Key Laboratory of Environmental Nanotechnology and Health Effects, State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Key Laboratory of Environmental Nanotechnology and Health Effects, State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Environ Int. 2023 May;175:107956. doi: 10.1016/j.envint.2023.107956. Epub 2023 May 5.
Microplastics (MPs) as emerging contaminants have become a major global concern, however, the distribution and origin of MPs in Qinghai-Tibet Plateau (QTP) and their impacts on ecosystem are poorly known. Hence, we systematically evaluated the profile of MPs on the representative metropolitan locations of Lhasa and Huangshui Rivers and the scenic sites of Namco and Qinghai Lake. The average abundance of MPs in the water samples was 7020 items/m, which was 34 and 52 times higher than those for the sediment (206.7 items/m) and soil samples (134.7 items/m), respectively. Huangshui River had the highest levels, followed by Qinghai Lake, Lhasa River and Namco. Human activities rather than altitude and salinity impacted the distribution of MPs in those areas. Besides the consumption of plastic products by locals and tourists, laundry wastewater and exogenous tributary inputs, the unique prayer flag culture also contributed to the MPs emission in QTP. Notably, the stability and fragment of MPs were crucial for their fate. Multiple assessment models were employed to evaluate the risk of MPs. PERI model took MP concentration, background value and toxicity into account, comprehensively describing the risk differences of each site. The large PVC proportion in Qinghai Lake posed the highest risk. Furthermore, concerns should be raised about PVC, PE and PET in Lhasa and Huangshui Rivers, and PC in Namco Lake. Risk quotient suggested that aged MPs in sediments slowly released biotoxic DEHP and should be cleaned up promptly. The findings offer baseline data of MPs in QTP and ecological risks, providing important support for the prioritization of future control measures.
微塑料（MPs）作为新兴污染物已成为一个全球性的主要关注点，然而，青藏高原（QTP）中 MPs 的分布和来源及其对生态系统的影响仍知之甚少。因此，我们系统地评估了拉萨和黄水河代表性城市地区以及纳木错和青海湖风景区的 MPs 分布特征。水样中 MPs 的平均丰度为 7020 个/ m，分别是沉积物（206.7 个/ m）和土壤样品（134.7 个/ m）的 34 倍和 52 倍。黄水河的 MPs 含量最高，其次是青海湖、拉萨河和纳木错。人类活动而不是海拔和盐度影响了这些地区 MPs 的分布。除了当地人和游客消费塑料产品、洗衣废水和外源支流输入外，独特的经幡文化也导致了 QTP 中 MPs 的排放。值得注意的是， MPs 的稳定性和碎片化对其归宿至关重要。采用多种评估模型评估 MPs 的风险。PERI 模型综合考虑了 MP 浓度、背景值和毒性，全面描述了每个站点的风险差异。青海湖大比例的聚氯乙烯（PVC）构成了最高的风险。此外，还应对拉萨河和黄水河的 PVC、PE 和 PET 以及纳木错湖的 PC 引起关注。风险商数表明，沉积物中老化的 MPs 缓慢释放出生物毒性 DEHP，应及时清理。研究结果提供了 QTP 中 MPs 的基线数据和生态风险，为未来控制措施的优先排序提供了重要支持。
