Occupational exposure in methyl bromide manufacturing workers: 17-year follow-up study of urinary bromide ion concentration for biological monitoring.

To elucidate the circumstances of their occupational exposure to methyl bromide (MeBr), we conducted a 17-yr study on 124 workers employed by a MeBr manufacturer. Subjects were classified into three groups according to the nature of their work: synthesis group, filling group, and other group. Urinary concentrations of bromide ion (Br(-)) were assessed, and data attained via MeBr-health examinations were analyzed. The highest Br(-) concentrations were seen in the synthesis group, with a median value of 13.0 µg/mg CRE (2.5-51.8), followed by the filling group, with a concentration of 11.9 µg/mg CRE (3.1-34.8). Both values were significantly higher than the levels noted in the other group (p<0.001). Three major opportunities for exposure were identified: during exchange of reaction equipment for maintenance or cleaning, during operations to adjust for weight variations after filling canisters, or when canisters were recycled. Overall, however, the workplace environment concentration remained largely below the administrative control level throughout the study period. Therefore, while this was a relatively well-controlled workplace, exposure opportunities still arose when performing certain tasks, indicating the need for ongoing improvement in workplace procedures and underscoring the importance of biological monitoring.

[Management of occupational bladder cancer in Japan (Vol. 1)].

By examining historical documents regarding occupational bladder cancer in Japan, we interpreted and followed the progress made in developing preventive measures against the outbreak of occupational bladder cancer in Japanese dye industries after World War II, and documented how these measures became well organized. During Dr. M. H. C. Williams's, who was an industrial physician for the British ICI Company, occasional visits to Japan, he encouraged the enforcement of such measures, considering them to be as important in occupational health in Japan as in Western countries. He received permission to implement these measures in Japanese dye companies. A urine cell diagnostic system was already being employed in Japanese industries as a method of diagnosing occupational bladder cancer, and its use was promoted by engineers, urologists, and pathologists even before the Industrial Safety and Health Law was enacted in 1972. It took about 10 years for these measures to become standardized industry-wide. The use of these measures has had a considerable effect on the early diagnosis of patients and extended patients' life spans. Eventually, the life spans of such patients became approximately the same as that of the average Japanese male. Some patients unfortunately died of occupational bladder cancer. Others were examined using these measures not only while employed but also after retirement. Therefore, some patients in whom occupational bladder cancer was detected are still alive at over eighty years of age.