I had the pleasure of talking to Professor Bill Field, who has been involved in radon-related research for 30 years. He received his PhD in Preventive Medicine from the University of Iowa, where he is currently a Professor of Public Health with dual appointments in the Department of Occupational and Environmental Health and the Department of Epidemiology.  Dr. Field was the lead author of the Iowa Radon Lung Cancer Epidemiologic Study and has been actively involved in the North American and global radon epidemiologic pooling efforts. He has worked to launch the WHO Handbook on Indoor Radon, served as a member of the US EPA’s Science Advisory Board, and currently serves as a Presidential Appointee on the Center for Disease Control’s Advisory Board on Radiation and Worker Health.  In 2012, Dr. Field was the recipient of the University of Iowa’s Michael J. Brody award for his long-term public health commitment to the community, state, region, and nation. In 2017, he received the Iowa Cancer Champion Award. 

We discussed his research on residential radon risk in North America, as well as the history of radon research. The health effects of radon exposure began to be reported in 1770 when Carl Lebrecht Scheffler published about diseases in underground miners in what is now Austria. In the late 19th century, this disease was determined to be lung cancer, and in the 20th century, the link between the radon gas due to uranium and hard-rock mining was established. The IARC has listed radon as a human carcinogen, and Dr. Field reviewed the broad international and professional scientific consensus on this link. Radon causes lung cancer by its decay particles, which are alpha particles that can damage the DNA in the lungs, leading to mutations that can cause cancer. This has been seen in experimental models as well as the large studies such as the ones Dr. Field has done. 

He has participated in “case-control studies,” which take people who have lung cancer and measure the radon in their homes, obtain their smoking history, etc and then match them to people of similar age, health, location, and smoking status and evaluate whether there is an increased risk of lung cancer. These carefully designed studies have shown a link between radon and lung cancer both in the US and around the world. When you put them together in even larger studies (“pooled studies”), the effect remains and is consistent with an increasing risk from increasing exposure. The odds of so many case-control studies (19 of 22) finding increased cancer risk at a similar level is less than 1 in a 1000, and when they are pooled, the risk remains consistent across studies, locations, etc. 

Let’s walk through an example of a pooled study. One group of researchers pooled 13 European studies of radon that included at least 150 people with lung cancer and 150 controls and had looked at their homes over the prior 15 years. They ended up with 7148 people with lung cancer (cases) and 14208 people without (controls). They adjusted for the original study, age, sex, where people lived and smoking status, and found a linear increase in lung cancer risk as radon concentrations increased. For reference, 100 Bq/m3 (European studies) is 2.7pCi/L (US measurement).