The growing concern regarding the origins of radon in the home has shifted recently to include natural stone products such as granite as possible sources of the gas. This focus of attention on the connection between granite and radon has been prompted by reports that radon emissions larger than 4 pCi/L have been measured from certain natural stone products. Radon is a byproduct of the decay of radioactive elements present in all soil and stone, and its presence in granite products is logical. Claims that these findings indicate that granite generally poses a health risk may be unreasonable, however. As with all radon mitigation measures, the extent of the risk should be positively established before taking any action.
Radon gas is a colorless, odorless and tasteless gas emitted as a byproduct of the radioactive decay of uranium. Uranium is present in natural stone products destined for decorative or functional domestic use. Recent concerns regarding granite and radon have focused on the potential health risks posed by these emissions in the home. Tests have indicated that radon emission levels in excess of the accepted maximum level of 4 pCi/L have been detected from certain granite products. There are, however, two points that have to be factored into the granite and radon equation when considering these results.
The first is the average size of granite surfaces in the home. Radon emitted from the soil in a basement originates from a far larger area than the average countertop. If a granite surface is emitting radon, its contribution to overall radon levels will be nowhere near as significant as soil-based emissions. The second point is that the basement of a home represents a captive environment where radon can accumulate to dangerous levels if unchecked. The opposite is true of natural stone products typically located in open and well-ventilated areas of the home.
When considering the health risk implications of granite and radon in the home, the first step would be to test granite surfaces for emission levels. There are several readily available self-test kits tests that homeowners can use to establish the radon emission profile of their granite surfaces. It may be wise though to have a professional test carried out with associated recommendations regarding the findings. Once the emission profile of the relevant surfaces has been established, an informed decision may be made regarding mitigation measures.
How the granite and radon question is approached remains an issue of personal preference but should be tempered by practical considerations. These should include the overall radon concentrations in the home, the extent of the emissions from the granite in question, and its potential contribution to the overall rating. These variables should, if at all possible, be established by a professional who would be able to assist the homeowner in making reasonable, informed choices regarding mitigation.