Dufresne A, Sébastien P, Perrault G, Massé S, Bégin R
McGill University School of Occupational Health, Montréal, Québec, Canada.
Ann Occup Hyg. 1992 Oct;36(5):519-30. doi: 10.1093/annhyg/36.5.519.
Both angular and fibrous SiC (carborundum) particulates can be emitted by SiC production operations. Carborundum pneumoconiosis is now recognized as an occupational lung disease with specific pathological features. These were previously reproduced in the sheep model of pneumoconiosis with fibrous SiC but not with angular SiC. To further document this question, the pulmonary retention in the sheep of the two morphological types was studied. Animals were injected in the tracheal lobe with equal mass (100 mg) of particulates prepared from SiC materials taken in the field. Particles were measured by analytical transmission electron microscopy in samples of bronchoalveolar lavage fluids (BAL) obtained at months 2, 4, 6 and 8 after the injection. They were also measured in samples of lung parenchyma obtained at month 8. Measurements in BAL and in lung samples both indicated a much lower retention for fibrous than for angular SiC. The retention rate in lung parenchyma at month 8 was 30 times lower for fibrous SiC. The half-life of decrease of concentrations was 3.4 times shorter for fibrous SiC. Other data in the literature support the notion that fine fibres are cleared more effectively than coarser angular particles.
碳化硅生产作业可排放出角形和纤维状碳化硅（金刚砂）颗粒。金刚砂尘肺现已被确认为一种具有特定病理特征的职业性肺病。此前在尘肺绵羊模型中用纤维状碳化硅成功再现了这些特征，但用角形碳化硅则未能成功再现。为进一步研究这一问题，对两种形态类型的碳化硅在绵羊肺部的潴留情况进行了研究。给动物的气管叶注射由现场采集的碳化硅材料制备的等质量（100毫克）颗粒。通过分析型透射电子显微镜对注射后第2、4、6和8个月采集的支气管肺泡灌洗（BAL）液样本中的颗粒进行测量。也对第8个月采集的肺实质样本中的颗粒进行了测量。BAL液样本和肺样本中的测量结果均表明，纤维状碳化硅的潴留量远低于角形碳化硅。第8个月时，纤维状碳化硅在肺实质中的潴留率低30倍。纤维状碳化硅浓度下降的半衰期短3.4倍。文献中的其他数据支持这样一种观点，即细纤维比粗角形颗粒更易被清除。
