2007 Fiscal Year Final Research Report Summary
Evaluation of biological effects of thermally decomposed asbestos
| Project/Area Number |
18590576
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Hygiene
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| Research Institution | St.Marianna University School of Medicine |
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Principal Investigator |
TAKATA Ayako St.Marianna University School of Medicine, Preventive Medicine, Lecturer (30321897)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAUCHI Hiroshi Kitasato University, School of Allied Health Science, Public Health, Professor (90081661)
AMINAKA Masahito St. Marianna University School of Medicine, Preventive Medicine, Assistant (30231997)
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| Project Period (FY) |
2006 – 2007
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| Keywords | asbestos / waste recycling / carcinogenicity / oxidative DNA damage / forsterite |
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| Research Abstract |
The conversion of chrysotile (CH) to forsterite (FO) by thermal treatment is considered to be an acceptable technique for detoxifying chrysotile. In this study, the biological effects of CH and an FO that is synthesized by heating CH at 1000℃ were compared with respect oxidative DNA damage and lung injury.
Following the administration of a single 1-mg intratracheal dose of CH or FO, we evaluated histopathological changes in the lung tissue, the lung concentrations of 8-hydroxy-2'-deoxyguanosine (8-OHdG) by HPLC-electrochemical detection (ECD) method, and the expression of 8-OHdG by immunostaining for 540 days. For the control group, we administered a single intratracheal dose of sterile saline.
In the early period following the intratracheal administration of CH, expression of 8-OHdG was observed in the bronchiolar and alveolar epithelial cells as well as in inflammatory cells and granulomas ; at the same time, an increase in the lung concentration of 8-OHdG was observed. As fibrosis progressed, expression of 8-OHdG became more apparent in the airway epithelial and inflammatory cells surrounding the fibrotic lesions ; even at 540 days post-administration, the expression of 8-OHdG was significantly higher than that of the control group. On the other hand, compared with the CH group, the acute lung inflammation observed in the FO group was less apparent and exhibited no progressive fibrosing lesions. The expression of 8-OHdG was transient and weak in the bronchiolar epithelial cells as well as in the inflammatory cells, which was consistent with the low concentration of 8-OHdG in the lungs. This study demonstrates that synthetic FO causes significantly less inflammation and oxidative DNA damage in the lungs than CH.
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Research Products
(12 results)
