engleski

Heavy metals content in soil near railway lines in northwestern Croatia

Railway transport contributes to heavy metals load in the environment due to fuel combustion, corrosion, rinsing of impregnating agents, herbicide use, transshipment and accidents during transport. The aim of this research was to determine potential heavy metals contamination in soil near the three railway lines in northwestern Croatia. In total, 60 samples of soil were collected from 60 localities near the Varaždin-Zagreb, the Varaždin-Golubovec and the Varaždin-Ludbreg railway lines in June and July 2014. Total mass concentrations of six heavy metals (Cd, Cr, Cu, Ni, Pb, Zn) were determined in soil samples with the method of a high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). Soil texture, pH and organic matter content were also determined. Soil contamination status was evaluated according to the Regulation on the protection of agricultural land from pollution (NN 9/14). Following mean values of the total heavy metal mass concentrations were obtained: Cd 0.62 mg/kg, Cr 96.5 mg/kg, Cu 120 mg/kg , Ni 60.9 mg/kg, Pb 67.8 mg/kg, and Zn 229 mg/kg. Evaluation of soil contamination degrees according to Croatian Regulation showed that soil in 16 localities (27 %) contained one or more heavy metals in concentration more than two times higher than the maximum permissible level (MPL), i.e. above 200 %. More specifically, contamination degree above 200 % was established in 6 localities for Cd, in 11 localities for Cr and Cu, in 12 localities for Ni, in 9 localities for Pb and in 21 locality for Zn. The highest degrees of heavy metal contamination were recorded at the railway station in Varaždin and Podsused, and none of the investigated localities have completely unpolluted soil. This study shows that soil near the mentioned railway lines may contain heavy metals in high concentrations. Since many railway lines in northwestern Croatia meander through arable land, they could also contribute to the entry of heavy metals in the human food chain and reduce the overall soil resource efficiency.

heavy metals, soil pollution, railroad, high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS)

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