Revision 1
March 19, 1998
by Radiation, Science, and Health, Inc.,
Edited by J. Muckerheide

1.2.6.3
Radon

1.2.6.3.2
Miners Studies

"The incidence of lung cancer for workers who had been exposed to insoluble arsenic in four mines was found to be 290/10⁵. A dose- dependent decrease in the incidence was associated with a reduction in the concentration of insoluble arsenic in the air. The content of arsenic (expressed as the geometric mean) in the lung of subjects exposed to insoluble arsenic was 51.4 micrograms/g per dry lung tissue which was 17 times higher than the value of 3.0 micrograms/g per day lung tissue found in control groups. Moreover, the content of arsenic was found to correlate with the number of years working in the mine and with the incidence of lung cancer.

"Metabolic studies of arsenopyrite showed that it is converted to products such as arsenous acid, arsenic acid, methyl arsenate and dimethyl arsenate, which are identical to those generated from As₂O₃. Although these metabolic products are formed at a lower rate, they nonetheless show that arsenopyrite should be considered a carcinogen. Potential carcinogens such as As, Cr, Ni, Be, and Cd were evaluated in lung specimens of miners with lung cancer and compared with values obtained in controls using logistic regression analysis.

"Only As was found to be significantly associated with lung cancer. The concentration of As in lung tissues correlated well with the amount found in the air of the mining environment. A retrospective/prospective interference epidemiological investigation performed over a 40-year period showed that the risk of radon had been overestimated. After regulatory measures were implemented in the mines to control for exposure to Rn, the risk of exposure to Rn was found to be RR/WLM (relative risk per working level month) = 0.17%, which was 9 times lower than the values previously estimated."