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 house-keeping. High pollutant concentrations can remain in the air for long periods after some of these activities.

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?

Ambient 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.

**Read more about ventilation in buildings

Asthma is a serious, sometimes life-threatening respiratory disease that affects the quality of life for millions of Americans. Although there is no cure for asthma yet, asthma can be controlled through medical treatment and management of environmental triggers. EPA is committed to educating all Americans about asthma so that everyone knows what asthma is, how the environment can affect asthma patients and how to manage environmental asthma triggers.  Learn more about factors found in the indoor and outdoor environment that can cause, trigger, or exacerbate asthma symptoms and what you can do to reduce their impact. You might be surprised by the list of common environmental asthma triggers and how simple it can be to eliminate them from your environment.

Americans spend up to 90% of their time indoors. Therefore, indoor allergens and irritants can play a significant role in triggering asthma attacks. It is important to recognize potential asthma triggers in the indoor environment and reduce your exposure to those triggers. You may not be affected by all of the triggers listed here. Your doctor can help you to determine which triggers affect your asthma and develop a customized asthma management plan.

**You can download an Asthma Action Card (PDF, 2 pp, 163KB About PDF) to help you work with your doctor to customize an asthma action plan for your individual circumstances.

When you and your doctor make the plan, be sure to include:

*Your child’s asthma triggers.

*Instructions for asthma medicines.

*What to do if your child has an asthma attack.

*When to call your doctor.

*Emergency telephone numbers.

*Some of the most common indoor asthma triggers include secondhand smoke, dust mites, mold, cockroaches and other pests, household pets, and combustion by products. Click on the links below to learn more about these triggers and how to reduce your exposure to them.

Secondhand smoke is a mixture of smoke from the burning end of a cigarette, pipe or cigar and the smoke exhaled by the smoker that is often found in homes and cars where smoking is allowed.

EPA and HHS Partnering to Promote Smoke-free Homes for Head Start Families

Secondhand smoke is harmful to everyone, especially to babies and young children of all communities. Millions of children six years old and younger are exposed to secondhand smoke in their home which can cause several health issues such as Middle ear infections – millions per year, Bronchitis/pneumonia and Sudden Infant Death Syndrome (SIDS) – 2,000 deaths per year. By increase awareness of the health impacts on children from exposure to secondhand smoke and helping families take action to protect children from exposure to secondhand smoke, you can help protect children’s health.

EPA and DHHS (Administration for Children and Families, Head Start Bureau) are working together to improve the quality of life for nearly a million Head Start children by conducting nationwide asthma and secondhand smoke outreach.

Asthma is a growing problem for Head Start families, as well as the nation as a whole. It is the most common chronic childhood disease and places a disproportionate burden on minority and low income groups, the population that Head Start serves.

Approximately 20 percent of children with asthma are exposed to secondhand smoke in their homes. By taking the actions to reduce exposure to asthma triggers and making their homes and cars smoke-free, Head Start families can help prevent serious health risks such as more frequent and severe asthma attacks among asthmatic children, upper and lower respiratory tract infections, and acute middle ear infections.

*To find out more about the importance of smoke-free homes and cars for children and related EPA materials, visit www.epa.gov/smokefree. 

 

Molds can be found almost anywhere; they can grow on virtually any organic substance, as long as moisture and oxygen are present. There are molds that can grow on wood, paper, carpet, foods, and insulation. When excessive moisture accumulates in buildings or on building materials, mold growth will often occur, particularly if the moisture problem remains undiscovered or unaddressed. It is impossible to eliminate all mold and mold spores in the indoor environment. However, mold growth can be controlled indoors by controlling moisture indoors.

After natural disasters such as hurricanes, tornadoes, and floods, excess moisture and standing water contribute to the growth of mold in homes and other buildings. When returning to a home that has been flooded, be aware that mold may be present and may be a health risk for your family.

People with asthma, allergies, or other breathing conditions may be more sensitive to mold. People with immune suppression (such as people with HIV infection, cancer patients taking chemotherapy, and people who have received an organ transplant) are more susceptible to mold infections.

People who are sensitive to mold may experience stuffy nose, irritated eyes, wheezing, or skin irritation. People allergic to mold may have difficulty in breathing and shortness of breath. People with weakened immune systems and with chronic lung diseases, such as obstructive lung disease, may develop mold infections in their lungs. If you or your family members have health problems after exposure to mold, contact your doctor or other health care provider.

You may recognize mold by:

**Sight (Are the walls and ceiling discolored, or do they show signs of mold growth or water damage?)

**Smell (Do you smell a bad odor, such as a musty, earthy smell or a foul stench?)

 

Clean up and dry out the building quickly (within 24 to 48 hours). Open doors and windows. Use fans to dry out the building. (See the fact sheet for drying out your house, Reentering Your Flooded Home).

**When in doubt, take it out! Remove all porous items that have been wet for more than 48 hours and that cannot be thoroughly cleaned and dried. These items can remain a source of mold growth and should be removed from the home. Porous, noncleanable items include carpeting and carpet padding, upholstery, wallpaper, drywall, floor and ceiling tiles, insulation material, some clothing, leather, paper, wood, and food. Removal and cleaning are important because even dead mold may cause allergic reactions in some people.

*To prevent mold growth, clean wet items and surfaces with detergent and water.

*Homeowners may want to temporarily store items outside of the home until insurance claims can be filed. See recommendations by the Federal Emergency Management Agency (FEMA) .

*If you wish to disinfect, refer to the U.S. Environmental Protection Agency (EPA) document, A Brief Guide to Mold and Moisture in Your Home.

If there is mold growth in your home, you should clean up the mold and fix any water problem, such as leaks in roofs, walls, or plumbing. Controlling moisture in your home is the most critical factor for preventing mold growth.

To remove mold growth from hard surfaces use commercial products, soap and water, or a bleach solution of no more than 1 cup of bleach in 1 gallon of water. Use a stiff brush on rough surface materials such as concrete.

*Never mix bleach with ammonia or other household cleaners. Mixing bleach with ammonia or other cleaning products will produce dangerous, toxic fumes

*Open windows and doors to provide fresh air.

*Wear non-porous gloves and protective eye wear.

*If the area to be cleaned is more than 10 square feet, consult the U.S. Environmental Protection Agency (EPA) guide titled Mold Remediation in Schools and Commercial Buildings . Although focused on schools and commercial buildings, this document also applies to other building types.

 

*You can get it free by calling the EPA Indoor Air Quality Information Clearinghouse at (800) 438-4318, or by going to the EPA web site at http://www.epa.gov/mold/mold_remediation.html .

*Always follow the manufacturer's instructions when using bleach or any other cleaning product.

*More information on personal safety while cleaning up after a natural disaster is available at emergency.cdc.gov/disasters/workers.asp.

If you plan to be inside the building for a while or you plan to clean up mold, you should buy an N95 mask at your local home supply store and wear it while in the building. Make certain that you follow instructions on the package for fitting the mask tightly to your face. If you go back into the building for a short time and are not cleaning up mold, you do not need to wear an N95 mask.

*Clean Up Safely After a Natural Disaster

*Reentering Your Flooded Home

*Mold - General Resources

*NIOSH Interim Recommendations for the Cleaning and Remediation of Flood-Contaminated HVAC Systems: A Guide for Building Owners and Managers

*Population-Specific Recommendations for Protection From Exposure to Mold in Buildings Flooded After Hurricanes Katrina and Rita

 

 

Radon is a cancer-causing natural radioactive gas that you can’t see, smell or taste. Its presence in your home can pose a danger to your family's health. Radon is the leading cause of lung cancer among non-smokers. Radon is the second leading cause of lung cancer in America and claims about 20,000 lives annually.

The Hazard with a Simple Solution:  EPA has designated January as National Radon Action Month, a time when state radon programs and other partners conduct special radon outreach activities and events across the country. The aim of National Radon Action Month is to increase the public's awareness of radon, promote radon testing and mitigation, and advance the use of radon-resistant new construction practices.

What Can Radon Do?   Radon can cause lung cancer.(Lung cancer is a disease of a person’s lungs, where the cells’ DNA is damaged and those damaged cells replicate uncontrollably). Radon is second only to smoking as a cause of lung cancer. It’s a silent killer, since people can’t tell if they’re being exposed. And its effects are more hazardous for children than adults.

Why are Children more Susceptible?  Children are more sensitive to radon because their lungs are smaller and their respiratory rates are twice as high. Doctors say that, by the age of 10, a child receives twice the lung dose of an adult who’s been exposed to radon for the same length of time.

What Parts of the Country Have a High Potential for Radon? In the northern states, particularly as you go northeast into Maine, there are significant pockets of high levels of radon. In the Midwest, northern Iowa and Minnesota are considered high areas as are the Dakotas, Montana, and Idaho. Radon levels are lower in Washington and Oregon.

How Do I Know if Radon is in my House?  You can buy a radon test kit at a department store from about $10-$40. These can be placed in the basement of your home.

Where Would Radon Be, if it’s where I Live, and How Does it get There? 

*If radon is in your house, it can get in through any tiny space that comes in contact with soil that contains radon or through groundwater. Radon can be anywhere, but it matters how much of it is present in relation to other air. If the concentration (amount) is high enough, then it can cause harm. In the outside air it is not harmful because radon is present in dilute (dilute means smaller or weaker concentration) enough amounts.

*Radon comes from the ground and can enter a building from the soil. Radon changes from a solid form into a gaseous or liquid form and can be released from the soil and groundwater. One way radon can get into buildings is by cracks in the basement, and if there is not good ventilation, radon concentration can be harmful.

 

The U.S. Surgeon General and EPA recommend that all homes be tested.  Read about radon health risks. [En Español]  You can test your home yourself or hire a professional. [En Español]  Fix your home if you have a radon level of 4 pCi/L or more [En Español].  Discounted radon test kits are available from the National Safety Council  (or call 1-800-SOS-RADON).  Some home improvement stores sell test kits.  To find a qualified testing or mitigation contractor, contact your state radon office (see our list of state contacts) or either of the private radon proficiency programs.

*Get a discounted Radon Test Kit from the National Safety Council www.nsc.org/issues/ radon/radonkitcoupons.pdf

*The National Safety Council's Radon Hotline 1-800-SOS-RADON [1-800-767-7236] provides an informational recording 24 hours a day. Through this automated system, callers can order a brochure on radon by leaving their name and address. The brochure contains information on ordering a low-cost short-term test kit.

*In addition, callers are advised to call 1-800-55-RADON [1-800-557-2366] to speak with an information specialist.  You may also write via airqual@nsc.org . They are available to assist callers between 9:00 p.m. to 5:00 p.m. eastern time on business days. Information specialists can answer specific questions and mail free, single copies of many radon documents, including EPA's Home Buyer's and Seller's Guide to Radon. More radon information from the National Safety Council is available at www.nsc.org

 

Indoor Air Pollution and 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 preexisting 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 symptoms occur. If the symptoms fade or go away when a person is away from home, for example, an effort should be made to identify indoor air sources that may be possible causes. 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.

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 occurs from the higher concentrations that occur for short periods of time.

 

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.

Mold, dust mites, pet dander, and pest droppings or body parts can trigger asthma. Biological contaminants, including molds and pollens can cause allergic reactions for a significant portion of the population. Tuberculosis, measles, staphylococcus infections, Legionella and influenza are known to be transmitted by air.

Treatment for indoor air pollution

How you react to indoor air pollutants depends on your age, health, and sensitivity to certain chemicals or biological pollutants, such as bacteria. Treatment can be as simple as removing and limiting your exposure to toxins in your home. But in some cases, serious illnesses, such as cancer, heart disease, and respiratory disease, can develop after long-term and repeated exposures. With such long-term exposures, treatment may be extensive, depending on the type of illness.

 

Additional Resources:

*Basic Information About Indoor Air Quality

*There are three basic strategies to improve indoor air quality

*Measuring Pollutant Levels and Weatherizing Your Home

*What if You Live in an Apartment?

*Do You Suspect Your Office Has an Indoor Air Problem?

*"The Inside Story: A Guide to Indoor Air Quality"

*To access EPA’s asthma materials, visit www.epa.gov/asthma

 

*You can order Indoor Air Quality publications from EPA's National Service Center for Environmental Publications (NSCEP):

U.S. Environmental Protection Agency National Service Center for Environmental Publications (NSCEP) P.O. Box 42419 Cincinnati, OH 45242-0419 Website: www.epa.gov/nscep Phone:  1-800-490-9198 Fax:  (301) 604-3408 E-mail:  nscep@bps-lmit.com

Indoor Air Quality Information Line:

Consumers may call the toll-free number 1-800-438-4318  (local number in the Washington DC Area - (703) 356-4020) to speak to an information specialist, Monday through Friday, 9:00am to 5:00pm eastern time. After hours, consumers may leave a voice message, or you may make inquiries by fax (703) 356-5386 or via e-mail:

 

This information courtesy of:

2007 U.S. Environmental Protection Agency

2007 RadonAwareness.org

2007 U.S. Department of Health and Human Services

2007 Center for Disease Control and Prevention

© 2007 Safety4Kids, LLC. All Rights Reserved. Safety 4 Kids, LLC assumes no liability or responsibility for the misuse of any of the information contained herein.

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