Radon: Real Issue for Those Responsible for Building Design

April 26, 2007Articles

The following is adapted from course materials developed for the seminar "What Builders, Owners and Realtors Need to Know About Mold, Radon, Asbestos and Lead," Chester County Bar Association, April 26, 2007.


Naturally occurring radon is the second leading cause of lung cancer in the United States. Many counties in Pennsylvania, including Chester, are classified as having the highest potential for radon exceedance in indoor air. Radon-safe design options for homes and schools and other buildings have been around for almost twenty years, and do not add significant costs. There are risks in ignoring this colorless, odor-less gas.


Radon is a colorless, odorless gas that is generated from the radioactive decay of radium-222, which in turn, is generated from the decay of uranium. Radon itself is radioactive, it decays by losing an alpha particle.

Uranium is found in nearly all soils at varying levels. The United States Environmental Protection Agency and the U.S. Geological Survey have mapped radon potential throughout the United States. Each county is identified as having: the highest potential for radon-exceedance in homes (greater than 4 pico-Curies/Liter); moderate potential (from 2-4 pCi/L); or low potential (less than 2 pCi/L). Many Pennsylvania counties, including Chester, Montgomery, Bucks, Delaware, Lancaster and Berks are identified as having the highest potential.

USEPA established 4pCi/L as the level above which it recommends steps to reduce the level of radon in homes. According to Pennsylvania’s Department of Environmental Protection, which tracks test results, the average levels of radon measured in homes in: the Malvern zip code (5,223 tests) was 7.7 pCi/L (0 to 250 pCi/L); Downingtown (9,923 tests) was 7.5 pCi/L (0 to 801 pCi/L); and West Chester (15 tests) was 3.1 pCi/L (0.4 to 11.5 pCi/L). Levels can vary significantly from building to building.

Radon has long been linked with lung cancer in miners. More recent is the recognition that radon in indoor air causes lung cancer. The United States Surgeon General and USEPA recognize radon as the second leading cause of lung cancer in the United States. Radon is estimated by USEPA to cause 20,000 cancer deaths per year, including as a result of residential exposures.

Radon typically migrates up through the ground into homes or other buildings through cracks and holes in foundations. To a lesser degree, it can also enter homes through well water. It is a concern in indoor air because it can concentrate there to levels higher than in outdoor air. Radon is, however, relatively easy to sample for and relatively inexpensive to abate. USEPA declared January 2006 “National Radon Action Month.” PaDEP had a parallel public awareness campaign focused on radon risks.


Congress passed the Indoor Radon Abatement Act, 15 USC §§ 2661-2671 in 1988, as part of the Toxic Substances Control Act. The general goal of the Act is that air within buildings in the United States should be as free of radon as the ambient air outside of buildings. The Act required EPA to develop a Citizens Guide to Radon and a model building code with standards for construction to control radon levels within new buildings; provided for assistance and grants to states; and required studies of radon levels in schools and federal buildings.

In 1987, the Pennsylvania legislature passed the Radon Certification Act, 63 P.S. § 2001-2014, requiring the establishment and carrying out of a program of certifications of persons who perform radon progeny testing or carry out remedial radon measures in the Commonwealth. The regulations implementing this Statute are found at 25 Pa. Code Chapter 240. The DEP also has authority regarding radiation protection under the Radiation Protection Act of 1984, 35 P.S. § 7110.101-7110.403.

In addition, EPA developed model building code provisions that include radon mitigation and control measures for new construction. These model provisions are designed to be incorporated into municipal codes (for example, a layer of sub-slab permeable material, sealing of joints, soil-gas-retarder sheeting, ventilated crawl spaces).

OSHA has established a standard at 29 CFR 1910.1096, which applies to most workplaces, that sets limits on radon exposure. According to OSHA, the presence of radon in a structure controlled by the employer that exposes employees to hazardous concentrations of airborne radiation as set forth in the standard, requires compliance with of 29 CFR 1910.1096. The radon-222 exposure limit for adult employees is 100 pCi/L, averaged over a 40 hour work week. The exposure limit for employees under the age of 18 is 3 pCi/L, averaged over a 40 hour work week. Areas where adult employees are exposed above 25% of the standard must be posted as “airborne radioactivity areas,” and meet other requirements.


Pennsylvania courts have recognized an affirmative duty on behalf of sellers of property to disclose dangerous conditions to purchasers. See Glanski v. Ervine, 269 Pa. Super. 182, 409 A.2nd 425 (1979) (termite damage); Quashnock v. Frost, 299 Pa. Super. 9, 445 A.2nd 121 (1982) (termite damage), and Roberts v. Estate of Barbagallo, 366 Pa. Super. 559, 531 A.2nd 1125 (1987) (presence of urea formaldehyde). In Roberts, the court applied Section 550 of the Restatement Second of Torts, which deals with an intentional concealment regarding material information to hold a seller accountable to the buyer for the dangerous condition. Section 353 of the Restatement Second of Torts also imposes liability on “a vendor of land who conceals or fails to disclose to his vendee any condition, whether natural or artificial, which involves unreasonable risk to persons on the land…if… the vendee does not know or have reason to know of the condition or the risk involved, and … the vendor knows or has reason to know of the condition… [and the risk] … and has reason to believe that the vendee will not discover the condition or realize the risk.”

Following the reasoning of the foregoing, including Section 353 of the Restatement Second of Torts, the Court of Common Pleas of Chester County found that the presence of radon gas is a dangerous defect in a home, and that there is a duty upon the homeowners, and those acting on behalf of the homeowners, to disclose the existence of that defect if known to them. Snyder v. Roach Brothers Realtors, 1992 W.L. 557661, 17 Pa. D.&C. 4th 60 (Court of Common Pleas, Chester County, August 27, 1992). In Snyder, a radon mitigation system existed in the home that was not discovered by the purchaser prior to purchase. Even though the remediation system could reduce the radon levels below the acceptable standard, the Court allowed the purchaser to rescind the contract and to recover incidental damages based on the seller’s failure to disclose this “dangerous defect.”

Most agreements of sale in Pennsylvania include a radon testing rider. In addition, the Seller’s Property Disclosure Statement includes radon among the hazardous substances as to which the seller is required to identify any awareness of its presence, and of any testing that has occurred.


There is no significant body of personal injury case law alleging harm as a result of indoor air radon exposure. Obstacles to such claims may be the need to hold a private or public party responsible for exposure to a naturally occurring substance, as well as the existence of other known causes of lung cancer, including cigarettes and asbestos exposure. However, given the science linking radon with lung cancer, the normal occurrence of lung cancers in our society, the increasing likelihood that persons will contract lung cancer without discernable links to cigarettes or asbestos, the ubiquitous nature of radon, and the existence of model building standards that can readily migitate radon risks, the factors may exist for such claims to arise.


There is a significant amount of information published both on the state and federal level that provides overviews and more detailed information regarding radon in indoor air. The Pennsylvania Department of Environmental Protection has a Bureau of Radiation Protection, which maintains a Radon Division. The Radon Division web page provides links to extensive information regarding indoor air radon. The radon home page is accessible directly from DEP’s primary website at In addition, the United States Environmental Protection Agency maintains an indoor air-radon home page that is also directly accessible from EPA’s primary home page at