The Northern Dvina River is one of the main sources of microplastic pollution entering to the White and Barents Seas. The coastal and bottom sediments of this river play an important role as a transfer link of microplastics. With Py-GC/MS and μFT-IR methods, it was found that the sediments contain up to 350 mg/kg or 650 particles/kg of microplastic (dry weight). The unique hydrologic conditions of the river branching area contribute to the formation of a microplastic pollution hotspot. The hotspot accumulates >30 % of microplastic pollution, mainly ABS plastic particles smaller than 0.3 mm with roughness and cracks, which increases the hazard class (from II to IV) of microplastic pollution. Obtained data and high annual variability of pollution indicates that this area acts as a place of accumulation, degradation and gradual release of microplastics into the White and Barents Seas, i.e. into the Arctic region.

中文翻译：

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关于沉积物在从北德维纳河（俄罗斯）到白海和巴伦支海的微塑料输入中的作用的新见解

北德维纳河是进入白海和巴伦支海的微塑料污染的主要来源之一。这条河流的沿岸和底部沉积物作为微塑料的转移纽带发挥着重要作用。通过 Py-GC/MS 和 μFT-IR 方法，发现沉积物中含有高达 350 mg/kg 或 650 个颗粒/kg 的微塑料（干重）。河流分流区独特的水文条件，形成了微塑料污染热点。该热点地区微塑料污染累积量超过30%，主要是小于0.3毫米的ABS塑料颗粒，颗粒粗糙、有裂纹，增加了微塑料污染的危险等级（从II级到IV级）。获得的数据和污染的高年度变化表明，该地区是微塑料积累、降解和逐渐释放到白海和巴伦支海（即北极地区）的地方。