Hemenway D R, Absher M P, Trombley L, Vacek P M
Department of Civil and Mechanical Engineering, University of Vermont, Burlington 05405.
Am Ind Hyg Assoc J. 1990 Jul;51(7):363-9. doi: 10.1080/15298669091369790.
The two silicon dioxide polymorphs, quartz and cristobalite, are known to have different toxicities. The clearance kinetics and biological response of two sources of quartz and one source of pure cristobalite were compared. Models were also developed to show the accumulation of cristobalite in the lungs of Fischer 344 rats as the result of short-term exposures at three different concentrations. The amount of cristobalite cleared from the lung was considerably less than that of the two quartz materials, with little or no clearance after the initial 30 days post exposure. As an indicator of the cellular biological response to the aerosols, total and differential cell counts were measured on bronchoalveolar lavage specimens. Cristobalite showed an early and sustained response with an elevated macrophage, neutrophil, and lymphocyte count through 180 days post exposure. The two quartz materials were not identical in their biological behavior even though they had identical crystal structure and similar trace element analysis. One quartz sample (MIN5) showed an increase in cell response (macrophage, neutrophils, and lymphocytes) approximately 30% that of cristobalite, whereas the other quartz material was not significantly different from control values. In addition, lung hydroxyproline content was greater in the cristobalite-exposed animals.
已知二氧化硅的两种多晶型物——石英和方石英具有不同的毒性。比较了两种石英来源和一种纯方石英来源的清除动力学及生物学反应。还建立了模型，以显示在三种不同浓度下短期暴露后，方石英在Fischer 344大鼠肺部的蓄积情况。从肺部清除的方石英量明显少于两种石英材料，暴露后最初30天内几乎没有清除。作为细胞对气溶胶生物学反应的指标，对支气管肺泡灌洗标本进行了总细胞计数和分类细胞计数。方石英显示出早期且持续的反应，在暴露后180天内巨噬细胞、中性粒细胞和淋巴细胞计数升高。尽管两种石英材料具有相同的晶体结构和相似的微量元素分析，但它们的生物学行为并不相同。一种石英样品（MIN5）的细胞反应（巨噬细胞、中性粒细胞和淋巴细胞）增加量约为方石英的30%，而另一种石英材料与对照值无显著差异。此外，暴露于方石英的动物肺部羟脯氨酸含量更高。
