Citation

Mukaida K, Hattori N, Iwamoto H, Onari Y, Nishimura Y, Kondoh K, Akita T, Tanaka J, Kohno N. Occup. Environ. Med. 2016; 74(5): 321-327.

Affiliation

Department of Molecular and Internal Medicine, Institute of Biomedical Sciences, Hiroshima University, Hiroshima, Japan.

Copyright

(Copyright © 2016, BMJ Publishing Group)

DOI

10.1136/oemed-2015-103437

PMID

27516111

Abstract

OBJECTIVES: Mustard gas (MG) has been the most widely used chemical warfare agent in the past century. However, few but conflicting data exist on the effects of MG exposure on long-term mortality. We investigated MG-related mortality in retired workers at a poisonous gas factory.

METHODS: We assessed mortality rates among 2392 male and 1226 female workers, whose vital status could be determined through 31 December 2009, at a poisonous gas factory operating from 1929 to 1945 in Okuno-jima, Japan. The analysis employed standardised mortality ratios (SMRs) calculated using national and prefectural references and a Cox proportional hazard regression model. Applying the Kaplan-Meier method, we compared cumulative death rates in the study cohort stratified by an 'Okuno-jima MG Index' which represented the product of HRs derived for job category and length of service.

RESULTS: Among male workers, we found significant excesses in mortality from upper respiratory tract cancer (SMR 3.06), liver cancer (1.67), lung cancer (2.01) and chronic bronchitis/emphysema (4.84) compared with the national population, as well as stomach cancer (1.20) versus the Hiroshima Prefecture population. When stratified into 3 subgroups by the Okuno-jima MG Index, those with a higher Okuno-jima MG Index had significantly higher cumulative rates of death from respiratory cancer and chronic bronchitis/emphysema.

CONCLUSIONS: MG exposure significantly increases the long-term risk of death from respiratory cancer and chronic bronchitis/emphysema. The Okuno-jima MG Index may be a useful indicator for estimating cumulative MG exposure.

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Language: en