Development of Lipoma among Residents Exposed to Glass Fiber Waste

Lim, Hyun Sul; Cheong, Hae Kwan; Kim, Ji Yong; Kim, Jung Ran; Sakai, Kiyoshi; Hisanaga, Naomi

Abstract

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.