Spatial geochemical distribution of some potentially toxic elements within river bed sediments from Rodna Mountains, Eastern Carpathians, Romania

Abstract

This study aims to determine the spatial distribution of some potentially toxic elements, namely As, Cd, Co, Cr, Cu, Ni, Pb, Sn and Zn within riverbed sediments of Izvorul Roşu and Izvorul Băilor rivers with their tributaries (Rodna mining area) from Rodna Mountains and to assess the contamination degree of sediments using some widely used pollution indices. The concentrations of the elements were obtained through ICP-MS analysis using Four-Acid Digestion method and the results show an average of 56.21 mg·kg−1 for As, 1.66 mg·kg−1 for Cd, 27.50 mg·kg−1 for Co, 86.67 mg·kg−1 for Cr, 38.62 mg·kg−1 for Cu, 45.46 mg·kg−1 for Ni, 205.25 mg·kg−1 for Pb, 2.65 mg·kg−1 for Sn and 449.70 mg·kg−1 for Zn. The geochemical background was calculated using the Median±2 MAD procedure. From the evaluation of the sediment’s pollution indices, contamination factor (CF), enrichment factor (EF), pollution load index (PLI), ecological risk index (RI), geoaccumulation index (Igeo) it can be seen that the studied river sediments in most cases, are either not contaminated or slightly contaminated. However, there are a few samples with moderate contamination by As, Cd, Pb and Zn due to former mining activities.

Keywords

• riverbed sediments
• geochemical distribution
• pollution indices
• environmental geochemistry
• rodna mountains
• mining area