Development of a simple identification system for floating dust containing acicular material

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K04635
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 25020:Safety engineering-related
• Research Institution: Yamaguchi University
• Principal Investigator: SHINJI MASATO 山口大学, 大学院創成科学研究科, 教授 (40335766)
• Co-Investigator(Kenkyū-buntansha): 林 久資 山口大学, 大学院創成科学研究科, 助教 (30633614)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 安全工学 / トンネル工学 / 土木工学

Outline of Final Research Achievements

The good working environment during tunnel construction is an extremely important research issue. In this study, we focused on dust measurement among the working environment items and investigated a simple method to detect and quantify needle-like minerals such as asbestos, which require special handling. Based on the principle of Mie scattering of floating dust, previous research has shown that the polarization of scattered light at 170 degrees, which is close to backscattering, differs greatly between cylindrical particles and spherical particles. We have developed a method for the identification of suspended needle-like particles by obtaining scattered light images that are unique to asbestos due to its needle-like shape. For this purpose, we used laser light and flash light with short wavelengths as light sources, and also worked on methods for identifying dust in images taken by AI and discriminating asbestos.

Free Research Field

トンネル工学，岩盤工学，安全工学

Academic Significance and Societal Importance of the Research Achievements

アスベストは，極めて細い針状の無機繊維鉱物である．この物質を多量に吸引すると，肺胞深部に蓄積され，中皮腫や肺機能障害などの健康被害の原因となる．また，アスベストを産出する岩石であるクリソタイルを有する蛇紋岩中を掘削するトンネル工事では，針状浮遊粉じんの発生の有無は工事進行に大きな影響を及ぼし，従来のガイドラインに基づく単位空間あたりの粉じん重量の規制だけではなく，単位空間あたりの本数の規制であるアスベストの飛散防止に関する規制を順守する必要が生じ，トンネル建設工事を安全に進めるには極めて大きな影響を及ぼす．そのため，簡便にアスベスト浮遊の有無を識別できる計測手法の開発が望まれている．