Long-Term Variations of Mercury Compound Concentrations in River Ecosystems in Russia Based on Monitoring Data

The problem of global environmental pollution by mercury is considered, including the sources, occurrence forms, and the specifics of mercury migration in surface water. Mercury and its compounds are among the priority biospheric pollutants. Global migration processes result in that various amounts of mercury can be seen in nearly all media of nonpolluted (background) natural ecosystems in various regions of Russia and in many world countries. The article presents data on mercury concentrations in river water in regions of Russia based on published data and the data of regular Roshydromet monitoring. The obtained results show a high heterogeneity of mercury compound concentrations in river water in various natural zones and altitudinal belts in Russia. Its concentrations vary from values below detection limit to those tens and hundreds of times the MAC, which corresponds to an extremely high level of water pollution. The highest concentrations were recorded in unique cases (the rivers of Ambarnaya, Norilka, Chumysh, Susuya, and Lyutoga). Despite of this, the median values of mercury concentration in river water in most cases are on the level below the detection limit of the method.