Asbestos and Mesothelioma in Thailand

Abstract

Chrysotile, or white asbestos, is a fi brous silicate mineral in the serpentine group of phyllosilicates. It has been used in a number of Thai industries for several decades. However, the material is known to be carcinogenic to humans, especially affecting the serous lining of cavitary organs, producing the rare and highly malignant tumour known as mesothelioma. Yet in almost six decades (1954-2011) there have been only 57 known mesothelioma cases in Thailand, and none of them showed pathological evidence of asbestos etiology; a single case among them had a history of asbestos exposure in a factory. The fi rst patient was diagnosed in 1954 as a case of tunica vaginalis. The fi rst reported case occurred 14 years thereafter.

Studies concerning asbestos in Thailand have been few, almost all of them being carried out under my guidance, i.e., surveys for asbestos bodies in 330 randomized autopsy lungs; determination of airborne asbestos dust in areas of Bangkok with heavy street traffic; verifi cation of asbestos as a contaminant in vermiculite, which is used in horticulture as a planting medium; and durability testing of asbestos and non-asbestos cement roof tiles. Details are described in the text.

Key words: chrysotile, asbestos, vermiculite, mesothelioma, Thailand