Health risk assessments and controlling factors of the dissolved trace element in river systems of the Tibetan Plateau

• Al, Fe, and Pb are the dominant elements causing water quality deterioration. • Cr poses the highest children risk, with non-carcinogenic index up to 0.12. • The carcinogenic risk in children is 1.5 times higher than that in adults. • Mining and farming elevate Cd, Pb, Sr, and U in rivers of the Tibetan Plateau. Dissolved trace elements (DTEs) are essential for water quality and ecosystem health, especially in vulnerable regions such as the Tibetan Plateau that are highly sensitive to climate and land-use changes. Here, fourteen DTEs are analyzed to explore the distribution control mechanism and health risk assessment of DTEs in river systems of the Tibetan Plateau. The results reveal that, except for Al, Fe, and Pb, concentrations of other DTEs are low and below the drinking water standard. Notably, concentrations of Cd, Fe, Li, Pb, and Zn are higher in the eastern regions, whereas Ba concentrations are higher in the west. Principal component analysis indicates that Al, Ba, Li, Mo, Sr, and U are mainly derived from natural sources, whereas Cd, Co, Cr, Cu, Fe, Mn, Pb, and Zn are primarily influenced by anthropogenic sources. Health risk assessment reveals that non-carcinogenic risk index (HI < 1) and carcinogenic risk index (CR < 10 −4 ) are acceptable, but children face higher non-carcinogenic risks, particularly from Cr (HI- child up to 0.12). The Mantel test and variance partitioning analysis show human activities explain the largest variation in DTE patterns, followed by lithology. Further analyses indicate that mining activities are associated with elevated Cd and Pb concentrations, while agricultural activities affect the distribution of Sr and U. These findings highlight the importance of anthropogenic drivers of DTE variability and the need for targeted pollution control in high-altitude river basins.