1. Studies on Asbestos and Related Health Impacts in Thailand
Somchai Bovornkitti, MD, DScMed, FRCP, FRACP, Hon.FACP
Emeritus Professor of Medicine
Mahidol University, Bangkok
Fellow of The Royal Institute, Thailand

2. Asbestos has been imported for use in Thai industries since 1938 = 75 years

3. Research on Asbestos in Thailand (1) In 1976, asbestos was noted in talcum powder as a source of contamination, where asbestos bodies were found in the lung of a patient with talc pneumoconiosis.

4. Asbestos body in the lung (upper left) and talcum double-refractile needle-shape crystal in the same lung (lower left) A puff-spray bottle is shown to the right

5. (2) Studies conducted in revealed asbestos bodies in autopsied lungs in 33% of patients who had neither a history of asbestos exposure nor asbestos-related diseases. (n=330)

6. Asbestos bodies in the lung preparation showing beading and segmentation in coating central core fibers (x450)

7. A SEM of a 5-month old girl showing an asbestos body in the lung (A) and the analytical result of chrysotile fiber (B)

8. (3) In air pollution studies, carried out in eight cement sheet factories and seven brake and clutch lining factories, disclosed the presence of asbestos fibers at negligible higher levels than the safety threshold. Studies of outdoor air around the factories showed 7.10 percent positivity among the 210 specimens.

9. (4) In 1984, an examination of 203 air samples from 10 different main streets in Bangkok during week-day rush hours showed absolute absence of asbestos fibers.

10. (5) In 2006, a study on asbestos exposure in workers demolishing a building with asbestos ceiling and roof tiles using personal and environmental air sampling analysis revealed fiber/mL. (ACGIH safety level was 0.1 fiber/ML)

11. (6) In 2006, a prevalence study on asbestos-fiber cement factory workers using CXR and HRCT. Although 39 of the 907 workers (4.3%) had abnormal chest images compatible with asbestos exposure, the report was not conclusive owing to the lack of supporting evidences.

12. (7) In 2009, air pollution analysis was conducted in 4 asbestos cement roof-tile factories found 0.73 asbestos fibers/mL in roof-fitting polishing areas.

13. (8) In 2010, a study on brake dust in 14 garages using x-ray diffractometer yielded chrysotile in 15 of 42 samples (35.7%); among 128 workers 14.8% had respiratory symptoms; but no information on health and no chest x-ray.

14. (9) Knowing that asbestos contamination occurred in vermiculite, a planting material, an investigation conducted on 4 brands of imported vermiculite gave no conclusive results.

15. The 4 brands of imported vermiculite

16. Vermiculite studied by x-ray diffractometry and SEM

17. (10) In , studies of BALF from autopsy patients, general chest patients and healthy workers from factories using chrysotile yielded asbestos bodies in one general patient and six factory workers.

18. Of Note Asbestos bodies present in 7. 77 % or 11
Of Note Asbestos bodies present in 7.77 % or % of BALF were incidents somewhat similar to previous findings of 33% in autopsied patients.

19. Asbestos body in the BALF of the elderly COPD patient

20. (11) Studies on asbestos biomarkers have recently been completed.

21. Asbestos Biomarkers determined in our study were adipokine adipsin, peroxiredoxin (PRX), tropomyosin (TPM), osteopontin (OPN), mesothelin-related peptide (MRP), and hydroxyproline (OHP)

22. Findings suggest that high plasma adipsin levels may be usable as biomarker in asbestos-exposed persons and in questionable asbestos-related diseases patients

23. Asbestos-related diseases comprise asbestos warts, pleural afflictions, asbestosis, mesothelioma, and certain lung cancers.

24. Asbestos warts

25. Asbestos pleural afflictions

26. Asbestosis in Thailand There was only one probable asbestosis case in The case occurred concomitantly with talc pneumoconiosis

27. Talcosis + asbestosis

28. Mesothelioma in Thailand There are 80 known cases
Mesothelioma in Thailand There are 80 known cases. A case of tunica vaginalis tumor in First pleural mesothelioma case in Four pleural tumor patients gave history working in factories using asbestos. No proof of asbestos etiology.

29. Chest radiographs of the first mesothelioma case in Thailand.

30. Gross pathologic specimens

31. Histo-pathology of mesothelioma

32. Q & A (1) Asbestos has been in use in Thailand for over 70 years, why have there been only a single case of asbestosis and 80 mesothelioma cases of unknown etiology?

33. Reply Brushing aside the remark that ‘Thai doctors are not efficient in diagnosing the cases’, Thai officials provide effective control of the factory works and healthy environment

34. (2) Why are asbestos bodies present in the lungs and in the BALF of subjects with unknown asbestos exposure ?

35. Reply Asbestos aerosols may fly from natural sources such as asbestos mines, active volcanoes, and asbestos-rich soil in some localities, such as Uttaradith Province in Thailand, and South Bulgaria.

36. Conclusions Asbestos has been used in Thailand for more than 70 years, it has not posed any significant hazards of special concern. Any appeal to ban asbestos use in the country must be considered on the basis of facts and in the spirit of righteousness”

37. THANKS FOR ATTENTION