Here's the text.
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 update date May 15, 2023
Results of fixed-point survey
| Date of investigation | Microplastic number density (unit / m3) ※1 | |||||
|---|---|---|---|---|---|---|
Tsurumi River | Katabira River | Ookagawa | Kashio River | |||
January, 2023 (FY2022 Winter) | Left bank 2.6 | 1.9 | － | 0.42 | ||
September, 2022 (Summer 2022) | Left bank 4.4 | 3.6 | － | 8.6 | ||
January and February 2022 (FY2021 Winter) | Left bank 3.9 | 2.1 | － | 0.57 | ||
September, 2021 (Summer 2021) | Left bank 2.0 | 2.7 | － | 2.3 | ||
January, 2021 (Fiscal 2020 Winter) | 5.0 | 1.7 | Missing measurement | － | ||
August, 2020 (Summer 2020) | 1.3 | 2.6 | 0.99 | － | ||
January, 2020 (Fiscal 2019 Winter) | 2.1 | 2.3 | 3.0 | － | ||
July and August 2019 (Summer of FY2019) | 6.7 | 2.5 | 0.70 | － | ||
※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, in addition to the middle point from FY2021, the left bank and right bank side in addition to the middle point.
It is collected at the same time.
※The three major Okagawa and Aokibashi Bridge have been conducting surveys until FY2020, while the Kashio River and Yoshikura Bridge have been conducting surveys since FY2021.
Please download a summary of the survey results here.
Outline of survey results up to fiscal 2022 (PDF: 339KB)
In order to open PDF files, you may need a separate PDF reader.
If you do not have it, you can download it free of charge from Adobe.
To download Adobe Acrobat Reader DC
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
