Open AccessCancer incidence among workers exposed to radon and thoron daughters at a niobium mine.
Author(s) -
Hans Magnus Solli,
Aage Andersen,
E. Stranden,
Sverre Langård
Publication year - 1985
Publication title -
scandinavian journal of work, environment and health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.621
H-Index - 103
eISSN - 1795-990X
pISSN - 0355-3140
DOI - 10.5271/sjweh.2261
Subject(s) - radon , lung cancer , radon daughters , medicine , incidence (geometry) , environmental health , uranium mine , demography , toxicology , nuclear medicine , uranium , metallurgy , oncology , materials science , physics , quantum mechanics , sociology , optics , biology
The aim of this study was to investigate the incidence of cancer among 318 male employees of a niobium mining company which was only operated between 1951 and 1965. Many of the workers, especially underground miners, were exposed to the daughters of radon and thoron and also to thorium. The accumulated doses to the workers from short-lived radon and thoron daughters in the mine atmosphere were assessed to be relatively low; up to 300 working-level months. During the follow-up period 1953-1981, 24 new cases of cancer were observed compared to an expected number of 22.8. Twelve cases of lung cancer had occurred versus 3.0 expected. Among the 77 miners, 9 cases of lung cancer were observed against 0.8 expected. Associations between the occurrence of lung cancer and exposure to alpha radiation and smoking were found. For the radon and thoron daughter exposure, about 50 excess cases per million person-years at risk per working-level month were observed.