A closer look: Additional study of relationship between indoor radon exposure and the Covid-19 case fatality rate

In September 2022, the author of this text asked the scientific community an astonishing question: is there a connection between the Covid-19 case fatality rate and the radon exposure in interior spaces? And – if so – is it a correlation? Is it just a coincidence or even a causality? Radon exposure is particularly high in regions that have seen high mortality rates related to SARS-CoV-2. It was demonstrated that there is at least a correlation. This statement based on a comparison of four states of Germany. Of course, such a comparison is rather vague due to various geological situations. It is relatively rough, as the measures against the spread of the SARS-CoV-2 have been different from one state in Germany to another. Due to that, this paper takes a closer look to that phenomenon. It focuses on three districts in northern Bavaria: Ansbach, Bad Kissingen and Wunsiedel. The last one is situated close to Thuringia as well as the Czech Republic. It was declared as radon preservation area – the only one in Bavaria – and is rather affected by radon. Bad Kissingen represents a region with a medium average indoor radon activity concentration. It is located at the north at the border to Hesse. Ansbach is characterized of a lower risk to get affected by radon. It is in the vicinity to Baden Wuerttemberg in the west. Even this second comparison cannot provide a definitive answer to the questions named above. Nevertheless, this article will push that topic a little forward and by that support the answer to a possible relationship between indoor radon activity concentration and the Covid-19 case fatality rate. Possibly it puts little more focus more on radon protection than it happened during the pandemic years.