ナノプラスチックの土壌および水生生態系における発生源、影響、および自然由来の修復戦略

Nanoplastics (NPs), defined as plastic particles smaller than 100 nm, are increasingly recognized as emerging contaminants in both soil and aquatic ecosystems. Their widespread presence, originating from plastic mulching, wastewater irrigation, atmospheric deposition, and the breakdown of larger plastics. Recent studies have reported NP concentrations in aquatic environments ranging from 0.3 to 488 μg/L, while agricultural soils may contain up to 6.6 million metric tons of microplastics annually, highlighting the scale of the problem. These particles can be taken up by plants via root and foliar pathways, with documented accumulation in edible tissues of fruits, vegetables, and cereals, raising direct concerns for food safety and human health. NPs can induce oxidative stress, impair photosynthesis, disrupt soil microbiota, and alter aquatic biodiversity, thereby threatening ecosystem stability and agricultural productivity. This review synthesizes current knowledge on NP sources, distribution, and behavior in terrestrial and aquatic systems, emphasizing their interactions with plants and soil microbiota. Special focus is given to nature-based remediation strategies, including phytoremediation and bioremediation, as eco-friendly and scalable approaches to mitigate NP contamination. By integrating environmental fate, ecological impacts, and remediation strategies, this reviw provides critical insights to support sustainable management of nanoplastic pollution in soil and aquatic ecosystems.