Prospective mortality study among iron miners.

: A prospective mortality study was conducted over a period of 5 years on a group of 13,801 iron miners, who were alive on January 1, 1982. During this 5-year period, 1813 deaths were registered. For 1222 (67.4%), the cause of death and work history are known. For 135 (7.4%), the cause of death is known, but not the work history. For 455 (25.1%), the cause of death is unknown. Proportional mortality ratio (PMR) is significantly higher than 1 for lung cancer (PMR = 2.51, p less than 0.001) and for stomach cancer (PMR = 2.31, p less than 0.001). The results are discussed in regard to occupational risks that result in these two kinds of increased mortality rates, and the hypothesis of redox activity on the surface of dust particles is advanced as a common denominator.