Microplastics are ubiquitous in our environment and are found in rivers, streams, oceans, and even tap water. Riverine microplastics are relatively understudied compared with those in marine ecosystems. In Oregon (USA), we sampled 8 sites along 4 freshwater rivers spanning rural to urban areas to quantify microplastics. Plankton tow samples from sites along the Columbia, Willamette, Deschutes, and Rogue Rivers were analyzed using traditional light microscopy for initial microplastic counts. Application of Nile Red dye to validate microplastics improved microplastic identification, particularly for particles (Wilcox test; p  = 0.001). Nile Red–corrected microfiber abundance was correlated with human population within 5 km of the sample site (R ² = 0.554), although no such relationship was observed between microparticles and population (R ² = 0.183). We found that plastics were present in all samples from all sites, despite the range from undeveloped, remote stretches of river in rural areas to metropolitan sites within Portland (OR, USA), demonstrating the pervasive presence of plastic pollution in freshwater ecosystems. Environ Toxicol Chem 2020;39:1590–1598. © 2020 SETAC

中文翻译：

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应用成本有效的验证技术，对俄勒冈州沿农村到城市的4条河流进行微塑性监测。

微塑料在我们的环境中无处不在，在河流，溪流，海洋甚至自来水中都可以找到。与海洋生态系统相比，河滨微塑料的研究相对较少。在美国俄勒冈州，我们沿着从农村到城市的4条淡水河对8个地点进行了采样，以对微塑料进行定量。使用传统的光学显微镜对哥伦比亚，威拉米特，德舒特和罗格河沿岸的浮游生物丝束样品进行了初步的微塑性计数分析。尼罗红染料在验证微塑料中的应用改善了微塑料的识别性，尤其是对于颗粒而言（Wilcox测试；p  = 0.001）。尼罗河红校正过的超细纤维丰度与采样点5公里以内的人口相关（R2 = 0.554），虽然微粒和人口（之间没有观察到这种关系，- [R 2 = 0.183）。我们发现，尽管从农村地区不发达的偏远河段到波特兰市（美国俄勒冈州）的大都市地区，所有地点的所有样品中都存在塑料，这表明淡水生态系统中普遍存在塑料污染。环境毒性化学2020； 39：1590-1598。©2020 SETAC