Sixty years on: the price of assembling military gas masks in 1940

Occupational and Environmental Medicine. 2006 Sep 19; [Epub ahead of print] [Link]

J Corbett McDonald 1*, Jessica Harris 1 and Geoffrey Berry 2

1 National Heart and Lung Institute, United Kingdom
2 University of Sydney, Australia


Background: Between 1940 and 1944 military gas masks with filterpads containing 20% crocidolite were assembled in a Nottinghamfactory.

Methods: Records supplied by the late Professor Stephen Jones were of 1154 persons, mainly women, who had worked inthe factory during this period and included many deaths from mesothelioma. A systematic effort was therefore made to establish causes of death for the whole cohort.

Findings: Of 640 employees with full name and sex recorded, 567 (89%) were traced. Ofthese, 491 had died, including 65 from mesothelioma, thoughonly 54 certified as such. After exclusion of these 54, standardised mortality ratios were significantly raised for respiratory cancer(SMR 2.5) and carcinomatosis (SMR 3.2). The pattern of mortality in the remaining 514 employees without full identification was similar, but a low tracing rate (40%) did not justify their further analysis. The first death from mesothelioma was in 1963 (22 years after first exposure) and the last in 1994, whereas a further 5.0 cases would have been expected (p = 0.0065).

Interpretation: These findings in a cohort followed over 60 years after brief exposure to crocidolite confirm a high and specific risk of mesothelioma (28% peritoneal) and perhaps of lung cancer some 20-50 years later. The statistically significant absence of further mesothelioma cases during the past eight years suggests that crocidolite, though durable, is slowly removed.

Keywords: biopersistence, crocidolite, mesothelioma, women’s work