Lung Cancer and Exposure to Chloro-Methyl-Ethers —An Occupational Epidemiological Survey

Abstract

There were four factories engaged in manufacturing and processing chloro-methyl-ethers (CME, including BCME and technical CMME) in Shanghai, prior to 1975, when the carcinogenicity of CME in humans was recognized and generally accepted. A cohort of 318 workers (approximately 2/3 male and 1/3 female), with 3980.5 person-years, exposed to CME at least one year during the period of 1958–1981 was established. Among them, 21 deaths, 16 cancer deaths and 12 deaths of lung cancer were recorded. Based on the sex, age and calendar-year-specific mortality derived from the death and cancer registry in the urban population of Shanghai, relative risks (rate ratios) were calculated. These include SMR (Standardized Mortality Ratio), PMR (Proportional Mortality Ratio), and PCMR (Proportional Cancer Mortality Ratio): All Cancer SMR 485 (16/3.3); Lung Cancer SMR 2,296 (12/0.52); All Cancer PMR 219 (16/7.29); Lung Cancer PMR 855 (12%/1.41%); Lung Cancer PCMR 390 (75%/19%). Figures in parentheses are the observed and expected numbers.