Safety evaluation of rock wool after nasal inhalation in rats.
Safety evaluation of rock wool after nasal inhalation in rats.
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DOI：
10.2486/indhealth.ms1146
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发表时间：
2011
影响因子：
2
通讯作者：
Yuichiro Kudo;Y. Aizawa
中科院分区：
文献类型：
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作者：
Yuichiro Kudo;Y. Aizawa
据报道，石棉会导致肺纤维化，目前石棉的使用已被禁止。通过鼻腔吸入暴露研究，我们检测了岩棉(RW)纤维在大鼠肺中的生物持久性和组织病理学效应。24只大鼠每天暴露于RW纤维6h，连续暴露5d。分别于染毒后即刻、染毒后1wk、2wk和4wk处死大鼠各6只，测定肺纤维数量和大小。暴露后4wk，肺内纤维数量明显减少。L 20μm纤维的清除半衰期为28d，世界卫生组织纤维的清除半衰期为50d。纤维数量和大小减少的原因包括：1)粘液纤毛运动排出体外，2)体液溶解，3)肺泡巨噬细胞吞噬和消化。取12只大鼠进行组织病理学检查，病理改变按Wagner标准分类。结果，只观察到了2级以下的变化。巨噬细胞数量增加的原因被认为是机体防御的短暂性反应。这些结果表明，RW的生物持久性低，仅有有限的病理效应。
Asbestos is reported to cause pulmonary fibrosis, and its use has been banned. We examined the biopersistence and histopathological effect of rock wool (RW) fibers in rat lungs by a nose-only inhalation exposure study. Twenty-four rats were exposed to RW fibers for 6 h daily for 5 consecutive days. Six rats each were sacrificed shortly and 1, 2, and 4 wk after exposure, and the fiber numbers and sizes in lungs were determined. The fiber number in the lungs 4 wk after exposure significantly decreased. The clearance half time was 28 d for fibers with L>20 μm and 50 d for World Health Organization fibers. The reasons for the decrease in number and size of fibers include: 1) discharge outside of the body by mucociliary movement, 2) dissolution by body fluid, and 3) phagocytosis and digestion by alveolar macrophages. Twelve rats were used for histopathological examination, and the pathological changes were classified by Wagner's criteria. As a result, changes up to only Grade 2 were observed. The reason for the increase in macrophage number was considered to be a transient reaction of body defense. These results suggest that RW has low biopersistence and only a limited pathological effect.