[An epidemiological study of lung cancer among workers exposed to bis(chloromethyl)ether].

An epidemiological study of lung cancer was carried out in two dyestuff factories (Factory K and U), where bis (chloromethyl) ether, BCME, was manufactured and used in the initial process of dyestuff production in Wakayama Prefecture, Japan. BCME was used from 1955 to 1970 in Factory K, and from 1960 to 1968 in Factory U. Subjects were 35 men who had been exposed to BCME in each factory. In this study 13 lung cancer cases were found (including 5 cases reported by Sakabe (Ind Health 1973]. The main results obtained were as follows: 1) The exposure period of 13 lung cancer cases to BCME was 86.9 +/- 34.9 months (mean +/- SD) and the latent period was 13.5 +/- 6.6 yr. The age at death was 46.1 +/- 9.5 yr and 7 cases died between the age of 40 and 49. 2) The initial symptoms of lung cancer due to BCME were not different from those of non-occupational lung cancer. The identified histological types of eight cancer cases were small cell carcinoma in 5 cases, adenocarcinoma in 3 cases and large cell carcinoma in the remaining case. 3) Standardized mortality ratio (SMR) was 23.5 at Factory K and 17.9 at Factory U. An excess death due to lung cancer among workers exposed to BCME was observed. 4) The shortest exposure period of the 13 lung cancer cases was only 23 months and therefore workers who had been exposed to BCME for under 3 yr must be examined for lung cancer periodically.