You've probably read about these problems over the last decade. They can still be serious concerns for some house hunters. Radon is a colorless, odorless gas that came to public attention in the mid-1980s and has been determined to have serious health risks, including cancer. It is found in the ground, as well as in some building materials. Radon testing is still a routine part of many home purchases. High radon levels can usually be corrected, and remediation can be arranged before the closing. Most house inspection firms will do radon checks. If yours does not, ask your real-estate agent where to get this done.

Lead-based paint is present in most houses built before 1950. If ingested, it can be very harmful to children, causing brain damage and even death. The federal government has explanations and guidelines for covering this problem. Call your local housing authority and/or health department. You should receive an EPA-approved lead-based paint pamphlet if the home was built before 1978. The pamphlet is called “Protect Your Family from Lead in Your Home.” For more on this issue, you can visit www.epa.gov or www.hud.gov.

If you know a seller has had previous toxic-hazard problems in the past, get the home tested for it. Another toxic hazard to be aware of is carbon monoxide, an odorless, invisible gas. Among the places it can be found are gas fireplaces, furnaces, stoves, space heaters, and wood-burning stoves. Formaldehyde, an acrid, colorless gas, can also be found in some building materials.