Publication: Radiographic progression of silicosis among Japanese tunnel workers in Kochi
Issued Date
2013-01-01
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ISSN
13489585
13419145
13419145
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2-s2.0-84880299839
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Mahidol University
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SCOPUS
Bibliographic Citation
Journal of Occupational Health. Vol.55, No.3 (2013), 142-148
Suggested Citation
Narongpon Dumavibhat, Tomomi Matsui, Eri Hoshino, Sasivimol Rattanasiri, Dittapol Muntham, Ryoji Hirota, Masamitsu Eitoku, Momo Imanaka, Basilua Andre Muzembo, Nlandu Roger Ngatu, Shinichi Kondo, Norihiko Hamada, Narufumi Suganuma Radiographic progression of silicosis among Japanese tunnel workers in Kochi. Journal of Occupational Health. Vol.55, No.3 (2013), 142-148. doi:10.1539/joh.12-0258-OA Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/32653
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Title
Radiographic progression of silicosis among Japanese tunnel workers in Kochi
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Abstract
The aim of our study was to investigate the natural course of silicosis in terms of radiographic progression among Japanese tunnel workers. Methods: Tunnel workers with silicosis were included in our study between January 2008 and June 2011. We retrospectively assessed workers' radiographs from their first through last visits to see whether there was progression. All films were interpreted by two physicians, who had been specially trained in using the ILO (2000) International Classification of Radiographs of Pneumoconioses (ILO/ICRP). We classified the radiographic findings according to the ILO/ICRP. Survival analysis was performed and then presented as time to progression. Subgroup analysis among the progressed group was performed to demonstrate duration of progression. Results: A total of 65 patients, who were no longer exposed to silica for the duration of the study, were included. The mean age at the first visit was 58.60 ± 7.10 years. The incidence rate of progression was 42 per 1,000 person-years with a median time to progression of 17 years. Progression was demonstrated among 33 cases (51%). The mean durations of progression from category 1 to category 4 and category 2 to category 4 were 14.55 and 10.65 years, respectively. Most patients (86%) had radiographic change from category 1 or 2 directly to category 4. Conclusion:2013Silicosis progressed at a relatively high rate among tunnel workers without further silica exposure. The high probability of progression directly from category 1 to category 4 may lead to further investigation for the improvement of disease prevention.