To reduce radon levels, homeowners may need to take steps as simple as installing fans for ventilation, (estimated to cost about $150) or as involved as sealing cracks along walls and floors ($300-$500) and installing exhaust pipes to draw the radon back outdoors (costing from $2,500 to $5,000).
Environmental officials said homeowners have to have their homes tested to find out if it contains the gas which can't be seen or smelled. Testing kits may be bought by homeowners for $10 to $50 apiece or private contractors can be hired.
The risk can usually be reduced by sealing floors so the gas cannot seep indoors, and sometimes by installing a small permanent fan below the floor to waft the gas out through air vents.