A comprehensive study of fens was carried out in the zone of weak influence of the enterprises in the Norilsk industrial region. Evidence for the present state of these fens was obtained for the first time as well as on their typization, the pollution level of vegetation and peat deposits by aerotechnogenic pollutants, namely, copper, nickel, cobalt, lead and sulfur for the lower reaches of the Keta-Irbo river (western macroslope of the Putorana plateau). It was established that the proportion of fens in the study region is not high. They are located along the river valley on poorly drained piedmont plains and also occur in the lower part of the mountain-tundra belt. The fens are of forest-marshy or marshy subtype. Sedge, horsetail and Hypnum mosses are the main peat-forming plants in this area. The thickness of the peat deposit of the valley and mountain-tundra bogs varies from 2 to 3 and from 0 to 1 m, respectively. It is composed of sedge, Hypnum, grass-Hypnum peats. The peat deposits are characterized by an acid pH throughout the profile and by a low degree of peat decomposition. Diagnostics of the degree of pollution of plants-indicators for fens in the key area showed an exceedance of concentrations in all elements with the exception of lead when compared to the background. The highest copper and nickel concentration was observed in true mosses of pools filled with abundant water. The highest cobalt concentration was observed in sphagnum mosses of dry ridges. An ecological-geochemical assessment was made of the peat pollution level in the fens (the upper 0.5 m layer of the deposit). It was found that its pollution level depends on the geomorphological position, hydrothermal regime, and on the phytocenosis type of fens. The study revealed that the concentration of copper, nickel, cobalt and sulfur in peats of the valley fens is much lower than in peats of fens of intermontane depressions and in peats of the swamped birch forest. It is shown that generally the concentration of pollutants in peats of the fens in the study area significantly exceeds the background, especially for copper and nickel.Keywords: fens, aerotechnogenic pollutants, plants-indicators, peat, pollution level.