Occurrence, Characteristics, and Risk Assessment of Microplastics in Tap Water and Bottled Water, China

Microplastic (MP) contamination in drinking water has emerged as a critical environmental and public health concern, particularly in rapidly industrializing regions like China. This study synthesizes the occurrence, characteristics, and risks of MPs in tap water (TW) and bottled water (BW) across China, utilizing a systematic review of peer-reviewed studies (2010–2024) and health risk modeling. Results reveal significant contamination variability: TW exhibits MP abundances ranging from 0.7 ± 0.6 p/L in rural areas to 1753 ± 693 p/L in urban surface water (SW), dominated by fibers (0.8%–97.8%) and fragments (48.1%–99.2%). In BW, the MPs reach alarming concentrations (8934 p/L for 1–50 µm particles), driven by packaging degradation, with cellulose anomalies (up to 68.3%) implicating non-plastic contamination pathways. Conventional water treatment processes (e.g., coagulation-sedimentation, membrane filtration) exhibit variable removal efficiencies (40%–99%), heavily dependent on particle size and polymer hydrophobicity. Infants face the highest estimated daily intake (5.85 MPs/kg/day), exceeding adults by 2–3 times, while ecological risk indices (53.41–289.8) highlight moderate-to-high threats in industrial zones. Methodological limitations, including nanoplastics (<1 µm) underdetection and inconsistent size classification, underscore the need for standardized protocols (e.g., ISO/TR 21960:2020) and advanced filtration technologies. This work advocates for policy reforms, infrastructure upgrades, and interdisciplinary research to mitigate MP exposure and safeguard drinking water quality.