Brown D M, Donaldson K
Institute of Occupational Medicine Ltd, Edinburgh.
Br J Ind Med. 1991 Mar;48(3):196-202. doi: 10.1136/oem.48.3.196.
Epidemiological studies of workers in wool textile mills have shown a direct relation between the concentration of wool dust in the air and respiratory symptoms. Injurious effects of wool dust on the bronchial epithelium could be important in causing inflammation and irritation. A pulmonary epithelial cell line in vitro was therefore used to study the toxic effects of wool dust. Cells of the A549 epithelial cell line were labelled with 51Cr and treated with whole wool dusts and extracts of wool, after which injury was assessed. Also, the effects of grain dust, which also causes a form of airway obstruction, were studied. The epithelial injury was assessed by measuring 51Cr release from cells as an indication of lysis, and by monitoring cells which had detached from the substratum. No significant injury to A549 cells was caused by culture with any of the dusts collected from the air but surface "ledge" dust caused significant lysis at some doses. Quartz, used as a toxic control dust, caused significant lysis at the highest concentration of 100 micrograms/well. To determine whether any injurious material was soluble the dusts were incubated in saline and extracts collected. No extracts caused significant injury to epithelial cells. A similar lack of toxicity was found when 51Cr labelled control alveolar macrophages were targets for injury. Significant release of radiolabel was evident when macrophages were exposed to quartz at concentrations of 10 and 20 micrograms/well, there being no significant injury with either wool or grain dusts. These data suggest that neither wool nor grain dust produce direct injury to epithelial cells, and further studies are necessary to explain inflammation leading to respiratory symptoms in wool and grain workers.
对毛纺织厂工人的流行病学研究表明，空气中羊毛粉尘浓度与呼吸道症状之间存在直接关联。羊毛粉尘对支气管上皮的有害影响可能在引发炎症和刺激方面具有重要作用。因此，利用一种体外培养的肺上皮细胞系来研究羊毛粉尘的毒性作用。用⁵¹Cr标记A549上皮细胞系的细胞，并用全羊毛粉尘和羊毛提取物进行处理，之后评估细胞损伤情况。此外，还研究了同样会导致某种形式气道阻塞的谷物粉尘的影响。通过测量细胞中⁵¹Cr的释放量以指示细胞裂解情况，并监测从基质上脱落的细胞，来评估上皮损伤。用从空气中收集的任何一种粉尘培养，均未对A549细胞造成显著损伤，但表面“壁架”粉尘在某些剂量下会导致显著的细胞裂解。用作毒性对照粉尘的石英，在最高浓度为100微克/孔时会导致显著的细胞裂解。为了确定是否有任何有害物质可溶，将粉尘在盐水中孵育并收集提取物。没有任何提取物对上皮细胞造成显著损伤。当以⁵¹Cr标记的对照肺泡巨噬细胞作为损伤靶点时，也发现了类似的无毒性情况。当巨噬细胞暴露于浓度为10和20微克/孔的石英时，放射性标记物有显著释放，而羊毛粉尘和谷物粉尘均未造成显著损伤。这些数据表明，羊毛粉尘和谷物粉尘均不会对上皮细胞产生直接损伤，需要进一步研究来解释导致羊毛和谷物加工工人出现呼吸道症状的炎症原因。
