COLUMN ONE : Clean Air Quest--an Inside Job : When it comes to human health, pollution in homes and offices may be the greatest threat.

Ever since Congress passed the Clean Air Act in 1970, the nation has marshaled its political, economic and technological forces to rid the skies of health-threatening air pollution.

Billions of dollars have been spent to control emissions from motor vehicles, factories, refineries and power plants. Still stricter standards are planned.

Yet, for all the efforts to restore blue skies to the nation’s smoggiest cities, a growing body of scientific evidence suggests that when it comes to human health, indoor contaminants may pose the most pervasive air pollution threat of all.

Concentrations of some toxic, cancer-causing and mutagenic pollutants found indoors are up to 100 times greater indoors than they are outdoors. They far exceed limits placed on the same pollutants in outdoor air by the federal Clean Air Act.

From tobacco smoke and radioactive radon gas to molds, fungi, combustion products and everyday household products like air fresheners and pesticides, humans are being exposed in their homes, offices and vehicles to thousands of chemical and biological agents.

Couple these concentrations with the fact that most people spend between 80% to 90% of their time in increasingly tight energy-efficient buildings, and indoor pollution becomes especially worrisome.

How worrisome remains an open question. Aside from the severe effects of indoor pollutants like asbestos, lead and carbon monoxide, little is known about the health threat posed by other pollutants commonly found in homes and offices.

Still, scientists say that it is reasonable to conclude that as exposures increase indoors, so do the risks.

“Sufficient evidence exists to conclude that indoor air pollution represents a major portion of the public’s exposure to air pollution and may pose serious acute and chronic health risks,” the U.S. Environmental Protection Agency said in a report to Congress earlier this year.

Estimates by some individual researchers indicate that indoor pollution could rank among the top 10 causes of death in the United States.

Scientists for years have appealed to the EPA for greater attention to indoor pollution issues. Their pleas have met with little success. During the Reagan Administration, EPA requests for research funds were repeatedly reduced, and the Bush Administration has allowed only modest increases.

While the EPA staff has estimated that $20 million a year would be needed for indoor air pollution research--the figure now proposed in legislation by Senate Majority Leader George J. Mitchell (D-Me.) and Rep. Joseph Kennedy (D-Mass.)--the Bush Administration this year is spending only $2.68 million. The Bush Administration opposes the Mitchell and Kennedy bills, which are scheduled for votes next year.

Still, even with limited funds, the EPA is calling for studies to pin down the health effects of indoor pollution. It is also seeking ways to reduce indoor contaminants as well as a joint effort by government and industry to develop a voluntary program to upgrade building ventilation standards as well as building design, and improved operation and maintenance of heating, air conditioning and ventilation systems.

In a report made public earlier this month, the EPA compared risks of 20 different environmental problems. Radon, indoor air pollution and pesticide residues on foods pose the greatest health risk but received the least amount of federal spending on those problems, the report said. Toxic dumps and leaking underground gasoline storage tanks pose far less risk but receive the lion’s share of money and attention from the EPA, the study said.

“We concentrate on the big visible sources, chemical plants and oil refineries and outdoor air but the true exposures are the little things under your nose,” said Lance Wallace, a leading authority on indoor pollution. Wallace, an EPA scientist, has pioneered studies aimed at determining the “total exposure” to pollutants from all sources, both outdoor and indoor.

The EPA has estimated that indoor pollution may cost “tens of billions” of dollars annually when medical spending and lost productivity are added up. The Consumer Federation of America has placed the costs as high as $100 billion a year.

List of Dangers

A bewildering array of organic compounds from household products form the catalogue of indoor pollution threats:

- Asbestos, found in cement and insulation, can lead to lung cancer or asbestosis, a chronic lung ailment. Numerous asbestos-abatement programs are under way in schools and public buildings. In July, the EPA banned most remaining uses of asbestos.

- Lead, which retards intellectual and emotional development in children, can be found in older plumbing and in household dust as old paint deteriorates or is chipped away during remodeling.

- Radon, a radioactive gas, invades homes through cracks in the foundation and is the nation’s second leading cause of lung cancer. It may be present at levels the EPA considers unsafe in as many as 12 million U.S. homes; levels have been found to be generally below EPA guidelines in Southern California.

- Formaldehyde, a probable human cancer-causing agent, wafts from foam insulation, plywood and particle board.

- Benzene, a known human carcinogen, is found in cigarette smoke and gasoline.

- Nitrogen dioxide, carbon monoxide and fine particulates that can cause respiratory illnesses spew from kerosene heaters and unvented or poorly maintained gas appliances.

- Chemicals that are known animal carcinogens or toxics are frequently found at very low levels in air fresheners, shoe polish, paints, printed materials, household cleaners, solvents, moth balls and dry-cleaned clothes.

- An estimated 84% of U.S. households use home pesticides, many of which have never been tested to determine their health effects.

The World Health Organization has estimated that up to 30% of new and remodeled buildings may be plagued by indoor air quality problems--an estimate borne out by widespread reports of “sick building” illnesses, including government workers at the EPA’s own headquarters in Washington. In California alone, there are 700 sick building reports a year.

EPA researchers have theorized that--based on available data--indoor pollution, including second-hand tobacco smoke, may account for up to 11,400 deaths each year. Radon exposures may result in anywhere from 3,000 to 20,000 additional deaths.

Up to an estimated 30,000 additional deaths annually have been attributed by one scientist, Harriet Burge of the University of Michigan, to legionella bacteria that thrive in poorly maintained hospital systems for hot water, heating, air conditioning and ventilation.

But even if far fewer cancers are caused by indoor pollutants than EPA estimates suggest, there remains cause for concern.

Many researchers believe that the greatest and most costly problem posed by indoor pollution may well be the chronic, non-cancerous but debilitating health effects that result in higher medical costs, absenteeism and reduced productivity in the workplace.

Few today say that efforts to control outdoor air pollution are unimportant or that they must stop. But a growing number of scientists say the threat to human health from indoor pollution can no longer be ignored.

“If we measured outdoors what we are measuring indoors, there would be a tremendous hue and cry to clean up outdoor air,” Wallace said.

The embryonic indoor air pollution programs of both the state and federal governments pale in significance when compared to spending on other environmental health problems. In California, while radon tied with worker exposure to hazardous chemicals as the No. 1 cancer risk, it ranked last in state spending on 25 environmental problems as recently as two years ago. Likewise, all other indoor air pollution ranked fourth on the list of cancer risks, but 11th in spending among the 25 environmental problems.

As early as 1981, the National Academy of Sciences described indoor air pollution as a potentially significant human health problem. It called for a wide-ranging research effort. But it wasn’t until 1985 that the magnitude of the indoor pollution threat became readily apparent. A five-year EPA study surveyed 600 individuals in six cities to find out what their exposure was to 20 different chemicals, some of which have been linked with cancer and birth defects.

Researchers were startled by the findings. It did not matter whether the study participants lived in the Los Angeles area next to an oil refinery or in a pristine rural setting. Indoor concentrations of the 20 chemical compounds studied were almost always higher, often by as much as 10 times or more, than they were outdoors. Peak concentrations in some homes were 200 to 500 times higher than outdoors.

Indoor Sources

Blood samples and breath tests revealed that participants from rural areas were burdened with as much chemical contaminants in their systems as urban dwellers--a fact that researchers said could only point to indoor sources of pollution common in every household.

The study’s findings left questions that must still be resolved:

Are higher exposures indoors necessarily dangerous? What are the cumulative and synergistic effects, if any, of simultaneous exposures to more than 600 compounds from building materials and household products found in homes?

Are health risks too high or are they comparable to everyday risks that most people take for granted, like driving on a freeway? Will serious health effects take years to show up, as proved to be the case with asbestos? Can it be reasonably assumed that because high doses of some pollutants produce unquestionable adverse health effects in animals that the low-level exposures that most humans experience indoors are also harmful?

What is clear is that the elderly, young children and those who suffer from respiratory problems or are chemically sensitive are particularly vulnerable to indoor contaminants.

Studies in the United States and Britain have found, for example, that children who are exposed to elevated levels of nitrogen dioxide, a combustion product emitted by kerosene heaters and gas appliances, had more than twice the incidence of respiratory illness as children who were not exposed. Their symptoms included fever, chest pain, productive cough, wheeze, chest cold, physician-diagnosed bronchitis, physician-diagnosed pneumonia and asthma.

Benzene, a known human carcinogen, has been found in far higher concentrations indoors than outdoors. In Los Angeles, the EPA found that 71.2% of exposure to benzene occurred indoors. Benzene is emitted by synthetic fibers, plastics and some cleaning solutions. It is also present in gasoline fumes and cigarette smoke.

Wallace said that 37 participants in the air pollution exposure studies who filled their own gasoline tanks at self-service pumps had twice as much benzene in their breath two to five hours after filling up the gas tank as 300 other participants who did not fill their own tanks. But Wallace added that “the most important exposure to benzene is cigarettes.”

Cigarette Smoke

Benzene levels in homes with smokers were 30% to 50% higher than in nonsmoking households. Smokers and those around them are exposed to an estimated 4,600 chemical constituents in cigarette smoke, a number of them cancer-causing. Various studies have estimated that environmental tobacco smoke may account for upwards of 5,000 deaths a year among nonsmokers.

Indeed, EPA scientist James L. Repace has said that the risks of indoor air pollution from tobacco smoke to nonsmokers are almost twice as great as from radon gas, and more than a hundred times as great as the total death rate from all cancer-causing hazardous outdoor air pollutants regulated by the EPA under the Clean Air Act.

Scientists have noted that a 1985 study published by the American Journal of Public Health showed “significant increases” in deaths due to leukemia and lymphomas among people who were exposed as children to parental smoking.

Each year, there are 200,000 emergency room admissions due to allergies and a third of them are believed to be caused by microbiologicals contaminants found indoors, according to Burge, the director of the University of Michigan’s allergy research laboratories at Ann Arbor. “We know that microbial contamination exists. We know that it causes disease and without a doubt it causes a significant number of lost work days at a cost to society,” said Burge.

Sources of Peril

Biological contaminants can thrive in building ventilation systems that are poorly maintained or designed. They can also proliferate in hot water systems if the water is not kept at temperatures of at least 113 degrees Fahrenheit. Porous insulation and filters combined with excessive humidity make for an ideal growing medium for microbiologicals.

Formaldehyde, which is widely used in building materials and furnishings, can cause eye, nose and throat irritation, coughing, skin rashes, headaches, dizziness, nausea, vomiting and nosebleeds. It also causes nasal cancer in rats and is thus a suspected human carcinogen.

Generally, the newer the building material or furnishings, the higher the formaldehyde gas emissions. High temperatures and humidity can compound the problem.

Today, most pressed-wood product manufacturers have taken steps to lower concentrations of formaldehyde to acceptable levels, even in mobile homes where the problem was once greatest. But researchers continue to find a 10-fold difference in emission from identical products produced by different manufacturers. Carpet makers stopped using formaldehyde in 1981.

Also of special concern is methylene chloride, which can produce cancer in animals and is widely used in paint removers and as a propellant in aerosol spray paint and can affect oxygen uptake in the blood like carbon monoxide. Some half billion pounds are produced annually, and half of that goes into consumer products.

“I think we have every right to be concerned about some of the consumer products that are used,” said John Girman of the California Department of Health Services, referring to methylene chloride.

Air refresheners used in rooms, cars, diaper pails and toilets are also of concern. Many of these products use p-Dichlorobenzene or limonene, both of which have been found to cause cancer in animals.

The EPA’s Wallace said his studies found that these two chemicals accounted for the greatest risk of cancer among 45 indoor air organic chemicals.

A good deal of scientific uncertainity exists over what, if any, the effects of long-term exposure to p-Dichlorobenzene may be, but the EPA said it would be “prudent” to avoid non-essential consumer products containing the chemical.

Behavior Changes

While the actual health threats of many indoor contaminants are not known, reducing or eliminating exposure to them in many cases is fairly straightforward. It could involve changes in behavior as obvious as stopping smoking (or only smoking outdoors) or making certain that ventilation systems are properly maintained and operated.

“To get substantial reductions, you don’t have to go off in the woods and eat nuts and berries,” said John Holmes, chief of the California Air Resource Board’s research division.

Ordinary house plants can help, a study by the National Aeronautics and Space Administration found. The study said that philodendrons, spider plants and the golden pothos were most effective at absorbing formaldehyde, while flowers like the gerbera daisy and chrysanthemums were best at reducing levels of benzene. Bamboo palm, English ivy, peace lily, mother-in-law’s tongue and Chinese evergreen also proved to be effective air purifiers, the study said.

Consumers can substitute safer products for those that give off toxic chemicals, and carefully follow directions on the use and storage of pesticides, paints and solvents.

“In a large number of cases we see it’s going to be pretty much up to individuals to make their own choices as to what steps they should or shouldn’t take to reduce their exposure to indoor air pollution,” said Robert Axelrad, director of the EPA’s indoor air division.

“These kinds of health risks have been there all along. We just haven’t realized it,” said Holmes. “But slowly we’re getting the results from what is a gigantic experiment. As it becomes clear what the risks are, at least on a selective basis, society will move to reduce or severely limit those risks.”

AIR POLLUTION SOURCES IN THE HOME

Concentrations of some airborne pollutants have been found to be up to 100 times greater indoors than outdoors. Scientists say much remains to be learned about the health effects of indoor air pollution. But they agree that higher pollution levels indoors mean higher health risks. Following is a list of air pollutants commonly found in homes and offices and what can be done to reduce exposures.

A pamphlet, “Inside Story: Guide to Indoor Pollution,” is available from the EPA Information Center, PM-211B, 401 M Street SW, Washington, D.C. 20460; phone: (202) 382-2080.

POLLUTANTS Radon SOURCES Uranium-bearing soil and rock beneath residences. HEALTH EFFECTS No immediate symptoms, but estimated to cause 10% of lung cancer deaths. Smokers are at higher risk. LEVELS IN HOMES National average is 1.5 picocuries per liter. STEPS TO REDUCE EXPOSURE Test your home for radon. Get professional advice in planning and carrying out radon-reduction measures if necessary. Ventilate crawl space. Smoking increases health risk from radon so stop smoking and discourage others from smoking, or smoke outdoors. POLLUTANTS Environmental tobacco smoke SOURCES Cigarette, pipe and cigar smoking. HEALTH EFFECTS Eye, nose and throat irritation; pneumonia. Increased risk of respiratory and ear infections in children. Can cause lung cancer and may contribute to heart disease. LEVELS IN HOMES Particle levels in homes without smokers are usually the same as outdoors. Homes with one or more smokers may have particle levels several times higher than outdoor levels. STEPS TO REDUCE EXPOSURE Stop smoking and discourage others from smoking, or smoke outdoors. Environmental tobacco smoke contains many compounds including benzopyrene, carbon monoxide, nitrogen dioxide and formaldehyde. POLLUTANTS Biologicals (house dust, insect parts, cat saliva, bacteria, molds; viruses) 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, asthma, influenza and other infectious diseases. LEVELS IN HOMES Indoor levels of pollen and fungi are lower than outdoors (except where indoor sources of fungi are present). Indoor levels of mites are higher than outdoor levels. STEPS TO REDUCE EXPOSURE Install and use fans vented to outdoors in kitchen and baths. Vent clothes dryers to outdoors. Ventilate attic and crawl spaces. Clean cool mist and ultrasonic humidifiers daily and use only distilled water in them. Empty water trays in humidifiers frequently. Clean and dry or remove water-damaged carpets. Use basements as living areas only if they are leakproof and have adequate ventilation. Use dehumidifiers if necessary to maintain humidity at 30% to 40%. POLLUTANTS Carbon monoxide SOURCES Unvented kerosene and gas heaters; leaking chimneys and furnaces; downdrafting from wood stoves and fireplaces; gas stoves; auto exhaust from attached garages; environmental tobacco smoke. HEALTH EFFECTS Impaired vision and coordination; headaches; fatigue; confusion; nausea. Flu-like symptoms that clear up after leaving the home. Fatal at high concentrations. LEVELS IN HOMES Average levels in homes vary from 0.5 to 5 ppm. Levels near well-adjusted gas stoves are often 5 to 15 ppm, and near poorly adjusted stoves may be 30 ppm or higher. STEPS TO REDUCE EXPOSURE Keep gas appliances properly adjusted. Vent outdoor heaters and furnaces to outdoors. Use proper fuel in kerosene space heaters; take outside to start and refuel. Use only in well-ventilated area. Install and use exhaust fan vented to outdoors over gas stoves. Choose properly sized wood stoves, equipped with pollution controls; make certain that doors on wood stoves fit tightly. Have annual inspection, cleaning and tune-up of central heating system (furnaces, flues and chimneys). Repair any leaks. Do not idle car inside attached garage. POLLUTANTS Nitrogen Dioxide SOURCES Unvented kerosene heaters, unvented gas stoves and heaters; environmental tobacco smoke; underground or attached garages; fireplaces. HEALTH EFFECTS Eye, nose and throat irritation; may cause impaired lung function and respiratory illness. LEVELS IN HOMES Average level in homes without combustion appliances is about half that outdoors. In homes with gas stoves, average concentrations over a 24-hour period range from .01 ppm to .13 ppm. Kerosene heaters and unvented gas space heaters may produce indoor levels from 0.1 ppm to 0.5 ppm. STEPS TO REDUCE EXPOSURE See steps under carbon monoxide POLLUTANTS Respirable Particles SOURCES Fireplaces, wood stoves, kerosene heaters; humidifiers; environmental tobacco smoke. HEALTH EFFECTS Eye, nose, and throat irritation; respiratory infections and bronchitis; lung cancer. Effects attributable to environmental tobacco smoke are listed above. LEVELS IN HOMES Particle levels in homes are typically the same as outdoors. STEPS TO REDUCE EXPOSURE Vent kerosene space heaters and all furnaces to outdoors; keep doors to rest of the house open when using unvented space heaters. Choose properly sized wood stoves equipped with pollution controls; make certain that doors on all wood stoves fit tightly. Have annual inspection of central heating system (furnaces, flues and chimneys). Repair any leaks that are found. Change filters on central heating and cooling systems and air cleaners according to manufacturer’s directions. POLLUTANTS Household products SOURCES Paints, paint strippers and other solvents; aerosol sprays, cleaners, and disinfectants; moth repellents and air fresheners; stored fuel and automotive products; hobby supplies; dry-cleaned clothes. HEALTH EFFECTS Eye, nose and throat irritation; headaches, loss of coordination, nausea; damage to liver, kidney and central nervous system; some organics may cause cancer. LEVELS IN HOMES Levels of several organics average 2 to 5 times higher indoors than outdoors. During and for several hours after certain activities such as paint stripping, levels may be 1,000 times average outdoor levels. STEPS TO REDUCE EXPOSURE Follow manufacturer’s directions carefully. Use outdoors or in well-ventilated places. Safely discard and dispose of any unused or little-used containers. If dry-cleaned clothes have strong odor, ask dry cleaner to dry them more or change dry cleaners. Keep indoor spaces well ventilated; minimize use of air fresheners. Keep clothes with moth repellents containing paradichlorobenzene tightly sealed in well-ventilated areas. Consider using cedar chips as moth repellents (if you are not sensitive to cedar oils.) POLLUTANTS Formaldehyde (an organic compound) SOURCES Pressed wood products (paneling, particle board, fiber board, plywood) and furniture made with pressed wood products; ureaformaldehyde foam insulation (known as UFFI). Drapes, carpets, other textiles and glues may contribute. Also combustion sources and environmental tobacco smoke. HEALTH EFFECTS Eye, nose and throat irritations; wheezing and coughing, fatigue, skin rash, severe allergic reactions. May cause cancer. May also cause effects listed under household products. LEVELS IN HOMES Average concentrations in older homes without UFFI are generally less than 0.1 ppm. Homes with significant amounts of new pressed wood products can reach levels greater than 0.3 ppm. STEPS TO REDUCE EXPOSURE Use pressed wood products that are lower in formaldehyde emissions. (Manufacturers in recent years have reduced formaldehyde in these products). Apply lacquer or polyurethane coatings to pressed wood products. (Carefully follow manufacturer’s directions when applying.) Use air-conditioning and dehumidifiers to maintain moderate temperatures and reduce humidity levels. Increase ventilation, particularly in new homes. POLLUTANTS Pesticides SOURCES Products sold to kill household and garden pests. HEALTH EFFECTS Irritation to eye, nose and throat; damage to central nervous system and kidneys; cancer. LEVELS IN HOMES Preliminary research shows widespread presence of pesticide residues in some homes. STEPS TO REDUCE EXPOSURE Use strictly according to manufacturer’s directions. Mix or dilute outdoors. Apply only in recommended quantities. Increase ventilation when using indoors. Use non-chemical methods of pest control when possible. If you use a pest control company, select it carefully. Do not store unneeded pesticides inside home; dispose of unwanted containers safely. POLLUTANTS Asbestos SOURCES Brittle or damaged insulation, fire-proofing or acoustical materials. HEALTH EFFECTS No immediate symptoms. Chest and abdominal cancers and other lung diseases. Smokers are at higher risk of developing asbestos-induced cancer. LEVELS IN HOMES Elevated levels are found in homes where materials containing asbestos are deteriorating or damaged. STEPS TO REDUCE EXPOSURE Seek professional advice to identify problems. Do not disturb materials suspected of containing asbestos. Use certified contractors for asbestos removal or cleanup. Follow proper procedures in replacing wood stove door gaskets that may contain asbestos. POLLUTANTS Chloroform SOURCES Hot tap water (chlorine in water combines with organic solids to form chloroform, which vaporizes when heated). HEALTH EFFECTS No immediate symptoms. LEVELS IN HOMES Levels vary. STEPS TO REDUCE EXPOSURE Use warm instead of hot water in showering. Place an activated charcoal filter on the shower head. Source: U.S. Environmental Protection Agency