The pollutants listed in this guide have been shown to cause the health effects mentioned. However, it is not necessarily true that the effects noted occur at the pollutant concentration levels typically found in the home. In many cases, our understanding of the pollutants and their health effects is too limited to determine the levels at which the listed effects could occur.

RADON (Rn)

Sources: Earth and rock beneath home; well water; building materials.

Health Effects: No immediate symptoms. Estimated to contribute to between 7,000 and 30,000 lung cancer deaths each year. Smokers are at higher risk of developing radon-induced lung cancer.

If you or others at your office are experiencing health or comfort problems that you suspect may be caused by indoor air pollution, you can do the following:

• Talk with other workers, your supervisor, and union representatives to see if the problems are being experienced by others and urge that a record of reported health complaints be kept by management, if one has not already been established.
• Talk with your own physician and report your problems to the company physician, nurse, or health and safety officer.
• Call your state or local health department or air pollution control agency to talk over the symptoms and possible causes.

Building a new home provides the opportunity for preventing indoor air problems. However, it can result in exposure to higher levels of indoor air contaminants if careful attention is not given to potential pollution sources and the air exchange rate.

Express your concerns about indoor air quality to your architect or builder and enlist his or her cooperation in taking measures to provide good indoor air quality. Talk both about purchasing building materials and furnishings that are low-emitting and about providing an adequate amount of ventilation.

The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) recommends a ventilation rate of 0.35 ach (air changes per hour) for new homes, and some new homes are built to even tighter specifications. Particular care should be given in such homes to preventing the build-up of indoor air pollutants to high levels.

In recent years, a number of consumers have associated a variety of symptoms with the installation of new carpet. Scientists have not been able to determine whether the chemicals emitted by new carpets are responsible. If you are installing new carpet, you may wish to take the following steps:

• Talk to your carpet retailer. Ask for information on emissions from carpet.
• Ask the retailer to unroll and air out the carpet in a well-ventilated area before installation.
• Ask for low-emitting adhesives if adhesives are needed.
• Consider leaving the premises during and immediately after carpet installation. You may wish to schedule the installation when most family members or office workers are out.
  

Source Control

Usually the most effective way to improve indoor air quality is to eliminate individual sources of pollution or to reduce their emissions. Some sources, like those that contain asbestos, can be sealed or enclosed; others, like gas stoves, can be adjusted to decrease the amount of emissions. In many cases, source control is also a more cost-efficient approach to protecting indoor air quality than increasing ventilation because increasing ventilation can increase energy costs. Specific sources of indoor air pollution in your home are listed later in this section.

The federal government recommends that homes be weatherized in order to reduce the amount of energy needed for heating and cooling. While weatherization is underway, however, steps should also be taken to minimize pollution from sources inside the home. (See "Improving the Air Quality in Your Home" for recommended actions.) In addition, residents should be alert to the emergence of signs of inadequate ventilation, such as stuffy air, moisture condensation on cold surfaces, or mold and mildew growth. Additional weatherization measures should not be undertaken until these problems have been corrected.

The most important things to know about air cleaners are:

• They cannot be used by themselves to clean the air. Pollutants have to be controlled at their source, and indoor air has to be well ventilated.
• Air cleaners have to be well maintained. Dirty air filters, for example, are not going to help you clean the air.
• Buy the right size of unit for the space you want to clean. The airflow should be sufficient to exchange the air in the room five or six times per hour; therefore, the size and efficiency of the filtering device should be determined in part by the size of the room. Do not waste your money buying models that sit on a table or hang around your neck.

• Install room-size units in rooms where you spend most of your time or have the worst symptoms.
• Locate the units as close as possible to any identifiable pollution source.
• Locate the unit away from doors, windows, and foot traffic, but not close to walls, corners, furniture, or other obstructions. This is so that air may easily reach the air cleaner.
• Air cleaners should always be used and maintained according to the manufacturer's instructions.

• Find out what kind of filter may be the best for you.
• Try renting a device and see if any health problems, such as allergies, improve.
• Be skeptical of exaggerated claims.
• Look for the CADR number; a larger CADR (Clean Air Delivery Rate is the amount of clean air measured in cubic feet per minute (cfm) that an air cleaner delivers to a room.) is better.
• Because larger units are noisier than smaller units are, just buy the size of unit you need for the size of room you need to clean.

Some air cleaners (called ozone generators) use an electrical charge to generate ozone in an attempt to clean the air. This has been done for more than 100 years.[7] Although ozone can be used in reducing odors and pollutants in unoccupied spaces (such as removing smoke odors from homes involved in fires), the levels needed to do this are much too dangerous to breathe. The levels of ozone produced by ozone generators sold as air cleaners are too low to clean the air and too high to be healthy. Scientific research has shown that low levels of ozone will not remove indoor air contaminants.[7]