Ecological evaluation of heavy metal pollution of different soil-climatic regions of Armenia by biogeochemical coefficients

Abstract

We assessed environmental risk factors, based on the biogeochemical coefficients of several heavy metals in the coastal areas of different rivers in Armenia. Environmental risk factors of some heavy metals in coastal areas of the Rivers Debet, Shnokh, and Araks (Armenia) were evaluated in various soil-climatic regions. A combined method for appraising biogeochemical risk factors in soil-plant systems of coastal areas of rivers was used. Values of several biogeochemical coefficients served as input Zea Maize L. being chosen as the model plant. The total indicator of contamination with heavy metals in the hazard group was calculated, according to the Russian GOST. We found the most polluted soil in Hushakert and the least contaminated in Tekhut. The use of European classification of heavy metals, by hazard class, to determine the maximum permissible additives was considered. Hazard classes, which allow categorizing heavy metals, primarily depend on the synergism of biota response to the degree of contamination. Using annual plants allows a comprehensive assessment of the migration characteristics of heavy metals in the examined soil-plant systems. As a result, one can expand the use of Zea Maize L. indicator plant, so that it becomes a natural filter of coastal areas for monitoring heavy metals migration.