By Environmental Health Watch
The Greater Cleveland Environment Book, published by EcoCity Cleveland (1998) <http://www.ecocitycleveland.org/>

Pollution may be a problem in the place we expect to be safest from harm — our homes. Indeed, many of the regulated outdoor pollutants are commonly found at higher levels indoors. Since we spend 90% of our time indoors, and most of that at home, the quality of our residential environment is a serious health concern.

Indoor pollution problems can cut across housing type, age, cost, location and condition. A brand-new, custom built, $400,000 house can makes its occupants sick. So can an energy-efficient, 15-year old tract house. And so can a restored century house, a well-maintained, 70-year old, suburban double, and a dilapidated, inner-city row house. However, low-income, deteriorated housing poses the greatest risks.

Young children, the elderly, and people with chronic health problems may be especially susceptible to the effects of indoor pollutants and they are also the people who spend the most time in the house. Asthma, for example can be aggravated by exposure to allergens and irritants in the home environment. The American Lung Association estimates that 23,000 children in Cuyahoga County suffer from asthma.

As with all toxic exposures, the health risk from residential pollution is a function of the toxicity of the pollutant, the nature of the exposure, and the susceptibly of the people exposed. In assessing the heath risk from an indoor pollutant, you need to ask a series of questions:

• Is the pollutant source present and at what strength? Is there a potential pathway for exposure from the source to the occupants? What is the level, duration and pattern of that exposure? How can exposure levels be tested?
• How does occupant behavior effect exposure? Does climate control (e.g., temperature, humidity, ventilation) effect source strength and exposure? Does the thoroughness or frequency of house cleaning make a difference? How about the use of consumer products such as hobby, decorating and building materials?
• What is the nature of the health effects of concern? Are there effects from short-term, high-level exposures? From long-term, low-level exposures? How potent is the pollutant in producing the effect? Is there a threshold? Are some people more vulnerable? How good is the evidence of health effects?
• What are the control options? How soon does action need to be taken? Can entry of the pollutant into the house be prevented. Can the source be removed from the house? Can the pollutant be diluted? Can it be treated? Can the exposure pathway be blocked? Can improper control efforts exacerbate the problem? Can control be a do-it-your-self job or does it require trained and specially equipped professionals? How might control actions effect other house systems?

Environmental Tobacco Smoke
Tobacco smoke is one of the most common indoor air quality problems. It contains over 4,000 compounds, at least 40 of which are known human carcinogens. A 1992 EPA report concluded that exposure to environmental tobacco smoke is responsible for approximately 3,000 lung cancer deaths each year in nonsmoking adults and impairs the respiratory health of many more children.  Infants and young children whose parents smoke in their presence are at increased risk of lower respiratory tract infections such as bronchitis and pneumonia and tend to display symptoms of respiratory irritation such as coughing, wheezing, and excess phlegm. Asthmatic children are especially at risk: exposure to secondhand smoke increases the number of episodes and severity of asthma attacks. Additionally, second-hand smoke may cause thousands of non-asthmatic children to develop the disease each year.

Suggestions: Don't smoke at home or permit others to do so. If you must smoke indoors, do it only in designated, well-ventilated rooms. Don't smoke if children are present, particularly infants and toddlers, and don't allow baby-sitters or others who interact with children to smoke around them either.

Biological Contaminants
Viruses, bacteria, fungi, mold, mildew, mites, pollen, arthropods, and animal dander and saliva are collectively known as biological contaminants. The sources are varied. Viruses and bacteria are carried into the home by people and animals, and animal dander and saliva originate from household pets, as well as rats and mice. Mold, mildew, and fungi can be introduced into the home by either natural ventilation or through the air intake of a ventilation system.

For many people, biological contaminants trigger allergic reactions such as allergic rhinitis ("hay fever") and some types of asthma. Some diseases, such as humidifier fever, have been linked to microorganisms that grow in ventilation systems and heating and cooling systems and are then dispersed throughout the home. Dust mites and roach dust (cockroach feces and parts) are common indoor contaminants which can trigger and exacerbate asthma attacks.

Suggestions: Control of moisture levels in the home is key to controlling many biological pollutants. Standing water, water-damaged materials, or wet surfaces serve as breeding grounds for molds, mildews, bacteria, and insects. Additionally, house dust mites and roaches thrive in damp, warm environments. Humidity levels can be reduced by installing and using exhaust fans in the kitchen and bathroom, venting clothes dryers outdoors, ventilating attics and crawl spaces, cleaning humidifiers on a regular basis, and cleaning and drying (or replacing) water-damaged carpets and building materials as soon as possible after the damage occurs. Keeping a house clean in general reduces the amount of pollens, animal dander, roach dust and dust mites present.

Combustion Products
Combustion products — dangerous gases and particles — can be generated by household appliances, such as furnaces, water heaters, gas stoves, space heaters, and fire places. If these appliances are not adjusted properly and/or they are not exhausted or vented adequately, they can release carbon monoxide, nitrogen dioxide, other gases, and small particles into the indoor air.

Carbon monoxide is a colorless, odorless gas which combines with the hemoglobin of the blood and interferes with its ability to deliver oxygen throughout the body. High concentrations are fatal. Lower concentrations can cause headaches, dizziness, nausea, confusion, fatigue, and chest pain, symptoms which are sometimes confused with the flu or food poisoning. Nitrogen dioxide is a colorless and odorless gas that can irritate the mucous membranes in the eye, nose, and throat. High concentrations can cause shortness of breath and may also increase the risk of respiratory infection and emphysema. Particulate matter from incompletely burned fuels can lodge in the lungs and irritate or damage lung tissue.

Suggestions: Furnaces and chimneys should be professionally inspected annually. Carbon monoxide detectors should be installed, but not in lieu of an annual furnace inspection. Signs of incomplete combustion or poor venting of flue gases may be foul smells from the appliance or unusual condensation and black soot on walls and windows. Other steps to take to reduce exposure to combustion products in homes include: not using unvented space heaters, installing and using exhaust fans over gas stoves, making certain that the doors on wood stoves and fire places are tight-fitting and that the wood burned is properly dried and not painted or treated.

Pesticides, Building Materials and Consumer Products
A wide variety of pesticides, building materials and consumer products used in and around the home contain toxic ingredients which can contaminate the indoor environment. Although indoor exposures are generally quite low, they are consistently higher than outdoor concentrations, and can be substantial following remodeling, pesticide application, or other product use.

Toxic chemicals can be emitted from numerous consumer products, building materials and pesticides:

• Formaldehyde, a chemical almost ubiquitous in the modern home, is found in wood products (e.g., fiberboard, plywood and particle board), fabrics (e.g., draperies and carpets), and finishes. Urea-formaldehyde foam insulation (UFFI) was generally not used after the 1980s because of problems with formaldehyde "off gassing" into the indoor air; now, years after installation, "UFFI homes" are generally not a problem.
• Other potential indoor air contaminants can be found in building materials such as adhesives, solvents and coatings, and in consumer products such as hobby materials and dry-cleaned clothes. New carpets may emit dozens of toxic chemicals.
• In addition to the toxic "active ingredients" in pesticides, hundreds of toxic chemicals are classified as "inert ingredients" in pesticide formulations, but are not listed on the label. A chemical banned as an active ingredient may be found as an "inert" component.

The patterns of residential exposure and the health effects of the mix of exposures at residential levels are not well-established, but some studies have found worrisome associations with serious illness, particularly in children. The chemicals  typically measured in residential indoor air, depending on level and duration of exposure and the sensitivity of the exposed population, can have a range of short- and long-term health effects, from eye irritation to neurotoxicity to cancer.

Suggestions: When considering purchases, read ingredient lists and warnings. Learn about alternative materials and products. For example exterior-grade pressed wood products emit less formaldehyde and newer water-based finishes eliminate problems with solvents. Buy the least amount necessary for the job.

Take label warnings seriously. Work outdoors if possible. Keep children, the elderly and people with chronic illnesses out of the work area. Wear protective gear. Ventilate aggressively with fans; ventilate closets and cupboards when finished.  Listen to your body—if you get a headache or skin irritation, stop. Do not use hazardous products while pregnant, smoking, consuming alcohol, eating or wearing contact lenses.

Pesticides are inherently toxic, so learn about environmental controls for pests and about least toxic pesticides. Of particular concern are home foggers, which can produce high concentrations and have caused acute health problems when rooms were reentered too soon after application. Even when used properly, some pesticides, such as subterranean termiticides, can produce long-term, low-level living area exposures.

Asbestos
Asbestos — a family of naturally-occurring mineral fibers — was commonly used in boiler and furnace insulation, floor tiles, roofing, siding, and other materials in houses built before the 1950s, but was not entirely banned until the late 1970s. Although there may be many sources of asbestos in houses, there is an exposure pathway only if the asbestos-containing material is disturbed and microscopic asbestos fibers are released into the air. If the asbestos is firmly embedded in the product, such as in vinyl-asbestos floor tile or asphalt-asbestos roofing material, or if the material is covered, such as intact boiler pipe insulation, there is likely minimal current exposure. However, dangerous amounts of asbestos fibers may be released if the material is demolished, sawed, drilled, or sanded.

Over a period as long as 20 or 30 years, breathed-in asbestos fibers in the lungs can increase the risk of lung cancer and mesothelioma (cancer of the lining of the chest and abdominal cavity). Smoking dramatically increases the risk of lung cancer from asbestos exposure. Average indoor asbestos levels are extremely low and so the related health risk is assumed to be low from the mere presence of asbestos-containing material. However, exposure levels can increase if the material is disturbed.

Suggestions: Generally it is best to just leave asbestos-containing material alone unless it must be disturbed for furnace replacement or for other repair or renovation. It may often be safer to cover the asbestos-containing material with an exposure barrier than to remove it. If removal or substantial covering is required, the work should be done by a licensed asbestos contractor.

Lead
Leaded paint was used in most houses and apartments built prior to the 1950s and in some until 1978. Leaded paint is most likely to be found on siding, porches, windows, kitchen and bath walls, and trim. Deteriorated or improperly removed leaded paint can contaminate household dust and soil. Lead was also used in gasoline until the 1980s and much of that lead still contaminates soil, which can be tracked into the house on shoes and be blown in through open windows and doors.

Children are poisoned by exposure to lead in peeling paint, and in lead-contaminated dust and soil. Children swallow lead that gets on their hands, toys, and pacifiers. Most children are poisoned by normal hand-to-mouth contact with lead-contaminated dust and soil around the house; some children eat paint chips and dirt. Other lead hazards include lead dust brought home on work clothes and lead in hobby and craft materials. Although drinking water is generally not a major source of lead poisoning, there are some public water systems, including Cleveland's, that have found elevated tap levels under worst-case testing. Corrosion control measures have been instituted to reduce the leaching of lead from the house plumbing system.

Childhood lead poisoning has been declared by the U.S. Public Health Service to be "the most common and societally devastating environmental disease of young children." Elevated blood lead has been associated with developmental delays, deficits in intellectual performance and neurobehavioral functioning, decreased stature, and diminished hearing acuity. Adverse effects have been established at blood lead levels  previously thought to be safe. Because lead hazards are so pervasive, all children under six years old should have blood test to determine lead levels.

Children between the ages nine months and three years are at the greatest risk because they have a high degree of hand-to-mouth activity, they absorb ingested lead more efficiently, and because of the heightened vulnerability of their developing nervous system to lead toxicity. However, lead accumulated during childhood can remain stored in bone for many years and may be released from bone latter in life. This may happen during pregnancy and thus poison the fetus. There is also speculation that adult neurotoxic effects may occur when lead is released from the bone as part of the aging process.

Over the past 15 years there has been a dramatic 77% decline in children's average blood-lead levels, due primarily to the elimination of lead from gasoline. However, for poor and minority children living in deteriorated housing, the rates remain at epidemic levels. Even children in well-maintained housing can be put at risk by lead-contaminated soil and by lead dust generated during home repair, renovation, and remodeling. In any event, the decline in average blood-lead level is not likely to continue at the same dramatic pace because the major control actions — elimination of lead from gasoline, paint, plumbing components, and food cans, and the more strict industrial release standards — have already had their effect.

Average adult blood lead levels are low and adult lead poisoning is overwhelmingly related to occupational exposure. However, adults can poison themselves (and their children) at home when engaged in renovation projects that involve torching, heat gunning or power sanding leaded paint.

Suggestions: Paint chips, dust  and soil samples can be sent to a lab for lead analysis or do-it-yourself test kits can be purchased at hardware stores. If you can not test, assume that paint in older homes is leaded and that bare soil is lead-contaminated.

The general lead hazard control strategy is to clean up immediate lead hazards and to prevent the creation of new lead hazards. In addition, provide good nutrition to reduce the child’s absorption of ingested lead. Call 800/424-LEAD for guidelines.

Here are some lead hazard control tips:

• Improper removal of leaded paint can spread dangerous lead dust; do not dry scrape, sand, torch or heat gun leaded paint. Before undertaking such work, get information about lead-safe work practices. The free booklet “Reducing Lead Hazards When Remodeling Your Home” is available by calling 1-800/LEAD-FYI.
• Cover or block children’s access to damaged leaded paint; clean-up paint chips immediately.
• Wash children’s hands, toys, and pacifiers frequently; provide meals and snacks high in iron and  calcium and low in fat.
• Wash floors, widow sills and window wells frequently with automatic dishwasher or other high-phosphate or lead-specific detergent to clean lead dust
• Cover bare soil — plant grass or other plants or cover with woods chips, gravel, top soil, sand, bricks; use washable mats, leave shoes at door.
• Do not bring work shoes or work clothes that may have lead dust into the house.
• Use only cold tap water for consumption; run water before using.
• Ohio law requires that all lead abatement work, other than that done by a home owner on their own house, must be done by a licensed contractor. Lead inspectors and risk assessors also must be licensed.

Radon
Radon gas, a naturally occurring, radioactive soil gas, can infiltrate the air in your house and increase the risk of lung cancer. Radon arises from uranium, which is present in small amounts in the soil and rock throughout the earth’s crust, but particularly in volcanic rocks such as granite and in dark shales such as those underlying west-central Ohio. As uranium undergoes natural radioactive decay, it gives off radiation and transforms into a series of elements which includes radon. Radon enters the home through cracks in the foundation, floor drains, sump pumps, and other openings.

When radon is inhaled, its radioactive breakdown products deliver a radioactive assault to the lungs, which increases the risk of lung cancer. Radon may be the leading cause of lung cancer among nonsmokers. But because smoking substantially increases the susceptibility to radon damage to the lungs, most lung cancer deaths due to radon are among smokers.

Radon radiation is measured in picocuries (trillionths of a curie) per liter of air (pCi/L). The average outdoor radon level is about 0.4 pCi/L; the average indoor level is about 1.3 pCi/L. Lifetime exposure to 4 pCi/L  means a 50% added lifetime risk of lung cancer. For men who are nonsmokers, this is estimated to increase lung cancer risk from 1% to 1.5%. But for men who are smokers, the increase is from 10% to 15%. The EPA has suggested 4 pCi/L (annual average) as an action level for taking steps to reduce radon in the home.

Homes with elevated levels of radon have been found in all counties in the United States, and therefore all homes should be tested for radon, regardless of their geographic location. Testing for radon is not difficult and need not be costly. Most people can use low-cost, do-it-yourself kits.

Suggestions: There are two basic strategies for reducing indoor radon: 1) stop radon from getting in and 2) remove it if it does get in. Radon entry can be stopped by sealing entry points (e.g., covering sump pumps, sealing crawl space soil), using sub-slab ventilation to draw off radon before it enters, and reducing air pressure differences between the basement and surrounding soil which drives radon in. Removing radon involves increasing ventilation of the basement.

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