A study on cadmium, lead, zinc and cobalt concentration in Baia Mare County, N-W Romania soils

Heavy metals are naturally present in soils, and are predominantly inherited from the soil ̉s parent material but are significantly altered by anthropogenic activity which can pose both environmentals and human health risks. The main soil pollution source is: mine entrances (mine openings) ore processing factories, metallurgical factories. Naturally around 0.9 million ha of soils are affected by chemical pollution and 0.2 million of them by excessive pollution. Between all the soil pollution contaminants heavy metals Cu, Pb, Zn and Cd or acid precipitation, this represent aggressive effects on soil and usually can be found in areas like Baia Mare, Copșa Mică and Zlatna. This paper aims to investigate the contents of heavy metals (Cd, Pb, Zn and Co) in soils from Baia Mare county from N-W Romania. Samples of soil was collected with the pedological drill, the sampling depths were 0-20 cm, 20- 40 cm, 40-60 cm and 60-80 cm, disaggregated in the Berghof MWS2 microwave and the chemical compositions of soil was determined through AAS method. Regarding the heavy metals from areas investigated, the highest concentration of this heavy metals was found in Ferneziu (F) area in 20-40 cm horizon (25.18 ± 1.53 mg/kg Cd; 3290.18 ± 177.42 mg/kg Pb; 1941.55 ± 28.51 mg/kg Zn). These values decrease with the soil depth, the soil profile at the depth of 60-80 cm being 16.86 ± 1.45 mg/kg Cd; 2531.20 ± 193.62 mg/kg Pb; 1364.74 ± 38.18 mg/kg Zn. These concentration values for heavy metals exceeded the maximum allowable limits (MAL) covered by law. The lowest concentrations of heavy metals was found in Tăuții Mărgherăuș (TM) area the concentratin in this case are below MAL (0.22 ± 0.03 mg/kg Cd [1 mg/kg MAL]); 13.49 ± 0.75 mg/kg Pb [20 mg/kg MAL]; 55.68 ± 1.57 mg/kg [100 mg/kg-MAL] and 9.19 ± 0.26 mg/kg-Co [15 mg/kg MAL]. These high concentrations could be an effect of pollution from tow metallurgical factories in Baia Mare, Romplumb and Cuprom which are the main sources of pollution from the city and also for the neighboring agricultural areas. The areas studied near the source of pollution have greatest heavy metals concentrations compared with Seini (S) and Tăuții Mărgherăuș (TM) areas which are at considerable distance from the source of pollution. Based on the data presented we also can say that in this area the effect of heavy metal pollution is lower than in other areas we studied. One possible explication for reducing heavy metals concentration is distance from the source of polution.