An epidemiological study on the cancer mortality in various industries in japan

Abstract

An epidemiological study on cancer deaths in the industrial population in Japan was conducted. Questionnaires were sent to chief health supervisors of 760 factories which included all the industries of more than 1,000 employees. Among those factories, 572 factories (75.3%) responded to the questionnaire. During the period of observation (1966 to 1968), 1,140 cancer deaths were reported among 1,200,000 workers. The age-adjusted death rates were calculated according to age and site, in order to compare the risk of cancer mortality by industry, occupation, duration of employment, and possible exposure to chemical or physical agents. The following results were obtained. 1) Among blue collar workers in the paper-pulp industry liver cancer deaths were observed more frequently than those in other industries. This difference is statistically significant, but the reason for this result is not clear. 2) Laryngeal carcinoma showed the highest risk in this population, the ratio of the observed to the expected number being about 2. Eleven out of twelve reported deaths of laryngeal carcinoma were found to be related to various irritant gases or dusts. It may be worth noting that 4 cases among these were reported from factories using or handling asbestos. 3) Lung cancer death rates of blue collar workers in total were generally higher than those of the general population, especially among the blue collar workers of iron and steel industries a high O/E ratio was observed which is statistically significant. As to whether the known carcinogens were related to the lung cancer, it was discovered that the highest risk of lung cancer was showed among coke oven workers in the iron and steel industries. This fact suggests that the exposure to polynuclear hydrocarbons including 3, 4-benzpyrene would lead to higher risks of producing lung cancer, in addition to other factors, particularly, cigarette smoking. © 1974, Japan Society for Occupational Health. All rights reserved.