BACKGROUND: White asbestos (chrysotile) has been used in dentistry since 1930 when it was introduced as a lining material for casting rings. METHODS: All three patients presented with pleural plaques on chest X-rays as well as on CT-scans. They were working as dentists for 35-45 years. Under the instructions of the first dentist we represented precisely the whole process of manipulating a kind of paper that contained asbestos. In order to measure asbestos fibers concentration we used the membrane filter method and phase contrast optical microscopy. Dry asbestos sheets were scanned with x-ray diffraction and electron microscope. RESULTS: Analysis of the filter demonstrated 0.008 fibers/cm(3) during the sampling period. X-ray diffraction analysis revealed that the material consisted of chrysotile exclusively. Electron microscope pictures confirmed the presence of chrysotile. CONCLUSION: Everyday occupational exposure for many years even to low asbestos levels, under poor ventilation conditions in a closed space, could cause pleural lesions. Copyright 2009 Wiley-Liss, Inc.
BACKGROUND:White asbestos (chrysotile) has been used in dentistry since 1930 when it was introduced as a lining material for casting rings. METHODS: All three patients presented with pleural plaques on chest X-rays as well as on CT-scans. They were working as dentists for 35-45 years. Under the instructions of the first dentist we represented precisely the whole process of manipulating a kind of paper that contained asbestos. In order to measure asbestos fibers concentration we used the membrane filter method and phase contrast optical microscopy. Dry asbestos sheets were scanned with x-ray diffraction and electron microscope. RESULTS: Analysis of the filter demonstrated 0.008 fibers/cm(3) during the sampling period. X-ray diffraction analysis revealed that the material consisted of chrysotile exclusively. Electron microscope pictures confirmed the presence of chrysotile. CONCLUSION: Everyday occupational exposure for many years even to low asbestos levels, under poor ventilation conditions in a closed space, could cause pleural lesions. Copyright 2009 Wiley-Liss, Inc.