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Microplastic abundance in the semi-enclosed Osaka Bay, Japan

Environmental Science and Pollution Research 2024 9 citations ? Citation count from OpenAlex, updated daily. May differ slightly from the publisher's own count. Score: 45 ? 0–100 AI score estimating relevance to the microplastics field. Papers below 30 are filtered from public browse.
Dorcas Uaciquete, Kensuke Mitsunaga, Katsumi Aoyama, K. Kitajima, Takashi Chiba, Daúd Jamal, Jheng‐Jie Jiang, Yoshifumi Horie

Summary

Researchers quantified microplastic abundance in the semi-enclosed Osaka Bay, Japan, finding elevated concentrations near river mouths and urban coastal zones, and characterizing dominant polymer types consistent with consumer plastics.

Study Type Environmental

Anthropogenic particles in sea surface water of the semi-enclosed Osaka Bay were identified using stereomicroscopy, classified according to polymer type using Fourier-transform infrared spectroscopy (FTIR), and categorized according to their physical characteristics. A total of 565.1 particles were detected in the water samples. However, plastic particles accounted for only 22.4% of the particles. Microplastic abundance in Osaka Bay showed seasonal variance from 8.9 ± 1.4 (in May) to 22.8 ± 6.5 particles/L (in July), which is consistent with previous reports in other semi-enclosed bays. Microplastics were mainly fragmented and fiber shaped, with gray and colorless/white coloration. The dominant polymer types were polypropylene, poly(methylmethacrylate), polyester, polyethylene, and polyethylene terephthalate. Generally, there were considerably higher abundances of microplastics at offshore sites compared with nearshore sites. The results of this study suggest that local river effluents and marine-related activities are probable sources of microplastics in Osaka Bay.

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