Residential pollution hazards:
By Environmental Health Watch
Pollution may be a problem in the place we expect to be safest from harmour homes. Indeed, many regulated outdoor pollutants are commonly found at higher levels indoors. Since we spend 90 percent 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 inside. 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:
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 that 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. [But dont forget to be careful when choosing finishing materials in your home today, everything from the fiberboard under the carpet, to the glue in the carpet to the plywood in your bookshelves still commonly has formaldehyde in it and can take years to complete off-gassing.]
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.
Actions: 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 bodyif 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.
Asbestosa family of naturally-occurring mineral fiberswas commonly used in boiler and furnace insulation, floor tiles, roofing, siding, and other materials in houses built before the 1950s, but it 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.
Actions: 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.
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 blown in through open windows and doors.
Children are poisoned by exposure to lead in peeling paint, 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 household plumbing.
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 tests 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 systems to lead toxicity. 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 percent 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.
Actions: 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 cannot 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 prevent the creation of new lead hazards. In addition, provide good nutrition to reduce a childs 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.
Ohio law requires that all lead abatement work, other than that done by homeowners on their own houses, must be done by a licensed contractor. Lead inspectors and risk assessors also must be licensed.
Radon gas, a naturally occurring, radioactive soil gas, can infiltrate the air in a 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 Earths crust, but particularly in volcanic rocks 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, including 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 percent added lifetime risk of lung cancer. For men who are nonsmokers, this is estimated to increase lung cancer risk from 1 percent to 1.5 percent. But for men who are smokers, the increase is from 10 percent to 15 percent. 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.
Actions: 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.
Environmental Health Watch is a nonprofit resource center for information on chemical hazards in the home and community.
Home pollution resources
Nontoxic cleaning and pest control
People are typically exposed to more toxic chemicals in their homes than anywhere else. And two potential sources of such chemicals are cleaning products and pesticides.
Another source of indoor pollution is pesticides used for insect control. A system called integrated pest management (IPM) offers a least-risk way of dealing with the situation. With IPM, first the problem is identified-what insects are present and why are they present. Bugs like to be where they are accommodated with food and shelter. Bugs must first find an access route, which is where the detective work begins. Perhaps there are cracks in walls or around windows. Perhaps there's rotted wood from a water drainage problem, and insects are coming in to eat the decaying wood. Perhaps a woodpile is too close to the house. After taking care of such causes, if a pesticide is needed, a least-risk one could be used, such as those derived from a biological source. Examples include boric acid compounds or diatomaceous earth (shell flour).
Laurel Hopwood, chair of the Northeast Ohio Sierra Club Human Health and Environment Committee
Five basic ingredients for home cleaning: