Natural and anthropogenic factors exacerbating mercury ecological risk in the Qilian Mountain Rivers: A threat to water resources - Xiwen Miao; Shiwei Sun; Zhengzheng Yang; Shichang Kang; Yulan Zhang; Qianggong Zhang; Tanuj Shukla; Junming Guo; Yujiao Zhao; Jie Huang (Science China Earth Sciences, 2026)