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

2005 Fiscal Year Final Research Report Summary

• Project/Area Number: 15590528
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Hygiene
• Research Institution: University of Occupational and Environmental Health
• Principal Investigator: OYABU Takako UOEH, Institute of Industrial Ecological Sciences, Research Associate, 産業生態科学研究所, 助手 (20320369)
• Co-Investigator(Kenkyū-buntansha): TANAKA Isamu UOEH, IIES, Professor, 産業生態科学研究所, 教授 (00038035) ; MORIMOTO Yasuo UOEH, IIES, Professor, 産業生態科学研究所, 教授 (30258628) ; YAMATO Hiroshi UOEH, IIES, Associate Professor, 産業生態科学研究所, 助教授 (90248592) ; OGAMI Akira UOEH, IIES, Associate Professor, 産業生態科学研究所, 助教授 (40301692) ; KURODA Kaori UOEH, IIES, Research Assistant, 産業生態科学研究所, 教務職員 (40389474)
• Project Period (FY): 2003 – 2005
• Keywords: Respirable particles / Bioperisitence / Solubility / Particle shape / Intratracheal instillation / Fibrosis

Research Abstract

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.