (such as humidifiers or air conditioners), and even some carpets and furniture.
Modern materials and construction techniques may reduce the amount of outside air brought into buildings which may result in high moisture levels inside. Using humidifiers, unvented heaters, and air conditioners in our homes has increased the chances of moisture forming on interior surfaces. This encourages the growth of certain biological pollutants.
Most information about sources and health effects of biological pollutants is based on studies of large office buildings and two surveys of homes in northern U.S. and Canada. These surveys show that 30% to 50% of all structures have damp conditions which may encourage the growth and buildup of biological pollutants. This percentage is likely to be higher in warm, moist climates.
Some diseases or illnesses have been linked with biological pollutants in the indoor environment. However, many of them also have causes unrelated to the indoor environment. Therefore, we do not know how many health problems relate only to poor indoor air.
All of us are exposed to biological pollutants. However, the effects on our health depend upon the type and amount of biological pollution and the individual person. Some people do not experience health reactions from certain biological pollutants, while others may experience one or more of the following reactions:
Except for the spread of infections indoors, ALLERGIC REACTIONS may be the most common health problem with indoor air quality in homes. They are often connected with animal dander (mostly from cats and dogs), with house dust mites (microscopic animals living in household dust), and with pollen. Allergic reactions can range from mildly uncomfortable to life-threatening, as in a severe asthma attack. Some common signs and symptoms are:
Health experts are especially concerned about people with asthma. These people have very sensitive airways that can react to various irritants, making breathing difficult. The number of people who have asthma has greatly increased in recent years. The number of people with asthma has gone up by 59 percent since 1970, to a total of 9.6 million people. Asthma in children under 15 years of age has increased 41 percent in the same period, to a total of 2.6 million children. The number of deaths from asthma is up by 68 percent since 1979, to a total of almost 4,400 deaths per year.
INFECTIOUS DISEASES caused by bacteria and viruses, such as flu, measles, chicken pox, and tuberculosis, may be spread indoors. Most infectious diseases pass from person to person through physical contact. Crowded conditions with poor air circulation can promote this spread. Some bacteria and viruses thrive in buildings and circulate through indoor ventilation systems. For example, the bacterium causing Legionnaire's disease, a serious and sometimes lethal infection, and Pontiac Fever, a flu-like illness, have circulated in some large buildings.
Are you concerned about the effects on your health that may be related to biological pollutants in your home? Before you discuss your concerns with your doctor, you should know the answers to the following questions. This information can help the doctor determine whether your health problems may be related to biological pollution.
TOXIC REACTIONS are the least studied and understood health problem caused by some biological air pollutants in the home. Toxins can damage a variety of organs and tissues in the body, including the liver, the central nervous system, the digestive tract, and the immune system.
There is no simple and cheap way to sample the air in your home to determine the level of all biological pollutants. Experts suggest that sampling for biological pollutants is not a useful problem-solving tool. Even if you had your home tested, it is almost impossible to know which biological pollutant(s) cause various symptoms or health problems. The amount of most biological substances required to cause disease is unknown and varies from one person to the next.
Does this make the problem sound hopeless? On the contrary, you can take several simple, practical actions to help remove sources of biological pollutants, to help get rid of pollutants, and to prevent their return.
Begin by touring your household. Follow your nose, and use your eyes. Two major factors help create conditions for biological pollutants to grow: nutrients and constant moisture with poor air circulation.
Before you give away the family pet or move, there are less drastic steps that can be taken to reduce potential problems. Properly cleaning and maintaining your home can help reduce the problem and may avoid interrupting your normal routine. People who have health problems such as asthma, or are allergic, may need to do this and more. Discuss this with your doctor.
Water in your home can come from many sources. Water can enter your home by leaking or by seeping through basement floors. Showers or even cooking can add moisture to the air in your home. The amount of moisture that the air in your home can hold depends on the temperature of the air. As the temperature goes down, the air is able to hold less moisture. This is why, in cold weather, moisture condenses on cold surfaces (for example, drops of water form on the inside of a window). This moisture can encourage biological pollutants to grow.
There are many ways to control moisture in your home:
Controlling dust is very important for people who are allergic to animal dander and mites. You cannot see mites, but you can either remove their favorite breeding grounds or keep these areas dry and clean. Dust mites can thrive in sofas, stuffed chairs, carpets, and bedding. Open shelves, fabric wallpaper, knickknacks, and venetian blinds are also sources of dust mites. Dust mites live deep in the carpet and are not removed by vacuuming. Many doctors suggest that their mite-allergic patients use washable area rugs rather than wall-to-wall carpet.
Protect yourself by inspecting your potential new home. If you identify problems, have the landlord or seller correct them before you move in, or even consider moving elsewhere.
What if damage is already done? Follow these guidelines for correcting water damage:
DISCLAIMER: This document may be reproduced without change, in whole or in part, without permission, except for use as advertising material or product endorsement. Any such reproduction should credit the American Lung Association and the U.S. Consumer Product Safety Commission. The use of all or any part of this document in a deceptive or inaccurate manner or for purposes of endorsing a particular product may be subject to appropriate legal action.
Contact your local American Lung Association for copies of: Indoor Air Pollution Fact Sheets, Air Pollution in Your Home? and other publications on indoor air pollution.
Contact the U.S. Consumer Product Safety Commission, Washington, D.C. 20207, for copies of Humidifier Safety Alert.
To report an unsafe consumer product or product-related health problem, consumers may call the U.S. Consumer Product Safety Commission at 1-800-638-2772. A teletypewriter for the hearing impaired is available at 1-800-638-8270; the Maryland TTY number is 1-800-492-8104.
You may also contact EPA's IAQ INFO Clearinghouse at 1-800-438-4318 (or (703) 356-4020) for more information on indoor air quality and to order publications from the list of IAQ publications.
Created: March 31, 1997, Last Modified:
March 19, 1998