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Microplastics Survey
The Yokohama Institute of Environmental Science conducts a fixed-point survey to understand the actual situation of microplastics (fine plastics with a size of less than 5 mm) in rivers in the city.
Last Updated May 16, 2024
Results of fixed-point survey
| Date of investigation | Microplastic number density (unit / m3) ※1 | ||||
|---|---|---|---|---|---|
Tsurumi River | Katabira River | Kashio River | |||
January, 2024 (R5 Winter) | Left bank 4.4 | 1.6 | 0.86 | ||
September, 2023 | Left bank 5.7 | 2.8 | 2.9 | ||
January, 2023 (R4 Winter) | Left bank 2.6 | 1.9 | 0.42 | ||
September, 2022 (R4 Summer) | Left bank 4.4 | 3.6 | 8.6 | ||
January and February 2022 (R3 Winter) | Left bank 3.9 | 2.1 | 0.57 | ||
September, 2021 (R3 Summer) | Left bank 2.0 | 2.7 | 2.3 | ||
January, 2021 (R2 Winter) | 5.0 | 1.7 | － | ||
August, 2020 (R2 Summer) | 1.3 | 2.6 | － | ||
January, 2020 (R1 Winter) | 2.1 | 2.3 | － | ||
July and August 2019 (R1 Summer) | 6.7 | 2.5 | － | ||
※1 Numerous density is the number of collected microplastics divided by the amount of water sampling (m3).
※2 Collected at the middle point from the riverbank to the opposite bank. However, only the Tsurumi River and Kamenoko Bridge are collected simultaneously at three points on the left bank and right bank in addition to the middle point.
※3 The Kashio River and Yoshikura Bridge have been conducting surveys since September 2021 (R3 summer).
Please download a summary of the survey results here.
Outline of survey results up to fiscal 2023 (PDF: 528KB)
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For inquiries to this page
Environmental Conservation Department, Green Environment Bureau
Phone: 045-453-2550
Phone: 045-453-2550
Fax: 045-453-2560
Email address: mk-kanken@city.yokohama.lg.jp
Page ID: 886-268-967
