HOW MUCH ADDITIONAL RADON DOSE WERE WE GETTING WHILE WE WERE HOME DURING THE PANDEMIC ? by Bruce Snead and Brian Hanson - National Radon Program Services at Kansas State University and thanks to Kevin Stewart of the American Lung Association for his input on this topic .
by Bruce Snead and Brian Hanson ‐ National Radon Program Services at Kansas State University and thanks to Kevin Stewart of the American Lung Association for his input on this topic .
The leading cause of lung cancer death in people who have never smoked is the person ' s radon dose . The primary place people get radon exposure is in our homes . The process by which long‐term lung cancer risk from radon exposure is calculated , however , is often not well understood by the public or the radon industry . Below we take a look at the potential increase in radon dose from radon levels in a home due to increased time at home during the Covid‐19 Pandemic .
The risk of cancer from a source of radiation like radon is called the dose which is equal to the radiation level of the radon source multiplied by the time of exposure .
Radon Dose = Radon Level X Time of Exposure
Approximately 6 % of all radon measurements reported are at or above the EPA Radon Action Level of 4.0 pCi / L . Approximately 2 %, or 2 out of every 100 homes , have radon levels above 20 pCi / L . Under normal circumstances many people would spend 8‐12 hours / day outside the home working , attending school , or running household and other errands , etc . However , during the pandemic , many spent those same hours at home for several months . Consequently , we can estimate how much one ' s radon dose changed based on radon levels in the home and the likely increase in the hours at home . Another factor in the radon dose change is what the radon levels are in the locations which were avoided due to Covid 19 . It is possible those levels could be higher than at home but there is greater probability of them being lower . EPA lung cancer risk estimate tables are based on 18‐hour per day average annual exposure at home and use 1.3 , 4.0 , 8.0 , and 20.0 pCi / L as common radon levels in homes .
A key point related to radon is that the primary exposure comes from the proportion of the two polonium particles produced in the air during the ongoing radioactive decay of the radon gas in the home . The unit of measurement for these decay products is known as the Working Level ( WL ), which is the amount of polonium available in the environment to be inhaled . 100 pCi / L of radon will produce 1 working level of the decay products . How much of those decay products that are airborne and breathable is determined by the Equilibrium Ratio ( ER ). In order to calculate the WL from a known radon concentration , the Equilibrium Ration ( ER ) of the home must be known or assumed ; in general , an ER = 0.5 is assumed for
most residences . An ER = 0.5 indicates that approximately 50 % of generated polonium is airborne and available to be inhaled by residents . This means that in such an environment , a radon level of 200 pCi / L results in 1 WL of the decay products . This relationship is shown in the formula .