What is radon?
Radon is an odorless, tasteless, colorless gas present in many areas of the world including Florida. It is formed by the decay of radioactive metals (e.g., radium, thorium) which are naturally occurring in many soils. Because radon is naturally occurring, exposure is common and unavoidable. The Florida Department of Health (FDOH) estimates that 1 in 5 Florida homes (20%) contain radon above the 4 picoCurie per liter (pCi/L) Action Level that was developed by the U.S. Environmental Protection Agency (USEPA). A picoCurie, one of the preferred radioactivity measurement units, is one-trillionth of a Curie, and represents an extremely small value.
The 4 pCi/L Action Level has been in place for nearly 40 years, and it was not established solely for health protection, but also as a value that testing procedures could achieve accurately and repeatably and was a level that could be achieved in indoor air when reasonable corrective efforts are employed. FDOH recommends retesting and consideration of mitigation for values in the 4 to 8 pCi/L range, and advises mitigation as soon as reasonable where values exceed 8 pCi/L. Immediate action is recommended by FDOH where detected radon values exceed 100 pCi/L. The U.S. Nuclear Regulatory Commission (USNRC) has established an exposure limit of 30 pCi/L for adult work exposures, and the Occupational Safety and Health Administration (OSHA) has set an acceptable occupational 8 hour Permissible Exposure Limit (PEL) of 100 pCi/L. Both values were developed under an assumption of protection for a typical 5-day workweek.
Lung cancer in some individuals is the only health effect which specifically has been attributed to significant radon exposure. That association primarily is based on data from some types of miners whose underground exposures were far greater than those experienced by the general population. Cigarette smoking remains by far the most definitive cause of lung cancer. FDOH reports that lung cancer related to radon would only be of potential interest following prolonged, repetitive radon exposure at elevated levels for decades.
Beginning in February 2022 and as of March 2024, more than 2,500 samples from more than 250 FSU buildings have been tested for radon. Sampling of all identified main campus, southwest campus, other Leon County FSU buildings, and non-Leon County remote facilities is complete. For the radon testing program, over 93% of sample results have been less than the 4 pCi/L Action Level recommended by USEPA and FDOH.
Frequently Asked Questions
What is radon?
Radon is an odorless, tasteless, colorless gas, present in many areas of the world including Florida. Radon is formed by the decay of some radioactive metals (e.g., radium, thorium) naturally occurring and present in soils. Because it is a gas, it may enter homes and commercial buildings because of its presence in underlying and surrounding soils. Since it is a naturally occurring substance, exposure is common and unavoidable. Outdoor radon levels typically are in the 0.4 to 0.5 picoCuries per liter range (pCi/L), and indoor levels generally range from 1 to 2 pCi/L. (A picoCurie, one of the preferred radioactivity measurement units, is one-trillionth of a Curie, and represents an extremely small value.)
What guidelines are available to evaluate potential residential radon exposure?
The U.S. Environmental Protection Agency (EPA), Florida Department of Health (FDOH), and other organizations employ a default recommendation of 4 pCi/L for radon in residential buildings. That value, which has been in place for over 20 years, was not established solely for health protection, but also is a value that testing procedures could achieve accurately and repeatably and was a level that could be achieved in indoor air when reasonable corrective efforts are employed.
FDOH recommends retesting and consideration of mitigation for values in the 4 to 8 pCi/L range, and advises mitigation as soon as reasonable where values exceed 8 pCi/L. Immediate action is recommended by FDOH where detected radon values exceed 100 pCi/L.
What health issues have been associated with radon?
Lung cancer in some individuals is the only health effect which specifically has been attributed to significant radon exposure. That association primarily is based on data from some types of miners whose underground exposures were far greater than those experienced by the general population. Cigarette smoking remains the most definitive cause of lung cancer.
Why is FSU testing for radon?
Florida State University is proactively conducting radon testing of all campus buildings as part of its ongoing commitment to campus health and safety.
What recommendations were made on the basis of the initial radon testing?
Mitigation was recommended for buildings with multiple radon values greater than 4 pCi/L. Appropriate mitigation measures have been completed successfully at those buildings identified for mitigation, and the evaluation process will continue.
Can radon be successfully removed from a building, or can the levels be lowered?
Because radon is naturally present in outdoor air and in the ground at many locations, it is not typically possible to remove all radon from building air. However, there are proven mitigation techniques to decrease radon levels, including installation of engineering barriers and venting to reduce or eliminate radon entry from surrounding natural soils, coupled with modifications to building ventilation systems. These measures can reduce radon to less than or equal to 4 pCi/L.
FSU Facilities and FSU Environmental Health & Safety are working with an industrial hygienist, a toxicologist, and external engineering firms to evaluate and implement radon mitigation and the other remedial measures for the buildings with multiple radon levels above the EPA and FDOH default recommendation.
Radon Resources
Agency for Toxic Substances and Disease Registry (ATSDR) Centers for Disease Control and Prevention (CDC)
https://www.atsdr.cdc.gov/csem/radon/radon.html
The Agency for Toxic Substances and Disease Registry (ATSDR) serves as a science-based public health agency working to address community concerns about hazardous waste and investigate environmental exposures to hazardous substances in communities and take action to reduce harmful exposures and their health consequences.
U.S. Environmental Protection Agency (USEPA)
https://www.epa.gov/radon
The mission of USEPA is to protect human health and environment. EPA was established on Dec. 2, 1970, to consolidate a variety of federal environmental responsibilities including research, monitoring, standard setting, and enforcement activities to ensure environmental protection while simultaneously safeguarding human health.
Florida Department of Health (FDOH)
https://www.floridahealth.gov/environmental-health/radon/index.html
Read about basic radon facts, health effects, sources of radon and entry routes, radon testing, and radon mitigation. The Florida Department of Health (FDOH) was established by the Florida Legislature in 1996; however, public health has its roots in Florida dating back to 1888 with the creation of the Florida State Board of Health.