The results of four years of continuous investigations (from May 2015 through April 2019) of the elemental composition of the water of the Northern Dvina River are presented; the water sampling was performed monthly year around at two sites in the lower reaches. More than 50 major and trace elements were determined in filtered water (0.45-µm membrane filter) and in suspended matter on filters, as well as Corg on GF/F glass fiber filters. The ICP MS and AAS methods were applied. The most important outcome is that the average weighted concentrations of elements in the water discharge (dissolved forms) and in suspended matter discharge (suspended form) were obtained in contrast to most similar previous publications; the average weighted concentrations allowed us to consider these results to be the most close to real. The Corg and Fe concentrations in waters of the Northern Dvina River are three- to fivefold higher compared to the average concentrations of these elements in the rivers of the world. This has a natural explanation, which includes the features of the watershed basin (widespread distribution of wetlands). The presence or absence of a correlation between elements and organoferric colloids significantly determines their concentration. The average content of elements in riverine suspended matter is very similar to the global levels, except for organic carbon and P. The annual element discharge for every year of study and the four-year average for two forms of matter (dissolved and suspended) were calculated.

New data on the elemental composition of the Severnaya Dvina River, the largest one in the White Sea region, are presented. The elemental composition of the river water in May, the period of the snowmelt flood, is similar to the upper layer of the Earth’s continental crust due to the active erosion of the earth material in the catchment area. In August, the period of the summer low water, the impact of biogenic components increases and elevated concentrations of Cd, Sb, Mn, Zn, Pb, and Cu are observed. At other times, no significant pollution by heavy and rare-earth elements is registered.

The elemental composition of ferromanganese sedimentary structures from the bottom of Lake Baikal represented by nodules and crusts, as well as the enclosing sediments, have been studied by the atomic absorption, chemical, and ICP-MS methods. It is established that the contents of the rock-forming and accompanying elements in them are highly variable. In this connection, the examined samples are divided in two groups differing by their Mn/Fe values. In most of the samples, they range from 0.01 to 0.1, although some of the ferromanganese structures or their parts are substantially enriched in manganese. The contents of most of the rare and dispersed elements in the ferromanganese structures are usually at the background level, although the samples maximally enriched in iron or manganese are characterized by relatively high copper, nickel, cobalt, vanadium, zinc, and molybdenum concentrations.