The Dose to the Trachea and Bronchi from the Decay Products of Radon and Thoron

Publisher Website
Google Scholar
Abstract
When air containing radon or thoron is breathed some of the decay products* are deposited on the surface of the respiratory system, and the radiation from this active deposit then gives a dose to the epithelium. The α radiation is probably of greatest importance because of its relative biological efficiency and also because the α dose is so greatly localised. For this reason an estimate of the dose requires a knowledge of the distribution of the active deposit in different parts of the respiratory system, with particular reference to the bronchi where the majority of lung cancers are first seen. Mitchell (1945) considered the dose to the bronchial epithelium on the assumptions that the concentration of radon in the bronchus is the same as in the outside air, and that all the active deposit formed in the bronchus is deposited on the walls and remains there until it decays. On these assumptions Mitchell's calculations gave the dose to the bronchial epithelium from a radon concentration of 10−9 c/1. in air as 0·8 mrep/h. More recently it has become clear that the active deposit formed in the outside air and breathed in along with the radon or thoron contributes more to the total dose than does the active deposit formed within the lung. Cohn, Skow and Gong (1953) exposed rats to the air in an air-tight but not dust-free room in which radon in equilibrium with radium had been allowed to stand for a period of 30 days.

This publication has 0 references indexed in Scilit: