石棉车间自然染尘犬的小气道病变及其病因学研究

Small--Airway Lesions Induced by Inhalation of Asbestos Dust in Dogs——Pathological and Aetiological Studies

家犬于石棉车间自然吸入染尘1～3年后,其呼吸性细支气管、肺泡管及膜性细支气管均显示不同程度的粉尘沉着伴纤维化。病变程度亦随染尘时间延长而逐渐加重,酷似人体石棉肺小气道病变。肺病灶内尘粒能谱分析揭示其病因相当复杂,原则上是一种混合粉尘,以硅酸盐为主,石棉占绝对优势,且闪石类多于温石棉,并存在明显剂量效应关系。

This paper pres?nts the patho-Iogical changes of the small airways of dogsinhaling asbetos dust in the wokshop of Xin Kong Asbestos Mine for 1 to 3 years.Dogs of the experimental group showedthat variable degrees of dust deposition and fibrous tissue reaction were found inall the three types of the small airways-respiratory bronchioles, alveolar ducts andmembranous bronchioles of both lungs.The lesions in the lung increased with theduration of exposure. These changes inthe canine small airways resulting fromasbestos dust were very much similar tothose of the humans. In addition, deposi-ted dust collected from the workshop othe asbestos mine, and 50 dust particlesselected randomly in foci were identifiedin situ by energy dispersive X-ray analy-sis. Findings demonstrated that the ma-jority of the dust particles in the foci wasprincipally mixed silicate dust. Amongthem asbestos dust predominated absolu-tely, and there were mor? amphibolesthan chrysotiles. Therefore, it is conclu-ded that the small airway lesions inducedin the dogs are mainly due to mixedasbestos dust, and that there appears toexist a dose-response relationship.