Mercury bioaccumulation by higher plants and mushrooms around chlor-alkali and metallurgical industries in the Baikal region, Southern Siberia, Russia

Abstract

ABSTRACT This investigation identified specific features of mercury bioaccumulation by higher plants and mushrooms growing around chlor-alkali and metallurgical plants. All samples analysed by the atomic absorption method. Various plant organs differently accumulate mercury that is regulated by their biochemical and physiological functions. Examination of different plant parts points out that the leaves and bark of trees and the leaves of herbs are the main Hg accumulators, which is explained both by the absorption of soil mercury and Hg input from the atmospheric air. The plants from the АМР surroundings show lower Hg concentrations (average 0.008 mg kg−1) when compared with those from the САР surroundings (average 0.040 mg kg−1). Mushrooms exhibit the highest bioaccumulation of Hg amount in the studied samples. The average Hg concentrations in mushrooms in CAP and AMP amount to 0.78 and 0.19 mg kg−1, accordingly. These concentrations are higher than Hg concentrations in soils, in which these mushrooms were growing. The ability of plants and mushrooms to take up mercury is directly related to its bioavailable forms in soils. The Hg–organic complexes play a crucial role the Hg bioaccumulation that is evidenced by a significant positive correlation in the ‘organic Hg fraction–plants’ system.