Radon is a radioactive gas that enters the home through the soil or water and may create increased risks of lung cancer. Most homes in the Boulder County and Denver Metro area real estate market have radon levels higher than those considered safe by the EPA. In Boulder County, radon testing is a routine component of home inspections, but it is less common in other area real estate markets.
Most professional home inspectors do radon testing, typically charging about $130. Mitigation for radon problems is generally not difficult, nor is it prohibitively expensive. Typically, a pipe is inserted through the basement slab and extended outside the home. A low volume fan then draws gases (including radon) through the gravel that is under the slab, into the pipe, and out of the home. This typically costs about $800-$1000.
Several issues are a constant source of problems in dealing with radon in the home buying process. First, the testing devices that are commonly used to measure radon levels can be left in the home only for a 2-5 day period. While these devises provide accurate measurements of the radon levels in the home during this period, radon levels vary dramatically from one day to the next depending on a variety of factors, including weather conditions, whether the ground is frozen, and whether fireplaces or furnaces are operating. A home that tests above or below the EPA limits one week may not the next. Second, while radon levels in most homes in our area exceed EPA recommendations, most exceed these recommendations by marginal amounts. Especially if the seller or listing agent understands the limitations of radon testing, this can make negotiations regarding mitigation difficult. Finally, while I would certainly rely on the EPA over a real estate agent in assessing the health risks of radon, there appears to be serious scientific debate over the health risks of low level radon exposure.
My recommendation would be to test for radon and try to negotiate mitigation if the results exceed EPA recommendations. Whatever the results of these short term screening tests, run a year long test after you move into the home so that you have a real measure of potential exposure. Just because your home tests within EPA recommended levels when you run your short term test doesn’t mean that it will if you run a more reliable long term test. Check the EPA radon home page for additional information and publications.