Cancer incidence of Taiwanese shipbreaking workers who have been potentially exposed to asbestos.
BACKGROUND
Shipbreaking remains one of the most dangerous jobs worldwide. Shipbreaking workers are exposed to many hazardous chemicals, especially asbestos. Unfortunately, long-term follow-up studies of cancer incidence patterns in shipbreaking workers are lacking. This study examines whether there is an increased risk of cancer among male shipbreaking workers over a 24-year follow-up period.


METHODS
4155 male shipbreaking worker's information was retrospectively collected from Kaohsiung's Shipbreaking Workers Union database from 1985. The study cohort was linked to the Taiwan Cancer Registry from 1985 to 2008 for new cancer cases. The expected number of cancers for shipbreaking workers was calculated by using the age (5-year intervals) and calendar time-specific annual rates of cancer incidence with reference to the general population of Taiwan from 1985 to 2008. Standardized incidence ratios (SIRs) were calculated as relative risk estimates. The hazard ratio (HR) for cancer was calculated for the shipbreaking workers with Total Exposure Potential Scores for asbestos.


RESULTS
After consideration of a 5-year latency period, an elevated incidence of overall cancer (N=368; SIR=1.13 (1.01-1.25)), oral cavity cancer (N=83; SIR=1.99 (1.58-2.46)), and trachea, bronchus, and lung cancers (N=53; SIR=1.36 (1.02-1.78)) was found among male shipbreaking employees. Moreover, mesothelioma cases were found in those who had the occupation of flame cutter. The high asbestos exposure group was associated with an increased SIR of developing overall cancer and oral cancer, whether we considered a 5-year or 10-year latency period.


CONCLUSIONS
Asbestos-related diseases, including lung cancer and mesothelioma, were seen in excess in these shipbreaking workers and some cases appeared to have a dose-dependent relationship. Preventative measures among male shipbreaking workers should be researched further.
Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Miaoli, Taiwan.
Wei-Te
WT
Wu
Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Miaoli, Taiwan.
Yu-Jen
YJ
Lin
Department of Public Health, China Medical University, Taichung, Taiwan.
Huei-Sheng
HS
Shiue
Department of Public Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
Chung-Yi
CY
Li
Department of Environmental and Occupational Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan; Department of Occupational Safety and Health, College of Public Health, China Medical University, Taichung, Taiwan.
Perng-Jy
PJ
Tsai
Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Miaoli, Taiwan; Institute of Public Health, Kaohsiung Medical University, Kaohsiung, Taiwan.
Chun-Yuh
CY
Yang
Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Miaoli, Taiwan; Department of Public Health, China Medical University, Taichung, Taiwan.
Saou-Hsing
SH
Liou
Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Miaoli, Taiwan; Graduate Institute of Biostatistics, China Medical University, Taichung, Taiwan. Electronic address: tnwu@mail.cmu.edu.tw.
Trong-Neng
TN
Wu
D000328:Adult; D001194:Asbestos / Q000009:adverse effects*; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D009369:Neoplasms / Q000453:epidemiology* / Q000209:etiology; D016273:Occupational Exposure / Q000009:adverse effects*; D012042:Registries; D012189:Retrospective Studies; D013624:Taiwan / Q000453:epidemiology
D001194:Asbestos
Asbestos; Cancer incidence; Shipbreaking workers; Standardized incidence ratios (SIRs)