Source Tracking and Prediction of Environmental Fate of Microplastics on Urban Water Cycle

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H00783
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Medium-sized Section 22:Civil engineering and related fields
• Research Institution: Kyoto University
• Principal Investigator: TANAKA Shuhei 京都大学, 地球環境学堂, 准教授 (00378811)
• Co-Investigator(Kenkyū-buntansha): 古米 弘明 中央大学, 研究開発機構, 機構教授 (40173546) ; 高田 秀重 東京農工大学, (連合)農学研究科(研究院), 教授 (70187970) ; 鈴木 裕識 岐阜大学, 工学部, 准教授 (20762272)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: マイクロプラスチック / 水循環系 / 路面粉塵 / 水田 / 畑地

Outline of Final Research Achievements

Water pollution by plastics smaller than 5 mm has become a problem. Where do microplastics (hereinafter referred to as MPs) occur, what size do they have, and where do they exist? The main objective of this study was to understand the distribution and dynamics of MPs in the urban water circulation system, identify the source, and predict the fate of the environment. By developing a procedure for collecting, measuring, and identifying components of 10 μm MPs, we have made it possible to discuss the enrichment process in living organisms. Using this procedure, the dynamics of MPs in road dust, runoff water, laundry wastewater, sewage treatment process water, agricultural wastewater, and surface water of river were investigated, and the amount generated in the basin was quantified by source. In particular, we focused on washing off the road surface in rainy weather and clarified the existence of MPs in overflowing water in rainy weather.

Free Research Field

環境工学

Academic Significance and Societal Importance of the Research Achievements

LDIRや顕微FTIR、熱分解GC-MSなどを駆使して、実環境中の極微小MPsの前処理、計測、成分同定方法を開発した結果、環境中のマイクロファイバーの存在やタイヤ由来の劣化ゴムの底質への蓄積が明らかとなった。そのレンジのMPsを摂食する生物も多いことから、生物濃縮過程を含めた議論が展開され、MPsの動態解明を飛躍的に進歩させるなど新たな学術分野を開拓することができた。例えば、PM2.5は肺の奥深くにまで入り込みやすく、呼吸器系疾患や循環器系疾患などのリスクを上昇させる。2.5μmのMPsの存在を知ることは、人体への曝露経路を知る上で重要であると考えられるため、社会的意義がある。