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Clinical study on mesothelioma in Japan: Relevance to occupational asbestos exposure
Takumi Kishimoto1, Kenichi Gemba, Nobukazu Fujimoto
1Okayama Rosai Hospital, Japan. nakisimt@okayamah.rofuku.go.jp
Background:
In 2003, the number of deaths due to malignant mesothelioma in Japan was 878; however, only 85 cases of mesothelioma due to asbestos exposure were authorized for compensation. The reasons for this discrepancy require evaluation.
Method:
We examined medical records, X-rays, and pathology results to evaluate mesothelioma cases in Japan between 2003 and 2005; used a questionnaire to identify occupational and environmental histories, and determined the concentration of asbestos fibers in pathology specimens.
Results:
We identified 442 definite cases of malignant mesothelioma with a median age of 68 years. There were 316 malignant mesothelioma cases with occupational asbestos exposure, 12 cases with neighborhood exposure and 5 cases with likely domestic exposure. Most (78%) of the 87 cases exceeded 1,000 asbestos particles per gram of dry lung tissue.
Conclusion:
We conclude that 79.2% of cases of mesothelioma in Japan in recent years were caused by asbestos exposure.
Insights
Most malignant mesothelioma cases in Japan are linked to asbestos exposure, despite discrepancies in compensation. This study evaluated 442 cases, finding 79.2% were asbestos-related, highlighting a significant public health issue.
Area of Science:
- Environmental Health
- Occupational Medicine
- Pathology
Background:
- Significant discrepancy noted between mesothelioma deaths and asbestos-related compensation in Japan.
- 878 mesothelioma deaths recorded in 2003, with only 85 asbestos-related cases compensated.
- Need for evaluation to understand the reasons for this disparity.
Purpose of the Study:
- To evaluate the causes of malignant mesothelioma in Japan.
- To determine the proportion of mesothelioma cases attributable to asbestos exposure.
- To investigate occupational, environmental, and domestic asbestos exposure histories.
Main Methods:
- Analysis of medical records, X-rays, and pathology results for mesothelioma cases (2003-2005).
- Utilized questionnaires to gather occupational and environmental exposure histories.
- Quantified asbestos fiber concentration in pathology specimens.
Main Results:
- Identified 442 definite cases of malignant mesothelioma.
- Occupational asbestos exposure was linked to 316 cases, with neighborhood and domestic exposure in 12 and 5 cases, respectively.
- Elevated asbestos fiber concentrations (>1,000 particles/gram) found in 78% of analyzed cases.
Conclusions:
- Asbestos exposure is the cause of 79.2% of recent malignant mesothelioma cases in Japan.
- The findings underscore the significant impact of asbestos on public health.
- Recommends further investigation into asbestos-related disease attribution and compensation.
