Cyclic methylsiloxanes and related compounds in the water environment: assessment of their persistent property and occurrence of total organic silicon

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K16189
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Environmental dynamic analysis
• Research Institution: Center for Environmental Science in Saitama
• Principal Investigator: Horii Yuichi 埼玉県環境科学国際センター, 化学物質・環境放射能担当, 専門研究員 (30509534)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: メチルシロキサン / 有機ケイ素 / 東京湾流域 / 環境分析 / 環境技術

Outline of Final Research Achievements

In this study, we conducted environmental monitoring for volatile methylsiloxanes (MSs) and related compounds and their risk assessment in water and sediment environment from Tokyo Bay watershed. In river water monitoring, the concentration profiles of methylsiloxanes for over five-years including previous data were determined and were analyzed for understanding its time trend. Owing to their persistence in the environment and high adsorption onto organic carbon, sediment is considered as final sink for MSs in aquatic environment. To investigate occurrence and fate of a wide range of MSs, we simultaneously measured 35 MSs, including 7 cyclic MSs, 13 linear MSs, and 15 other MSs (e.g. hydrogen-, vinyl-, and phenyl-modified) in river sediment samples. Moreover, total organic silicon (TOSi) was tried to use as indicator for understanding the environmental distribution for whole silicone compounds.

Free Research Field

環境分析化学

Academic Significance and Societal Importance of the Research Achievements

環状シロキサン類に関する各国の詳細リスク評価から、特に水系への排出実態及び環境中濃度分布の把握が急務となっている。しかしながら、国内における環境データは非常に限られる状況にあり、本研究で得られた成果は、学術的にも新規性が高く、また、これら化学物質のリスク評価にも大いに貢献できるものと考えられる。
現在、欧州における環状シロキサンに関する化学物質管理体制の強化から、国際的にも、その用途や代替物質を含む環境への排出量が激変すると予想され、本研究で確立したGC/MSターゲット分析と全有機ケイ素の総量分析の組合せは，シロキサン類全体の環境内分布及び濃度推移を把握する上で強力なツールとなり得る。