Malignant mesothelioma in Australia, 1945-2000.
BACKGROUND
Australia has maintained a total national malignant mesothelioma case register since 1980. There has been a marked increase in the incidence of mesothelioma in the last 20 years. Currently 450-600 cases are notified annually in a population of 20 million. While the history of the Wittenoom (Western Australia) crocidolite mine and its aftermath is well known, these cases comprise only 5% of the total. This study describes the incidence of mesothelioma in Australia from 1945 to 2000.


METHODS
Using register data, time trends in mesothelioma incidence were calculated. Analyses of incidence are reported by age, sex, anatomical site, and state of notification. Associations with occupational and environmental asbestos exposure histories are described. Lung fiber content measurements were made on a subset of cases.


RESULTS
Australia has had 6,329 cases of mesothelioma from 1 January 1945 to 31 December 2000. (A further 620 cases were notified in the period from 1 January 2001 to 31 October 2001.) Annual incidence rates for Australia per million population > or = 20 years (1997) were: male, 59.8; female, 10.9; total, 35.4. Incidence rates have been continually increasing and are the highest reported national rates in the world. While Western Australia has the highest rate (1997 total rate, 52.8), most cases arise from the two most populous eastern states, New South Wales and Victoria. In 88% (male 90%, female 61%) of cases, a history of asbestos exposure was obtained. Exposures occurred in a wide variety of occupational and environmental circumstances. In 80% of cases with no history of exposure, TEM lung asbestos fiber counts > 200,000 fibers > 2 microm length per gm dry lung were obtained, suggesting unrecognized exposure.


CONCLUSIONS
Australia's high incidence of mesothelioma is related to high past asbestos use, of all fiber types, in a wide variety of occupational and environmental settings. The number of cases in total is expected to be about 18,000 by 2020, with about 11,000 yet to appear.
Leigh
James
J
Center for Occupational and Environmental Health, Department of Public Health and Community Medicine, University of Sydney, Sydney, NSW, Australia. jleigh@bigpond.com
Davidson
Patricia
P
Hendrie
Leigh
L
Berry
Dale
D
D000328:Adult; D001194:Asbestos; D001315:Australia / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008654:Mesothelioma / Q000453:epidemiology*; D008906:Mining / Q000706:statistics & numerical data; D009784:Occupational Diseases / Q000453:epidemiology*; D016273:Occupational Exposure / Q000706:statistics & numerical data; D010997:Pleural Neoplasms / Q000453:epidemiology*; D012042:Registries
D001194:Asbestos