ИСТИНА

Northern rivers transport vast quantities of water and constituents from the continents to the Arctic Ocean. Snow and ice melt in Polar regions are associated with dramatic changes in the hydrological regime and significantly enhance erosional processes. Such changes are the most important driver of the hydrological cycle of Polar rivers and dominate the fluxes of dissolved and particulate substances from land to the Arctic Ocean. This study aims at understanding interbasinal and seasonal variations of metals and metalloids (B, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Mo, Cd, Sb, Sn, W, Pb, U) at the lower Ob, Yenisey, Lena, and Kolyma rivers, as well as Selenga River catchment which represents the upper part of Yenisey river basin – the region most subjected to anthropogenic impact (most agriculture, mining, and urbanization). The dataset on elements in river water and suspended solids for the Ob, Yenisey, Lena, and Kolyma rivers was collected during 2018-2021 regularly at the stations located upstream from deltaic areas and includes 435 suspended matter grain sizes estimates, chemical results from 449 water and suspended matter samples. The dataset on the Selenga River was collected during 2011-2017 at around 76–110 monitoring locations distributed over the catchment area (477,000 km2) during different hydrological seasons. The approach enables differentiation of background, baseline, and anthropogenic levels of dissolved and suspended metal(loid)s. The study emphasizes average regional concentration levels of metal(loid)s for each river and reveals elevated relative pollution of Ob and Lena compared to Yenisey and Kolyma, as well as seasonal and cross-sectional variations. The results were used to calculate the particulate flux of studied metal(loid)s, which constitute over 13% of the total annual sediment load for the Ob River, 31% for the Yenisey River, 19% for the Lena River, and 20% for Kolyma River.