"Most people are aware that outdoor air pollution can damage their health but may not know that indoor air pollution can also have significant effects. EPA studies of human exposure to air pollutants indicate that indoor air levels of many pollutants may be 2-5 times, and occasion more than 100 times, higher than outdoor levels. These levels of indoor air pollutants are of particular concern because it is estimated that most people spend as much as 90% of their time indoors." Unlike outdoor air, indoor air is recycled again and again. This causes it to trap and build up pollutants. Common pollutants include dust, mold and spores, pollen, pet dander and smoke.

Learn About Allergies and Asthma
The human body has developed an intricate system for getting rid of harmful foreign substances such as bacteria and viruses. When one of these enters the body, the immune system begins to manufacture antibodies to fight it off.

Most people can breathe in pollen, dust, and dander with no problem. But for people who are allergic to these ordinary everyday things, these substances present more serious consequences. They set off a complicated chain reaction in which the body works hard to expel them. That's why your nose runs, your eyes water, you sneeze and cough.

1. Identify Your Allergy Causes and Triggers
2. Know Your Allergy Triggers
3. Allergy Trigger List
4. Take Steps to Help Prevent Your Allergy Symptoms
5. An Unwelcome Return! 10 tips to ease your allergy symptoms
6. What Can You do for Year-Round Allergies?
7. What is Mold?
8. How Does Mold Get Into a House or Building?
9. Why is Mold Growing in My Home?
10. How Can I Prevent Mold Growth?
11. Can Mold Be Toxic?
12. Can Mold Cause Health Problems?
13. What is Black Mold?
14. Why Are we Concerned About Mold?
15. How do Molds Affect People?
16. 10 Things You Should Know About Mold
17. Who is Affected by Exposure to Mold?
18. What Should I do if I See or Smell Mold in my Home?
19. How to Identify the Cause of a Mold and Mildew Problem
20. Should I Test my Home for Mold?
21. Tips or Techniques to Avoid or Remove Mold
22. Moisture and Mold Prevention and Control Tips
23. Researchers Develop New Method for Determining Moldiness of Home, from the Journal of Allergy and Clinical Immunology
24. Age Healthier, Breathe Easier: Solutions You Can Use to Control or Reduce Environmental Triggers
25. What is Asthma?
26. What Makes Someone Develop Asthma?
27. How Can a Person Tell If He or She Suffers From Asthma?
28. How Many People Suffer From Asthma?
29. What Can Be Done to Prevent Asthma and to Avoid Asthma Episodes?
30. National Environment Leadership Award in Asthma Management
31. Gaining Better Control of Your Child’s Asthma
32. Indoor Air Quality and Schools
33. Suggestions for Reducing Mold Growth in Schools
34. Daycare Facilities an Important Source for Common Indoor Allergens from the Journal of Allergy and Clinical Immunology
35. Classroom Triggers for Asthma and Allergies
36. EPA’s Tools for Schools
37. NSC’s Teacher’s Guide to Indoor Air Pollutants
38. Columbus Elementary School Receives Leadership Awards
39. What is Sick School Syndrome?
40. What Causes It?
41. Signs and Symptoms
42. When to Call the Doctor
43. How Can I Help My Child?
44. Can Sick School Syndrome Be Treated?
45. How Does Outdoor Air Enter a House?
46. Weatherizing You Home
47. Three Basic Statagies for Weatherizing Your Home
48. Pollutant Sources
49. Biologicals
50. Health Effects from Bilogical Contaminants
51. Reducing Exposure to Biological Contaminants
52. The World Health Organization Says Radon Causes up to 15% of Lung Cancers Worldwide
53. Indoor Air Pollution
54. Indoor Air Quality in the Home
55. History of Indoor Air Quality
56. Indoor Air- A Fact Sheet for Homeowners
57. Contaminants of Indoor Air
58. What You Can Do
59. What is Air Duct Cleaning?
60. Other Important Considerations on Duct Cleaning
61. Suggestions for Choosing a Duct Cleaning Service Provider
62. What to Expect from an Air Duct Cleaning Service Provider
63. How to Determine if the Duct Cleaner Did a Thorough Job
64. How to Prevent Duct Contamination
65. Unresolved Issues of Duct Cleaning
66. Should I Have My Indoor Air Tested?
67. What Are Some Common Air Pollutants that Cause Problems?
68. How Can Indoor Air Pollutants Affect My Health?
69. Where are indoor air pollutants found?
70. Biological Contaminants
71. How is This Possible?
72. Amount of Ventilation
73. Keeping You, Your Family and Your Employees Safe
74. Stoves, Heaters, Fireplaces and Chimneys
75. Health Effects of Combustion Products
76. Reducing Exposure to Combustion Products in Homes
77. Household Products
78. Health Effects of Household Chemicals
79. Reducing Exposure to Household Chemicals
80. Indoor Air Pollution and Health
81. What if You Live in an Apartment?
82. The Air You Breathe Indoors
83. What Causes Indoor Air Problems?
84. Safety and Health Topics: Indoor Air Quality
85. Indoor Air Quality Evaluation and Control
86. How Does Secondhand Smoke Affect Asthma?
87. Environmental Tobacco Smoke
88. Health Effects of Environmental Tobacco Smoke
89. Reducing Exposure to Environmental Tobacco Smoke
90. Use of the Building
91. Ventilation Systems
92. Replacement Grant to Increase Awareness of Adverse Effects of Environmental Tobacco Smoke/ Secondhand Smoke on Children
93. What is Sick Building Syndrome?
94. What Are the Symptoms of SBS?
95. What Causes SBS?
96. What Are the Solutions to Sick Building Syndrome?
97. Air Cleaning
98. Should You Use An Air Cleaner?
99. Types of Air Cleaners
    

100. Assessing Potential Performance

1. Identify Your Allergy Causes & Triggers
Any substance (allergen) that causes an allergic reaction when you are exposed to it is an allergy trigger. Knowing your allergy triggers is an important part of your treatment - if you know what you're allergic to, you can try to avoid it. One way to find out what allergens are bothering you is to write down what you were doing and where you were when your symptoms started getting worse.

2. Know Your Allergy Triggers
Any substance (allergen) that causes an allergic reaction when you are exposed to it is an allergy trigger. Knowing your allergy triggers is an important part of your treatment – if you know what you're allergic to, you can try to avoid it. One way to find out what allergens are bothering you is to write down what you were doing and where you were when your symptoms started getting worse. Use the Allergy Trigger List below to identify your allergy triggers...

3. Allergy Trigger List
Rate the severity of your symptoms on a scale of 1 to 5 for each situation (1 = no symptoms; 5 = worst symptoms). Write the numbers on the lines in front of each situation. There is space at the bottom of the page to write down when, and where, your symptoms were the worst. Bring this sheet with you to your next doctor's visit.

If your symptoms get worse:	You might be allergic to:
___In the spring	Tree and grass pollens
___In the summer	Tree, grass, or weed pollens, and mold spores
___In the fall	Ragweed and other weed pollens, and mold spores
___In the garden	Pollen, ragweed, mold spores, dust mites
___Indoors	Dust mites, mold spores (from plants), cockroach droppings, pet dander
___In the bedroom	Feathers, down, dust mites, mold spores
___In the kitchen	Dust mites, mold spores, cockroaches
___Around animals	Pet hairs, pet dander, saliva, or the urine of some small animals (hamsters, gerbils)
Where were you and what were you doing when your symptoms got worse?

4. Take Steps to Help Prevent Your Allergy Symptoms
One way to feel your best during allergy season and all year round is to get your allergy symptoms under control and keep them under control, by following the treatment plan you and your doctor have decided upon. Once an allergic reaction starts, it triggers other chemicals in your body to keep the allergic reaction going.

5. An Unwelcome Return!
10 tips to ease your allergy symptoms In addition to timing medication, the AAAAI offers the following tips to help allergy sufferers find some relief this spring:

• Do a thorough spring cleaning - windows, book shelves and air conditioning vents collect dust and mold throughout the winter that can provoke allergy symptoms.
• Minimize outdoor activity when pollen counts are high. Peak pollen times are usually between 10 am and 4 pm.
• Take medications at least 30 minutes prior to outdoor activity. Consult with an allergist/immunologist to ensure medications are helping you and notify an allergist/immunologist when reactions to medications occur.
• Shut windows in your house on days pollen counts are high. Avoid using windows or fans that may draw pollen inside. · Wash bedding weekly in hot water.
• Dry laundry indoors. Sheets hanging on an outside line are an easy target for blowing pollen.
• Shower and wash your hair before bed - pollen can collect on your hair and skin.
• Keep pets off of furniture and out of the bedroom. Pollen can cling to the dog or cat after being outside.
• Keep car windows closed during peak season. Use air conditioning and point vents away from face.
• When mowing lawn or doing gardening, wear a filter mask.

6. What can you do for year-round allergies?

1. Fight Mites
   Dust mites are too small to see, but lurk anywhere that dust collects, like bedding, upholstered furniture, and carpets- especially in warm, humid homes. Their waste products, which circulate in the air, can trigger an allergic reaction. To help limit your exposure to this common allergen, follow these simple suggestions:
   
   
   • Wash bedding in hot water every week
   • Wrap mattresses, pillows, and box springs in allergen-proof covers
   • Vacuum and dust frequently
   • Remove carpeting from bedroom floors if possible
   • Wash children’s stuffed animals frequently in hot water


2. Dodge the Dander
   Having a pet can be wonderful. The problem is that many of us are allergic to the Dander, saliva, or urine of the cats, dogs, guinea pigs, rabbits, or birds that share our homes. There are, fortunately, certain things you can do to minimize allergens in the air:
   
   
   • Keep your pet out of the bedroom to reduce the amount of dander on your bed, carpeting, and clothing
   • Bathe your pet once a week to get rid of allergens that collect in hair or fur
   • Wash your clothing after wearing it – do not put anything that’s been exposed to allergens back in your closet with clean clothes
   • If your pet is a bird, hamster, mouse, or other rodent, ask someone who does not have allergies to clean the cage when necessary


3. Get Rid of Roaches
   Cockroaches can live and die completely out of sight, without you ever noticing them. Their eggs, waste products, and bodies can cause allergic reactions. Here are some easy ways to limit these allergens:
   
   
   • Keep food covered in airtight containers, and keep the kitchen clean
   • Wash and dry dirty dishes right after you use them
   • Empty garbage cans every day
   • Don’t let newspapers, grocery bags or cardboard boxes pile up
   • If you see cockroaches, exterminate your home
   
   
   The AAAAI is the largest professional medical specialty organization in the United States representing allergists, asthma specialists, clinical immunologists, allied health professionals and others with a special interest in the research and treatment of allergic disease. Allergy/immunology specialists are pediatric or internal medicine physicians who have elected an additional two years of training to become specialized in the treatment of asthma, allergy and immunologic disease. Established in 1943, the AAAAI has more than 6,000 members in the United States, Canada and 60 other countries.



4. Minimize Molds
   Molds grow in dark, damp places such as in basements, bathrooms, closets, mattresses and upholstered furniture, and on houseplants. Millions of microscopic mold spores get into the air we breathe. Try to follow these tips to reduce your exposure to allergy-causing molds:
   
   
   • Use air conditioners or dehumidifiers to reduce dampness and humidity in your home
   • Change the filters on air conditioners and dehumidifiers
   • Keep your kitchen, bathroom, closets and laundry room well ventilated
   • Dry off the walls in the shower and the bathroom floor after bathing
   • Get rid of stale food, and empty and clean garbage pails directly
   • Don’t put damp clothes in a laundry hamper
   • Limit the number of plants you keep in your home

7. What is Mold?
Molds are forms of fungi that are found everywhere -- both indoors and outdoors all year round. Outdoors, molds live in the soil, on plants and on dead or decaying matter. Another common term for mold is mildew. Mold growth is encouraged by warm and humid conditions, although it can grow during cold weather also. There are many thousands of species of mold and they can be in any color, including white, orange, green, brown, or black. Many times, mold can be detected by a musty odor. Most fungi, including molds, produce microscopic cells called "spores" that spread easily through the air. Live spores act like seeds, forming new mold growths (colonies) when they find the right conditions. All of us are exposed to fungal spores daily in the air we breathe, both outside and inside.

8. How Does Mold Get Into a House or Building?
Most if not all of the mold found indoors comes from outdoor sources. It seems likely to grow and become a problem only where there is water damage, high humidity, or dampness. All molds need moisture to grow. Common sources of indoor moisture that can cause mold problems include flooding, roof and plumbing leaks, damp basement or crawl spaces, or anywhere moist air condenses on cold surfaces. Bathroom showers and steam from cooking may also create problems if not well ventilated.

9. Why is Mold Growing in my Home?
Molds are part of the natural environment. Outdoors, molds play a part in nature by breaking down dead organic matter such as fallen leaves and dead trees, but indoors, mold growth should be avoided. Molds reproduce by means of tiny spores; the spores are invisible to the naked eye and float through outdoor and indoor air. Mold may begin growing indoors when mold spores land on surfaces that are wet. There are many types of mold, and none of them will grow without water or moisture.

10. How Can I Prevent Mold Growth?
Controlling excess moisture is the key to preventing and stopping indoor mold growth. Keeping susceptible areas in the home clean and dry is very important. Ventilate or use exhaust fans (to the outdoors) to remove moisture where it accumulates: bathrooms; kitchens; and laundry areas. Be sure the clothes dryer vents to outside the house. Repair water leaks promptly, and either dry out and clean or replace any water-damaged materials. Materials that stay wet for longer than 48 hours are likely to produce mold growth. Lowering the humidity in the home also helps prevent condensation problems. To lower humidity during humid weather, air conditioners and dehumidifiers may be used. Proper exterior wall insulation helps prevent condensation inside the home during cold weather that could cause mold growth.

11. Can Mold be Toxic?
Some molds can produce toxic substances called mycotoxins. Airborne mycotoxins have not been shown to cause health problems to occupants in residential or commercial buildings. The health effects of breathing mycotoxins are not well understood and are currently under study.

High or chronic airborne exposures, typically associated with certain occupations like agricultural work, have been associated with illnesses, although these are rare. More is known about eating mycotoxins (from humans and animals consuming moldy foods or feed) and the resulting health effects than is known about breathing mycotoxins.

12. Can Mold Cause Health Problems?
Molds are usually not a problem indoors, unless mold spores land on a wet or damp spot and begin growing. Molds have the potential to cause health problems. Molds produce allergens (substances that can cause allergic reactions), irritants, and in some cases, potentially toxic substances (mycotoxins). Inhaling or touching mold or mold spores may cause allergic reactions in sensitive individuals. Allergic responses include hay fever-type symptoms, such as sneezing, runny nose, red eyes, and skin rash (dermatitis). Allergic reactions to mold are common. They can be immediate or delayed. Molds can also cause asthma attacks in people with asthma who are allergic to mold. In addition, mold exposure can irritate the eyes, skin, nose, throat, and lungs of both mold-allergic and non-allergic people. Symptoms other than the allergic and irritant types are not commonly reported as a result of inhaling mold. Research on mold and health effects is ongoing. This brochure provides a brief overview; it does not describe all potential health effects related to mold exposure. For more detailed information consult a health professional. You may also wish to consult your state or local health department.

13. What is Black Mold?
The news media often refer to "black mold" or "toxic black mold." It has usually been associated with the mold Stachybotrys chartarum, a type of greenish-black mold commonly associated with heavy water damage. Known health effects are similar to other common molds. It has been inconclusively associated with more severe health effects in some people. While there are only a few molds that are truly black, many can appear black. Not all mold that appears to be black is Stachybotrys.

14. Why Are We Concerned About Mold?
Small amounts of mold growth in workplaces or homes (such as mildew on a shower curtain) or workplaces are not a major concern, but no mold should be permitted to grow and multiply indoors. When molds are present in large quantities, they may cause nuisance odors and health problems for some people. Mold can damage building materials, finishes and home furnishings. Some molds can cause structural damage to wood.

15. How Do Molds Affect People?
Most people will have no reaction at all when exposed to molds. Allergic reactions, similar to common pollen or animal allergies, are the most common health effects for individuals sensitive to molds. Flu-like symptoms and skin rash may occur. Molds may also aggravate asthma. Fungal infections from building-associated molds may occur in people with serious immune disease but this is very rare. Most symptoms are temporary and eliminated by correcting the mold problem in the home.

16. 10 Things You Should Know About Mold
Potential health effects and symptoms associated with mold exposures include allergic reactions, asthma, and other respiratory complaints. There is no practical way to eliminate all mold and mold spores in the indoor environment; the way to control indoor mold growth is to control moisture. If mold is a problem in your home or school, you must clean up the mold and eliminate sources of moisture. Fix the source of the water problem or leak to prevent mold growth. Reduce indoor humidity (to 30-60% ) to decrease mold growth by: venting bathrooms, dryers, and other moisture-generating sources to the outside; using air conditioners and de-humidifiers; increasing ventilation; and using exhaust fans whenever cooking, dishwashing, and cleaning. Clean and dry any damp or wet building materials and furnishings within 24-48 hours to prevent mold growth. Clean mold off hard surfaces with water and detergent, and dry completely. Absorbent materials such as ceiling tiles, that are moldy, may need to be replaced. Prevent condensation: Reduce the potential for condensation on cold surfaces (i.e., windows, piping, exterior walls, roof, or floors) by adding insulation. In areas where there is a perpetual moisture problem, do not install carpeting (i.e., by drinking fountains, by classroom sinks, or on concrete floors with leaks or frequent condensation). Molds can be found almost anywhere; they can grow on virtually any substance, providing moisture is present. There are molds that can grow on wood, paper, carpet, and foods.

17. Who is Affected by Exposure to Mold?
For those who are affected by mold exposure, there can be a wide variation in how they react. People who may be affected more severely and quickly than others include:

• infants and children
• elderly people
• pregnant women
• individuals with respiratory conditions or allergies and asthma
• persons with weakened immune systems (for example, people with HIV infection, chemotherapy patients, or organ or bone marrow transplant recipients, autoimmune diseases.)

Those with special health concerns should consult their doctor if they are concerned about mold exposure. The symptoms that may seem to occur f from mold exposure can also be due to other causes such as bacterial or viral infections, or other allergies.

18. What Should I Do If I See or Smell Mold in My Home?
The most important step in solving a mold problem is to identify and fix the moisture sources that caused the mold growth. For small mold problems, use detergent and water to wash mold off hard surfaces and dry completely. Porous or absorbent materials (such as ceiling tiles, wallboard and carpeting) that become moldy should be replaced. If you do not see mold growth, but notice a musty odor, mold may be growing behind water-damaged materials, such as walls, carpeting or wallpaper. Persons cleaning mold should wear gloves, eye protection and a dust mask or respirator to protect against breathing airborne spores (an N95 dust mask or respirator may be purchased in hardware stores). If you have health concerns, you should consult your doctor before doing any mold cleanup.

19. How to Identify the Cause of a Mold and Mildew Problem
Mold and mildew are commonly found on the exterior wall surfaces of corner rooms in heating climate locations. An exposed corner room is likely to be significantly colder than adjoining rooms, so that it has a higher relative humidity (RH) than other rooms at the same water vapor pressure. If mold and mildew growth are found in a corner room, then relative humidity next to the room surfaces is above 70%. However, is the RH above 70% at the surfaces because the room is too cold or because there is too much moisture present (high water vapor pressure)? The amount of moisture in the room can be estimated by measuring both temperature and RH at the same location and at the same time. Suppose there are two cases. In the first case, assume that the RH is 30% and the temperature is 70oF in the middle of the room. The low RH at that temperature indicates that the water vapor pressure (or absolute humidity) is low. The high surface RH is probably due to room surfaces that are "too cold." Temperature is the dominating factor, and control strategies should involve increasing the temperature at cold room surfaces. In the second case, assume that the RH is 50% and the temperature is 70oF in the middle of the room. The higher RH at that temperature indicates that the water vapor pressure is high and there is a relatively large amount of moisture in the air. The high surface RH is probably due to air that is "too moist." Humidity is the dominating factor, and control strategies should involve decreasing the moisture content of the indoor air.

20. Should I Test My Home for Mold?
Probably not. It should not be your first step. Your first step should be to inspect your home for any evidence of water damage and any visible mold growth. Testing for mold is expensive, and you should have a clear reason for doing so. In most cases, it is not economically practical or useful to test for mold growth on surfaces or for airborne spores in the home. Testing also tells you little about where mold is located and how to clean it up. In addition, there are no standards for "acceptable" levels of mold in buildings, so when testing is done, it is usually to compare the levels and types of mold spores found inside the home with those found outside the home. If you know you have a mold problem, it is more important to spend time and resources to get rid of the mold and solve the moisture problem causing the moldy conditions rather than to test for the mold problem.

21. Tips or Techniques to Avoid or Remove Mold
Fix plumbing leaks and other water problems as soon as possible. Dry all items completely. Scrub mold off hard surfaces with detergent and water, and dry completely. Absorbent or porous materials, such as ceiling tiles and carpet, may have to be thrown away if they become moldy. Mold can grow on or fill in the empty spaces and crevices of porous materials, so the mold may be difficult or impossible to remove completely. Avoid exposing yourself or others to mold (see discussions: What to Wear When Cleaning Moldy Areas and Hidden Mold). Do not paint or caulk moldy surfaces. Clean up the mold and dry the surfaces before painting. Paint applied over moldy surfaces is likely to peel. If you are unsure about how to clean an item, or if the item is expensive or of sentimental value, you may wish to consult a specialist. Specialists in furniture repair, restoration, painting, art restoration and conservation, carpet and rug cleaning, water damage, and fire or water restoration are commonly listed in phone books. Be sure to ask for and check references. Look for specialists who are affiliated with professional organizations.

22. Moisture and Mold Prevention and Control Tips
Moisture control is the key to mold control, so when water leaks or spills occur indoors - ACT QUICKLY. If wet or damp materials or areas are dried 24-48 hours after a leak or spill happens, in most cases mold will not grow. Clean and repair roof gutters regularly. Make sure the ground slopes away from the building foundation, so that water does not enter or collect around the foundation. Keep air conditioning drip pans clean and the drain lines unobstructed and flowing properly. Keep indoor humidity low. If possible, keep indoor humidity below 60 percent (ideally between 30 and 50 percent) relative humidity. Relative humidity can be measured with a moisture or humidity meter, a small, inexpensive ($10-$50) instrument available at many hardware stores. If you see condensation or moisture collecting on windows, walls or pipes ACT QUICKLY to dry the wet surface and reduce the moisture/water source. Condensation can be a sign of high humidity. Actions that will help to reduce humidity: Vent appliances that produce moisture, such as clothes dryers, stoves, and kerosene heaters to the outside where possible. (Combustion appliances such as stoves and kerosene heaters produce water vapor and will increase the humidity unless vented to the outside.) Use air conditioners and/or de-humidifiers when needed. Run the bathroom fan or open the window when showering. Use exhaust fans or open windows whenever cooking, running the dishwasher or dishwashing, etc. Actions that will help prevent condensation: Reduce the humidity (see above). Increase ventilation or air movement by opening doors and/or windows, when practical. Use fans as needed. Cover cold surfaces, such as cold water pipes, with insulation. Increase air temperature.

23. Researchers develop new method for determining moldiness of home, from the Journal of Allergy and Clinical Immunology:
MILWAUKEE – Comparing the levels of airborne fungi inside the house with those found outdoors may provide a method for determining the moldiness of a home, according to a study found in the September 2004 Journal of Allergy and Clinical Immunology (JACI). The JACI is the peer-reviewed scientific journal of the American Academy of Allergy, Asthma and Immunology (AAAAI).

As part of the Inner-City Asthma Study, George T. O'Connor, MD, MS, Boston University School of Medicine, and colleagues measured the concentrations of airborne fungi inside and outside the homes of 414 mold-sensitive children with moderate to severe asthma in seven low-income urban communities across the United States . Researchers analyzed the relation of the concentration of fungi in indoor air to home characteristics and to the outdoor concentration on the day of the measurement. The research was done as part of the Inner-City Asthma Study.

Previous studies have shown that the most common types of airborne fungi, Alternaria, Cladosporium, Penicillium, and Aspergillus, are present in outdoor air and in many indoor environments. The current study found that the levels of these fungi found indoors actually matched those found outdoors across all seven cities, suggesting that the outdoor concentration is an important determinant of the indoor concentration.

Researchers noted:

• Higher levels of fungi were significantly more likely to be found in homes with reported water damage, dampness, or leaks in the past 12 months. This supports the belief that fungi play a role in the association between home dampness and respiratory symptoms.
• Evidence of cockroach infestation in the child's bedroom was found in homes with higher levels.
• Higher levels of fungi were also found in homes
containing cats. This may be the result of fungal growth in a damp litter box or the large amounts of organic material that cats add to house dust.
• Researchers noted that a higher concentration of fungi was less likely in homes with forced air heating and in homes with higher bedroom temperatures.

Exposure to airborne fungi may lead to allergic sensitization and provoke allergy and asthma symptoms. This is the first study to report on the exposure to airborne fungi in asthmatic children living in U.S. inner cities, a group with high morbidity and frequent sensitization to mold. The results of the JACI study may provide a valuable metric for future epidemiologic investigations of the role of fungal exposure as a risk factor for disease.

24. Age Healthier, Breathe Easier: Solutions You Can Use to Control or Reduce Environmental Triggers
Chronic Obstructive Pulmonary Disease (COPD) is the fourth leading cause of death in the United States , claiming approximately 119,000 lives each year. COPD includes chronic bronchitis and emphysema. Asthma is a chronic lung disease which can be life threatening for older adults. More than 2.5 million Americans age 65 and older have asthma, and in 2002 more than 970,000 older adults suffered an asthma episode. The highest mortality rate for asthma occurs in the older population.

Environmental hazards can pose a significant risk to older adults, especially those with COPD and/or asthma. The following charts “Age Healthier, Breathe Easier: Solutions You Can Use” provides a list of useful solutions and some websites which may help you or your loved one avoid or control environmental triggers for COPD and asthma. While there are other non-environmental triggers, these suggestions are limited to environmental triggers.

• http://www.epa.gov/aging/solutions/45 National Institute on Heart, Lung and Blood, NIH, U.S. DHHS, Mortality and Morbidity Chart book 2002 on Cardiovascular, Lung and Blood Diseases.
• National Center for Health Statistics, Centers for Disease Control and Prevention, U.S. DHHS, Summary Health Statistics for U.S. Adults, National Health Interview Surveys, 2001, and 2002 Data File
• American Academy of Asthma, Allergy and Immunology: Seniors and Asthma

25. What Is Asthma?
According to the American Lung Association, asthma is the seventh-ranked chronic health condition in the United States and the leading chronic illness of children. It is a chronic inflammatory disease that makes airways (bronchial tubes) particularly sensitive to irritants.

During an asthma episode, tightening of the smooth muscles around the bronchial tubes causes them to become inflamed, narrow inside, and produce excess mucus. This makes it difficult for air to pass in and out of the lungs and decreases the oxygen levels in the blood. A person suffering from an asthma attack has a sensation similar to drowning.

26. What Makes Someone Develop Asthma?
Some people are born with a predisposition toward developing asthma. However, what actually triggers the disease can vary from person to person. Common triggers include environmental tobacco smoke, air pollution, pollen, allergens from animals and insects, abrupt weather changes, biological contaminants such as mold, and viral infections.

Studies show that children whose parents smoke are twice as likely to develop asthma as children of nonsmoking parents. Also, children whose mothers smoked during pregnancy tend to be born with smaller airways, which greatly increase their chances of developing the disease.

27. How Can a Person Tell If He or She Suffers from Asthma?
Diagnosis is the first step in keeping the condition under control. Early warning signs include fatigue; coughing, even when the person does not have a cold; wheezing; difficulty breathing; tightness in the chest; runny nose; itchy throat; and a change in the thickness, amount, or color of the mucus.

Anyone regularly exhibiting any of the symptoms should see a doctor or allergist as soon as possible. The earlier it is diagnosed the earlier the condition can be controlled.

28. How Many People Suffer from Asthma?
An estimated 23.2 million Americans suffer from asthma, almost 9 million of whom are under the age of 18 - that's 12 percent of children. Asthma is the leading chronic illness of children in the United States and the leading cause of school absenteeism due to chronic illness.

Asthma causes almost 500,000 hospitalizations and about 5,000 deaths annually. Health care costs associated with asthma are estimated at $14.5 billion a year. The number of deaths due to asthma, the number of Americans diagnosed with asthma, and the health care costs of asthma continue to increase each year.

29. What Can Be Done to Prevent Asthma and to Avoid Asthma Episodes?

• Do not allow smoking indoors unless there is a room reserved for smokers and which has a separate ventilation system to exhaust smoke outside. Never allow smoking around anyone with asthma.
• Try to keep humidity levels in the home between 30 and 50 percent. High humidity can promote growth of biological agents that may trigger asthma episodes. Use exhaust fans or open windows in the kitchen or bathroom areas when cooking, using the dishwasher, or taking showers. Make sure clothes dryers are vented to the outdoors, and use a dehumidifier in the basement if necessary.
• Avoid using humidifiers. If it cannot be avoided, clean it according to the manufacturer’s instructions. Refill it daily with fresh water to prevent the growth of harmful microbes.
• Minimize exposure to combustion particles and gases that can cause breathing difficulties for people with asthma. Have combustion-powered furnaces, stoves, or heaters checked yearly to make sure they are operating properly. Change furnace filters according to the manufacturer’s instructions, or every month or two during periods of use. Consider installing higher efficiency filters to reduce the number of particles in the air. Never use a gas stove to heat the home, and always use the exhaust fan when cooking on a gas stove.
• Sprays like deodorants, perfumes, or air fresheners, odors from paint, and strong smelling cleaners may start a child's asthma attack.
• Keep the house clean to reduce allergens like microscopic dust mites, pollen, and animal dander. Use an allergen-proof comforter and encase mattresses and box springs in vinyl covers. Wash bedding frequently in hot (130°F) water. Avoid furnishings that collect dust. Try to eliminate cockroaches. Try to keep pets out of the bedrooms of family members with asthma. Consider using a high-efficiency vacuum filter or a vacuum system that is vented to the outside to clean the house. If possible remove the carpeting, drapes, and all upholstered furniture from the bedrooms of those suffering from asthma.

30. National Environmental Leadership Award in Asthma Management
This awards program recognizes health plans and health care providers for leadership in addressing management of environmental triggers as part of a comprehensive asthma management program. This year's winners were recognized at a national event May 3rd, 2005.

31. Gaining better control of your child's asthma
MILWAUKEE - In conjunction with National Asthma and Allergy Awareness Month in May, the American Academy of Allergy, Asthma & Immunology (AAAAI) is urging parents to ensure that their child's asthma is properly controlled. Of the more than 20 million people in the United States suffering from asthma, 9 million are under the age of 18, according to the AAAAI.

The AAAAI urges parents to use the following checklist on the next visit to their child's allergist/immunologist:

• Ask about steps you can take to make your home a better living environment for your child. Most children with asthma also have allergies that make their symptoms worse. It's important to know what your child is allergic to and how you can provide an allergen free environment.
• Work with your child's allergist/immunologist to create a daily management plan, which describes the regular medications and measures to keep your child's asthma under control.
• Ask the doctor for a peak flow meter – an instrument that measures the airflow of your child when he/she blows into it quickly and forcefully. Experts recommend asthmatic children use them at home to guide decisions about when medications need to be increased or decreased, and to determine when to call a physician or seek urgent care.
• Ask for a demonstration on how to properly use an inhaler.
• Ask about creating an asthma action plan, which describes actions to take when your child's asthma worsens, including what medications to take and when to contact a physician.

32. Indoor Air Quality and Schools
An issue of growing importance these days is the air quality in our nation's schools. A study published by the Government Accounting Office and the Department of Health and Human Services estimates that 8.4 million students attend schools with poor indoor air quality. Poor air quality can affect children's desire and ability to learn and can cause them to miss valuable days of school.

33. Suggestions for Reducing Mold Growth in Schools
Reduce Indoor Humidity: Vent showers and other moisture-generating sources to the outside. Control humidity levels and dampness by using air conditioners and de-humidifiers. Provide adequate ventilation to maintain indoor humidity levels between 30-60%. Use exhaust fans whenever cooking, dishwashing, and cleaning in food service areas. Inspect the building for signs of mold, moisture, leaks, or spills: Check for moldy odors. Look for water stains or discoloration on the ceiling, walls, floors, and window sills. Look around and under sinks for standing water, water stains, or mold. Inspect bathrooms for standing water, water stains, or mold. Do not let water stand in air conditioning or refrigerator drip pans. Respond promptly when you see signs of moisture and/or mold, or when leaks or spills occur: Clean and dry any damp or wet building materials and furnishings within 24-48 hours of occurrence to prevent mold growth. Fix the source of the water problem or leak to prevent mold growth. Clean mold off hard surfaces with water and detergent, and dry completely. Absorbent materials such as ceiling tiles, that are moldy, may need to be replaced. Check the mechanical room and roof for unsanitary conditions, leaks, or spills. Prevent moisture condensation: Reduce the potential for condensation on cold surfaces (i.e., windows, piping, exterior walls, roof, or floors) by adding insulation. Floor and carpet cleaning: Remove spots and stains immediately, using the flooring manufacturer’s recommended techniques. Use care to prevent excess moisture or cleaning residue accumulation and ensure that cleaned areas are dried quickly. In areas where there is a perpetual moisture problem, do not install carpeting (i.e., by drinking fountains, by classroom sinks, or on concrete floors with leaks or frequent condensation). An issue of growing importance these days is the air quality in our nation's schools. A study published by the Government Accounting Office and the Department of Health and Human Services estimates that 8.4 million students attend schools with poor indoor air quality. Poor air quality can affect children's desire and ability to learn and can cause them to miss valuable days of school.

34. Day care facilities an important source for common indoor allergens from the Journal of Allergy & Clinical Immunology
MILWAUKEE - Day care facilities were shown to be an important source for allergen exposure, according to a study featured on the online version of the Journal of Allergy & Clinical Immunology (JACI). The JACI is the peer-reviewed journal of the American Academy of Allergy, Asthma & Immunology (AAAAI).

Indoor allergies have been associated with an increased risk of allergy and asthma development in children. Many studies have examined this relationship using levels found in the child's home since this is where they typically spend most of their time.

Many children also spend a significant amount of time in day care. In 1997, 63% of the country's 19.6 million children under the age of five were in some form of regular child care during a typical week. However, little information is known on allergy levels in day care facilities in the United States.

Samuel J. Arbes, DDS, MPH, PhD, and colleagues from the National Institute of Environmental Health Sciences examined the levels of seven indoor allergens (dog, cat, mouse, American and European dust mite, fungus, and cockroach) in 89 day care facilities located in two North Carolina counties. At each facility, researchers administered questionnaires and collected dust samples from the room where children spent the most time. They collected either a carpet sample, hard surfaces sample, or one of each if both were present.

Researchers discovered:

• Detectable levels of each allergen were found in a majority of the day care facilities examined.
• Dog and cat allergen were detected in 97% and 100% of the facilities, even though dogs and cats were not present in the majority of the facilities.
• The highest concentrations were for fungus, American dust mite allergen, and dog and cat allergen.
• The lowest concentrations were for cockroach allergen, European dust mite allergen and mouse allergen.
• Carpeted surfaces had significantly higher levels of dog, cat and dust allergens, indicating that carpets provide a reservoir for these allergens.

This study provides evidence that day care settings are an important source of exposure to indoor allergens. Further research should be conducted to examine relationships between allergen exposure in day-care faculties and the effect on the health of children and day-care workers.

35. Classroom triggers for asthma and allergies
Challenges facing students range from discomfort that makes it hard to concentrate on school work, to symptoms that reduce their ability to participate in recess or physical education class, to life-threatening reactions to food or insect stings.

The most common allergens at school that may cause an allergic or asthmatic reaction include:

• Dust mites
• Chalk dust
• Animal dander from class pets of pet hair on student's clothing
• Pollen and molds
• Exercise

36. EPA's Tools for Schools
In response to this threat, the Environmental Protection Agency (EPA), in conjunction with the National PTA, National Education Association, Council for American Private Education, Association of School Business Officials, American Federation of Teachers, and the American Lung Association, has developed a packet of materials called Indoor Air Quality (IAQ) Tools for Schools. This kit is designed for use by teachers, school administrators, maintenance staff, school nurses, community leaders, and school boards to help them improve the air quality in their schools with little or no cost, using practical actions and in-house staff.

The kit includes an "Indoor Air Quality Problem Solving Wheel"; checklists for school employees; a step-by-step guide to using the checklists; fact sheet on pollution sources, symptoms, and solutions; and sample memos and forms to aid staff in reporting and responding to incidences and notifying students, staff, and parents of new policies.

37. NSC's Teacher's Guide to Indoor Air Pollutants
The National Safety Council's Environmental Health Center has developed the Teacher's Guide to Indoor Air Quality. This guide contains all the information that teachers will need to teach an educational unit on indoor air quality. The guide is designed for use in fourth through sixth grade classrooms and can easily be incorporated into the general science or health sections of the curriculum. The activities draw on a variety of students' skills including science, vocabulary, reasoning, math, and basic biology.

If your school is currently using IAQ Tools for Schools — this guide is an excellent companion tool.

38. Columbus Elementary School ( Medford, MA) Receives Leadership Awards
On June 3rd, the Columbus Elementary School staff in Medford, MA received EPA’s Environmental Leadership in Indoor Air Awards for their efforts to help students understand and minimize the health risks of exposure to environmental tobacco smoke. The nurses worked with the fourth and fifth grade teachers to incorporate ETS education in their classroom activities. The art teacher guided the children in creating posters that illustrated the dangers of ETS. The posters were used for student-to-student teaching between the fifth and third graders and were displayed at the local mall along with an educational booth display.

39. What Is Sick School Syndrome?
When a building has indoor air problems, it is known as a sick building. Sick building syndrome (SBS) has gotten a lot of attention in the past decade or so, and it's no surprise that "sick schools" have also been put in the spotlight. When a school is deemed sick, it means that the people inside experience health problems that have no other obvious cause and that these symptoms or problems disappear or improve when they leave the building.

There are no strict criteria for diagnosing sick school syndrome; health experts make a diagnosis by examining the child and assessing whether her symptoms seem related to entering or leaving the school building. Sick school syndrome is often wrongly blamed for several illnesses and disorders ranging from winter flu outbreaks to attention deficit hyperactivity disorder. Therefore, it is important for health experts to look for other explanations for a child's symptoms before attributing them to the school environment.

Sick school syndrome is different from building-related illness (BRI), which is any illness that is associated with a building but that can be specifically diagnosed as caused by an identifiable biological or chemical agent. People who have BRI develop an illness related to something specific in the building, and they usually require time to recover from (or sometimes to develop symptoms of) the illness. Examples of building-related illnesses include carbon monoxide poisoning; asbestos, lead, or mercury poisoning; or Legionnaires ‘disease.

Another similar illness is known as multiple chemical sensitivity (MCS). People with MCS get sick when they come into close contact with certain substances, including tobacco smoke, formaldehyde, pesticides, and other pollutants that don't significantly affect most other people. MCS is considered a chemical hypersensitivity or allergy. With sick school syndrome, usually many people become ill, not just one. And the illness is not caused by a specifically identifiable factor; for example, if several kids get sick after a spill in chemistry class, it is not considered to be due to sick school syndrome.

40. What Causes Sick School Syndrome?
Sick school syndrome can be hard to nail down because there is usually no easily identifiable cause for the variety of problems and symptoms that people are experiencing. The most frequent contributing factor, though, is poor indoor air quality.

"The most common problem is that buildings don't have enough ventilation," said Kristy Miller, spokeswoman for the indoor environments division of the U.S. Environmental Protection Agency (EPA).

"Without ventilation, too much moisture leads to mold and bacteria," she says. "Also, using chemicals or paints and not ventilating properly can make people sick. Ventilating is fundamental."

Buildings are more tightly sealed today than they were 50 years ago, mainly because of energy concerns, and this can result in poorer air quality indoors. In addition, synthetic building materials and furnishings and pesticides add to indoor chemical pollution.

Both new and old buildings can be affected. With new buildings, the combination of the tight seal and the presence of chemical materials are often at fault. With older buildings, according to Miller, ventilation systems may have been turned off or allowed to fall into disrepair.

Moisture can also contribute to the development of a sick building, Miller notes. If a roof leaks and carpets are damp, they can become a breeding ground for bacteria, mold, and fungi that can make people sick. In addition, housekeeping supplies, copy machine chemicals, and pesticides can add to the problem.

The problem may also result from a simple miscalculation, like allowing school buses to idle outside an air vent that brings fresh air into the building.

41. Signs and Symptoms of Sick School Syndrome
The most common symptoms of sick school syndrome are headache, fatigue, and shortness of breath. Sinus congestion, sneezing, coughing, and nausea have also been reported, as well as eye, nose, throat, and skin irritation and dizziness.

Because the symptoms of sick school syndrome are similar to those of many other illnesses, it can be difficult to pinpoint indoor air pollutants as the cause. Children with asthma are particularly susceptible to indoor pollutants. The federal government estimates that one in 13 schoolchildren has asthma, and that the number of children with the condition is increasing. A parent may want to consider whether a child's asthma symptoms seem to flare when she is in school compared with when she is at home or outdoors.

42. When to Call the Doctor for Sick School Syndrome
If your child has possible symptoms of sick school syndrome - such as otherwise unexplained headache, fatigue, nausea, dizziness, shortness of breath, sinus congestion, or coughing - or if other children at the school are exhibiting symptoms, contact your child's doctor. Even if it turns out that they're not related to school, the symptoms could mean your child has another problem that needs medical attention.

43. How Can I Help My Child if I Think They Have Sick School Syndrome?
If you think your child might be suffering from symptoms related to poor indoor air quality at school, you should contact the school. Check to see if the school is participating in the "Tools for Schools" program or if they need information. Ask whether other parents have concerns and attend parent group meetings to find out if there are other children with symptoms.

Because sick school syndrome can be the result of many factors, it can be difficult to fix. If your child has asthma, make sure her medicine is available so that she'll be prepared if symptoms flare up at school.

44. Can Sick School Syndrome Be Treated?
There is no specific test for sick school syndrome. The most important way to diagnose the illness is to keep a written record of when your child experiences the symptoms in question - and whether they flare up when your child is at school.

The best way to treat the illnesses triggered by indoor air pollutants is to fix the environmental problem. The EPA has launched an "Indoor Air Quality Tools for Schools" program as a preventive measure that all schools should consider using to ensure good indoor air quality.

The six basic methods for getting rid of indoor air pollution are removal or relocation of the source of pollution; providing exhaust systems in rooms where there are pollutants, such as science labs, industrial arts classrooms, and copy machine rooms; improving ventilation throughout the school; planning use of chemicals for times when children aren't in school, such as waxing floors on the weekends; using clean air filters in ventilation systems; and making sure the school staff is familiar with the importance of clean indoor air.

45. 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.

46. 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.

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

48. Pollutant Sources
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.

49. Biologicals
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 perce.

Sources: Fireplaces, woodstoves, 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 woodstoves, certified to meet EPA emission standards; make certain that doors on all woodstoves 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.

50. Health Effects of 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.

51. 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. These actions can eliminate much of the moisture that builds up from everyday activities. There are exhaust fans on the market that produce little noise, an important consideration for some people. Another benefit to using kitchen and bathroom exhaust fans is that they can reduce levels of organic pollutants that vaporize from hot water used in showers and dishwashers. Ventilate the attic and crawl spaces to prevent moisture build-up. Keeping humidity levels in these areas below 50 percent can prevent water condensation on building materials. If using cool mist or ultrasonic humidifiers, clean appliances according to manufacturer's instructions and refill with fresh water daily. Because these humidifiers can become breeding grounds for biological contaminants, they have the potential for causing diseases such as hypersensitivity pneumonitis and humidifier fever. Evaporation trays in air conditioners, dehumidifiers, and refrigerators should also be cleaned frequently. Thoroughly clean and dry water-damaged carpets and building materials (within 24 hours if possible) or consider removal and replacement. Water-damaged carpets and building materials can harbor mold and bacteria. It is very difficult to completely rid such materials of biological contaminants. Keep the house clean. House dust mites, pollens, animal dander, and other allergy-causing agents can be reduced, although not eliminated, through regular cleaning. People who are allergic to these pollutants should use allergen-proof mattress encasements, wash bedding in hot (130o F) water, and avoid room furnishings that accumulate dust, especially if they cannot be washed in hot water. Allergic individuals should also leave the house while it is being vacuumed because vacuuming can actually increase airborne levels of mite allergens and other biological contaminants. Using central vacuum systems that are vented to the outdoors or vacuums with high efficiency filters may also be of help.

52.
The World Health Organization (WHO) says radon causes up to 15% of lung cancers worldwide.
In an effort to reduce the rate of lung cancer around the world, the World Health Organization (WHO) is launching a new international radon project to help countries increase awareness, collect data and encourage action to reduce radon-related risks. The U.S. EPA is one of several countries supporting this initiative and is encouraged by WHO’s attention to this important public health issue. "Radon poses an easily reducible health risk to populations all over the world, but has not up to now received widespread attention," said Dr. Michael Repacholi, coordinator of WHO’s Radiation and Environmental Health Unit. He went on to say that "radon in our homes is the main source of exposure to ionizing radiation, and accounts for 50% of the public’s exposure to naturally-occurring sources of radiation in many countries."

53. Indoor Air Pollution
The South Carolina Department of Health and Environmental Control, Bureau of Air Quality recognizes Indoor Air Quality as a growing public concern. Currently there is no state or federal regulations addressing indoor air quality in South Carolina (except the control of asbestos). Therefore, the Bureau does not perform any testing or inspections. Please consult the yellow pages of the telephone book under “Environmental Consultants” and/or “Mold and Mildew Services” for professional advice and further assistance with indoor air and mold matters.

Air pollution can be a problem where you least expect it, in the places you may have thought the safest - your home, school or workplace. Studies have shown that the air in our homes and buildings can be even more polluted than the outdoor air.

Many Americans spend up to 90% of their time indoors. Therefore, breathing clean indoor air is important to our health. People who are inside a lot may be at greater risk of developing health problems or have health problems made worse by indoor air pollutants. These people include infants, young children, the elderly, and those who are chronically ill.

54. Indoor Air Quality in the Home
Indoor air affects everyone, and it often contains higher concentrations of hazardous pollutants than outdoor air. However, the good news is that everyone can reduce indoor air pollution.

How can the air inside our homes be so bad for us? Over the years, buildings have been made more airtight to conserve energy. A variety of methods have been employed to keep the hot or cool air from escaping from our homes: installing storm windows and insulation; applying caulk and weather-stripping to seal cracks and other openings; and heating our homes with kerosene, wood, coal, and natural gas. Unfortunately, when we trap in hot or cool air, we also trap in pollutants and sometimes generate more.

On average, people spend about 90 percent of their time indoors. Sixty-five percent of that is spent at home. To make matters worse, those who are most susceptible to indoor air pollution are the ones who are home the most: children, pregnant women, the elderly, and those with chronic illnesses. Children breathe in 50 percent more air per pound of body weight than adults. EPA studies have found that pollutant levels inside can be two to five times higher than outdoors. After some activities, indoor air pollution levels can be 100 times higher than outdoors.

There are many sources of pollutants in the home, including chemicals, cleaning products, and pesticides. Less obvious pollutants are caused by simple tasks such as cooking, bathing, or heating the home. Fortunately, there are easy steps that everyone can take to reduce the potential for indoor air pollution and to improve the quality of the air they breathe.

How do you know if the air inside your home is dangerous to your health? Often, it is difficult to determine which pollutant or pollutants are the sources of a person’s ill health, or even if indoor air pollution is the problem. Many indoor air pollutants cannot be detected by our senses (e.g., smell) and the symptoms they produce can be vague and sometimes similar, making it hard to attribute them to a specific cause. Some symptoms may not show up until years later, making it even harder to discover the cause. Common symptoms of exposure to indoor air pollutants include: headaches, tiredness, dizziness, nausea, itchy nose, and scratchy throat. More serious effects are Asthma and other breathing disorders and cancer.

Children may be more susceptible to environmental exposures than adults, and, due to their developing systems, particularly vulnerable to their effects. Asthma is a case in point. About 8.9 million children in the United States , and more than 12.4 million people total, are affected by asthma each year. A recent study, published in the American Journal of Respiratory and Critical Care Medicine concluded that 65 percent of asthma cases among elementary school-age children could be prevented by controlling exposure to indoor allergens and environmental tobacco smoke (ETS). By controlling biological contaminants (e.g., dust mites and cat allergens), asthma cases could be reduced by 55 to 60 percent

55. History of Indoor Air Quality
Indoor air issues have plagued mankind since there have been dwellings. Prehistoric records show that openings in caves were made to let out the smoke from fires. Changes in construction methods and materials, and a better understanding of the effects of indoor air contaminants, have increased awareness of indoor air quality issues in the past 50 years.

In the mid-1940s, after World War II, the population was on the rise and people wanted a better standard of living. The construction industry responded by developing new building materials – plywood, particleboard, foam insulation, and floor tile. Plywood, particleboard, and foam insulation are made with adhesives and solutions that were not commonly found inside the home previously -- such as formaldehyde, a chemical suspected of causing cancer in some individuals. Some floor tiles and their adhesives were made with asbestos, a material which can cause cancer.

The development of new materials was not restricted to the building trade. Foam padding began to appear in furniture. Permanent press and stain-resistant finishes were applied to fabrics to protect them and make their care easier. At the same time, products to make housework easier began appearing on store shelves. Soon homes were filled with cleaners, insecticides, and other products constructed of manmade materials.

The effects of these materials and the contaminants they can release into the indoor air were compounded when the energy crisis hit in the mid-1970s. To conserve energy, homes were more tightly constructed and better insulated. Energy-efficient homes do not let much fresh air in or contaminated air out, unless they have an air exchanger. And most homes do not have such air exchange devices. Tightly-built homes also keep moisture in, which promotes the growth of fungi and other microorganisms.

56. Indoor Air—A Fact Sheet for Homeowners
People spend about 90% of their time indoors and most of that time is spent in their homes. It is important to keep the air inside your home as healthy and fresh as possible. Your home’s building materials, furnishings, and products, in addition to the activities that are carried on in your home, can have an effect on the quality of the air inside. While office buildings, schools, hospitals, and other buildings can have indoor air quality problems that can give rise to health effects or discomfort for occupants, this fact sheet focuses on some simple steps you can take to improve your home indoor environment.

57. Contaminants of Indoor Air
There are many things in homes that can contaminate the air you breathe. Gases and particles may be released from the materials used to construct your home, as well as the furniture, cleaning products, and other items in your home. Radon gas can seep in from the soil. Products you burn in your home, like tobacco, candles, and fuels for furnaces and stoves, give off gases and particles.

To conserve energy, many newer and remodeled homes are well-insulated and tightly built. Less fresh air can get in and the stale, contaminated air can not escape. The levels of contaminants inside a home can build-up until they are many times greater than the levels in outdoor air.

58. What You Can Do to Reduce the Contaminants n Your Home
There are things you can do to reduce the levels of air contaminants in your home. Most of these things are simple and involve you making decisions about the furnishings, products, and activities that you allow in your home.

Have your home tested for radon and take remedial action if necessary. Improve the filtration of your heating, ventilating, and air conditioning system. The common furnace filters used in most homes do little to remove contaminants from the air. However, not all homes HVAC systems can use high-efficiency filters. Check with an HVAC professional or the manufacturer before installing high-efficiency filters. Consider using air cleaning devices known as electrostatic precipitators, or ESP, in your HVAC system. Such air cleaners can be effective in removing small particles from the air but they must be maintained and cleaned regularly to function properly.

Restrict indoor smoking.

Provide ample ventilation when using products containing VOCs, or when new furnishings are first brought into the home.

When purchasing composite wood products, such as particleboard or plywood, look for products that are labeled or stamped as conforming to American National Standard Institute (ANSI) standards that specify lower formaldehyde levels. These Standards are “ANSI A208.1-1993” for particleboard; ANSI grade “PBU”, “D2”, and “D3” for particleboard flooring; “ANSI A208.2-1994” for fiberboard; and “ANSI/HPVA HP-1-1994” for plywood.

When shopping for upholstered furniture, such as a couch or chair, read the label to find what materials are used for the padding. Some manufacturers stuff their furniture with cotton or feathers, which do not emit the VOCs that foam might.

If you have a gas stove, make sure your exhaust fan is functioning properly and that you use it every time you use your stove. Use a pressure cooker or microwave when possible. The pressure cooker cooks food faster than an oven and the microwave uses electricity, which doesn’t contribute directly to the level of indoor air contaminants. Choose sheets, blankets, window treatments, and other fabrics that are made of cotton and not treated with finishes to resist stains or wrinkles. If you do purchase treated fabrics, wash them thoroughly before storage or use to reduce the amount of VOCs. Use a potpourri of dried flowers, herbs, or citrus peels instead of chemicals if you wish to add fragrance to the air. Open windows and use kitchen and bathroom exhaust fans when you use products such as paint, varnish, glues, cleaning compounds, and other materials that give off VOCs.

NEVER MIX AMMONIA WITH BLEACH. The chlorine in the bleach reacts with the ammonia to produce a very hazardous chlorine gas.

Replace any porous materials that have been damaged by water, such as sheetrock, carpeting, and upholstered furniture. A water-damaged wall should be opened to allow for drying of the interior surfaces ideally drying the wall cavity interior surface within 72 hours. Patching and repainting or wallpapering water-damaged drywall without proper drying can promote growth of biological materials in the damp, interior space in the wall cavity.

The most important action you can take when using household cleaning products is READ THE LABEL AND FOLLOW THE MANUFACTURERS’ DIRECTIONS. Misuse and overuse of household products can lead to overexposure to potentially harmful materials. Common household products can be used safely by most individuals. However, here are some alternatives that you may want to consider:

All-Purpose Cleaner: 1 gallon hot water, 2/3 cup baking soda, 1/4 cup ammonia, 1/4 cup vinegar. You can make the solution stronger by doubling all the ingredients except the water.

Window Cleaner: Mix 1/4 cup ammonia with 1 quart water.

Furniture Polish: Mix 1 teaspoon lemon oil and 1 pint mineral oil.

Oven Cleaner: Wash the oven frequently with a mixture of warm water and baking soda. Soften burned-on spills by placing a small pan of ammonia in the oven overnight. Sprinkle salt onto fresh grease spills and then wipe clean.

Toilet Cleaner: Use baking soda, a mild detergent, and a toilet brush. Floor Polish: Polish floors with club soda.

Silver Cleaner: To a small pan of warm water add 1 teaspoon baking soda, 1 teaspoon salt and a 2” x 2” piece of aluminum foil. Soak silverware overnight.

Rug Cleaner: Sprinkle cornstarch on carpets and vacuum.

Drain Opener: To loosen clogs, spoon 1 tablespoon baking soda into drain and then slowly add 1/3 cup white vinegar. Use a plunger to get rid of the loosened clog. Prevent clogs by pouring boiling water down drains once a week, using drain strainers, and not pouring grease down drains.

Moth Balls: Place cedar chips or blocks in closets and drawers.

Insecticides: Wipe houseplant leaves with soapy water.

59. What is Air Duct Cleaning?
Most people are now aware that indoor air pollution is an issue of growing concern and increased visibility. Many companies are marketing products and services intended to improve the quality of your indoor air. You have probably seen an advertisement, received a coupon in the mail, or been approached directly by a company offering to clean your air ducts as a means of improving your home's indoor air quality. These services typically -- but not always -- range in cost from $450 to $1,000 per heating and cooling system, depending on the services offered, the size of the system to be cleaned, system accessibility, climatic region, and level of contamination. Duct cleaning generally refers to the cleaning of various heating and cooling system components of forced air systems, including the supply and return air ducts and registers, grilles and diffusers, heat exchangers heating and cooling coils, condensate drain pans (drip pans), fan motor and fan housing, and the air handling unit housing (See diagram). If not properly installed, maintained, and operated, these components may become contaminated with particles of dust, pollen or other debris. If moisture is present, the potential for microbiological growth (e.g., mold) is increased and spores from such growth may be released into the home's living space. Some of these contaminants may cause allergic reactions or other symptoms in people if they are exposed to them. If you decide to have your heating and cooling system cleaned, it is important to make sure the service provider agrees to clean all components of the system and is qualified to do so. Failure to clean a component of a contaminated system can result in re-contamination of the entire system, thus negating any potential benefits. Methods of duct cleaning vary, although standards have been established by industry associations concerned with air duct cleaning. Typically, a service provider will use specialized tools to dislodge dirt and other debris in ducts, then vacuum them out with a high-powered vacuum cleaner. In addition, the service provider may propose applying chemical biocides, designed to kill microbiological contaminants, to the inside of the duct work and to other system components. Some service providers may also suggest applying chemical treatments (sealants or other encapsulants) to encapsulate or cover the inside surfaces of the air ducts and equipment housings because they believe it will control mold growth or prevent the release of dirt particles or fibers from ducts. These practices have yet to be fully researched and you should be fully informed before deciding to permit the use of biocides or chemical treatments in your air ducts. They should only be applied, if at all, after the system has been properly cleaned of all visible dust or debris.

60. Other Important Considerations on Duct Cleaning
Duct cleaning has never been shown to actually prevent health problems. Neither do studies conclusively demonstrate that particle (e.g., dust) levels in homes increase because of dirty air ducts or go down after cleaning. This is because much of the dirt that may accumulate inside air ducts adheres to duct surfaces and does not necessarily enter the living space. It is important to keep in mind that dirty air ducts are only one of many possible sources of particles that are present in homes. Pollutants that enter the home both from outdoors and indoor activities such as cooking, cleaning, smoking, or just moving around can cause greater exposure to contaminants than dirty air ducts. Moreover, there is no evidence that a light amount of household dust or other particulate matter in air ducts poses any risk to health. EPA does not recommend that air ducts be cleaned except on an as-needed basis because of the continuing uncertainty about the benefits of duct cleaning under most circumstances. If a service provider or advertiser asserts that EPA recommends routine duct cleaning or makes claims about its health benefits, you should notify EPA by writing to the address listed at the end of this guidance. EPA does, however, recommend that if you have a fuel burning furnace, stove, or fireplace, they be inspected for proper functioning and serviced before each heating season to protect against carbon monoxide poisoning. Some research also suggests that cleaning dirty cooling coils, fans and heat exchangers can improve the efficiency of heating and cooling systems. However, little evidence exists to indicate that simply cleaning the duct system will increase your system's efficiency. If you think duct cleaning might be a good idea for your home, but you are not sure, talk to a professional. The company that services your heating and cooling system may be a good source of advice. You may also want to contact professional duct cleaning service providers and ask them about the services they provide. Remember, they are trying to sell you a service, so ask questions and insist on complete and knowledgeable answers.

61. Suggestions for Choosing a Duct Cleaning Service Provider
To find companies that provide duct cleaning services, check your Yellow Pages under "duct cleaning" or contact the National Air Duct Cleaners Association (NADCA) at the address and phone number in the information section located at the end of this guidance. Do not assume that all duct cleaning service providers are equally knowledgeable and responsible. Talk to at least three different service providers and get written estimates before deciding whether to have your ducts cleaned. When the service providers come to your home, ask them to show you the contamination that would justify having your ducts cleaned. Do not hire duct cleaners who make sweeping claims about the health benefits of duct cleaning -- such claims are unsubstantiated. Do not hire duct cleaners who recommend duct cleaning as a routine part of your heating and cooling system maintenance. You should also be wary of duct cleaners who claim to be certified by EPA. EPA neither establishes duct cleaning standards nor certifies, endorses, or approves duct cleaning companies. Do not allow the use of chemical biocides or chemical treatments unless you fully understand the pros and the cons (See "Unresolved Issues of Duct Cleaning). Check references to be sure other customers were satisfied and did not experience any problems with their heating and cooling system after cleaning. Contact your county or city office of consumer affairs or local Better Business Bureau to determine if complaints have been lodged against any of the companies you are considering. Interview potential service providers to ensure: they are experienced in duct cleaning and have worked on systems like yours; they will use procedures to protect you, your pets, and your home from contamination; and they comply with NADCA's air duct cleaning standards and, if your ducts are constructed of fiber glass duct board or insulated internally with fiber glass duct liner, with the North American Insulation Manufacturers Association's (NAIMA) recommendations. Ask the service provider whether they hold any relevant state licenses. As of 1996, the following states require air duct cleaners to hold special licenses: Arizona, Arkansas, California, Florida, Georgia, Michigan and Texas. Other states may require them as well. If the service provider charges by the hour, request an estimate of the number of hours or days the job will take, and find out whether there will be interruptions in the work. Make sure the duct cleaner you choose will provide a written agreement outlining the total cost and scope of the job before work begins.

62. What to Expect from an Air Duct Cleaning Service Provider
If you choose to have your ducts cleaned, the service provider should: Open access ports or doors to allow the entire system to be cleaned and inspected. Inspect the system before cleaning to be sure that there are no asbestos-containing materials (e.g., insulation, register boots, etc.) in the heating and cooling system. Asbestos-containing materials require specialized procedures and should not be disturbed or removed except by specially trained and equipped contractors. Use vacuum equipment that exhausts particles outside of the home or use only high-efficiency particle air (HEPA) vacuuming equipment if the vacuum exhausts inside the home. Protect carpet and household furnishings during cleaning. Use well-controlled brushing of duct surfaces in conjunction with contact vacuum cleaning to dislodge dust and other particles. Use only soft-bristled brushes for fiberglass duct board and sheet metal ducts internally lined with fiberglass. (Although flex duct can also be cleaned using soft-bristled brushes, it can be more economical to simply replace accessible flex duct.) Take care to protect the duct work, including sealing and re-insulating any access holes the service provider may have made or used so they are airtight. Follow NADCA's standards for air duct cleaning and NAIMA's recommended practice for ducts containing fiber glass lining or constructed of fiber glass duct board.

63. How to Determine if the Duct Cleaner Did a Thorough Job
A thorough visual inspection is the best way to verify the cleanliness of your heating and cooling system. Some service providers use remote photography to document conditions inside ducts. All portions of the system should be visibly clean; you should not be able to detect any debris with the naked eye. Show the Post-Cleaning Consumer Checklist to the service provider before the work begins. After completing the job, ask the service provider to show you each component of your system to verify that the job was performed satisfactorily. If you answer "No" to any of the questions on the checklist, this may indicate a problem with the job. Ask your service provider to correct any deficiencies until you can answer "yes" to all the questions on the checklist. Post-Cleaning Consumer Checklist Yes No General Did the service provider obtain access to and clean the entire heating and cooling system, including ductwork and all components (drain pans, humidifiers, coils, and fans)? Has the service provider adequately demonstrated that duct work and plenums are clean? (Plenum is a space in which supply or return air is mixed or moves; can be duct, joist space, attic and crawl spaces, or wall cavity.) Heating Is the heat exchanger surface visibly clean? Cooling Components Are both sides of the cooling coil visibly clean? If you point a flashlight into the cooling coil, does light shine through the other side? It should if the coil is clean. Are the coil fins straight and evenly spaced (as opposed to being bent over and smashed together)? Is the coil drain pan completely clean and draining properly? Blower Are the blower blades clean and free of oil and debris? Is the blower compartment free of visible dust or debris? Plenums Is the return air plenum free of visible dust or debris? Do filters fit properly and are they the proper efficiency as recommended by HVAC system manufacturer? Is the supply air plenum (directly downstream of the air handling unit) free of moisture stains and contaminants? Metal Ducts Are interior ductwork surfaces free of visible debris? (Select several sites at random in both the return and supply sides of the system.) Fiber Glass Is all fiber glass material in good condition (i.e., free of tears and abrasions; well adhered to underlying materials)? Access Doors Are newly installed access doors in sheet metal ducts attached with more than just duct tape (e.g., screws, rivets, mastic, etc.)? With the system running, is air leakage through access doors or covers very slight or non-existent? Air Vents Have all registers, grilles, and diffusers been firmly reattached to the walls, floors, and/or ceilings? Are the registers, grilles, and diffusers visibly clean? System Operation Does the system function properly in both the heating and cooling modes after cleaning?

64. How to Prevent Duct Contamination
Whether or not you decide to have the air ducts in your home cleaned, committing to a good preventive maintenance program is essential to minimize duct contamination. To prevent dirt from entering the system: Use the highest efficiency air filter recommended by the manufacturer of your heating and cooling system. Change filters regularly. If your filters become clogged, change them more frequently. Be sure you do not have any missing filters and that air cannot bypass filters through gaps around the filter holder. When having your heating and cooling system maintained or checked for other reasons, be sure to ask the service provider to clean cooling coils and drain pans. During construction or renovation work that produces dust in your home, seal off supply and return registers and do not operate the heating and cooling system until after cleaning up the dust. Remove dust and vacuum your home regularly. (Use a high efficiency vacuum (HEPA) cleaner or the highest efficiency filter bags your vacuum cleaner can take. Vacuuming can increase the amount of dust in the air during and after vacuuming as well as in your ducts). If your heating system includes in-duct humidification equipment, be sure to operate and maintain the humidifier strictly as recommended by the manufacturer.

65. Unresolved Issues of Duct Cleaning
Does duct cleaning prevent health problems? The bottom line is: no one knows. There are examples of ducts that have become badly contaminated with a variety of materials that may pose risks to your health. The duct system can serve as a means to distribute these contaminants throughout a home. In these cases, duct cleaning may make sense. However, a light amount of household dust in your air ducts is normal. Duct cleaning is not considered to be a necessary part of yearly maintenance of your heating and cooling system, which consists of regular cleaning of drain pans and heating and cooling coils, regular filter changes and yearly inspections of heating equipment. Research continues in an effort to evaluate the potential benefits of air duct cleaning.

66. Should I have my indoor air tested?
If you can see mold, or if there is an earthy or musty odor, you can assume you have a mold problem. Reliable sampling for mold can be expensive and will have to be done by a private contractor. Also, there are few available standards for judging what an acceptable quantity of mold is. The simplest approach is - if you can see or smell mold, you have a problem. Unless the source of moisture is removed and the contaminated area and/or materials are cleaned and disinfected, mold growth is likely to recur.

67. What are some common indoor air pollutants that cause problems?
Indoor air pollutants are also called biological pollutants. They promote poor indoor air quality. Some of these pollutants can damage surfaces inside and outside your house. They can travel through the air and may not be seen. Some common biological indoor pollutants are:

• Animal dander
• Dust mite and cockroach parts
• Indoor Molds
• Infectious agents (bacteria or viruses)
• Pollen

Other sources of indoor air pollution are:
• Household cleaning and maintenance products
• Perfumes
• Tobacco Smoke
• Wood Smoke

Some of these are in every home and it's impossible to get rid of them all.

68. How can indoor air pollutants affect my health?
All of us are exposed to indoor air pollutants. However, the effects on our health depend on the type and amount of pollution and the person. Some people do not have any health problems from the pollutants, while others do. Allergic reactions are the most common health problem from poor indoor air quality. Some common signs and symptoms of poor indoor air quality are:

• Watery eyes
• Runny nose and sneezing
• Nasal congestion
• Itching
• Coughing
• Wheezing and difficulty breathing
• Headaches
• Fatigue

69. Where are indoor air pollutants found?

• Dirty Heating, Ventilation/Air Conditioning (HVAC) system
• Dirty humidifiers and/or dehumidifiers
• Bathroom and/or kitchen without vents or windows
• Refrigerator drip pans
• Laundry room with unvented dryer
• Unventilated attic
• Bedding
• Dogs or cats
• Anyplace that has water damage

70. Biological Contaminants
Fungi and bacteria can breed in humidifiers and heating, ventilating, and air conditioning (HVAC) systems if this equipment is not properly cleaned and maintained. These systems can also bring biological contaminants indoors and circulate them throughout your home. Contaminants such as pollen, fungi, animal dander; bacteria, viruses, dust mites, and the chemicals or by-products released by these contaminants can cause allergic reactions, colds, influenza and other health effects.

71. How is This Possible?
Improved construction methods have created new air-tight homes, in which air quality has become a serious concern. While outdoor air continually circulates and is refreshed, air in a closed home continually re-circulates the same exhaled cold and flu viruses, pet dander, mold spores, and other potential disease and allergy-causing agents.

People who get sick during the winter often attribute their illness to cold weather outside. In fact, the microorganisms being circulated through home and office ventilation systems are most often the cause of these illnesses.

Those who are indoors for the longest periods are the most vulnerable. A simple cold or flu virus can become deadly for people who are elderly, very young or chronically ill and for those with weak or compromised immune systems. People who fall into these categories are highly susceptible to the effects of indoor air pollution and must be particularly careful.

72. 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."

73. Keeping You, Your Family and Your Employees Safe
Ultraviolet light is the safest, most reliable and most affordable method available for eliminating airborne pathogens.

Breathe CLEAN uses concentrated ultraviolet light to destroy up to 99.9% of the dangerous microbes you breathe, from cold and flu viruses, to mold and mildew, to anthrax and the smallpox virus (particularly important in these uncertain times!)

ISIAQ is an international, independent, multidisciplinary, scientific, non-profit organization whose purpose is to support the creation of healthy, comfortable and productive indoor environments by:

Advancing the science and technology of indoor air quality and climate as it relates to indoor environment design, construction, operation and maintenance, air quality measurement and health sciences;

Facilitating international and interdisciplinary communication and information exchange by publishing and fostering publication on indoor air quality and climate; organizing, sponsoring and supporting initiatives such as meetings, conferences, and seminars on indoor air quality and climate; developing, adapting and maintaining codes, standards, and guidelines for the improvement of indoor air quality and climate;

74. Stoves, Heaters, Fireplaces and Chimneys
In addition to environmental tobacco smoke, other sources of combustion products are unvented kerosene and gas space heaters, woodstoves, 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 woodstoves with no dedicated outdoor air supply can be "back-drafted" from the chimney into the living space, particularly in weatherized homes.

75. 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.

76. Reducing Exposure to Combustion Products in Homes
Take special precautions when operating fuel-burning unvented space heaters. Consider potential effects of indoor air pollution if you use an unvented kerosene or gas space heater. Follow the manufacturer's directions, especially instructions on the proper fuel and keeping the heater properly adjusted. A persistent yellow-tipped flame is generally an indicator of maladjustment and increased pollutant emissions. While a space heater is in use, open a door from the room where the heater is located to the rest of the house and open a window slightly. Install and use exhaust fans over gas cooking stoves and ranges and keep the burners properly adjusted. Using a stove hood with a fan vented to the outdoors greatly reduces exposure to pollutants during cooking. Improper adjustment, often indicated by a persistent yellow-tipped flame, causes increased pollutant emissions. Ask your gas company to adjust the burner so that the flame tip is blue. If you purchase a new gas stove or range, consider buying one with pilotless ignition because it does not have a pilot light that burns continuously. Never use a gas stove to heat your home. Always make certain the flue in your gas fireplace is open when the fireplace is in use. Keep woodstove emissions to a minimum. Choose properly sized new stoves that are certified as meeting EPA emission standards. Make certain that doors in old woodstoves are tight-fitting. Use aged or cured (dried) wood only and follow the manufacturer's directions for starting, stoking, and putting out the fire in woodstoves. Chemicals are used to pressure-treat wood; such wood should never be burned indoors. (Because some old gaskets in woodstove doors contain asbestos, when replacing gaskets refer to the instructions in the CPSC, ALA, and EPA booklet, Asbestos in Your Home, to avoid creating an asbestos problem. New gaskets are made of fiberglass.) Have central air handling systems, including furnaces, flues, and chimneys, inspected annually and promptly repair cracks or damaged parts. Blocked, leaking, or damaged chimneys or flues release harmful combustion gases and particles and even fatal concentrations of carbon monoxide. Strictly follow all service and maintenance procedures recommended by the manufacturer, including those that tell you how frequently to change the filter. If manufacturer's instructions are not readily available, change filters once every month or two during periods of use. Proper maintenance is important even for new furnaces because they can also corrode and leak combustion gases, including carbon monoxide.

77. Household Products
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.

78. 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.

79. Reducing Exposure to Household Chemicals
Follow label instructions carefully. Potentially hazardous products often have warnings aimed at reducing exposure of the user. For example, if a label says to use the product in a well-ventilated area, go outdoors or in areas equipped with an exhaust fan to use it. Otherwise, open up windows to provide the maximum amount of outdoor air possible. Throw away partially full containers of old or unneeded chemicals safely. Because gases can leak even from closed containers, this single step could help lower concentrations of organic chemicals in your home. (Be sure that materials you decide to keep are stored not only in a well-ventilated area but are also safely out of reach of children.) Do not simply toss these unwanted products in the garbage can. Find out if your local government or any organization in your community sponsors special days for the collection of toxic household wastes. If such days are available, use them to dispose of the unwanted containers safely. If no such collection days are available, think about organizing one. Buy limited quantities. If you use products only occasionally or seasonally, such as paints, paint strippers, and kerosene for space heaters or gasoline for lawn mowers, buy only as much as you will use right away. Keep exposure to emissions from products containing methylene chloride to a minimum. Consumer products that contain methylene chloride include paint strippers, adhesive removers, and aerosol spray paints. Methylene chloride is known to cause cancer in animals. Also, methylene chloride is converted to carbon monoxide in the body and can cause symptoms associated with exposure to carbon monoxide. Carefully read the labels containing health hazard information and cautions on the proper use of these products. Use products that contain methylene chloride outdoors when possible; use indoors only if the area is well ventilated. Keep exposure to benzene to a minimum. Benzene is a known human carcinogen. The main indoor sources of this chemical are environmental tobacco smoke, stored fuels and paint supplies, and automobile emissions in attached garages. Actions that will reduce benzene exposure include eliminating smoking within the home, providing for maximum ventilation during painting, and discarding paint supplies and special fuels that will not be used immediately. Keep exposure to perchloroethylene emissions from newly dry-cleaned materials to a minimum. Perchloroethylene is the chemical most widely used in dry cleaning. In laboratory studies, it has been shown to cause cancer in animals. Recent studies indicate that people breathe low levels of this chemical both in homes where dry-cleaned goods are stored and as they wear dry-cleaned clothing. Dry cleaners recapture the perchloroethylene during the dry-cleaning process so they can save money by re-using it, and they remove more of the chemical during the pressing and finishing processes. Some dry cleaners, however, do not remove as much perchloroethylene as possible all of the time. Taking steps to minimize your exposure to this chemical is prudent. If dry-cleaned goods have a strong chemical odor when you pick them up, do not accept them until they have been properly dried. If goods with a chemical odor are returned to you on subsequent visits, try a different dry cleaner.

80. Indoor Air Pollution and Health
Immediate effects 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. Long-term effects 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.

81. 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.

Some days, it seems as if your child spends almost as much time at school as she does at home. As a parent, you worry about whether she does her homework, understands her lessons, and gets along with her classmates.

But should you be concerned about whether her school building is making her sick? The federal government, in a 1995 study, found that half of the nation's schools have poor ventilation and significant sources of pollution inside the buildings. For children with asthma, particularly, indoor pollutants can be a problem.

82. The air you breathe indoors
While you work, play, sleep and relax with your family - may be five times more polluted than the air outside. Americans spend over 85% of every day sealed within increasingly airtight homes and offices, breathing bad air for hours at a stretch. Each breath brings with it a host of germs and allergens: mold spores, bacteria, pollen, dust mites and viruses. The American College of Allergy, Asthma and Immunology estimates that half of all common illnesses are caused or aggravated by poor indoor air quality. And it gets worse... Consider the fumes from cleaning products, paints, solvents, adhesives, and industrial chemicals and emissions; imagine the exhaust from tens of thousands of automobiles in constant motion around you. Your home, far from a haven of safety, can trap and magnify these airborne dangers exponentially.

83. 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.

84. Safety and Health Topics: Indoor Air Quality
Concerns with Indoor Air Quality (IAQ) have increased since energy conservation measures were instituted in office buildings during the 1970’s, minimizing the infiltration of outside air and contributing to the buildup of indoor air contaminants. IAQ generally refers to the quality of the air in an office environment. Other terms related to IAQ include Indoor Environment Quality (IEQ) and “Sick Building Syndrome.”

Complaints about IAQ range from simple complaints such as the air smelling odd to more complexes, where the air quality causes illness and lost work time. It may not be easy to identify a single reason for IAQ complaints because of the number and variety of possible sources, causes, and varying individual sensitivities.

85. Indoor Air Quality: Evaluation and Control
Methods used in an Indoor Air Quality (IAQ) investigation may include: identification of pollutant sources; evaluation of the heating, ventilating, and air conditioning (HVAC) system performance; observation of production processes and work practices; measurement of contamination levels and employee exposure; medical testing or physical examinations; employee interviews; and review of records of medical tests, job histories and injuries and illnesses.

86. How Does Secondhand Smoke Affect Asthma?
Secondhand smoke can trigger asthma episodes and increase the severity of attacks. Secondhand smoke is also a risk factor for new cases of asthma in preschool aged children who have not already exhibited asthma symptoms. Scientists believe that secondhand smoke irritates the chronically inflamed bronchial passages of people with asthma. Secondhand smoke is linked to other health problems, including lung cancer, ear infections and other chronic respiratory illnesses, such as bronchitis and pneumonia. Many of the health effects of secondhand smoke, including asthma, are most clearly seen in children because children are most vulnerable to its effects. Most likely, children's developing bodies make them more susceptible to secondhand smoke's effects and, due to their small size, they breathe more rapidly than adults thereby taking in more secondhand smoke. Children receiving high doses of secondhand smoke, such as those with smoking mothers, run the greatest relative risk of experiencing damaging health effects.

87. Environmental Tobacco Smoke
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."

88. 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 nonsmoking 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 Smoke Free Homes web site, the IAQ Publications page, or contact EPA's Indoor Air Quality Information Clearinghouse (IAQ INFO), 800-438-4318 or (703) 356-4020.

89. Reducing Exposure to Environmental Tobacco Smoke
Don't smoke at home or permit others to do so. Ask smokers to smoke outdoors. The 1986 Surgeon General's report concluded that physical separation of smokers and nonsmokers in a common air space, such as different rooms within the same house, may reduce - but will not eliminate - non-smokers' exposure to environmental tobacco smoke. If smoking indoors cannot be avoided, increase ventilation in the area where smoking takes place. Open windows or use exhaust fans. Ventilation, a common method of reducing exposure to indoor air pollutants, also will reduce but not eliminate exposure to environmental tobacco smoke. Because smoking produces such large amounts of pollutants, natural or mechanical ventilation techniques do not remove them from the air in your home as quickly as they build up. In addition, the large increases in ventilation it takes to significantly reduce exposure to environmental tobacco smoke can also increase energy costs substantially. Consequently, the most effective way to reduce exposure to environmental tobacco smoke in the home is to eliminate smoking there. Do not smoke if children are present, particularly infants and toddlers. Children are particularly susceptible to the effects of passive smoking. Do not allow baby-sitters or others who work in your home to smoke indoors. Discourage others from smoking around children. Find out about the smoking policies of the day care center providers, schools, and other care givers for your children. The policy should protect children from exposure to ETS.

90. 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.

91. Ventilation Systems
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.

92. Replacement Grant to Increase Awareness of Adverse Effects of Environmental Tobacco Smoke (ETS)/Secondhand Smoke on Children
This notice announces the availability of funds and solicits applicants from eligible entities to undertake national education, training, and outreach projects that: promote awareness and understanding of the environmental health benefits of smoke-free environments from children, strengthen the capacity of families and communities to create and sustain a smoke-free environment for children, reduce children's exposure to ETS, and assess the effectiveness and sustainability of education and outreach strategies that reduce and/or prevent children's exposure to ETS.

93. What Is Sick Building Syndrome?
Sick building syndrome (SBS) is a situation in which occupants of a building experience acute health effects that seem to be linked to time spent in a building, but no specific illness or cause can be identified. The complaints may be localized in a particular room or zone, or may be widespread throughout the building.

Frequently, problems result when a building is operated or maintained in a manner that is inconsistent with its original design or prescribed operating procedures. Sometimes indoor air problems are a result of poor building design or occupant activities.

94. What Are the Symptoms of Sick Building Syndrome?
Building occupants complain of symptoms associated with acute discomfort. These symptoms include headaches; eye, nose, and throat irritation; a dry cough; dry or itchy skin; dizziness and nausea; difficulty in concentrating; fatigue; and sensitivity to odors. With SBS, no clinically defined disease or specific chemical or biological contaminant can be determined as the cause of the symptoms. Most of the complainants feel relief soon after leaving the building.

SBS reduces worker productivity and may also increase absenteeism.

95. What Causes Sick Building Syndrome?
While specific causes of SBS remain unknown, the following have been cited as contributing factors to sick building syndrome. These elements may act in combination or may supplement other complaints such as inadequate temperature, humidity, or lighting.

• Chemical contaminants from outdoor sources: Outdoor air that enters a building can also be a source of indoor pollution. Pollutants from motor vehicle exhausts, plumbing vents, and building exhausts (bathrooms and kitchens) can enter the building through poorly located air intake vents, windows, and other openings. Combustion byproducts can also enter a building from a nearby garage.
• Chemical contaminants from indoor sources: Most indoor air pollution comes from sources inside the building. For example, adhesives, upholstery, carpeting, copy machines, manufactured wood products, cleaning agents and pesticides may emit volatile organic compounds (VOCs) including formaldehyde. Research shows that some VOCs can cause chronic and acute health effects at high concentrations, and some are known carcinogens. Low to moderate levels of multiple VOCs may also produce acute reactions in some individuals. Environmental tobacco smoke and combustion products from stoves, fireplaces, and unvented space heaters all can put chemical contaminants into the air. It can also come from synthetic fragrances in personal care products or in cleaning and maintenance products
• Biological contaminants: Biological contaminants include pollen, bacteria, viruses, and molds. These contaminants can breed in stagnant water that has accumulated in humidifiers, drain pans, and ducts, or where water has collected on ceiling tiles, insulation, or carpet. Biological contaminants can cause fever, chills, cough, chest tightness, muscle aches, and allergic reactions. One indoor air bacterium, Legionella, has caused both Pontiac Fever and Legionnaire’s Disease.
• Inadequate ventilation: In the 1970s the oil embargo led building designers to make buildings more airtight, with less outdoor air ventilation, in order to improve energy efficiency. These reduced ventilation rates have been found to be, in many cases, inadequate to maintain the health and comfort of building occupants.

96. What Are the Solutions to Sick Building Syndrome?
Solutions to SBS problems usually include combinations of the following measures:

• Increasing the ventilation rates and air distribution is often a cost-effective means of reducing indoor pollutant levels. At a minimum, heating, ventilating, and air conditioning (HVAC) systems should be designed to meet ventilation standards in local building codes. Make sure that the system is operated and maintained to ensure that the design ventilation rates are attained. If possible, the HVAC system should be operated to the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 62-1989. If there are strong pollutant sources, air may need to be vented directly to the outside. This method is especially recommended to remove pollutants that accumulate in specific areas such as restrooms, copy rooms, and printing facilities.
• Removal or modification of the pollutant source is the most effective approach to solving a known source of an indoor air quality problem when this solution is practicable. Ways to do this include routine maintenance of HVAC systems; replacing water-stained ceiling tiles and carpets; banning smoking or providing a separately ventilated room; venting contaminant source emissions to the outdoors; using and storing paints, solvents, pesticides, and adhesives in closed containers in well-ventilated areas; using those pollutant sources in periods of low or no occupancy; and allowing time for building materials in new or remodeled areas to off-gas pollutants before occupancy.
• Air cleaning has some limitations, but it can be a useful addition to source control and ventilation. Air filters are only effective at removing some, not all, of the pollution.
• Education and communication are important parts of any air quality management program. When everyone associated with the building, from occupants to maintenance, fully understands the issues and communicates with each other they can work more effectively together to prevent and solve problems.

97. Air Cleaning

Air cleaning is one of three methods of reducing pollutants in indoor air. In order of effectiveness, the three methods are:

1. removal of the source or control of its emissions,
2. ventilation,
3. air cleaning.

Air cleaning can be used as an adjunct to source control and ventilation. However, air cleaning alone cannot adequately remove all of the pollutants typically found in indoor air.

98. Should You Use An Air Cleaner?
Many factors need to be considered in determining whether use of an air cleaner is appropriate in a particular setting. Therefore, the decision whether or not to use an air cleaner is left to the individual. EPA has not taken a position either for or against the use of these devices in the home.

99. Types of Air Cleaners
Some air cleaners may be installed in the ducts which are part of central heating or air-conditioning systems in homes. Portable air cleaners stand alone in a room. Types of air cleaners include:

• Mechanical filters, similar to, and including, the typical furnace filter.
• Electronic air cleaners (for example, electrostatic precipitators) which trap charged particles using an electrical field.
• Ion generators which act by charging the particles in a room. The charged particles are then attracted to walls, floors, draperies, etc. or a charged collector.
• "Hybrid" devices, which contain two or more of the particle removal devices discussed above.

100. Assessing Potential Performance of Your Air Cleaner

At a minimum, you should consider the following major factors affecting the performance of the air cleaner:

1. The percentage of the particles removed as they go through the device (that is, the efficiency).
2. The amount of air handled by the device. For example, an air cleaner may have a high efficiency filter, but it may process only 10 cubic feet of air each minute. Suppose that the air cleaner is put in a room of typical size, containing 1000 cubic feet of air. In this room, it will take a long time for all the air to be processed. In some cases, pollutants may be generated more quickly than they are removed.
3. The effective volume of the air to be cleaned. A single portable unit used in a room within a large building in which the air flows between several apartments or offices would be of little or no value.
4. The decrease in performance which may occur between maintenance periods and if periodic maintenance is not performed on schedule.