January is National Radon Awareness Month. Radon is the second leading cause of lung cancer in the U.S. The odorless, invisible and tasteless gas may be a natural breakdown product of soil and water.  The Brookfield Health Department has a limited quantity of free radon test kits, available to Brookfield residents. The kits come with a postage-paid, mail-in envelope to be sent to the Connecticut State Lab for testing. Reports are returned to the Health Department and in turn, to the homeowner.  Radon typically enters closed-up homes through openings and cracks in foundations and walls. Or, it can be aerosolized when one takes a shower.