Incidence of lung cancer among iron miners

A study has been performed using 5300 iron miners from Lorraine (France) with ages ranging from 35 to 55 years, who were working, and had a normal chest radiography. 1173 workers were chosen randomly and given the following examinations: questionnaire, clinical examination and function tests (VC, FEV1, residual volume (RV), acetylcholine test, carbon monoxide steady-state test). This group of 1173 was followed for 5 years. 40 died and the exact causes of death were known. 13 had lung cancer, which is more than three times the number expected in the French male population of the same ages. All subjects who died from lung cancer were underground miners and, at the first examination, had a higher incidence of bronchitis and more functional defects than both the 27 who died from other causes and the underground miner group as a whole. The excess mortality due to lung cancer is discussed with regard to noxious agents that were measured (radioactivity, which was rather low, total and respirable dusts, Nox, CO) and with regard to both the work environment and duration of work.