SOIL HEAVY METALS CONTENT AND BIOACCUMULATION BY THE BLACK MEDICK (MEDICAGO LUPULINA L.) PLANTS HARVESTED FROM THE POLLUTED GRASSLANDS IN COPȘA MICĂ AREA

Abstract

Environmental contamination with heavy metals resulting from anthropogenic activities affects the quality of human life. Heavy metals enter the human body mainly by ingesting contaminated food or water. Due to the extraction of non-ferrous ores for about half a century, Copșa Mică has been one of the most polluted cities in Europe. In this study, soil and plant samples were collected from polluted grasslands and analyzed for cadmium (Cd), lead (Pb), zinc (Zn), and copper (Cu) content. The mean values (mg/kg dry weight) obtained for heavy metals total content in soil were as follows: Cd = 5.07 mg/kg D.W., Pb = 183.3 mg/kg D.W., Zn = 330.8 mg/kg D.W., and Cu = 40.3 mg/kg. Analyzing the heavy metals content in the plant, Cd recorded a mean value of 1.19 mg/kg D.W., Pb had a value of 1.75 mg/kg D.W., while Zn and Cu content recorded values of 67.8 mg/kg D.W., respectively 5.47 mg/kg D.W. According to Ministerial Order 756/1997, the values obtained for Cd, Pb, and Zn concentrations in the soil exceeded the permitted limits while Cu remained within normal values.