It may take several hours for a normal lung to clear particulates . Perhaps you may recall working in a dusty environment like a crawlspace without respiratory protection
( not a good idea ) and you blow your nose and see the guick on the tissue
. It may be several hours before that goes away . Furthermore , you can smell or taste it for even hours more . Within that time frame , a Polonium 218 atom with a 3-minute half-life and a
Polonium 214 atom with a half-life of 163 microseconds can surely decay and release an alphaa particle while it is still in the lung or air passage .
The Figure below is a slide from the CERTI Entry-Level radon course that shows the relative time frames at which radon and its decay products radioactively decay . Sure , a radon atom might decay while it is in the lung beforee it is respired , but it is the attachment of the radon decay products , coupled with their short half-lives that make them the actual health risk . So , the health effect of radon is not because radon is trapped in the lungs as stated in the solicitation , but rather , the decay products of radon that are inhaled . If radon , as well as other gasses were held up in the lung , we would quickly expire from accumulated carbon dioxide .
One can see this mechanism explained in many authoritative works on the health effects of radon , such as : Biological Effects of Ionizing Radiation ( BEIR VI )
“ Alpha particles released by 2 radioisotopes in the radon decay chain , polonium-
218 and polonium-214 , deliver to target cells in the respiratory epithelium the energy that is considered to cause radon-associated lung cancer ”[ 2 ] Technical Support Document for the 1992 Citizen ’ s Guide to Radon : “ Of the short-lived radon decay products ( polonium-218 . Lead-214 , bismuth 214 and polonium-214 ), the polonium isotopes contribute most of the radiological dose to the lung . The risk from inhaled radon-222 is small compared to the risk from inhaled radon 222 decay products ”[ 3 ]
Exposure vs Dose It comes down to the difference between being exposed to a hazard , versus receiving a body-harming dose . Radon in indoor air representss an exposure much like the sun represents an exposure for potential skin melanomaa , but the actual risk is what is absorbed by the body — or if you are indoors or outdoors , or you wear a hat or long- sleeved shirts .
In the case of elevated indoor radon , there are a known amount of radon decay products that will be formed in the air around us . However , that does not mean thatt is