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Microplastic Survey
The Yokohama Institute of Environmental Science conducts a fixed-point survey to understand the actual situation of microplastics (fine plastics less than 5 mm in size) in rivers in the city.
Last updated on April 10, 2025.
Results of fixed-point survey
| Date of investigation | Number density (individual/m3) ※1 | ||||
|---|---|---|---|---|---|
Tsurumi River | Katabira River | Kashio River | |||
January, 2025 (R6 Winter) | 4.3 | 1.8 | 0.44 | ||
September, 2024 (R6 Summer) | 4.2 | 2.3 | 1.9 | ||
January, 2024 (R5 Winter) | 4.7 | 1.6 | 0.86 | ||
September, 2023 | 5.5 | 2.8 | 2.9 | ||
January, 2023 (R4 Winter) | 4.4 | 1.9 | 0.42 | ||
September, 2022 (R4 Summer) | 4.2 | 3.6 | 8.6 | ||
January and February 2022 (R3 Winter) | 4.0 | 2.1 | 0.57 | ||
September, 2021 (R3 Summer) | 3.8 | 2.7 | 2.3 | ||
※The number density is calculated by dividing the number of microplastics collected by the amount of water collected (m3).
※2 The Tsurumi River and Kamenoko Bridge are collected at the same time at three crossing directions (left bank, middle, right bank), so the average value of the three points is shown.
Please download the summary of the survey results here.
Overview of the survey results from FY2021 to FY2024 (PDF: 279KB)
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Inquiries to this page
Green Environment Bureau Institute of Environmental Science, Environmental Conservation Department
Phone: 045-453-2550
Phone: 045-453-2550
Fax: 045-453-2560
E-Mail address [email protected]
Page ID: 886-268-967
