Impact of the Mednogorsk copper smelter on human health and soil environmental quality in Orenburg Region, Russia

Abstract

Nonferrous metal smelting operations are a recognized source of metal accumulation in surrounding soils. In Mednogorsk, Russia, soil contamination results from atmospheric emissions from a local copper (Cu) smelter. This study aimed to assess health risks by analyzing the levels of Cu, arsenic (As), cadmium (Cd), lead (Pb), and zinc (Zn) in 20 Mednogorsk topsoil samples and three background area samples. The phytotoxicity of metals to Lolium perenne was also evaluated. The soil ingestion protocol of the US Environmental Protection Agency was used for health risk assessment. Phytotoxicity tests were performed on ryegrass using a standard protocol. The levels of Cu correlated with those of other elements, indicating that the smelter was the source. Of concern, the carcinogenic risk exceeded the 10^-04 threshold in 85% and 15% of the samples for children under five years of age and adults, respectively. In addition, 60% of the samples exceeded the safe Pb threshold for children's health (80 mg kg^-1). These risk levels are unacceptable and require specific intervention by the relevant authorities. However, only 20% of the samples showed high phytotoxicity, mostly in acidic soils (pH<4.0). This discussion focuses on the potential of soil phytostabilization to reduce human metal exposure, as the results provide valuable insights for managing metal pollution in regions affected by nonferrous smelter emissions worldwide.