Beginning on March 1, 2014, all landlords or owners of residential buildings who enter into a lease or tenancy at will agreement must test the building for the presence of radon; this requirement was originally slated to apply in 2012 but was pushed back to 2014 at the last legislativeåÊsession. Radon is a naturally occurring radioactive gas which results from the normal breakdown of uranium found in most rocks and soil and which has been proven to cause lung cancer. The testing must be conducted by a person registered with the Department of Health and Human Services pursuant to Title 22, chapter 165. Once the testing has taken place, the landlord or owner must disclose the results of the test in writing to all tenants and/or potential tenants. If the testing reveals radon levels of 4.0 picocuries per liter of air or above, the landlord or owner must mitigate the level of radon and notify the tenants of such mitigation efforts. A violation of this statutory requirement will result in a civil fine of up to $250 per violation. For more information about radon in Maine, including a listing of individuals and entities registered to conduct radon testing and mitigation, please visit www.maineradiationcontrol.org.