Radon Gas: the Natural Hazard
| Publication year | 1989 |
| Pages | 623 |
| Citation | Vol. 04 No. 1989 Pg. 623 |
1989, April, Pg. 623. Radon Gas: The Natural Hazard
The National Academy of Sciences estimates that radon gas causes approximately 13,000 cancer deaths annually.(fn1) An Environmental Protection Agency ("EPA") study released in 1986 found that one in every eight homes in the United States is contaminated by radon gas, with a cancer-causing equivalent of smoking a half pack of cigarettes each day.(fn2) Some experts believe that radon presents a health risk greater than asbestos, dioxins, polychlorinated biphenyls and toxic waste dumps.
On September 12, 1988, the EPA and the Surgeon General announced the results of a seven-state survey for radon. The study showed that one in three homes had screening levels that exceeded the recommended safe radon level.(fn3) In Colorado, 45 percent of homes tested were found to have elevated levels of radon. The highest radon levels came from eight counties: Clear Creek, Teller, Boulder, Pitkin, Fremont, Park, Gilpin and Kiowa.(fn4)
To protect their clients from radon-related liability, it is important for Colorado real estate lawyers to understand how radon gas occurs, the health hazards it presents and the methods for testing and mitigating radon gas. This article discusses those subjects, in addition to the liability and damage issues pertaining to radon gas exposure.
Two factors are important in understanding radon gas. First, Radon-222 has a half-life of 3.82 days, meaning that in 3.82 days radon decays to half its original volume. If its half-life were shorter, radon would not have the time to travel into the ambient air in a home. Second, as radon decays, it produces "daughter products" that readily form chemical bonds. The daughter products, unlike the inert gas, are chemically charged so that they readily form bonds with actual portions of the lung or with dust particles which may be inhaled (as discussed below).
As an inert gas, radon moves quickly and easily through soils and permeable building materials without forming bonds. Radon occurs naturally in low level background amounts and becomes a danger only when a structure impedes the natural outdoor dilution. As a result of the fact that heat rises and due to the development of certain energy efficient construction techniques, radon becomes trapped inside buildings, causing radon levels to become unsafe.
As uranium decays, three types of radiation are produced: alpha particles, beta particles and gamma rays. Alpha particles can be likened to cannon balls because they are relatively large, do not travel far and cause a great deal of damage upon impact. Beta particles are similar to gunshot---they travel fairly far and have good penetration. Gamma rays are beams with a wavelength, rather than particles. Gamma rays are usually the most dangerous form of radiation.
However, because of their effects on the inhalation process, radon's alpha particles are the most dangerous. Radon alpha particles emerge from the decay process positively charged and cling to other particles, such as dust. They may then be inhaled and cling to the bronchial epithelium, which takes the full brunt of radioactive bursts as the alpha particles decay. Alpha particles may also cling directly to the lung tissue. Due to the process of inhalation, the lungs receive more radiation than any other organ.
Information used in determining the health effects of radon was developed from studies of miners exposed to high levels of radiation.(fn5) These studies show that sufficient doses of radon and its progeny can produce lung cancer in humans. In fact, radon is responsible for the lung cancer risk to most of the nonsmoking general public.(fn6) The levels of radon necessary to cause cancer are generally ten times higher than the radon levels found in the normal indoor environment.
These studies also show that radon is a particular risk for cigarette smokers. Smoking and radon have a synergistic effect (like asbestos and smoking), increasing the combined cancer causing effects beyond the sum of the effects of each independently.
Although there is a greater risk of developing cancer from longer exposure to a high level radon environment, exposure to any...
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