Asbestos and Non-Asbestos Fiber Content in Lungs of Autopsied Subjects in Pohang with no Known History of Occupational Asbestos Exposure / 예방의학회지

OBJECTIVES: To obtain reference values for the pulmonary asbestos and non-asbestos fiber contents of residents in Korea and to compare them with similar results from Japan. METHODS: The autopsied lung specimens from 22 deceased people (20 males and 2 females) in Pohang, without any known occupational history of asbestos exposure, were analyzed for incidence of asbestos and non-asbestos fibers by transmission electron microscopy with energy dispersive X-ray analysis after using low temperature ashing procedures. RESULTS: Chrysotile fiber (46.2%) was the major fiber type found in the lungs of the subjects. The asbestos fiber concentrations found in males and females were 0.09x106 fibers/(g of dry lungs) and 0.30x106 fibers/(g of dry lungs), respectively, showing a geometric mean concentration 0.09x106 fibers/(g of dry lung tissue), due to the predominance of males in the sample. The non-asbestos fiber contents in males and females were 4.61x106 fibers/(g of dry lungs) and 17.79x106 fibers/(g of dry lungs), respectively, with a geometric mean concentration 5.21x106 fibers/(g of dry lung tissue). CONCLUSIONS: Residents in Pohang had significantly lower levels of both asbestos and non-asbestos fibers than urban residents in Korea. Furthermore, Koreans had significantly lower levels of both asbestos and non-asbestos fibers than Japanese.

Development of Lipoma among Residents Exposed to Glass Fiber Waste / 한국역학회지

This study was conducted to determine the relationship between exposure to glass fiber waste from an insulator factory and the development of cluster of lipomas among local residents in suburb Incheon, Korea. Authors surveyed 152 residents(71 males and 81 females) living near an insulator factory with a questionnaire and physical examination. Unused and disposed fiberglass from the waste site, along with ground water samples were examined under light and polarizing microscope and scanning electron microscope(SEM). Subcutaneous tumors excised from three of the residents were also examined under light and polarizing microscope, SEM with energy dispersive X-ray analysis(EDX), and transmission electron microscope(TEM). Analysis of elemental composition of the fibers and fiber concentration was done by with EDX under SEM and TEM after low temperature ashing. Twelve(7.9%) had subcutaneous tumors among the 152 residents. Tumors were surgically excised from 3 of them and they were all lipomas, consisting of mature fat tissue. These lipomas contained abundant birefringent fibers and particles under polarizing microscope. The concentrations of the fibers were 6.7, 71.8 and 499.2 million fibers per gram dry tissue, respectively. The birefringent fibers were composed of needle shaped particles with rectangular fractured ends up to 17 micrometer in length and 0.5 micrometer in diameter. EDX and x-ray diffraction analysis of the fibers showed that 71 to 100% of the fibers were magnesium silicate, talc. Magnesium silicate fibers were also found in the glass fiber sampled from the waste site. Glass fibers and magnesium silicate fibers were also identified in the ground water. Based on the fact that the magnesium silicate fibers found in the lipomas were similar in morphology and elemental composition to those found in the ground water and those from the waste site, these particles are likely to be introduced into the gastrointestinal tract through consumption of the contaminated ground water. It is suggested that fibrous magnesium silicate, talc, a component of fiberglass waste, may be associated with the development of lipomas.

Talc Deposition in Lipoma: A Pathologic and Mineralogic Study

Three cases of lipomas associated with heavy talc deposits are reported in local inhabitants near a fiber glass factory. Pathologic and mineralogical analysis by polarizing microscopy, scanning and transmission electron microscopy with energy dispersive X-ray analysis and X-ray diffraction of mass were done. Simultaneously, we performed an epidemiological survey and a mineralogical study of disposed fiber glass from waste site and ground water. All tumors consisted of mature fat tissue containing an abundant birefringent talc fibers and particles under polarized light. The concentrations of the fibers were 494.7, 6.7 and 50.7 million fibers per gram of dry tissue. The fibers were needlelike with rectangular fractured ends, up to 17 micrometer in length and 0.5 micrometer in diameter. EDX and X-ray diffraction analysis of the fibers showed that 71 to 100% of the fibers were magnesium silicate, talc. We also identified magnesium silicate fibers in the fiber glass from the waste site and in the ground water which were similar to talc fibers in lipomas,. We concluded that fibrous talc, a component of fiberglass waste, might be associated with the development of lipomas via unknown exposure route.