Information provided in this booklet is based on current scientific and technical understanding of the issues presented and is reflective of the jurisdictional boundaries established by the statutes governing the co-authoring agencies. Following the advice given will not necessarily provide complete protection in all situations or against all health hazards that may be caused by indoor air pollution.
Indoor Air Quality Concerns
All of us face a variety of risks to our health as we go about our day-to-day lives. Driving in cars, flying in planes, engaging in recreational activities, and being exposed to environmental pollutants all pose varying degrees of risk. Some risks are simply unavoidable. Some we choose to accept because to do otherwise would restrict our ability to lead our lives the way we want. And some are risks we might decide to avoid if we had the opportunity to make informed choices. Indoor air pollution is one risk that you can do something about.
In the last several years, a growing body of scientific evidence has indicated that the air within homes and other buildings can be more seriously polluted than the outdoor air in even the largest and most industrialized cities. Other research indicates that people spend approximately 90 percent of their time indoors. Thus, for many people, the risks to health may be greater due to exposure to air pollution indoors than outdoors.
In addition, people who may be exposed to indoor air pollutants for the longest periods of time are often those most susceptible to the effects of indoor air pollution. Such groups include the young, the elderly, and the chronically ill, especially those suffering from respiratory or cardiovascular disease.
Why a Booklet on Indoor Air?
While pollutant levels from individual sources may not pose a significant health risk by themselves, most homes have more than one source that contributes to indoor air pollution. There can be a serious risk from the cumulative effects of these sources. Fortunately, there are steps that most people can take both to reduce the risk from existing sources and to prevent new problems from occurring. This booklet was prepared by the U.S. Environmental Protection Agency (EPA) and the U.S. Consumer Product Safety Commission (CPSC) to help you decide whether to take actions that can reduce the level of indoor air pollution in your own home.
Because so many Americans spend a lot of time in offices with mechanical heating, cooling, and ventilation systems, there is also a short section on the causes of poor air quality in offices and what you can do if you suspect that your office may have a problem. A glossary and a list of organizations where you can get additional information are available in this document.
INDOOR AIR QUALITY IN YOUR HOME
What Causes Indoor Air Problems?
Indoor pollution sources that release gases or particles into the air are the primary cause of indoor air quality problems in homes. Inadequate ventilation can increase indoor pollutant levels by not bringing in enough outdoor air to dilute emissions from indoor sources and by not carrying indoor air pollutants out of the home. High temperature and humidity levels can also increase concentrations of some pollutants.
There are many sources of indoor air pollution in any home. These include combustion sources such as oil, gas, kerosene, coal, wood, and tobacco products; building materials and furnishings as diverse as deteriorated, asbestos-containing insulation, wet or damp carpet, and cabinetry or furniture made of certain pressed wood products; products for household cleaning and maintenance, personal care, or hobbies; central heating and cooling systems and humidification devices; and outdoor sources such as radon, pesticides, and outdoor air pollution.
The relative importance of any single source depends on how much of a given pollutant it emits and how hazardous those emissions are. In some cases, factors such as how old the source is and whether it is properly maintained are significant. For example, an improperly adjusted gas stove can emit significantly more carbon monoxide than one that is properly adjusted.
Some sources, such as building materials, furnishings, and household products like air fresheners, release pollutants more or less continuously. Other sources, related to activities carried out in the home, release pollutants intermittently. These include smoking, the use of unvented or malfunctioning stoves, furnaces, or space heaters, the use of solvents in cleaning and hobby activities, the use of paint strippers in redecorating activities, and the use of cleaning products and pesticides in housekeeping. High pollutant concentrations can remain in the air for long periods after some of these activities.
Amount of Ventilation
If too little outdoor air enters a home, pollutants can accumulate to levels that can pose health and comfort problems. Unless they are built with 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.”
How Does Outdoor Air Enter a House?
Outdoor air enters and leaves a house by: infiltration, natural ventilation, and mechanical ventilation. In a process known as infiltration, outdoor air flows into the house through openings, joints, and cracks in walls, floors, and ceilings, and around windows and doors. In natural ventilation, air moves through opened windows and doors. Air movement associated with infiltration and natural ventilation is caused by air temperature differences between indoors and outdoors and by wind. Finally, there are a number of mechanical ventilation devices, from outdoor-vented fans that intermittently remove air from a single room, such as bathrooms and kitchen, to air handling systems that use fans and duct work 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.
What If You Live in an Apartment?
Apartments can have the same indoor air problems as single-family homes because many of the pollution sources, such as the interior building materials, furnishings, and household products, are similar. Indoor air problems similar to those in offices are caused by such sources as contaminated ventilation systems, improperly placed outdoor air intakes, or maintenance activities.
Solutions to air quality problems in apartments, as in homes and offices, involve such actions as: eliminating or controlling the sources of pollution, increasing ventilation, and installing air cleaning devices. Often a resident can take the appropriate action to improve the indoor air quality by removing a source, altering an activity, unblocking an air supply vent, or opening a window to temporarily increase the ventilation; in other cases, however, only the building owner or manager is in a position to remedy the problem. (See the section “What to Do If You Suspect a Problem”) You can encourage building management to follow guidance in EPA and NIOSH’s “Building Air Quality: A Guide for Building Owners and Facility Managers“. To obtain the looseleaf-format version of the Building Air Quality, complete with appendices, an index, and a full set of useful forms, and the newly released, Building Air Quality Action Plan, order GPO Stock # 055-000-00602-4, for $28, contact the: Superintendent of Documents, U.S. Government Printing Office (GPO), P.O. Box 371954, Pittsburgh, PA 15250-7954, or call (202) 512-1800, fax (202) 512-2250.
IMPROVING THE AIR QUALITY IN YOUR HOME
Indoor Air and Your Health
Health effects from indoor air pollutants may be experienced soon 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 pre-existing 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 section “Reference Guide to Major Indoor Air Pollutants in the Home.”
Identifying Air Quality Problems
Some health effects can be useful indicators of an indoor air quality problem, especially if they appear after a person moves to a new residence, remodels or refurnishes a home, or treats a home with pesticides. If you think that you have symptoms that may be related to your home environment, discuss them with your doctor or your local health department to see if they could be caused by indoor air pollution. You may also want to consult a board-certified allergist or an occupational medicine specialist for answers to your questions.
Another way to judge whether your home has or could develop indoor air problems is to identify potential sources of indoor air pollution. Although the presence of such sources does not necessarily mean that you have an indoor air quality problem, being aware of the type and number of potential sources is an important step toward assessing the air quality in your home.
A third way to decide whether your home may have poor indoor air quality is to look at your lifestyle and activities. Human activities can be significant sources of indoor air pollution. Finally, look for signs of problems with the ventilation in your home. Signs that can indicate your home may not have enough ventilation include moisture condensation on windows or walls, smelly or stuffy air, dirty central heating and air cooling equipment, and areas where books, shoes, or other items become moldy. To detect odors in your home, step outside for a few minutes, and then upon reentering your home, note whether odors are noticeable.
Measuring Pollutant Levels
The federal government recommends that you measure the level of radon in your home. Without measurements there is no way to tell whether radon is present because it is a colorless, odorless, radioactive gas. Inexpensive devices are available for measuring radon. EPA provides guidance as to risks associated with different levels of exposure and when the public should consider corrective action. There are specific mitigation techniques that have proven effective in reducing levels of radon in the home. (See “Radon” for additional information about testing and controlling radon in homes.)
For pollutants other than radon, measurements are most appropriate when there are either health symptoms or signs of poor ventilation and specific sources or pollutants have been identified as possible causes of indoor air quality problems. Testing for many pollutants can be expensive. Before monitoring your home for pollutants besides radon, consult your state or local health department or professionals who have experience in solving indoor air quality problems in non-industrial buildings.
Weatherizing Your Home
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.
Weatherization generally does not cause indoor air problems by adding new pollutants to the air. (There are a few exceptions, such as caulking, that can sometimes emit pollutants.) However, measures such as installing storm windows, weather stripping, caulking, and blown-in wall insulation can reduce the amount of outdoor air infiltrating into a home. Consequently, after weatherization, concentrations of indoor air pollutants from sources inside the home can increase.
Three Basic Strategies
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.
Another approach to lowering the concentrations of indoor air pollutants in your home is to increase the amount of outdoor air coming indoors. Most home heating and cooling systems, including forced air heating systems, do not mechanically bring fresh air into the house. Opening windows and doors, operating window or attic fans, when the weather permits, or running a window air conditioner with the vent control open increases the outdoor ventilation rate. Local bathroom or kitchen fans that exhaust outdoors remove contaminants directly from the room where the fan is located and also increase the outdoor air ventilation rate.
It is particularly important to take as many of these steps as possible while you are involved in short-term activities that can generate high levels of pollutants–for example, painting, paint stripping, heating with kerosene heaters, cooking, or engaging in maintenance and hobby activities such as welding, soldering, or sanding. You might also choose to do some of these activities outdoors, if you can and if weather permits.
Advanced designs of new homes are starting to feature mechanical systems that bring outdoor air into the home. Some of these designs include energy-efficient heat recovery ventilators (also known as air-to-air heat exchangers). For more information about air-to-air heat exchangers, contact the Conservation and Renewable Energy Inquiry and Referral Service (CAREIRS), PO Box 3048, Merrifield, VA 22116; (800) 523-2929.
There are many types and sizes of air cleaners on the market, ranging from relatively inexpensive table-top models to sophisticated and expensive whole-house systems. Some air cleaners are highly effective at particle removal, while others, including most table-top models, are much less so. Air cleaners are generally not designed to remove gaseous pollutants.
The effectiveness of an air cleaner depends on how well it collects pollutants from indoor air (expressed as a percentage efficiency rate) and how much air it draws through the cleaning or filtering element (expressed in cubic feet per minute). A very efficient collector with a low air-circulation rate will not be effective, nor will a cleaner with a high air-circulation rate but a less efficient collector. The long-term performance of any air cleaner depends on maintaining it according to the manufacturer’s directions.
Another important factor in determining the effectiveness of an air cleaner is the strength of the pollutant source. Table-top air cleaners, in particular, may not remove satisfactory amounts of pollutants from strong nearby sources. People with a sensitivity to particular sources may find that air cleaners are helpful only in conjunction with concerted efforts to remove the source.
Over the past few years, there has been some publicity suggesting that house plants have been shown to reduce levels of some chemicals in laboratory experiments. There is currently no evidence, however, that a reasonable number of houseplants remove significant quantities of pollutants in homes and offices. Indoor houseplants should not be over-watered because overly damp soil may promote the growth of microorganisms which can affect allergic individuals.
At present, EPA does not recommend using air cleaners to reduce levels of radon and its decay products. The effectiveness of these devices is uncertain because they only partially remove the radon decay products and do not diminish the amount of radon entering the home. EPA plans to do additional research on whether air cleaners are, or could become, a reliable means of reducing the health risk from radon. EPA’s booklet, “Residential Air-Cleaning Devices“, provides further information on air-cleaning devices to reduce indoor air pollutants.
For most indoor air quality problems in the home, source control is the most effective solution. This section takes a source-by-source look at the most common indoor air pollutants, their potential health effects, and ways to reduce levels in the home. (For a summary of the points made in this section, see the section entitled “Reference Guide to Major Indoor Air Pollutants in the Home.”) EPA has recently released, “Ozone Generators That Are Sold As Air Cleaners”. The purpose of this document (which is only available via this web site) is to provide accurate information regarding the use of ozone-generating devices in indoor occupied spaces. This information is based on the most credible scientific evidence currently available.
EPA has recently published, “Should You Have the Air Ducts in Your Home Cleaned?” EPA-402-K-97-002, October 1997. This document is intended to help consumers answer this often confusing question. The document explains what air duct cleaning is, provides guidance to help consumers decide whether to have the service performed in their home, and provides helpful information for choosing a duct cleaner, determining if duct cleaning was done properly, and how to prevent contamination of air ducts.
A LOOK AT SOURCE-SPECIFIC CONTROLS
The most common source of indoor radon is uranium in the soil or rock on which homes are built. As uranium naturally breaks down, it releases radon gas which is a colorless, odorless, radioactive gas. Radon gas enters homes through dirt floors, cracks in concrete walls and floors, floor drains, and sumps. When radon becomes trapped in buildings and concentrations build up indoors, exposure to radon becomes a concern.
Any home may have a radon problem. This means new and old homes, well-sealed and drafty homes, and homes with or without basements.
Sometimes radon enters the home through well water. In a small number of homes, the building materials can give off radon, too. However, building materials rarely cause radon problems by themselves.
Health Effects of Radon
The predominant health effect associated with exposure to elevated levels of radon is lung cancer. Research suggests that swallowing water with high radon levels may pose risks, too, although these are believed to be much lower than those from breathing air containing radon. Major health organizations (like the Centers for Disease Control and Prevention, the American Lung Association (ALA), and the American Medical Association) agree with estimates that radon causes thousands of preventable lung cancer deaths each year. EPA estimates that radon causes about 14,000 deaths per year in the United States–however, this number could range from 7,000 to 30,000 deaths per year. If you smoke and your home has high radon levels, your risk of lung cancer is especially high.
Reducing Exposure to Radon in Homes:
Measure levels of radon in your home.
Refer to the EPA guidelines on how to test and interpret your test results.
Learn about radon reduction methods.
Stop smoking and discourage smoking in your home.
Treat radon-contaminated well water.
ENVIRONMENTAL TOBACCO SMOKE (ETS)
Environmental tobacco smoke (ETS) is the mixture of smoke that comes from the burning end of a cigarette, pipe, or cigar, and smoke exhaled by the smoker. It is a complex mixture of over 4,000 compounds, more than 40 of which are known to cause cancer in humans or animals and many of which are strong irritants. ETS is often referred to as “secondhand smoke” and exposure to ETS is often called “passive smoking.”
Health Effects of Environmental Tobacco Smoke
In 1992, EPA completed a major assessment of the respiratory health risks of ETS (Respiratory Health Effects of Passive Smoking: Lung Cancer and Other Disorders EPA/600/6-90/006F). The report concludes that exposure to ETS is responsible for approximately 3,000 lung cancer deaths each year in non-smoking adults and impairs the respiratory health of hundreds of thousands of children.
Infants and young children whose parents smoke in their presence are at increased risk of lower respiratory tract infections (pneumonia and bronchitis) and are more likely to have symptoms of respiratory irritation like cough, excess phlegm, and wheeze. EPA estimates that passive smoking annually causes between 150,000 and 300,000 lower respiratory tract infections in infants and children under 18 months of age, resulting in between 7,500 and 15,000 hospitalizations each year. These children may also have a build-up of fluid in the middle ear, which can lead to ear infections. Older children who have been exposed to secondhand smoke may have slightly reduced lung function.
Asthmatic children are especially at risk. EPA estimates that exposure to secondhand smoke increases the number of episodes and severity of symptoms in hundreds of thousands of asthmatic children, and may cause thousands of non-asthmatic children to develop the disease each year. EPA estimates that between 200,000 and 1,000,000 asthmatic children have their condition made worse by exposure to secondhand smoke each year. Exposure to secondhand smoke causes eye, nose, and throat irritation. It may affect the cardiovascular system and some studies have linked exposure to secondhand smoke with the onset of chest pain. For publications about ETS, go to the IAQ Publications page, or contact EPA’s Indoor Air Quality Information Clearinghouse (IAQ INFO), 800-438-4318 or (703) 356-4020.
Reducing Exposure to Environmental Tobacco Smoke
Don't smoke at home or permit others to do so. Ask smokers to smoke outdoors.
If smoking indoors cannot be avoided, increase ventilation in the area where smoking takes place.
Do not smoke if children are present, particularly infants and toddlers.
Biological contaminants include bacteria, molds, mildew, viruses, animal dander and cat saliva, house dust mites, cockroaches, and pollen. There are many sources of these pollutants. Pollens originate from plants; viruses are transmitted by people and animals; bacteria are carried by people, animals, and soil and plant debris; and household pets are sources of saliva and animal dander. The protein in urine from rats and mice is a potent allergen. When it dries, it can become airborne. Contaminated central air handling systems can become breeding grounds for mold, mildew, and other sources of biological contaminants and can then distribute these contaminants through the home.
By controlling the relative humidity level in a home, the growth of some sources of biologicals can be minimized. A relative humidity of 30-50 percent is generally recommended for homes. Standing water, water-damaged materials, or wet surfaces also serve as a breeding ground for molds, mildews, bacteria, and insects. House dust mites, the source of one of the most powerful biological allergens, grow in damp, warm environments.
Health Effects From Biological Contaminants
Some biological contaminants trigger allergic reactions, including hypersensitivity pneumonitis, allergic rhinitis, and some types of asthma. Infectious illnesses, such as influenza, measles, and chicken pox are transmitted through the air. Molds and mildews release disease-causing toxins. Symptoms of health problems caused by biological pollutants include sneezing, watery eyes, coughing, shortness of breath, dizziness, lethargy, fever, and digestive problems.
Allergic reactions occur only after repeated exposure to a specific biological allergen. However, that reaction may occur immediately upon re-exposure or after multiple exposures over time. As a result, people who have noticed only mild allergic reactions, or no reactions at all, may suddenly find themselves very sensitive to particular allergens.
Some diseases, like humidifier fever, are associated with exposure to toxins from microorganisms that can grow in large building ventilation systems. However, these diseases can also be traced to microorganisms that grow in home heating and cooling systems and humidifiers. Children, elderly people, and people with breathing problems, allergies, and lung diseases are particularly susceptible to disease-causing biological agents in the indoor air.
Reducing Exposure to Biological Contaminants
Install and use exhaust fans that are vented to the outdoors in kitchens and bathrooms and vent clothes dryers outdoors.
Ventilate the attic and crawl spaces to prevent moisture build-up.
If using cool mist or ultrasonic humidifiers, clean appliances according to manufacturer's instructions and refill with fresh water daily.
Thoroughly clean and dry water-damaged carpets and building materials (within 24 hours if possible) or consider removal and replacement.
Keep the house clean. House dust mites, pollens, animal dander, and other allergy-causing agents can be reduced, although not eliminated, through regular cleaning.
Take steps to minimize biological pollutants in basements.
To learn more about biological pollutants, read Biological Pollutants in Your Home issued by the U.S. Consumer Product Safety Commission and the American Lung Association. For contact information, see the section, “Where to Go For Additional Information.”
STOVES, HEATERS, FIREPLACES, AND CHIMNEYS
In addition to environmental tobacco smoke, other sources of combustion products are unvented kerosene and gas space heaters, wood stoves, fireplaces, and gas stoves. The major pollutants released are carbon monoxide, nitrogen dioxide, and particles. Unvented kerosene heaters may also generate acid aerosols.
Combustion gases and particles also come from chimneys and flues that are improperly installed or maintained and cracked furnace heat exchangers. Pollutants from fireplaces and wood stoves with no dedicated outdoor air supply can be “back-drafted” from the chimney into the living space, particularly in weatherized homes.
Health Effects of Combustion Products
Carbon monoxide (CO) is a colorless, odorless gas that interferes with the delivery of oxygen throughout the body. At high concentrations it can cause unconsciousness and death. Lower concentrations can cause a range of symptoms from headaches, dizziness, weakness, nausea, confusion, and disorientation, to fatigue in healthy people and episodes of increased chest pain in people with chronic heart disease. The symptoms of carbon monoxide poisoning are sometimes confused with the flu or food poisoning. Fetuses, infants, elderly people, and people with anemia or with a history of heart or respiratory disease can be especially sensitive to carbon monoxide exposures.
Nitrogen dioxide (NO2) is a colorless, odorless gas that irritates the mucous membranes in the eye, nose, and throat and causes shortness of breath after exposure to high concentrations. There is evidence that high concentrations or continued exposure to low levels of nitrogen dioxide increases the risk of respiratory infection; there is also evidence from animal studies that repeated exposures to elevated nitrogen dioxide levels may lead, or contribute, to the development of lung disease such as emphysema. People at particular risk from exposure to nitrogen dioxide include children and individuals with asthma and other respiratory diseases.
Particles, released when fuels are incompletely burned, can lodge in the lungs and irritate or damage lung tissue. A number of pollutants, including radon and benzo(a)pyrene, both of which can cause cancer, attach to small particles that are inhaled and then carried deep into the lung.
Reducing Exposure to Combustion Products in Homes
Take special precautions when operating fuel-burning unvented space heaters.
Install and use exhaust fans over gas cooking stoves and ranges and keep the burners properly adjusted.
Keep wood stove emissions to a minimum. Choose properly sized new stoves that are certified as meeting EPA emission standards.
Have central air handling systems, including furnaces, flues, and chimneys, inspected annually and promptly repair cracks or damaged parts.
Read the booklet What You Should Know About Combustion Appliances and Indoor Air Pollution to learn more about combustion pollutants.
Organic chemicals are widely used as ingredients in household products. Paints, varnishes, and wax all contain organic solvents, as do many cleaning, disinfecting, cosmetic, degreasing, and hobby products. Fuels are made up of organic chemicals. All of these products can release organic compounds while you are using them, and, to some degree, when they are stored.
EPA’s Total Exposure Assessment Methodology (TEAM) studies found levels of about a dozen common organic pollutants to be 2 to 5 times higher inside homes than outside, regardless of whether the homes were located in rural or highly industrial areas. Additional TEAM studies indicate that while people are using products containing organic chemicals, they can expose themselves and others to very high pollutant levels, and elevated concentrations can persist in the air long after the activity is completed.
Health Effects of Household Chemicals
The ability of organic chemicals to cause health effects varies greatly, from those that are highly toxic, to those with no known health effect. As with other pollutants, the extent and nature of the health effect will depend on many factors including level of exposure and length of time exposed. Eye and respiratory tract irritation, headaches, dizziness, visual disorders, and memory impairment are among the immediate symptoms that some people have experienced soon after exposure to some organics. At present, not much is known about what health effects occur from the levels of organics usually found in homes. Many organic compounds are known to cause cancer in animals; some are suspected of causing, or are known to cause, cancer in humans.
Reducing Exposure to Household Chemicals
Follow label instructions carefully.
Throw away partially full containers of old or unneeded chemicals safely.
Buy limited quantities.
Keep exposure to emissions from products containing methylene chloride to a minimum.
Keep exposure to benzene to a minimum.
Keep exposure to perchloroethylene emissions from newly dry-cleaned materials to a minimum.
Formaldehyde is an important chemical used widely by industry to manufacture building materials and numerous household products. It is also a by-product of combustion and certain other natural processes. Thus, it may be present in substantial concentrations both indoors and outdoors.
Sources of formaldehyde in the home include building materials, smoking, household products, and the use of unvented, fuel-burning appliances, like gas stoves or kerosene space heaters. Formaldehyde, by itself or in combination with other chemicals, serves a number of purposes in manufactured products. For example, it is used to add permanent-press qualities to clothing and draperies, as a component of glues and adhesives, and as a preservative in some paints and coating products.
In homes, the most significant sources of formaldehyde are likely to be pressed wood products made using adhesives that contain urea-formaldehyde (UF) resins. Pressed wood products made for indoor use include: particleboard (used as sub-flooring and shelving and in cabinetry and furniture); hardwood plywood paneling (used for decorative wall covering and used in cabinets and furniture); and medium density fiberboard (used for drawer fronts, cabinets, and furniture tops). Medium density fiberboard contains a higher resin-to-wood ratio than any other UF pressed wood product and is generally recognized as being the highest formaldehyde-emitting pressed wood product.
Other pressed wood products, such as softwood plywood and flake or oriented strand board, are produced for exterior construction use and contain the dark, or red/black-colored phenol-formaldehyde (PF) resin. Although formaldehyde is present in both types of resins, pressed woods that contain PF resin generally emit formaldehyde at considerably lower rates than those containing UF resin.
Since 1985, the Department of Housing and Urban Development (HUD) has permitted only the use of plywood and particleboard that conform to specified formaldehyde emission limits in the construction of prefabricated and mobile homes. In the past, some of these homes had elevated levels of formaldehyde because of the large amount of high-emitting pressed wood products used in their construction and because of their relatively small interior space.
The rate at which products like pressed wood or textiles release formaldehyde can change. Formaldehyde emissions will generally decrease as products age. When the products are new, high indoor temperatures or humidity can cause increased release of formaldehyde from these products.
During the 1970s, many homeowners had urea-formaldehyde foam insulation (UFFI) installed in the wall cavities of their homes as an energy conservation measure. However, many of these homes were found to have relatively high indoor concentrations of formaldehyde soon after the UFFI installation. Few homes are now being insulated with this product. Studies show that formaldehyde emissions from UFFI decline with time; therefore, homes in which UFFI was installed many years ago are unlikely to have high levels of formaldehyde now.
Health Effects of Formaldehyde
Formaldehyde, a colorless, pungent-smelling gas, can cause watery eyes, burning sensations in the eyes and throat, nausea, and difficulty in breathing in some humans exposed at elevated levels (above 0.1 parts per million). High concentrations may trigger attacks in people with asthma. There is evidence that some people can develop a sensitivity to formaldehyde. It has also been shown to cause cancer in animals and may cause cancer in humans.
Reducing Exposure to Formaldehyde in Homes
Ask about the formaldehyde content of pressed wood products, including building materials, cabinetry, and furniture before you purchase them.
According to a recent survey, 75 percent of U.S. households used at least one pesticide product indoors during the past year. Products used most often are insecticides and disinfectants. Another study suggests that 80 percent of most people’s exposure to pesticides occurs indoors and that measurable levels of up to a dozen pesticides have been found in the air inside homes. The amount of pesticides found in homes appears to be greater than can be explained by recent pesticide use in those households; other possible sources include contaminated soil or dust that floats or is tracked in from outside, stored pesticide containers, and household surfaces that collect and then release the pesticides. Pesticides used in and around the home include products to control insects (insecticides), termites (termiticides), rodents (rodenticides), fungi (fungicides), and microbes (disinfectants). They are sold as sprays, liquids, sticks, powders, crystals, balls, and foggers.
In 1990, the American Association of Poison Control Centers reported that some 79,000 children were involved in common household pesticide poisonings or exposures. In households with children under five years old, almost one-half stored at least one pesticide product within reach of children.
EPA registers pesticides for use and requires manufacturers to put information on the label about when and how to use the pesticide. It is important to remember that the “-cide” in pesticides means “to kill.” These products can be dangerous if not used properly.
In addition to the active ingredient, pesticides are also made up of ingredients that are used to carry the active agent. These carrier agents are called “inerts” in pesticides because they are not toxic to the targeted pest; nevertheless, some inerts are capable of causing health problems.
Health Effects From Pesticides
Both the active and inert ingredients in pesticides can be organic compounds; therefore, both could add to the levels of airborne organics inside homes. Both types of ingredients can cause the effects discussed in this document under “Household Products,” however, as with other household products, there is insufficient understanding at present about what pesticide concentrations are necessary to produce these effects.
Exposure to high levels of cyclodiene pesticides, commonly associated with misapplication, has produced various symptoms, including headaches, dizziness, muscle twitching, weakness, tingling sensations, and nausea. In addition, EPA is concerned that cyclodienes might cause long-term damage to the liver and the central nervous system, as well as an increased risk of cancer.
There is no further sale or commercial use permitted for the following cyclodiene or related pesticides: chlordane, aldrin, dieldrin, and heptachlor. The only exception is the use of heptachlor by utility companies to control fire ants in underground cable boxes.
Reducing Exposure to Pesticides in Homes
Read the label and follow the directions. It is illegal to use any pesticide in any manner inconsistent with the directions on its label.
Ventilate the area well after pesticide use.
Use non-chemical methods of pest control when possible.
If you decide to use a pest control company, choose one carefully.
Dispose of unwanted pesticides safely.
Keep exposure to moth repellents to a minimum.
Call the National Pesticide Telecommunications Network (NPTN).
Asbestos is a mineral fiber that has been used commonly in a variety of building construction materials for insulation and as a fire-retardant. EPA and CPSC have banned several asbestos products. Manufacturers have also voluntarily limited uses of asbestos. Today, asbestos is most commonly found in older homes, in pipe and furnace insulation materials, asbestos shingles, mill board, textured paints and other coating materials, and floor tiles.
Elevated concentrations of airborne asbestos can occur after asbestos-containing materials are disturbed by cutting, sanding or other remodeling activities. Improper attempts to remove these materials can release asbestos fibers into the air in homes, increasing asbestos levels and endangering people living in those homes.
Health Effects of Asbestos
he most dangerous asbestos fibers are too small to be visible. After they are inhaled, they can remain and accumulate in the lungs. Asbestos can cause lung cancer, mesothelioma (a cancer of the chest and abdominal linings), and asbestosis (irreversible lung scarring that can be fatal). Symptoms of these diseases do not show up until many years after exposure began. Most people with asbestos-related diseases were exposed to elevated concentrations on the job; some developed disease from exposure to clothing and equipment brought home from job sites.
Reducing Exposure to Asbestos in Homes
Learn how asbestos problems are created in homes.
If you think your home may have asbestos, don't panic!
Do not cut, rip, or sand asbestos-containing materials.
When you need to remove or clean up asbestos, use a professionally trained contractor.
Lead has long been recognized as a harmful environmental pollutant. In late 1991, the Secretary of the Department of Health and Human Services called lead the “number one environmental threat to the health of children in the United States.” There are many ways in which humans are exposed to lead: through air, drinking water, food, contaminated soil, deteriorating paint, and dust. Airborne lead enters the body when an individual breathes or swallows lead particles or dust once it has settled. Before it was known how harmful lead could be, it was used in paint, gasoline, water pipes, and many other products.
Old lead-based paint is the most significant source of lead exposure in the U.S. today. Harmful exposures to lead can be created when lead-based paint is improperly removed from surfaces by dry scraping, sanding, or open-flame burning. High concentrations of airborne lead particles in homes can also result from lead dust from outdoor sources, including contaminated soil tracked inside, and use of lead in certain indoor activities such as soldering and stained-glass making.
Health Effects of Exposure to Lead
Lead affects practically all systems within the body. At high levels it can cause convulsions, coma, and even death. Lower levels of lead can adversely affect the brain, central nervous system, blood cells, and kidneys.
The effects of lead exposure on fetuses and young children can be severe. They include delays in physical and mental development, lower IQ levels, shortened attention spans, and increased behavioral problems. Fetuses , infants, and children are more vulnerable to lead exposure than adults since lead is more easily absorbed into growing bodies, and the tissues of small children are more sensitive to the damaging effects of lead. Children may have higher exposures since they are more likely to get lead dust on their hands and then put their fingers or other lead-contaminated objects into their mouths.
Get your child tested for lead exposure. To find out where to do this, call your doctor or local health clinic. For more information on health effects, get a copy of the Centers for Disease Control’s, Preventing Lead Poisoning in Young Children (October 1991).
Ways to Reduce Exposure to Lead
Keep areas where children play as dust-free and clean as possible.
Reduce the risk from lead-based paint.
Leave lead-based paint undisturbed if it is in good condition - do not sand or burn off paint that may contain lead.
Do not remove lead paint yourself.
Do not bring lead dust into the home.
Find out about lead in drinking water.
You can get a brochure, Lead Poisoning and Your Children, and more information by calling the National Lead Information Center, 800-LEAD-FYI.
WHAT ABOUT CARPET?
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.
Be sure the retailer requires the installer to follow the Carpet and Rug Institute’s installation guidelines.
Open doors and windows. Increasing the amount of fresh air in the home will reduce exposure to most chemicals released from carpet. During and after installation, use window fans, room air conditioners, or other mechanical ventilation equipment you may have installed in your house, to exhaust fumes to the outdoors. Keep them running for 48 to 72 hours after the new carpet is installed.
Contact your carpet retailer if objectionable odors persist.
Follow the manufacturer’s instructions for proper carpet maintenance.
WHEN BUILDING A NEW HOME
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.
Here are a few important actions that can make a difference:
Use radon-resistant construction techniques.
Obtain a copy of the EPA booklet, Model Standards and Techniques for Control of Radon in New Residential Buildings, from your state radon office or health agency, your state homebuilders’ association, or your EPA regional office. [You can also visit EPA’s Radon Resistant New Construction (RRNC) site on the WWW.]
Choose building materials and furnishings that will keep indoor air pollution to a minimum.
There are many actions a homeowner can take to select products that will prevent indoor air problems from occurring – a couple of them are mentioned here. First, use exterior-grade pressed wood products made with phenol-formaldehyde resin in floors, cabinetry, and wall surfaces. Or, as an alternative, consider using solid wood products. Secondly, if you plan to install wall-to-wall carpet on concrete in contact with the ground, especially concrete in basements, make sure that an effective moisture barrier is installed prior to installing the carpet. Do not permanently adhere carpet to concrete with adhesives so that the carpet can be removed if it becomes wet.
Provide proper drainage and seal foundations in new construction.
Air that enters the home through the foundation can contain more moisture than is generated from all occupant activities.
Become familiar with mechanical ventilation systems and consider installing one.
Advanced designs of new homes are starting to feature mechanical systems that bring outdoor air into the home. Some of these designs include energy-efficient heat recovery ventilators (also known as air-to-air heat exchangers).
Ensure that combustion appliances, including furnaces, fireplaces, wood stoves, and heaters, are properly vented and receive enough supply air.
Combustion gases, including carbon monoxide, and particles can be back-drafted from the chimney or flue into the living space if the combustion appliance is not properly vented or does not receive enough supply air. Back-drafting can be a particular problem in weatherized or tightly constructed homes. Installing a dedicated outdoor air supply for the combustion appliance can help prevent back-drafting.
DO YOU SUSPECT YOUR OFFICE HAS AN INDOOR AIR PROBLEM?
Indoor air quality problems are not limited to homes. In fact, many office buildings have significant air pollution sources. Some of these buildings may be inadequately ventilated. For example, mechanical ventilation systems may not be designed or operated to provide adequate amounts of outdoor air. Finally, people generally have less control over the indoor environment in their offices than they do in their homes. As a result, there has been an increase in the incidence of reported health problems.
A number of well-identified illnesses, such as Legionnaires’ disease, asthma, hypersensitivity pneumonitis, and humidifier fever, have been directly traced to specific building problems. These are called building-related illnesses. Most of these diseases can be treated, nevertheless, some pose serious risks.
Sometimes, however, building occupants experience symptoms that do not fit the pattern of any particular illness and are difficult to trace to any specific source. This phenomenon has been labelled sick building syndrome. People may complain of one or more of the following symptoms: dry or burning mucous membranes in the nose, eyes, and throat; sneezing; stuffy or runny nose; fatigue or lethargy; headache; dizziness; nausea; irritability and forgetfulness. Poor lighting, noise, vibration, thermal discomfort, and psychological stress may also cause, or contribute to, these symptoms.
There is no single manner in which these health problems appear. In some cases, problems begin as workers enter their offices and diminish as workers leave; other times, symptoms continue until the illness is treated. Sometimes there are outbreaks of illness among many workers in a single building; in other cases, health symptoms show up only in individual workers.
In the opinion of some World Health Organization experts, up to 30 percent of new or remodeled commercial buildings may have unusually high rates of health and comfort complaints from occupants that may potentially be related to indoor air quality.
Three major reasons for poor indoor air quality in office buildings are the presence of indoor air pollution sources; poorly designed, maintained, or operated ventilation systems; and uses of the building that were unanticipated or poorly planned for when the building was designed or renovated.
Sources of Office Air Pollution
As with homes, the most important factor influencing indoor air quality is the presence of pollutant sources. Commonly found office pollutants and their sources include environmental tobacco smoke; asbestos from insulating and fire-retardant building supplies; formaldehyde from pressed wood products; other organics from building materials, carpet, and other office furnishings, cleaning materials and activities, restroom air fresheners, paints, adhesives, copying machines, and photography and print shops; biological contaminants from dirty ventilation systems or water-damaged walls, ceilings, and carpets; and pesticides from pest management practices.
Mechanical ventilation systems in large buildings are designed and operated not only to heat and cool the air, but also to draw in and circulate outdoor air. If they are poorly designed, operated, or maintained, however, ventilation systems can contribute to indoor air problems in several ways.
For example, problems arise when, in an effort to save energy, ventilation systems are not used to bring in adequate amounts of outdoor air. Inadequate ventilation also occurs if the air supply and return vents within each room are blocked or placed in such a way that outdoor air does not actually reach the breathing zone of building occupants. Improperly located outdoor air intake vents can also bring in air contaminated with automobile and truck exhaust, boiler emissions, fumes from dumpsters, or air vented from restrooms. Finally, ventilation systems can be a source of in door pollution themselves by spreading biological contaminants that have multiplied in cooling towers, humidifiers, dehumidifiers, air conditioners, or the inside surfaces of ventilation duct work.
Use of the Building
Indoor air pollutants can be circulated from portions of the building used for specialized purposes, such as restaurants, print shops, and dry-cleaning stores, into offices in the same building. Carbon monoxide and other components of automobile exhaust can be drawn from underground parking garages through stairwells and elevator shafts into office spaces.
In addition, buildings originally designed for one purpose may end up being converted to use as office space. If not properly modified during building renovations, the room partitions and ventilation system can contribute to indoor air quality problems by restricting air recirculation or by providing an inadequate supply of outdoor air.
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.
- Encourage building management to obtain a copy of Building Air Quality: A Guide for Building Owners and Facility Managers from the EPA. Building Air Quality (BAQ) is simply written, yet provides comprehensive information for identifying, correcting, and preventing indoor air quality problems. BAQ also provides supporting information such as when and how to select outside technical assistance, how to communicate with others regarding indoor air issues, and where to find additional sources of information. To obtain the looseleaf-format version of the Building Air Quality, complete with appendices, an index, and a full set of useful forms, and the newly released, Building Air Quality Action Plan, order GPO Stock # 055-000-00602-4, for $28, contact the: Superintendent of Documents, U.S. Government Printing Office (GPO), P.O. Box 371954, Pittsburgh, PA 15250-7954, or call (202) 512-1800, fax (202) 512-2250.
- Obtain a copy of “An Office Building Occupant’s Guide to Indoor Air Quality,” EPA-402-K-97-003, October 1997 from IAQ INFO at 1-800-438-4318.
- Frequently, indoor air quality problems in large commercial buildings cannot be effectively identified or remedied without a comprehensive building investigation. These investigations may start with written questionnaires and telephone consultations in which building investigators assess the history of occupant symptoms and building operation procedures. In some cases, these inquiries may quickly uncover the problem and on-site visits are unnecessary.
- More often, however, investigators will need to come to the building to conduct personal interviews with occupants, to look for possible sources of the problems, and to inspect the design and operation of the ventilation system and other building features. Because taking measurements of pollutants at the very low levels often found in office buildings is expensive and may not yield information readily useful in identifying problem sources, investigators may not take many measurements. The process of solving indoor air quality problems that result in health and comfort complaints can be a slow one, involving several trial solutions before successful remedial actions are identified.
- If a professional company is hired to conduct a building investigation, select a company on the basis of its experience in identifying and solving indoor air quality problems in non-industrial buildings.
- Work with others to establish a smoking policy that eliminates involuntary nonsmoker exposure to environmental tobacco smoke.
- Call the National Institute for Occupational Safety and Health (NIOSH) for information on obtaining a health hazard evaluation of your office (800-35NIOSH), or contact the Occupational Safety and Health Administration, (202) 219-8151.
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.
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.
Levels in Homes: Based on a national residential radon survey completed in 1991, the average indoor radon level is 1.3 picocuries per liter (pCi/L). The average outdoor level is about 0.4 pCi/L.
Steps to Reduce Exposure:
Test your home for radon_it’s easy and inexpensive.
Fix your home if your radon level is 4 picocuries per liter (pCi/L) or higher.
Radon levels less than 4 pCi/L still pose a risk, and in many cases may be reduced.
If you want more information on radon, contact your state radon office, or call 800-SOS-RADON.
Source: Cigarette, pipe, and cigar smoking.
Health Effects: Eye, nose, and throat irritation; headaches; lung cancer; may contribute to heart disease. Specifically for children, increased risk of lower respiratory tract infections, such as bronchitis and pneumonia, and ear infections; build-up of fluid in the middle ear; increased severity and frequency of asthma episodes; decreased lung function.
Levels in Homes: Particle levels in homes without smokers or other strong particle sources are the same as, or lower than, those outdoors. Homes with one or more smokers may have particle levels several times higher than outdoor levels.
Steps to Reduce Exposure:
Do not smoke in your home or permit others to do so.
Do not smoke if children are present, particularly infants and toddlers.
If smoking indoors cannot be avoided, increase ventilation in the area where smoking takes place. Open windows or use exhaust fans.
Sources: Wet or moist walls, ceilings, carpets, and furniture; poorly maintained humidifiers, dehumidifiers, and air conditioners; bedding; household pets.
Health Effects: Eye, nose, and throat irritation; shortness of breath; dizziness; lethargy; fever; digestive problems. Can cause asthma; humidifier fever; influenza and other infectious diseases.
Levels in Homes: Indoor levels of pollen and fungi are lower than outdoor levels (except where indoor sources of fungi are present). Indoor levels of dust mites are higher than outdoor levels.
Steps to Reduce Exposure:
Install and use fans vented to outdoors in kitchens and bathrooms.
Vent clothes dryers to outdoors.
Clean cool mist and ultrasonic humidifiers in accordance with manufacturer’s instructions and refill with clean water daily.
Empty water trays in air conditioners, dehumidifiers, and refrigerators frequently.
Clean and dry or remove water-damaged carpets.
Use basements as living areas only if they are leak-proof and have adequate ventilation. Use dehumidifiers, if necessary, to maintain humidity between 30-50 percent.
Sources: Unvented kerosene and gas space heaters; leaking chimneys and furnaces; back-drafting from furnaces, gas water heaters, wood stoves, and fireplaces; gas stoves. Automobile exhaust from attached garages. Environmental Tobacco Smoke.
Health Effects: At low concentrations, fatigue in healthy people and chest pain in people with heart disease. At higher concentrations, impaired vision and coordination; headaches; dizziness; confusion; nausea. Can cause flu-like symptoms that clear up after leaving home. Fatal at very high concentrations.
Levels in Homes: Average levels in homes without gas stoves vary from 0.5 to 5 parts per million (ppm). Levels near properly adjusted gas stoves are often 5 to 15 ppm and those near poorly adjusted stoves may be 30 ppm or higher.
Steps to Reduce Exposure:
Keep gas appliances properly adjusted.
Consider purchasing a vented space heater when replacing an unvented one.
Use proper fuel in kerosene space heaters.
Install and use an exhaust fan vented to outdoors over gas stoves.
Open flues when fireplaces are in use.
Choose properly sized wood stoves that are certified to meet EPA emission standards. Make certain that doors on all wood stoves fit tightly.
Have a trained professional inspect, clean, and tune-up central heating system (furnaces, flues, and chimneys) annually. Repair any leaks promptly.
Do not idle the car inside garage.
Sources: Kerosene heaters, unvented gas stoves and heaters. Environmental tobacco smoke. Health Effects: Eye, nose, and throat irritation. May cause impaired lung function and increased respiratory infections in young children.
Levels in Homes: Average level in homes without combustion appliances is about half that of outdoors. In homes with gas stoves, kerosene heaters, or unvented gas space heaters, indoor levels often exceed outdoor levels.
Steps to Reduce Exposure: See steps under carbon monoxide.
Sources: Household products including: paints, paint strippers, and other solvents; wood preservatives; aerosol sprays; cleansers and disinfectants; moth repellents and air fresheners; stored fuels and automotive products; hobby supplies; dry-cleaned clothing.
Health Effects: Eye, nose, and throat irritation; headaches, loss of coordination, nausea; damage to liver, kidney, and central nervous system. Some organics can cause cancer in animals; some are suspected or known to cause cancer in humans.
Levels in Homes: Studies have found that levels of several organics average 2 to 5 times higher indoors than outdoors. During and for several hours immediately after certain activities, such as paint stripping, levels may be 1,000 times background outdoor levels.
Steps to Reduce Exposure:
Use household products according to manufacturer’s directions.
Make sure you provide plenty of fresh air when using these products.
Throw away unused or little-used containers safely; buy in quantities that you will use soon.
Keep out of reach of children and pets.
Never mix household care products unless directed on the label.
Sources: Fireplaces, wood stoves, and kerosene heaters. Environmental tobacco smoke.
Health Effects: Eye, nose, and throat irritation; respiratory infections and bronchitis; lung cancer. (Effects attributable to environmental tobacco smoke are listed elsewhere.)
Levels in Homes: Particle levels in homes without smoking or other strong particle sources are the same as, or lower than, outdoor levels.
Steps to Reduce Exposure:
Vent all furnaces to outdoors; keep doors to rest of house open when using unvented space heaters.
Choose properly sized wood stoves, certified to meet EPA emission standards; make certain that doors on all wood stoves fit tightly.
Have a trained professional inspect, clean, and tune-up central heating system (furnace, flues, and chimneys) annually. Repair any leaks promptly.
Change filters on central heating and cooling systems and air cleaners according to manufacturer’s directions.
Sources: Pressed wood products (hardwood plywood wall paneling, particleboard, fiberboard) and furniture made with these pressed wood products. Urea-formaldehyde foam insulation (UFFI). Combustion sources and environmental tobacco smoke. Durable press drapes, other textiles, and glues.
Health Effects: Eye, nose, and throat irritation; wheezing and coughing; fatigue; skin rash; severe allergic reactions. May cause cancer. May also cause other effects listed under “organic gases.”
Levels in Homes: Average concentrations in older homes without UFFI are generally well below 0.1 (ppm). In homes with significant amounts of new pressed wood products, levels can be greater than 0.3 ppm.
Steps to Reduce Exposure:
Use “exterior-grade” pressed wood products (lower-emitting because they contain phenol resins, not urea resins).
Use air conditioning and dehumidifiers to maintain moderate temperature and reduce humidity levels.
Increase ventilation, particularly after bringing new sources of formaldehyde into the home.
Sources: Products used to kill household pests (insecticides, termiticides, and disinfectants). Also, products used on lawns and gardens that drift or are tracked inside the house.
Health Effects: Irritation to eye, nose, and throat; damage to central nervous system and kidney; increased risk of cancer.
Levels in Homes: Preliminary research shows widespread presence of pesticide residues in homes.
Steps to Reduce Exposure:
Use strictly according to manufacturer’s directions.
Mix or dilute outdoors.
Apply only in recommended quantities.
Increase ventilation when using indoors. Take plants or pets outdoors when applying pesticides to them.
Use non-chemical methods of pest control where possible.
If you use a pest control company, select it carefully.
Do not store unneeded pesticides inside home; dispose of unwanted containers safely.
Store clothes with moth repellents in separately ventilated areas, if possible.
Keep indoor spaces clean, dry, and well ventilated to avoid pest and odor problems.
Sources: Deteriorating, damaged, or disturbed insulation, fireproofing, acoustical materials, and floor tiles.
Health Effects: No immediate symptoms, but long-term risk of chest and abdominal cancers and lung diseases. Smokers are at higher risk of developing asbestos-induced lung cancer.
Levels in Homes: Elevated levels can occur in homes where asbestos-containing materials are damaged or disturbed.
Steps to Reduce Exposure:
It is best to leave undamaged asbestos material alone if it is not likely to be disturbed.
Use trained and qualified contractors for control measures that may disturb asbestos and for cleanup.
Follow proper procedures in replacing wood stove door gaskets that may contain asbestos.
Sources: Lead-based paint, contaminated soil, dust, and drinking water.
Health Effects: Lead affects practically all systems within the body. Lead at high levels (lead levels at or above 80 micrograms per deciliter (80 ug/dl) of blood) can cause convulsions, coma, and even death. Lower levels of lead can cause adverse health effects on the central nervous system, kidney, and blood cells. Blood lead levels as low as 10 ug/dl can impair mental and physical development.
Steps to Reduce Exposure:
Keep areas where children play as dust-free and clean as possible.
Leave lead-based paint undisturbed if it is in good condition; do not sand or burn off paint that may contain lead.
Do not remove lead paint yourself.
Do not bring lead dust into the home.
If your work or hobby involves lead, change clothes and use doormats before entering your home.
Eat a balanced diet, rich in calcium and iron.
WHERE TO GO FOR ADDITIONAL INFORMATION ON INDOOR AIR QUALITY
DISCLAIMER: Links to other Federal Agencies on this page are pointers to other hosts and locations in the Internet. The information on this is provided here as a service.
Federal Information Sources for Indoor Air Quality
Federal agencies with indoor air quality information may be contacted as follows:
INDOOR AIR QUALITY – Information Clearinghouse (IAQ INFO)
P.O. Box 37133
Washington, DC 20013-7133
(800) 438-4318; (703) 356-4020
(fax) 703-356-5386 or e-mail: email@example.com
Operates Monday to Friday from 9a.m. to 5p.m. Eastern Standard Time (EST). Distributes EPA publications, answers questions on the phone, and makes referrals to other nonprofit and governmental organizations.
NATIONAL RADON HOTLINES
Information recording operates 24 hours a day.
NATIONAL LEAD INFORMATION CENTER
Operates 24 hours a day, seven days a week. Callers may order an information package. To speak to an information specialist, call (800) 424-5323. Operates Monday to Friday from 8:30a.m. to 5p.m. EST.
NATIONAL PESTICIDES TELECOMMUNICATIONS NETWORK
National toll-free number: (800) 858-PEST
[In Oregon – (800) 858-7378]
Operates Monday to Friday from 6:30a.m. to 4:30p.m. Pacific Time. Provides information about pesticides to the general public and the medical, veterinary, and professional communities. Medical and government personnel may call 800-858-7377.
National toll-free number: (800) 424-9346
In Washington, DC area: (703) 412-9810
Operates Monday to Friday from 8:30a.m. to 7:30p.m. EST. Provides information on regulations under both the Resources Conservation and Recovery Act (including solid and hazardous waste issues) and the Superfund law.
SAFE DRINKING WATER HOTLINE
Operates Monday to Friday from 8:30a.m. to 5p.m. EST. Provides information on regulations under the Safe Drinking Water Act, lead and radon in drinking water, filter information, and a list of state drinking water offices.
TSCA ASSISTANCE INFORMATION SERVICE
Operates Monday to Friday from 8:30a.m. to 5p.m. EST. Provides information on regulations under the Toxic Substances Control Act and on EPA’s asbestos program.
U.S. Consumer Product Safety Commission (CPSC) [http://www.cpsc.gov/]
Washington, DC 20207-0001
Product Safety Hotline: (800) 638-CPSC
Teletypewriter for the hearing impaired (outside Maryland): (800) 638-8270;
Maryland only: (800) 492-8104.
Recorded information is available 24 hours a day when calling from a touch-tone phone. Operators are on duty Monday to Friday from 10:30 to 4 EST to take complaints about unsafe consumer products.
CPSC Regional Offices
Eastern Regional Center
6 World Trade Center
Vesey Street, 3rd Floor Room 350
New York, NY 10048-0950
States in Eastern Region: Connecticut, District of Columbia, Delaware, Florida, Massachusetts, Maryland, Maine, North Carolina, New Hampshire, New York, Pennsylvania, South Carolina, Rhode Island, Virginia, Vermont, West Virginia
Central Regional Center
230 South Dearborn Street, Room 2944
Chicago, IL 60604-1601
States in Central Region: Alabama, Georgia, Iowa, Illinois, Indiana, Kansas, Kentucky, Michigan, Minnesota, Missouri, Mississippi, North Dakota, Nebraska, Ohio, South Dakota, Tennessee, Wisconsin
Western Regional Center
600 Harrison Street, Room 245
San Francisco, CA 94107
States in Western Region: Alaska, Arkansas, Arizona, California, Colorado, Hawaii, Idaho, Louisiana, Montana, New Mexico, Nevada, Oklahoma, Oregon, Texas, Utah, Washington, Wyoming
U.S. Department of Housing and Urban Development [http://www.hud.gov/]
Office of Energy and the Environment, Washington, DC 20410
HUD USER National toll-free number: (800) 245-2691
In Washington, DC area: (301) 251-5154
U.S. Department of Energy [http://www.doe.gov/]
Office of Conservation and Renewable Energy
1000 Independence Ave., SW, Washington, DC 20585
Conservation and Renewable Energy Inquiry and Referral Service (CAREIRS)
PO Box 3048, Merrifield, VA 22116; (800) 523-2929.
Operates Monday to Friday from 9 to 5 EST. Provides consumer information on conservation and renewable energy in residences.
Division of Federal Occupational Health
Office of Environmental Hygiene, Region III, Room 1310
3535 Market St., Philadelphia, PA 19104
(215) 596-1888; fax: 215-596-5024
Provides indoor air quality consultative services to federal agency managers.
Centers for Disease Control and Prevention [http://www.cdc.gov]
Lead Poisoning Prevention Branch
Centers for Disease Control and Prevention
4770 Buford Highway, NE (F-42)
Atlanta, GA 30341-3724
Office on Smoking and Health
Centers for Disease Control and Prevention
4770 Buford Highway, NE (K-50)
Atlanta, GA 30341-3724
Occupational Safety and Health Administration (OSHA) [http://www.osha.gov/]
Office of Information and Consumer Affairs
Room N-3647, 200 Constitution Avenue, NW
Washington, DC 20210
Portland, OR 97208
18th and F Streets, NW
Washington, DC 20405
Industrial Hygiene Branch
Multipurpose Building (1-B)
Muscle Shoals, AL 35660
State and Local Organizations
Your questions or concerns about indoor air problems can frequently be answered by the government agencies in your state or local government. Responsibilities for indoor air quality issues are usually divided among many different agencies. Calling or writing the agencies responsible for health or air quality control is the best way to start getting information from your state or local government. To obtain state agency contacts, write or call EPA’s IAQ Information Clearinghouse, (800) 438-4318, (703) 356-4020 in the Washington, D.C. area.
The following organizations have information specifically discussed in this booklet. Call the IAQ Information Clearinghouse at (800) 438-4318 for the names of a variety of organizations that have more information on specific and general indoor air quality issues.
American Association of Poison Control Centers (AAPCC)
3800 Reservoir Road, NW
Washington, DC 20007
Association of Home Appliance Manufacturers (AHAM)
20 North Wacker Drive
Chicago, IL 60606
(312) 984-5800, ext. 308
American Society of Heating, Refrigerating, and Air-Conditioning (ASHRAE)
1791 Tullie Circle NE
Atlanta, GA 30329
World Health Organization (WHO)
49 Sheridan Avenue
Albany, NY 12210
Your Local American Lung Association (ALA)
National ALA Headquarters
New York, NY 10019
GLOSSARY OF TERMS
ACID AEROSOL: Acidic liquid or solid particles that are small enough to become airborne. High concentrations of acid aerosols can be irritating to the lungs and have been associated with some respiratory diseases, such as asthma.
ANIMAL DANDER: Tiny scales of animal skin.
ALLERGEN: A substance capable of causing an allergic reaction because of an individual’s sensitivity to that substance.
ALLERGIC RHINITIS: Inflammation of the mucous membranes in the nose that is caused by an allergic reaction.
BUILDING-RELATED ILLNESS: A discrete, identifiable disease or illness that can be traced to a specific pollutant or source within a building. (Contrast with “Sick building syndrome”).
CHEMICAL SENSITIZATION: Evidence suggests that some people may develop health problems characterized by effects such as dizziness, eye and throat irritation, chest tightness, and nasal congestion that appear whenever they are exposed to certain chemicals. People may react to even trace amounts of chemicals to which they have become “sensitized.”
ENVIRONMENTAL TOBACCO SMOKE (ETS): Mixture of smoke from the burning end of a cigarette, pipe, or cigar and smoke exhaled by the smoker (also secondhand smoke or passive smoking).
FUNGI: Any of a group of parasitic lower plants that lack chlorophyll, including molds and mildews.
HUMIDIFIER FEVER: A respiratory illness caused by exposure to toxins from microorganisms found in wet or moist areas in humidifiers and air conditioners. Also called air conditioner or ventilation fever.
HYPERSENSITIVITY PNEUMONITIS: A group of respiratory diseases that cause inflammation of the lung (specifically granulomatous cells). Most forms of hypersensitivity pneumonitis are caused by the inhalation of organic dusts, including molds.
ORGANIC COMPOUNDS: Chemicals that contain carbon. Volatile organic compounds vaporize at room temperature and pressure. They are found in many indoor sources, including many common household products and building materials.
PICOCURIE (pCi): A unit for measuring radioactivity, often expressed as picocuries per liter (pCi/L) of air.
PRESSED WOOD PRODUCTS: A group of materials used in building and furniture construction that are made from wood veneers, particles, or fibers bonded together with an adhesive under heat and pressure.
RADON (Rn) AND RADON DECAY PRODUCTS: Radon is a radioactive gas formed in the decay of uranium. The radon decay products (also called radon daughters or progeny) can be breathed into the lung where they continue to release radiation as they further decay.
SICK BUILDING SYNDROME: Term that refers to a set of symptoms that affect some number of building occupants during the time they spend in the building and diminish or go away during periods when they leave the building. Cannot be traced to specific pollutants or sources within the building. (Contrast with “Building related illness”).
VENTILATION RATE: The rate at which indoor air enters and leaves a building. Expressed in one of two ways: the number of changes of outdoor air per unit of time (air changes per hour, or “ach”) or the rate at which a volume of outdoor air enters per unit of time (cubic feet per minute, or “cfm”).
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