Radon is a radioactive gas recognized to be the leading cause of lung cancer in non-smokers according to the US EPA. The United States Environmental Protection Agency explains radon is formed during the decay of uranium. Radioactive uranium is a naturally occurring element found at low levels within all rock, soil, and water throughout the world. They quote “Any radon exposure has some risk of causing lung cancer. The lower the radon level in your home, the lower your family’s risk of lung cancer.”
The US EPA also states it doesn’t matter how new or old, drafty or sealed a residence is or whether the residence has a basement, is on a raised foundation or is on a concrete slab. Radon can infiltrate the living space through miniature cracks and voids in the foundation and pass directly into a residence where once trapped, can present major health risks to the occupants.
There is no amount of radon gas that is considered harmless but the US EPA has identified concentrations of radon at levels of 4 picocuries per liter (4 pCi/l) or higher to be a notable health risk. When found at these levels the gas should be reduced through approved mitigation procedures.
Since radon has no odor, is invisible and has no taste the only way to determine if it is present is through controlled testing by specially designed equipment and procedures. Fortunately screening for radon is relatively simple and inexpensive considering the health risks and testing can quickly determine if mitigation of the gas should be conducted.
Official screening by a certified radon professional takes anywhere from 2 days to 3 months and could be extended for up to a year depending on the preliminary test results. If levels are found to be between 2 pCi/l and 4 pCi/l mitigation is usually not conducted but a long term test is recommended. The long term testing is conducted to monitor the radon levels in the building over an extended period of time. This is done to compensate for the many variables that affect the movement of the gas including the weather conditions, atmospheric pressure and moisture in the soil. Radon levels can change significantly from day to day, week to week and month to month.
It is important to remember that no amount of radon can be considered harmless and mitigation is designed to lower radon levels in the home to match levels common to a natural outdoor environment. Outdoor levels average around .4 pCi/l.
Records of radon levels done at a county level can be viewed here:
California Health and Safety Code
California Health and Safety Code Section 106750 – 106795 (PDF) states:
(a) Except as provided in Section 106790, no person may provide radon services for the general public, or represent or advertise that he or she may provide radon services unless that person meets both of the following requirements:
(1) Successfully completes the National Radon Measurement Proficiency Program of the National Radon Proficiency Program (NRPP) or the National Radon Safety Board Certified Radon Professional Program.
(2) Submits to the department a copy of certificate demonstrating successful completion of either program.
(b) Persons certified to provide radon services shall successfully complete and submit to the department proof of completion of the National Radon Measurement Proficiency Program of the National Radon Proficiency Program (NRPP) or the National Radon Safety Board Certified Radon Professional Program every two years after initial certification.
(c) A copy of the current certificate of completion shall be submitted to the department at least 14 days prior to conducting radon services within the state.