Construction joints 3. Cracks in walls 4. Gaps in suspended floors 5. Gaps around service pipes 6. Cavities inside walls 7.
Radon is the second leading cause of lung cancer in the United States.
The proposed MCLG for radon in drinking water is zero. This is a non-enforceable goal. The proposed regulation provides two options for the maximum level of radon that is allowable in community water supplies. EPA is encouraging States to adopt this option because it is the most cost-effective way to achieve the greatest radon risk reduction. L standard would not be required to treat their water for radon.