Persistent influx of atmospheric microplastics and nanoplastics to Mount Everest driven by large scale circulation

The Third Pole receives long-range transported pollutants, yet atmospheric micro- and nanoplastics inputs remain poorly constrained. Here we report year-long monitoring on the northern slope of Mount Everest using dry, wet, and total deposition sampling. Microplastic deposition fluxes at Qomolangma Station (64.0 n m−2 d−1) significantly exceed those at Everest Base Camp (23.0 n m−2 d−1), reflecting topographic and anthropogenic differences. Deposited microplastics are dominated by fragments, mainly polyamide, polyethylene terephthalate, and polyethylene. Nanoplastic concentrations across five representative months are higher at Qomolangma Station than at Everest Base Camp and include polyethylene, polyethylene terephthalate, polyvinyl chloride, and polypropylene. Monsoon periods enhance wet deposition via short-range transport, whereas non-monsoon periods receive long-range continental inputs. Upscaling suggests an annual atmospheric input of 56.4 tons of microplastic to the Tibetan Plateau above 4000 m. These results identify the atmosphere as an efficient pathway for plastic delivery to the Third Pole, with potential ecological risks despite low ambient concentrations. Microplastic deposition fluxes at Qomolangma Station exceed those at Everest Base Camp, reflecting topographic and anthropogenic differences, with an estimated annual atmospheric input of 56 tons to the Tibetan Plateau above 4000 m, based on year-long monitoring on Mount Everest’s northern slope.