Development of a simple method for measuring the weight of microplastic content

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K12208
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 64010:Environmental load and risk assessment-related
• Research Institution: Nagasaki University
• Principal Investigator: Asakura Hiroshi 長崎大学, 水産・環境科学総合研究科(環境), 教授 (00391061)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: マイクロプラスチック / 含有重量 / 測定方法 / 重液 / 蓄積速度

Outline of Final Research Achievements

The certainty of a simple beach microplastics (MPs) survey method was evaluated. We were able to recover 89% of MPs without the use of heavy liquids. The MPs content could be accounted for even when the surface layer of the sand was sampled. Without concern for pumice contamination, the over-estimation of MPs was about 1.5 times lower. Even with a simple laboratory apparatus, a lower limit of determination of MPs of 13 mg-MPs/m2-sand could be achieved.
The rate of accumulation of MPs in the study area was determined by periodic collection and measurement of MPs at fixed points. By weighting the MPs content in hot spots and non-hot spots by their respective areas, the mean value and error of the MPs content in the entire surveyed area could be shown.

Free Research Field

廃棄物工学

Academic Significance and Societal Importance of the Research Achievements

簡単な器具と方法におけるMPs調査の精度を表現できた。職業研究者だけでなく，高校生を巻き込むことによって環境中MPs存在量のデータが蓄積できれば，長期的なMPs動向を明らかにすることができるであろう。
砂をふるいで排除して，ふるい上に残った試料を測定対象にする方法も考えられる。しかしながら，本研究での方法は，小粒径のMPsを排除していないという優位性がある。塩化カルシウムは海水の主要成分から構成されるため，海岸における選別作業において環境汚染のリスクが少ない。