Heavy Metals in Birch Leaves during Reduction of Emissions from a Large Copper Smelter

Abstract—

The concentrations of heavy metals Cu, Zn, Cd, and Pb in the leaves of Betula pubescens were analyzed at ten sites along the pollution gradient near the Middle Ural copper smelter. The studies were carried out during the period of moderate emissions (2009) and after their reduction to a minimum (2019). Leaf samples were collected in early and late summer. Cu and Cd showed a strong negative correlation with the distance to the smelter. The interannual differences are most pronounced for Pb, the concentration of which significantly decreased in 2019 at the sites closest to the smelter compared to 2009. In both years, the concentrations of metals in the leaves increased towards the end of the growing season.