Potential lung cancer risk from indoor radon exposure

Abstract

The contribution of radon daughter exposure to excess lung cancer in underground miners is universally accepted. These miners received exposures from tens to thousands of WLM in a relatively few years. Although the miners were also exposed to other noxious agents in mines, the appearance of the excess lung cancer mortality in several types of mines and the increase with increasing exposure provide convincing evidence of the role of radon as the carcinogen. It is conceivable that exposures to radon at an average concentration of one to two pCi/liter, the levels for a majority of homes, might not produce excess lung cancers. This would require that a lifetime exposure at low concentrations produce a different response from that of a few years at higher levels for the miners. This is unlikely but not impossible. The current environmental epidemiology is of varying quality. The better studies may give some answers in a few years. These studies are more likely to establish an upper limit of risk than to provide an exposure-response model. Present risk estimates cannot be used accurately in estimating the overall lung cancer risk to the US population, since there are no good data on average exposure and exposure distribution. For example, the number of homes above the EPA guideline of four pCi/liter may range from two million to 10 million. An estimate of the actual radon exposure in the US may be forthcoming from a planned EPA survey, but these data will not be available for a few years. In the conservative tradition of radiation protection, indoor radon exposures in homes are estimated to produce a number of excess lung cancers in the population. One estimate by the NCRP is about 10,000 deaths per year in the US, for an average annual estimated exposure of 0.2 WLM (about one pCi/liter). The National Academy of Sciences (BEIR IV) estimates 13,000 deaths for the same exposure, and the EPA's estimate is 5,000 to 20,000.

Indoor and outdoor Radon concentration measurements in Sivas, Turkey, in comparison with geological setting

“…There are many studies about the effects of geological and environmental factors on 222 Rn measurements in a number of other countries (Botkin and Keller, 1988;Harley and Harley, 1990;Hubbard and Swedjemark, 1991;Robinson and Sextro, 1995;Yamasaki and Lida, 1995;Vaupotic et al, 2003;Yu et al, 1995). Programmed indoor 222 Rn measurements in Turkey were started in 1984 by the Health Physics Department of the Cekmece Nuclear Research and Training Centre (CNAEM).…”

An Algorithm for Automatic Counting of Electrochemically Etched Tracks in Compact Disks Used for Retrospective Measurements of Rn-222

“…R ADON-222 is the second most important cause for lung cancer after smoking [1]. Since the risk for lung cancer is formed during a long period of time (years), representative for the risk of exposure to 222Rn are the long-term retrospective measurements [2].…”

Radon daughters’ concentration in air and exposure of joggers at the university campus of Bangalore, India

“…The dose for the respiratory tract and the lungs is predominantly caused by the deposition of Rn progeny via aerosol particles. The alpha particles emitted by the decay of deposited Rn daughters bombard the sensitive lung tissues, and continuous exposure may lead to malignant transformation, which results in lung cancer [1][2][3]. Chromosome aberrations in peripheral lymphocytes were also reported for individuals living in the dwellings of high radon concentrations of 80-13,000 Bq/m 3 [4].…”

“…The PAEC in air of any mixture of radon progeny is the sum of the potential alpha energy of all the daughter atoms present per unit volume of air and is expressed in the unit working level (WL). 1 WL (radon) corresponds to a PAEC of short-lived radon daughters in equilibrium with a radon air concentration of 3700 Bq/m 3 . From the measured concentration, an attempt was made to estimate the inhalation dose to the general public of the study area.…”