Investigation of physicochemical property of respirable dust for predicators of lung injury

工作环境中可吸入颗粒物的不良健康影响被认为取决于吸入颗粒物在肺中的生物持久性。微粒在肺中的溶解度和微粒形状是影响其生物持久性的两个主要理化因素。本研究选取了三种不同类型的可吸入颗粒物，利用自行设计的溶解度测定装置，首次准确测定了这三种颗粒物的溶解度，并探讨了颗粒物的“溶解度”和“形状”对其生物持久性的影响。我们还测量了纤维状颗粒的几何平均直径和长度，以及非纤维状颗粒的几何平均直径。将颗粒的理化性质的结果与体内生物持久性进行比较，我们得出以下结论：1.通过对形状几乎相同的八钛酸钾晶须和硫酸镁晶须的比较，发现低溶解度的晶须比高溶解度的晶须具有更长的生物持久性。八钛酸钾颗粒和八钛酸钾晶须的比较结果，其溶解度几乎相同，表明纤维状颗粒的生物持久性比非纤维状颗粒的生物持久性长。3.可吸入颗粒的溶解度和形态可作为肺损伤的一个有用指标。

The adverse health effects of respirable particles in the working environment are thought to depend on the biopersistence of the inhaled particles in the lung. The solubility of the particle in the lung and particle shape are two main physicochemical factors which have an influence on the biopersistence. In this study, three different types of respirable particles were selected and the effect of "solubility" and "shape" of the particles on their biopersistence was investigated.We first measured the solubilities of three types of particles accurately by using a solubility measurement apparatus which we devised. We also measured the geometric mean diameter and length for fibrous particles and the geometric mean diameter for non-fibrous particles.Comparing the results of the physicochemical properties with the biopersistence of the particles in vivo, we concluded as follows :1.The results of a comparison between potassium octatitanate whisker and magnesium sulfate whisker, whose shapes are almost identical, showed that biopersistence was longer for the low solubility than for that of the high solubility.2.Similarly, the comparison results for potassium octatitanate particle and potassium octatitanate whisker, whose solubility is almost identical, showed that biopersistence was longer for the fibrous particle than that of the non-fibrous particle.3.It is suggested that the solubility and the shape of respirable particles will be a useful indicator for lung injury.