Churg A
Department of Pathology, University of British Columbia, Vancouver, Canada.
Br J Ind Med. 1990 Oct;47(10):677-81. doi: 10.1136/oem.47.10.677.
Although theoretical models and experiments on animals exist that predict the distribution of asbestos fibres in the lung, there are few studies in man that relate to this question and they have generated contradictory results. To examine this distribution analytical electron microscopy was employed to determine the amosite fibre concentration, size, surface area, and mass in 29 circumferential sites around the periphery of a mid-sagittal slice from nine morphologically normal left lungs of heavily exposed shipyard workers and insulators. Fibre concentrations were heaviest in the apical segment of the upper lobe, and low concentrations were seen in the posterior basal portion of the lower lobe. Overall, the upper lung zones had significantly greater concentrations than the lower lung zones. Fibre length was shortest in the anterior portion of the upper lobe, greater in the lingula, and greatest in the posterior basal portion of the lower lobe; fibre length overall was significantly greater in the lower compared with the upper zones. Aspect ratio followed a similar pattern. Distinct geographic runs of high or low concentrations and long or short lengths and aspect ratios were present. No consistent distribution patterns for fibre width, surface area, or mass were found. It is concluded that: (1) in the periphery of the normal lung, concentration of amosite fibres is greatest in the apex and least in the peripheral lower lobe. This distribution is the opposite of what would be expected from the known distribution of asbestosis (peripheral lower zone); nor does it correlate with bronchial pathlength or branch number, contrary to predictions from studies on animals and theoretical models; (2) fibre length and related parameters show a distribution opposite to that of fibre concentration and again do not correlate with theoretical predictions.
虽然存在预测石棉纤维在肺部分布的理论模型和动物实验，但关于这个问题的人体研究很少，且结果相互矛盾。为了研究这种分布情况，采用分析电子显微镜来测定来自9名重度暴露的造船厂工人和绝缘工人形态正常的左肺矢状中切片周边29个圆周部位的铁石棉纤维浓度、尺寸、表面积和质量。纤维浓度在上叶尖段最高，在下叶后基底部分最低。总体而言，肺上部区域的浓度明显高于肺下部区域。纤维长度在上叶前部最短，在舌叶较长，在下叶后基底部分最长；总体而言，下部区域的纤维长度明显长于上部区域。纵横比也呈现类似模式。存在高浓度或低浓度以及长或短长度和纵横比的明显地理分布趋势。未发现纤维宽度、表面积或质量的一致分布模式。得出以下结论：（1）在正常肺的周边，铁石棉纤维浓度在肺尖最高，在周边下叶最低。这种分布与已知的石棉肺分布（周边下区）相反；也与支气管路径长度或分支数量无关，这与动物研究和理论模型的预测相反；（2）纤维长度及相关参数的分布与纤维浓度相反，同样与理论预测无关。
