Asbestos and nonasbestos fiber content in lung tissue of Japanese patients with malignant mesothelioma

Abstract

Background. Pulmonary fiber content of both asbestos and nonasbestos types were evaluated in Japanese patients with malignant pleural mesotheliomas. Methods. Pulmonary fiber content was analyzed in 16 patients and 16 case‐matched control subjects by transmission electron microscopy with energy‐dispersive X‐ray analysis using a low‐temperature ashing procedure. Results. The geometric mean content of total asbestos was significantly higher in the patients (22.0 × 106 fibers/g dry lung) than in the control subjects (2.24 × 106 fibers/g dry lung) (P < 0.01). When the asbestos content was analyzed by fiber type, the geometric means were also consistently and significantly higher among the patients compared with the control subjects (P < 0.01). Results were as follows: (1) amosite: patients 3.94 times 106 versus control subjects 0.23 × 106; (2) crocidolite: patients 3.56 times 106 versus control subjects 0.35 times 106; (3) total amphiboles: patients 16.0 times 106 versus control subjects 0.77 times 106; and (4) chrysotile: patients 3.76 times 106 versus control subjects 1.01 times 106. However, when individual total asbestos content was considered, 7 of the 16 patients (44%) had levels lower than the highest value noted among the control subjects. Pulmonary fiber content of patients and control subjects also revealed the presence of nonasbestos fibers. The geometric mean of nonasbestos fibers was significantly higher in the patients (87.3 × 106) than in control subjects (33.8 × 106) (P × 0.01). The major type of nonasbestos fibers in both groups was aluminum silicates. The mean of ratios of nonasbestos fiber contents to total asbestos contents in the patients and control subjects was 7.0 and 17.3, respectively. Conclusions. The results were mainly in agreement with the findings of earlier investigations, but fiber content of both chrysotile and nonasbestos fiber as well as those of amphibole asbestos were significantly higher in the patients than in the control subjects.

Pulmonary Asbestos and Non-Asbestos Fiber Concentrations in Autopsied Inhabitants in Pohang, Korea.

“…Yu's study 6) with Seoul residents revealed that predominant non-asbestos fibers were composed of aluminum silicate (56.2%) and iron phosphate (22.7%), whereas Sakai's study 5) with Japanese subjects also showed that the percentages of aluminum silicate and iron phosphate were 62.3 and 18.4%, respectively. Their study results were consistent with those in this study.…”

“…Before analysis, all the tissues were stored in 10% formaldehyde with phosphate buffered saline. The methods developed by Sakai and his colleagues 5) were employed for the preparation and analysis of the lung tissues. After about 0.5 g (wet weight) lung samples had been rinsed in distilled water to remove any fiber materials, they were cut into small pieces and lyophilized.…”

“…Many studies have reported the concentrations of asbestos and non-asbestos fibers in lungs [1][2][3][4][5] , but in Korea, there has only been one study with subjects from Seoul 6) . Sakai and his colleagues 7) conducted comparative studies, with both Korean and Japanese subjects in terms of their gender and location, and found that the Japanese had higher concentrations of asbestos in their lungs than the Koreans.…”

Formation of the Nitrative DNA Lesion 8‐Nitroguanine is Associated with Asbestos Contents in Human Lung Tissues: A Pilot Study

“…Tissue specimens were resected at 16 hospitals from 1980 to 2008. The diagnosis of malignant mesothelioma was made as described previously 15) . Cases of asbestos-related diseases, such as lung cancer and asbestosis, were not included as subjects without mesothelioma.…”

Asbestos-Related Lung Cancer and Mesothelioma in Japan.

“…Sakai et al examined asbestos fibers and non-asbestos fibers in the lungs of 16 malignant pleural mesothelioma (12 males, 4 females) and 16 non-asbestos-related diseases 31) . These cases were diagnosed between 1983 and 1990.…”