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Published on: October 2, 2015
Fiber concentration in lung tissue of patients with malignant mesothelioma. A case-control study
Abstract:
The risk of malignant mesothelioma associated with low-level asbestos exposure is an important unresolved issue today. We have analyzed the asbestos fiber concentration in lung tissue from 14 cases of malignant mesothelioma and 28 case-matched controls by scanning electron microscopy. The cases represent 86% of all mesotheliomas recorded by the Cancer Registry of Norway from the county of Hordaland between 1970 and 1979. Based on 1 million fibers per g of dried tissue as an indicator of cumulated asbestos exposure, the odds ratio (relative risk) was 8.5 (95% confidence limits, 2.3-31.1). Assuming that the risk of malignant mesothelioma is related to mineral fiber concentration in lung tissue, it is concluded that a fiber concentration exceeding 1 million fibers per g of dried tissue is associated with an increased risk of malignant mesothelioma. Furthermore, the results are consistent with a no-threshold response.
Insights
Low-level asbestos exposure can increase malignant mesothelioma risk. A study found over 1 million asbestos fibers per gram of lung tissue significantly elevates this cancer risk, suggesting a no-threshold response.
Area of Science:
- Environmental Health
- Occupational Medicine
- Pathology
Background:
- The link between asbestos exposure and malignant mesothelioma is well-established.
- However, the specific risk associated with low-level asbestos exposure remains an unresolved issue in public health.
Purpose of the Study:
- To investigate the association between asbestos fiber concentration in lung tissue and the risk of malignant mesothelioma.
- To determine if a threshold exists for asbestos exposure to cause malignant mesothelioma.
Main Methods:
- Lung tissue samples from 14 malignant mesothelioma cases and 28 matched controls were analyzed.
- Asbestos fiber concentration was quantified using scanning electron microscopy.
- Data represented mesotheliomas recorded in Hordaland, Norway, between 1970-1979.
Main Results:
- An asbestos fiber concentration exceeding 1 million fibers per gram of dried lung tissue was associated with an odds ratio of 8.5 for malignant mesothelioma.
- This indicates a significantly increased relative risk (95% confidence limits, 2.3-31.1).
Conclusions:
- A lung tissue fiber concentration above 1 million fibers per gram is linked to a higher risk of malignant mesothelioma.
- The findings suggest a potential no-threshold response, meaning any asbestos exposure may carry some risk.
