The contamination of the environment with microplastic, defined as particles smaller than 5 mm, has emerged as a global challenge because it may pose risks to biota and public health. Current research focuses predominantly on aquatic systems, whereas comparatively little is known regarding the sources, pathways, and possible accumulation of plastic particles in terrestrial ecosystems. We investigated the potential of organic fertilizers from biowaste fermentation and composting as an entry path for microplastic particles into the environment. Particles were classified by size and identified by attenuated total reflection-Fourier transform infrared spectroscopy. All fertilizer samples from plants converting biowaste contained plastic particles, but amounts differed significantly with substrate pretreatment, plant, and waste (for example, household versus commerce) type. In contrast, digestates from agricultural energy crop digesters tested for comparison contained only isolated particles, if any. Among the most abundant synthetic polymers observed were those used for common consumer products. Our results indicate that depending on pretreatment, organic fertilizers from biowaste fermentation and composting, as applied in agriculture and gardening worldwide, are a neglected source of microplastic in the environment.

中文翻译：

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有机肥料作为微塑料进入环境的媒介。

微塑料（定义为小于5毫米的颗粒）对环境的污染已成为全球性挑战，因为它可能对生物群和公共健康构成威胁。当前的研究主要集中在水生系统上，而关于陆生生态系统中塑料颗粒的来源，途径和可能的积累知之甚少。我们调查了生物废物发酵和堆肥中有机肥料作为微塑料颗粒进入环境的进入途径的潜力。通过尺寸对颗粒进行分类，并通过衰减全反射-傅立叶变换红外光谱法进行鉴定。来自转化为生物废物的植物的所有肥料样品均含有塑料颗粒，但其含量随底物预处理，植物和废物的不同而有显着差异（例如，家庭与商业）类型。相反，经测试用于比较的农业能源作物蒸煮器中的消化液仅包含分离的颗粒（如果有的话）。观察到的最丰富的合成聚合物是用于普通消费品的那些。我们的结果表明，依靠预处理，来自生物废物发酵和堆肥的有机肥料已被广泛用于农业和园艺领域，是环境中微塑料的来源。