(MONEY Magazine) – Reports now abroad of household toxic hazards can alarm even the unflappable. Fibers of asbestos from building and insulating materials can cause cancer and , respiratory damage. Traces of radon gas emitted by uranium in the subsoil may also lead to lung cancer if breathed for several decades. Formaldehyde compounds used in insulation and wood products make some sensitive people cough or gasp for air. The presence, real or suspected, of these pollutants can also hurt real estate sales and values. Compounding the problem are stories of incompetent contractors charging high prices for inferior service. Still, it costs little to find out if a house harbors the more serious hazards. The particulars: Radon. In high concentrations it has given lung cancer to uranium miners, but there is no proof that the levels most often detected in homes here and there across the country are lethal. With the threshold of risk still uncertain, however, the U.S. Environmental Protection Agency has cautiously set a low exposure limit of four picocuries -- four-trillionths of a curie, the basic unit of radioactivity. Concentrations of radon vary widely from place to place. If you live in a hotspot, or suspect so from news reports, have your home checked for radon, preferably by a testing company that has been approved by a state or federal EPA office. These agencies can supply names of certified testers, who generally charge $50 to $200, depending on the size of your house and on the inspection method. After seeing several house sales fall through because radon was identified, one big broker in New Jersey, Schlott Realtors, now puts a clause in its sales contracts requiring the seller to fix the problem or to release the buyer from the agreement. Sometimes the fix is cheap. If the culprit is exposed earth in the cellar, you may be able to seal off the leakage for $100 or so. But if radon is penetrating concrete-block walls, you may need to install a ventilation system costing as much as $5,000 in large houses. Some state EPAs or radiological health offices can give you the names of the few contractors who have experience with radon. For further help, write to your regional EPA office or the Public Information Center, U.S. Environmental Protection Agency (Washington, D.C. 20460) for two booklets, A Citizen's Guide to Radon and Radon Reduction Methods. Asbestos. This fire-resistant mineral is now banned from most uses because microscopic particles of asbestos cling tenaciously to the lungs. Some years later serious or fatal respiratory damage can show up. For generations asbestos was packed around furnaces and heat pipes, mixed in wall plaster and used in floor and ceiling tiles. The best advice from the U.S. Consumer Product Safety Commission, however, is not to remove it unless the asbestos seems to be cracking, flaking or powdering. State and local health departments can advise you on how to identify and deal with the problem. The removal of asbestos is hazardous unless performed by trained workers who, for instance, may charge you as much as $5,000 for replacing the insulation in a large heating system. Two alternatives: covering the asbestos with protective tape or specially formulated paint ($10 to $50). The Consumer Product Safety Commission (Washington, D.C. 20207) publishes a free advice booklet, Asbestos in the Home, and answers questions over a hotline (800-638-2772). Formaldehyde. This chemical is often a bonding agent in plywood and particle board in kitchen cabinets and furniture and in foam insulation blown into walls. There is no practical way of measuring formaldehyde levels. But unless someone in your household is hypersensitive to this chemical, only fresh formaldehyde is likely to cause trouble: itching eyes, wheezing, coughing or other respiratory distress. To avoid the risk, don't buy a house or install wood cabinets without getting a written guarantee that no formaldehyde is present.

CHART: TOXIC COST OF COST OF HAZARD DETECTION REMOVAL

Radon gas $100 to $200 $50 to $5,000 Asbestos $100 to $500 $100 to $5,000 Formaldehyde Impractical Expensive

CREDIT: ROBERT CONRAD CAPTION: WHAT PRICE DECONTAMINATION? You can detect and if necessary get rid of two of these household pollutants at the range of costs shown, but you may have to live with the third one, formaldehyde, or move. DESCRIPTION: Color drawing of house emitting cloud of fumes.