Global Asbestos Congress 2004

Pleural Mesothelioma in Shipyard Workers in the Miura Peninsula

Naohiko Inase and Hirotaro Miura
Yokosuka Kyosai Hospital, Japan.


Most patients with mesothelioma have a long-term history of occupational exposure to asbestos. Yokosuka in the Miura Peninsula has been known as 'a town of shipyards' for more than 100 years and also known to have high incidence of mesothelioma.

To clarify the incidence of shipyard-exposure to asbestos in our patients with pleural mesothelioma and characterize the exposure, we reviewed our medical records.

We have managed 38 patients with pleural mesothelioma (31 men and 7 women; from 30 to 86 years old) between 1991 and 2003. Pathologically, 24 patients with epithelial type, 8 patients with biphasic type, and 6 patients with sarcomatous type were included.

With regard to asbestos exposure, 34 patients had occupational exposure and 2 female patients, whose husbands were shipyard workers, had para-occupational domestic exposure; however, exposure of the last 2 was undetermined. Among 34 patients with occupational exposure, 27 patients (79%) worked in shipyards, 4 patients (12%) were involved in the building industry, and 3 patients (9%) were mechanics. In the 27 shipyard workers, the latent period from the first exposure to asbestos to onset of mesothelioma was 24-70 (mean was 46) years, which was longer than that in builders (mean was 32 years) and in mechanics (mean was 34 years). The duration of asbestos exposure was 6-43 (mean was 26) years in the shipyard workers.

The latent period of pleural mesothelioma in shipyard workers tends to be longer than in other occupationally exposed patients.