Radon is a colorless and odorless radioactive gas that has been estimated to cause 5,000 to 20,000 lung cancer deaths yearly, second only to smoking as a cause of lung cancer. It has been estimated that nearly 1 out of every 15 homes in the US has elevated radon levels.

Radon is produced when small amounts of uranium and radium in soil and rocks decay. Radon gas will also decay into smaller radioactive particles that, when inhaled into the lungs, can damage cells and cause lung cancer.

Radon is mainly released from soil, water and natural gas sources previously exposed to radon, solar-heating systems that employ the use of radon-emitting rocks and uranium or phosphate mine tailings. Radon is naturally released in low concentrations, but inside your home, radon gas can become much more concentrated. Lack of ventilation exhaust fans, which bring in fresh air from the outside, can dramatically increase the amount of radon in your home.

The Environmental Protection Agency suggests that all homes should be tested for radon. A safe home should have a radon level of 4 picocuries per liter or less. If you are selling your home and you have not had your home tested previously, the EPA recommends that you do so, and that radon levels be reduced prior to sale, if necessary. Radon levels can be reduced by increasing the airflow into the house, keeping the vents open year round, and discouraging smoking inside the house. Before you purchase a new home, the EPA suggests that you obtain the radon test results, as well as information about radon reduction systems.

If you are planning to have your home tested for radon, the EPA recommends that the test be conducted in the lowest level of the home that is suitable for occupancy. Make sure that the test is conducted correctly by following the EPA Test Checklist.

There are two different types of testing devices available: passive devices and active devices. Passive devices, such as charcoal canisters, alpha track detectors and charcoal liquid scintillation devices are exposed to air in the home for a specified amount of time, and are sent to a laboratory to be analyzed. Active devices, such as continuous radon monitors and continuous working level monitors, continuously measure and record the amount of radon in the air and require operation by trained testers. These tests can be performed over a long or short period of time; however the long term tests by active devices are considered to be more accurate.