Zhou Mi, Yanai Hirofumi, Yap Chee Kong, Emmanouil Christina, Okamura Hideo
Graduate School of Maritime Sciences, Kobe University, Fukaeminami-machi, Higashinada-ku, Kobe 658-0022, Japan.
Department of Biology, Faculty of Science, Universiti Putra Malaysia, UPM Serdang, Serdang 43400, Selangor, Malaysia.
J Xenobiot. 2023 Nov 7;13(4):685-703. doi: 10.3390/jox13040044.
The abundance, distribution, and composition of microparticles (MPs) in the sea-surface microlayer (S-SML, less than 100 μm of sea surface in this experiment) and in bulk water (1 m under the sea surface) were investigated to evaluate the pollution level of MPs in Osaka Bay in Japan. Both seawater fractions were collected at eight sites including ship navigation routes, the coastal area, and the center of Osaka Bay for 2021-2023. MPs were filtered for four size ranges (10-53, 53-125, 125-500, and >500 μm) and then digested with HO. MPs' abundance was microscopically assessed; and polymer types of MPs were identified by a Fourier transform infrared spectrometer (FTIR). For the 22 collections performed along eight sites, the average MPs' abundance was 903 ± 921 items/kg for S-SML, while for the 25 collections performed along the same sites, the average MPs' abundance was 55.9 ± 40.4 items/kg for bulk water, respectively. MPs in both S-SML and bulk water exhibited their highest abundance along the navigation routes. The smallest MPs (10-53 μm) accounted for 81.2% and for 62.2% of all MPs in S-SML and in bulk water among all sites, respectively. Polymethyl methacrylate (PMMA) was the major type of MPs identified while minor ones were polyethylene, polyesters, polystyrene, polypropylene, polyvinyl chloride, polyamide, etc. PMMA comprised 95.1% of total MPs in S-SML and 45.6% of total MPs in bulk water. In addition, PMMA accounted for 96.6% in S-SML and 49.5% in bulk water for the smallest MP category (10-53 μm). It can be assumed that the MP sources were marine paints-primarily APPs (antifouling paint particles)-as well as land coatings. Sea pollution due to microparticles from ship vessels should be given proper attention.
为评估日本大阪湾微塑料（MPs）的污染水平，对海面微层（S-SML，本实验中为海面以下100μm以内）和水体（海面以下1m）中微塑料的丰度、分布及组成进行了调查。2021年至2023年期间，在包括船舶航行路线、沿海区域和大阪湾中心在内的8个地点采集了这两种海水样本。微塑料按四个尺寸范围（10-53、53-125、125-500和>500μm）进行过滤，然后用HO消化。通过显微镜评估微塑料的丰度；并用傅里叶变换红外光谱仪（FTIR）鉴定微塑料的聚合物类型。在沿8个地点进行的22次采集样本中，S-SML中微塑料的平均丰度为903±921个/千克，而在沿相同地点进行的25次采集样本中，水体中微塑料的平均丰度分别为为55.9±40.4个/千克。S-SML和水体中的微塑料在航行路线沿线的丰度均最高。在所有地点，最小的微塑料（10-53μm）分别占S-SML和水体中所有微塑料的81.2%和62.2%。已鉴定出的微塑料主要类型为聚甲基丙烯酸甲酯（PMMA），次要类型为聚乙烯、聚酯、聚苯乙烯、聚丙烯、聚氯乙烯、聚酰胺等。PMMA在S-SML中占微塑料总量的95.1%，在水体中占45.6%。此外，对于最小尺寸的微塑料类别（10-53μm），PMMA在S-SML中占96.6%，在水体中占49.5%。可以推测，微塑料的来源是海洋涂料——主要是防污漆颗粒（APPs）——以及陆地涂料。船舶产生的微塑料对海洋的污染应得到应有的重视。
