Evidence Hub

Low abundance but high microplastic toxicity and potential ecological risks in a drinking-water source

Cai X, Wen X, Wang J

Journal of environmental management, 2026

Abstract

Microplastics (MPs) in drinking-water sources pose potential health risks, yet their ecological threats under low-intensity anthropogenic activities remain poorly understood. To address this, this study focused on the Miyun Reservoir (Beijing's primary drinking-water source), and systematically collected surface water and sediment samples from the reservoir, its upstream protection zones, and downstream reaches. MP abundance and characteristics were determined using stereomicroscopy and micro-Fourier transform infrared spectroscopy. Potential sources and fragmentation characteristics were identified by comprehensively applying characteristic-based source identification, diversity index, and a conditional fragmentation model. Ecological risks were evaluated using pollution load index (PLI), polymer hazard index (PHI), and potential ecological risk index (PERI). Results showed low MP abundance (water: 0.56 ± 0.36 items/L; sediment: 74.48 ± 54.91 items/kg), dominated by fibers and films (<1 mm). Major polymers included rayon, polyethylene, polypropylene, and polyethylene terephthalate. Domestic wastewater and agriculture were considered as the primary potential contributors. PLI indicated Level I (lowest risk) at all sites, whereas PHI and PERI revealed high risks at multiple sites, and correlated positively with agricultural and built-up land area, underscoring land-use control over toxicity. Within the reservoir, all sites except R2 had PHI/PERI values at Levels IV-V,…

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free