The air you breathe in your home or office may be hazardous to your health – more dangerous, in fact, than the outdoor air in the most polluted of cities. This is especially so during the cold months, when windows and doors are kept tightly shut and homes, schools and office buildings are made as airtight as possible to conserve energy.
Many people don’t realize that their ”perpetual cold” or other nagging symptoms may be caused by the very air they breathe in their own homes, at school or on the job. Some have been plagued for years and have visited doctor after doctor in a vain attempt to uncover the cause of their problem.
Once the real culprit is suspected or identified, many sources of indoor pollution can be greatly reduced and perhaps prevented entirely, sometimes with little loss of costly heat to the great outdoors.
Indoor air pollution has been linked to a wide variety of adverse health effects, including headaches, respiratory problems, frequent colds and sore throats, chronic cough, skin rashes, eye irritation, lethargy, dizziness and memory lapses.
Long-term effects may include an increased risk of cancer. Though children, the elderly and those with chronic ailments like asthma, allergies and heart and lung diseases seem especially vulnerable, symptoms may also occur in otherwise normal, healthy persons.
Virtually every household and office building is a potential source of excessive amounts of one or another toxic pollutant – nitrogen dioxide, carbon monoxide, hydrocarbons, formaldehyde, radon (a radioactive product of radium), sulphur dioxide, asbestos, not to mention the chemicals in hairsprays, deodorants, oven cleaners, paints, pesticides, laundry aids, floor and furniture polishes, glue and, ironically, air fresheners.
Your kitchen range, fireplace, heater, rugs, walls, furniture, clothing, even the sheets you sleep on, can be significant sources of indoor air pollutants.
The levels of potentially hazardous substances in indoor air often exceed those allowed outside and are sometimes as great or greater than permissible industrial exposures. Yet, a study by the Environmental Protection Agency showed, the average person spends about 90 percent of his or her time indoors, and most of that time is spent at home. The average industrial exposure is only 40 hours a week, but an infant is exposed to home pollutants for nearly 24 hours a day.
The pollution problem is most serious in homes tightly sealed to keep out the winter cold. In a typical ”leaky” house, all the air is exchanged with fresh outdoor air about once an hour, but a wellsealed house may take four to 10 times longer to completely replace the indoor air. This allows an enormous buildup of potentially harmful substances in the air.
Therefore, better ventilation – not sealing up the house too tightly and proper use of venting systems – is the main key to solving problems with indoor pollution. A side benefit of a not-sotight house may be a reduction in indoor humidity, which means less growth of mold spores, a common cause of allergic reactions.
Although not perfect, heat exchangers – duct systems in which the incoming outdoor air picks up most of the heat in the stale indoor air as it is vented outside – can greatly improve the air exchange in a tightly sealed home without much increase in energy cost. Electrostatic air cleaners can filter out many air pollutants in the home, but they also create ozone, itself a respiratory irritant. The effectiveness of ion exchangers as air cleaners is controversial.
Following is a description of the major indoor pollutants identified so far, their sources, their effects and what you can do to protect yourself and your family from exposure to them.
Formaldehyde. This ubiquitous chemical is by far the most worrisome indoor pollutant. It seeps out of urea formaldehyde foam insulation (not polyurethane foam); particle board used in walls, partitions and virtually all the cupboards and furniture made in recent years; rugs and carpets made from synthetic fibers; drapes; permanent press clothing and linens, and many drugs and cosmetics.
A study by Seattle researchers of the occupants of more than 400 mobile homes (which use particle board and are made tight) and 200 regular homes with formaldehyde insulation revealed a high concentration of formaldehyde in the air and complaints from a large proportion of occupants of eye irritation, frequent upper respiratory infections, chronic headaches, periodic memory lapses or drowsiness and, in the elderly, chest pains and heart problems.
A study in laboratory rats showed a high rate of nasal cancers developed in those animals that chronically breathed formaldehyde at levels often found in mobile homes; based on this and other findings, the Consumer Product Safety Commission has proposed a ban on urea formaldehyde foam insulation.
Studies have shown that a sensitivity to formaldehyde can develop through repeated exposure. To protect yourself against this chemical, wash new permanent press items several times before using them; avoid products made from particle board (or coat them with a sealant); check the ingredients list on cosmetics before you buy them, and don’t use formaldehyde foam to insulate your house. Dr.John Spengler, environmental health expert at the Harvard School of Public Health, advises against buying a new house in the summer, when it’s harder to detect the smell of formaldehyde.
Nitrogen dioxide. As a major byproduct of combustion, this irritating air pollutant is commonly found in homes with gas (both natural and liquid propane) cookstoves and heaters at levels far higher than outdoors.
A Harvard study showed that children living in homes with gas stoves had a significant reduction in lung function. A British study revealed an increase in colds and bronchitis among children whose homes had gas ovens. Nitrogen dioxide has been implicated in longterm respiratory problems, and possibly heart disease and cancer.
Gas ranges should be fitted with a hood that is vented to the outside, and the vent should be turned on whenever a burner is lighted or the oven in use.
Carbon monoxide and hydrocarbons. These chemicals are also released into the air when substances burn. Carbon monoxide is an insidious pollutant that can cause drowsiness and headache, impair heart function and even cause death in high concentrations. The hydrocarbons, such as benzpyrene, cause cancer in laboratory animals and can damage the liver, respiratory system and nerve tissue.
Indoors, the main sources of these pollutants are tobacco smoke, wood-and coal-burning stoves, fireplaces, gas ranges, self-cleaning electric ovens, pesticides and automobiles in garages attached to or beneath the house.
Studies have shown that the children of smoking parents have more respiratory infections and asthmatic symptoms than other children. Persons who work next to someone who smokes are more likely to have impaired lung function. The nonsmoking wives of men who smoke die on the average four years sooner and, according to a major Japanese study, face a significantly greater risk of developing lung cancer than they would if their husbands did not smoke.
To reduce the hazards of passive smoking, restrict smoking in your home and agitate at work for a smoking ban (or at least for placing all smokers together in a well-ventilated area). If a family member smokes, ask that all smoking be done as far from others as possible, preferably near an open window, in the basement or, even better, out of doors.
Self-installation of wood- or coal-burning stoves invites disaster. Experts should be consulted on proper ventilation. Follow the manufacturer’s operating guidelines and make sure the draft is set properly before lighting.
Fireplace flues should be cleaned periodically and the damper always opened before the fire is lighted. When operating the selfcleaning device on an oven, open the kitchen window, leave the room and close the door.
Radon. This radioactive gaseous element comes from radium in the soil, rocks, bricks, concrete and water (primarily well water) in and around many homes throughout the country. Levels in homes often exceed those outdoors and may reach the amount in a uranium mine.
Though this is not yet directly linked to specific health risks, radiation experts estimate that thousands of lung cancer cases result each year from exposure to household radon.
Proper radon measurements are not readily available to the public. They require a month-long measurement on a film that registers radioactivity. A home found to be heavily contaminated can be protected by applying epoxy or other sealant to the basement floor and walls and sealing all cracks between the basement and first floor and around utility intakes.
Household chemicals. The toxic effects of substances in household products are many and varied. Few are fully labeled as to their potentially hazardous contents. But all tell the consumer how to use the product safely. Be sure to follow instructions, using adequate ventilation and perhaps a face mask when working with products like oven cleaners, paints and paint removers, floor and furniture waxes and pesticides.
If you are unwilling to open a window wide, it may be safest not to use these products until warmer weather arrives.