Mortality among masons in Iceland.

An investigation was carried out to determine the cause of death among 450 masons in Iceland who had been exposed to hexavalent chromium, a trace element in cement. The cohort was defined as all men born between 1905 and 1945 who had, according to the Register of Masons and Stone-cutters, finished vocational training as masons. For deaths occurring between 1951 and 1982 information was obtained from the Statistical Bureau of Iceland. Expected death rates were calculated, based on the national rates for men in the corresponding age groups. The total number of deaths from all causes was less than expected for the whole study period (81 v 85.86) but, with a 20 year latent period, 58 deaths were found against 50.57 expected; with a 30 year latent period, 38 deaths were found against 27.82 expected, which may, to a large extent, be accounted for by an excess of deaths from lung cancer. Nine deaths from lung cancer were found in the cohort, eight with 20 and 30 year latent periods compared with expected rates of 2.87, 2.19, and 1.28 respectively. The results seem to indicate that the increased number of deaths from lung cancer among the masons has a causal relation to occupational exposure.