by Margaret Henderson
A television news article in November 2016 drew attention to recent testing of a home in Lehigh County, Pennsylvania, that tested extremely high for radon. I asked Bob Lewis, of the Pennsylvania Department of Environmental Protection Radon Division to elaborate on the findings and he contributed this clarifying information.
We are testing all of these homes [in that particular area] that are newly built prior to occupancy since we know that this particular development is very prone to high radon levels, and that was the case with this recent home. We actually, tested this home under two circumstances, one with the passive system open (normal operation) and one with the passive system blocked. With the passive system blocked we got the sky-high basement reading of 6,176 pCi/L. [The EPA recommended action level is 4pCi/L.] The previous high that I am aware of was published in the Health Physics Journal back in the 1990s and measured 5,400 pCi/L. It was a 200-year old house in Austria. All of the high homes in this development have radon due to a very unique geologic formation that has significant amount of mineralized uranium and radium and the permeable rocks and soil that allow for ease of transport. There are about 20 lots yet to be built on, which we will be keeping a very close eye on. The builder does install passive systems in all of these homes. Bill Brodhead has done most of the work in this development and has been getting something like 99.99 % reductions by activating the passive systems--that’s the good news. This certainly shows that even the highest radon levels can be effectively mitigated.
With the builders permission we plan to do some outdoor gamma measurements and ambient radon measurements. The few ambient radon measurements that we have made have been above 4 pCi/L. This poses the question -- how to mitigate outdoor air? The gamma in the soil in the in the home yards is also elevated, often > 100 microR/hr, with normal soil being about 8-10 microR/hr. Soil and rock gamma spectrometry analyses show 100-400 pCi/g of uranium and radium, with “normal” values of these typically at 1 pCi/g.
Due to this latest press release I have another town hall type meeting in December down in the area Township Building. I will be getting some help from our Norristown Regional office staff and Michelle Moyer from EPA Region III in Philadelphia. The local state representative is sponsoring this meeting.
For more information, contact:
Bob Lewis
Pennsylvania Department of Environmental Protection
Radon Division
http://www.dep.pa.gov/Business/RadiationProtection/RadonDivision/Pages/default.aspx
Phone: 717-783-3594
Fax: 717-783-8965
Radon Hotline: 800-237-2366
United States