New October 2000
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Have you ever stopped to think about the air quality inside your home? Many people associate air pollution with large, industrial cities and know that this air is often a health hazard. However, they are less likely to realize that the air inside one's home is often more hazardous than polluted outdoor air. Due to technology, changes in work patterns and a variety of other factors, most people spend at least 90 percent of their time indoors. Young children, the elderly and people with health problems -- those who are most susceptible to the effects of poor indoor air -- are likely to spend even more time inside. Therefore, it is crucial that you are aware of the condition of the air inside your home and how to improve it when needed.
Is the air inside your home putting you and your family at risk for health problems? The following are some indications that indoor air may need some improvement:
If you notice one or more of these conditions, you can probably improve the air quality in your home. This guide helps you to improve your home's air quality by highlighting several substances that commonly pollute indoor air, including:
This guide lists some potential problems specific to each room of the house and suggests methods for improving indoor air quality. There is also a section highlighting the relationship between asthma and indoor air quality.
Biological contaminants include a wide variety of living or once-living organisms that can pollute the air. Some common types include:
Some of these pollutants, like mold, have the potential to damage the interior surfaces of a home. These pollutants are a common cause of illness. The air quality of every home suffers to some degree from biological contamination. However, even though these organisms cannot be eliminated entirely, they can be adequately controlled with proper prevention methods.
Sources of biological contamination in the home
Molds
Mold can grow in any climate and region of the country. However, the warm, humid environments in kitchens, bathrooms, laundry rooms and basements are especially optimal. As mold grows, it releases spores into the air. These spores settle and form new colonies of mold on other surfaces. Mold grows on organic surfaces, such as paper, wood, textiles, grease and soap scum. It can eventually eat away at the growing surface itself. Mold is not always readily visible because it often grows inside walls and insulation or behind furniture. However, mold may be detected by a musty odor.
Animal products
Pets are a source of several contaminants, including hair, dander (flakes of skin), dried saliva and dried urine. These particles float easily in the air and spread throughout a home. In addition, insects and their body parts can also pollute the air.
Microscopic organisms
Dust mites are tiny organisms that feed on dead human skin cells. They are found in bedding, clothing and other textiles and become airborne during activities such as vacuuming and making beds. Bacteria and viruses also fall into this category and cause infectious diseases. They are usually spread through person-to-person contact, but they can also circulate in a home's ventilation system.
Pollen
Pollen comes from plants and may enter a home through open windows or on pets. Some houseplants may contribute to pollen levels in the home.
Health effects
Biological contaminants are a very common cause of illness. Infants and children, older persons and people with respiratory problems are particularly susceptible to the effects of biological pollutants. Many people are sensitive to at least one of these organisms and experience allergic reactions to them when levels are high. Symptoms of an allergic reaction include:
These pollutants are also frequent triggers of:
Bacteria and viruses may cause infectious diseases, such as tuberculosis and influenza. Some molds release toxins dangerous enough to damage body tissues and organs and can even cause death. (For information about a particularly dangerous mold, Stachybotrys atra, see below.)
Prevention and solutions
Moisture control
In order to prevent problems related to excessive moisture, the relative humidity of a home should be kept within the range of 30 percent to 50 percent. Although Missouri is a humid state, there are many ways to control moisture levels in the home.
Cleaning
Cleaning is important because surfaces coated with grease, soap scum and other organic materials are very susceptible to mold growth. Cleaning also helps eliminate the buildup of animal products and microscopic organisms.
Sources for additional information
What is Stachybotrys?
Stachybotrys is a greenish-black, slimy mold that grows on materials that contain cellulose, such as sheetrock, ceiling tiles, wood, wallpaper and cardboard. Stachybotrys thrives when these materials are chronically wet, due to high humidity levels, water leakage, condensation or flooding.
Why is Stachybotrys a problem?
Stachybotrys is a very dangerous mold because it produces airborne toxins that can cause serious health problems and even death. Anyone can be affected, but infants and people with respiratory problems are at greatest risk. Symptoms of exposure to Stachybotrys include chronic fatigue, memory and hearing loss, severe breathing problems, flu-like symptoms and bleeding in the lungs.
How do I know if my house has Stachybotrys growth?
Stachybotrys is black and slimy and grows on materials that have been wet for several days. However, there are more common molds that look very similar to Stachybotrys. The only way to determine with certainty that mold growth is Stachybotrys is to have it tested in a laboratory.
How do I get rid of Stachybotrys?
In all cases, the source of water accumulation must be attended to or the mold will return. If Stachybotrys contamination is minimal, it may be killed with a bleach-water solution that is applied to the affected surface and rinsed after 15 minutes. The person cleaning should protect his or her face and hands and make sure the area is well ventilated. Surfaces larger than one or two square feet should only be treated by a qualified professional.
Carbon monoxide and other combustion by-products
Combustion by-products are gases or pollutants that are emitted from burning fuels. These by-products include carbon monoxide, secondhand smoke, nitrogen dioxide and sulfur dioxide. Carbon monoxide, a colorless and odorless gas, is the most deadly of these by-products. It prevents the blood from delivering oxygen to the rest of the body and, at high levels, can kill a person in minutes. In 1998, 7,700 people were treated in hospital emergency rooms for carbon monoxide poisoning due to leakage from home heating systems. However, the Missouri Department of Health states that carbon monoxide poisoning is extremely underreported and more poisonings usually occur than are documented.
Sources of carbon monoxide in the home
Carbon monoxide and other combustion by-products are produced when fuels such as wood, coal, charcoal, natural gas, oil and propane are burned. Carbon monoxide is also emitted from unvented space heaters, furnaces, gas stoves, fireplaces, water heaters, dryers and the auto exhaust in attached garages.
Health effects
The effects of exposure to carbon monoxide are often confused with the flu or food poisoning. At low levels, carbon monoxide exposure can result in:
High levels can cause:
Hundreds of people die each year from carbon monoxide poisoning. Particularly at risk are:
Prevention and solutions
There are many ways people can prevent combustion by-products from accumulating in their homes.
Sources for additional information
Lead is a highly toxic soft metal that was once widely used in paint, gasoline, pipes and other products. The federal government banned the use of lead in paint and plumbing products in 1978, but homes built before then are likely to contain lead in one form or another. According to the U.S. Department of Housing and Urban Development, 74 percent of houses built before 1980 contain potentially dangerous levels of lead paint. Homes build before 1950 are very likely to have high lead levels, especially paint used on windows and exterior surfaces. In Missouri, 28 percent of the housing was built before 1950. Additionally, Missouri is the largest producer of lead in the United States. Missouri Department of Health figures (1999) show that an estimated 10.9 percent of children tested, between ages birth to 6 years old, had elevated blood lead levels (greater than 9 millograms per deciliter). The Environmental Protection Agency ranked Missouri ninth among all states on a scale of estimated lead risk, based on the age of the state's housing, the number of children in poverty and the number of young children. The risk of lead poisoning is significant for Missourians and should be given serious attention.
Lead-based paint
Paint in good condition is usually not a hazard. However, aging lead paint chips easily and can crumble into dust. These paint particles then contaminate the air in the home. Lead paint is especially hazardous in easy-to-reach places that receive a lot of use, such as window sills, doors and door frames, stairs and banisters, and porches. The paint is more likely to chip due to frequent contact, and young children can easily touch these places. These particles could be ingested by hand-to-mouth contamination and lead to poisoning. Old toys and furniture coated with lead paint are also sources of contamination.
Lead pipes and lead solder
Lead pipes and solder are a concern because they contaminate the water that runs through them, especially when the water is soft, corrosive or acidic. The longer water stands in pipes, the greater opportunity there is for lead to dissolve into the water. One cannot see, smell or taste lead in water, and boiling does not rid water of lead.
People who work in certain occupations, such as construction, plumbing and auto repair, encounter lead products regularly. They may bring lead dust into the home via their clothes or shoes. Engaging in hobbies such as stained glass work or target shooting also exposes individuals to lead products.
Health effects
Lead is toxic at both low and high concentrations and accumulates in the body over time, causing irreversible effects. Children are especially at risk for lead poisoning because their growing bodies absorb lead more readily and they are more likely to put contaminated objects or dirty hands in their mouths. Effects of lead poisoning in children include:
In the United States, 1 out of 11 children have dangerous levels of lead in their bloodstream; however, many children with high lead levels seem normal and healthy. The Environmental Protection Agency recommends that all children ages six and younger should be tested for lead poisoning. Testing is inexpensive and readily available.
Although children are most susceptible to lead poisoning, adults also suffer negative health effects from exposure to lead. Pregnant women and their growing fetuses are particularly at risk. Negative health consequences include:
Treatment of lead poisoning for people of all ages depends on the severity of the problem, but it can include changes in diet, medication and/or hospitalization.
Prevention and solutions
There are many ways to prevent lead poisoning in the home.
Sources for additional information
Secondhand smoke is smoke from another person's cigarette, pipe, or cigar. It comes from:
In the United States, more than 40 percent of children live in a home with at least one smoker. Thirty-seven percent of nonsmoking adults live or work with someone who smokes. Missouri's smoking prevalence rate of 28.6 percent of adults ranks second only to Kentucky. In Missouri, 24 percent of adults and 27 percent of children are exposed to secondhand smoke in their homes.
Health effects
In 1995, smoking was responsible for 70 percent of all cancer deaths and 19 percent of cardiovascular disease deaths in Missouri. Exposure to secondhand smoke can be even more dangerous than smoking itself, because sidestream smoke contains up to 100 times more toxins than the smoke inhaled by smokers. Harmful effects of secondhand smoke include:
Thousands of nonsmokers die each year from lung cancer and heart disease because of exposure to secondhand smoke. Infants and children are particularly susceptible to the effects of secondhand smoke, and they are more likely to develop respiratory infections, asthma, and bronchitis when exposed to it.
Prevention and solutions
In order to keep indoor air free from secondhand smoke, the source of the smoke must be removed. A separate indoor smoking area, proper ventilation and air cleaners can reduce the amount of smoke in the air. However, it will not eliminate the smoke entirely and the risks involved. The best way to prevent the harmful effects of secondhand smoke is to stop smoking and not allow others to smoke inside the home. If adults do smoke, they should do so outdoors.
Sources for additional information
Formaldehyde and volatile organic compounds
Volatile Organic Compounds (VOC's) are liquid and solid chemicals that readily evaporate into the air. Formaldehyde, a particularly harmful VOC, is a chemical released into the air as a strong-smelling gas and is found in many products.
Sources of VOC's and formaldehyde in the home
There are many household products with potentially dangerous chemicals, including:
A major source of formaldehyde gas is particleboard. The adhesive that holds the layers of wood together can break down and release formaldehyde gas. Other sources of formaldehyde include:
Products usually emit less formaldehyde as they age, so formaldehyde pollution is more commonly found in new homes.
Health effects
The health risks associated with VOC's depend on the type of chemical, its concentration, and the length of exposure. Exposure to low levels of VOC's does not appear to be too dangerous, but the effects of breathing in harmful fumes can accumulate over time. VOC's can also be harmful if they make contact with the eyes or skin or are ingested. Formaldehyde is a strong irritant and can cause:
Large doses can trigger asthma attacks and even cause damage to internal organs, although some people are more sensitive to it than others.
Prevention and solutions
The best way to prevent exposure to VOC's is to avoid using them whenever possible by using non-hazardous or less hazardous alternatives.
In order to prevent formaldehyde buildup:
Sources for additional information
Asbestos is a mineral that easily separates into small fibers. It was once widely used in many products because it is fireproof, a good thermal insulator, and can easily be manipulated into a variety of materials. However, it was banned from several substances in the 1970's when scientists learned asbestos fibers cause serious lung diseases.
Sources of asbestos in the home
Because its fibers are strong, asbestos is used to reinforce a variety of products, such as:
Although it was banned many years ago, asbestos is still a problem in older homes. It is estimated that 20 percent of all buildings contain some asbestos material.
Health effects
As asbestos ages, it breaks down into microscopic fibers that are released into the air. These fibers remain suspended in the air for long periods of time, and people inhale them. Once inhaled, they usually remain in a person's lungs until death. Inhaling high concentrations of asbestos fibers over long periods of time can lead to lung disease. Asbestosis is a disease that scars the lungs, makes breathing difficult, and can lead to death. Breathing asbestos also increases the risk of developing lung cancer, especially in smokers. Exposure to asbestos can also contribute to other cancers, such as stomach, rectal and colon. Diseases caused by asbestos take many years to develop (about 20 to 40 years), but since the accumulation of asbestos fibers in the lungs is gradual, a person may be at risk and not know it. Currently, there is no known safe level of exposure.
Prevention and solutions
Asbestos is usually not a problem in most homes, especially if the asbestos is in good condition. If asbestos is in good condition and remains undisturbed, it will not harm people. However, deteriorating asbestos is a problem and can be treated several ways, depending on the location and extent of the problem. There are four main methods of treating deteriorating asbestos:
Sources for additional information
Radon is a naturally occurring radioactive gas produced by the breakdown of uranium and radium in rocks and soil. It is colorless, odorless and tasteless. As the second leading cause of lung cancer in the United States, radon is a serious air pollutant. In Missouri, testing has revealed that about 18 percent of homes have radon levels elevated above the EPA's acceptable limit of 4.0 picocuries per liter of air (4 pC/L). The EPA has designated 11 of the 114 counties in Missouri as having the potential for high radon concentrations, including counties in the northwest region of the state and those containing the St. Francois Mountains. However, high levels of radon in homes have been found in all areas of the state. Because indoor radon levels can vary widely in a small geographic area, all homeowners should have their homes tested for radon levels.
Radon is found everywhere at varying levels. The most common source of indoor radon comes from the rock and soil that surrounds a house's foundation. It moves up through the soil where it originates, and moves into the air. Radon is then drawn indoors through cracks, openings around sump pumps and drains, and construction joints when the pressure in the lower levels of the house is lower than the air pressure outside. Hence, the highest concentrations of radon are found in the lowest levels of the home. Radon can also leach from rocks into the ground water. This can be a problem if a person's drinking water comes from an underground source, such as a well. Radon contamination is usually more of a problem in soil, although high concentrations of radon in drinking water can also create serious health effects.
Health effects
Radon is responsible for 10 percent of all lung cancer deaths. It is estimated that 14,000 deaths per year are related to high amounts of radon exposure. As people inhale radon gas released from the soil or water, the radioactive particles of which it is comprised become entrapped in the lungs. These particles continue to emit radiation as they break down. This radiation can damage the delicate lung tissues over time, increasing the risk for developing lung cancer. Ingesting water contaminated with radon may also put people at risk. Because radon does not cause any short term health effects and lung cancer takes many years to develop, it can go undetected for a long period of time. Smokers are especially susceptible to the development of radon-induced lung cancer.
Prevention and solutions
The Environmental Protection Agency and Surgeon General recommend that all homes be tested for radon, regardless of their geographic location. Radon levels are dependent upon many factors, and two houses next to each other may have very different radon levels.
Radon may be easily tested with a radon detector. Hardware stores sell many inexpensive, do-it-yourself test kits as well. There are two types of test kits: short-term and long-term. Short-term kits test radon levels for 2 to 7 days, while long-term kits require a testing period anywhere from one month to one year. Long-term detectors are more accurate. Homeowners can hire professionals to test the level in their homes if the home tests show levels over recommended standards. Radon levels found above the acceptable limit set by the EPA (4 pCi/L) can easily be reduced in most homes. There are several methods available, each depending upon the construction and location of the home. Contact the Missouri Department of Health to get more information.
Sources for additional information
Asthma is a respiratory disease that makes the airways particularly susceptible to irritation and is a serious health condition. It is the seventh-ranked chronic condition in the United States and the leading chronic illness in children. Over 17 million Americans suffer from asthma, and five million of these individuals are children under the age of 18.
Although some people are born with a genetic predisposition toward developing asthma, there are many common triggers of asthma in the environment. Some of these include:
Many of these triggers are indoor air pollutants that have been discussed previously in this guide. Some indicators that a person may have asthma include:
During an asthma attack, a person's bronchial tubes become inflamed and produce excess mucus. Breathing becomes extremely difficult, and the amount of oxygen in the blood is reduced. About 4,000 people die each year from asthma attacks, 80 percent of whom are children.
Because asthma is often triggered by indoor air contaminants, there are several things individuals can do to prevent asthma and asthma attacks.
With proper prevention, people can do much to reduce the development of asthma and asthma attacks.
Sources for additional information
Although indoor air quality problems may be present throughout an entire home, certain rooms are likely to be more susceptible to specific problems than others. The following chart lists several areas of the home and their potential problems, as well as remedies for improving the air quality in each room. As you seek to improve the air quality in your home by following the suggestions in this guide, you and your family will have cleaner air to breathe and be able to live healthier lives.
Table 1
Room-by-room indoor air quality checklist.
| Problem | Remedies |
|---|
| Kitchen | |
| Unvented gas stove and range |
|
| Household cleaners |
|
| Moisture from cooking and dishwashing |
|
| Pressed wood cabinets |
|
| Bathroom | |
| Cleaning supplies |
|
| Moisture, mold, mildew |
|
| Personal care products |
|
| Bedrooms | |
| Humidifiers |
|
| Moth repellents |
|
| Dust mites |
|
| All rooms | |
| Animal dander, hair or feathers |
|
| Carpets |
|
| Draperies |
|
| Secondhand smoke |
|
| Dust mites |
|
| Lead-based paint |
|
| Moisture |
|
| Basement and grouond floor | |
| Asbestos pipe wrap insulation |
|
| Moisture |
|
| Radon |
|
| Unvented clothes dryer |
|
| Garage | |
| Car exhaust |
|
| Paint/hobby products |
|
| Pesticides |
|
| Stored fuels (e.g. gasoline or kerosene) |
|
| Heating and cooling systems | |
| Air conditioner |
|
| Furnace |
|
| Fireplace |
|
| Kerosene heater |
|
| Wood stove |
|
Sources for additional information
GH5001, new October 2000