General Radon Information

Minnesota specific radon and radon level information can be found throughout this site. You will be able to find information about certified radon inspectors in Minnesota, as well as detailed radon level information for every county in Minnesota.

While most people are aware that air pollution can be hazardous to their health, many do not know that the air they breathe inside their own homes could be killing them. Millions of homes and buildings contain high levels of radon gas. What is radon? Radon is a colorless, odorless and tasteless radioactive gas that occurs naturally in most rocks and soil. It is produced by the breakdown of uranium in soil, rock and water. Radon is harmlessly dispersed in outdoor air, but when trapped in buildings can increase the risk of lung cancer, especially at elevated levels. It typically enters a home the same way air and other soil gases enter the home, through cracks in the foundation, floor or walls, hollow-block walls, and openings around pipes, sump pumps, and floor drains. It can also be present in some construction materials and in water from underground sources including private wells. Any home, regardless of age, energy-efficiency, or foundation type, could have a radon problem. The only way to know whether or not a particular home has a problem is to test THAT home.

Much of the soil in the Upper Midwest contains widespread uranium and radium. These minerals continuously break down to release radon gas. Therefore, Minnesota's geology provides an ongoing supply of radon. In addition, a large percentage of Minnesota homes have high levels of radon in the indoor air because of how they are built and the local climate. One important risk factor is that many Minnesota homes have basements that are used as living spaces. MDH estimates that about one in three (1/3) Minnesota homes has enough radon to pose a large risk to the occupants' health over many years of exposure. In some areas of the state, the percentage of homes that have high levels of radon is even larger. Homeowners can reduce this risk by mitigating if they have radon problems, which typically costs between $800 to $1200.

When radon decays and is inhaled into the lungs, it releases energy that can damage the DNA in sensitive lung tissue and lead to lung cancer. In fact, prolonged exposure to high levels of radon is the second leading cause of lung cancer in the United States, contributing to between 7,000 and 30,000 lung cancer deaths each year. Smokers are at higher risk of developing radon-induced lung cancer. There are no short-term radon exposure symptoms that have ever been documented. You will not have any other bodily symptoms such as joint pain, stomach or intestinal problems, headaches, or rashes from short-term radon exposure at natural environmental levels (4 pCi/liter or less).

Radon is not regulated in Minnesota, so it is up to homeowners to decide for themselves how much radon is acceptable in their home. However, the USEPA action level for radon is 4.0 picocuries per liter of air (pCi/L). The risk of developing lung cancer at 4.0 pCi/L is estimated at about 7 lung cancer deaths per 1000 persons. Thousands of preventable lung cancer deaths annually in the United States are attributable to indoor residential exposure to radon. Either smoking or radon exposure can independently increase the risk of lung cancer. However, exposure to both greatly enhances that risk. (At exposures to 4 pCi of radon per liter of air, the lifetime lung cancer risk attributable to radon rises from 2 cases per thousand in non-smokers to 29 cases per thousand in smokers). The USEPA and IEMA recommends reducing your radon level if the concentration is 4.0 pCi/L or more.

The MDH recommends that all Minnesota homeowners test their homes for radon. The results of a properly performed radon test will help homeowners determine for themselves if they need to take further action to protect their family from the health risks of radon in the home.

Contact the MDH Indoor Air Unit for more information on where to obtain low cost radon test kits, the types of test kits, how to perform tests properly and how to use the results. You may also consult the MDH fact sheet Minnesota Radon Testing and Use of Test Results which is available by calling MDH or on our website.

MDH recommends that all new homes in Minnesota be built to include radon-resistant construction features that minimize radon entry into the home and make future radon problems easier to fix should they occur. It is more cost-effective to include radon-resistant features when building a home rather than retrofitting an existing home. If elevated radon levels are found after you move in, radon-resistant features can be easily activated to become radon reduction systems. Ask your builder if they are currently using radon-resistant construction techniques.

Additionally, all newly built homes in Minnesota should be tested for radon after they are completed and occupied. Early detection of elevated radon levels can help protect the homeowner's financial interests if the radon problem is due to construction problems and can allow the homeowner to take appropriate actions to lower the radon level and protect the health of their family.