Spatial distribution and contamination of heavy metals in surface water, groundwater and topsoil surrounding Moghan’s tannery site in Ardabil, Iran

Abstract

ABSTRACT Discharge of heavy metals from industrial complexes especially tanneries has considerably increased the levels of heavy metals in water and soil worldwide. This work was aimed to determine the levels of heavy metal (As, Cd, Cr, Cu, Ni, Pb and Zn) contamination of surface water, groundwater and soils in the site surrounding Moghan’s tannery in Ardabil, Iran. Fifteen composite samples (totally 45) were collected from surface water, groundwater and soils surrounding the tannery site. In this study, the levels of metals were determined by inductively coupled plasma mass spectrometry (ICP-MS) and the results were compared to the national and international standards. The results showed that 73% of water samples from wells and 80% of samples from surface water had levels above maximum permissible levels. The levels of metals in the remaining samples were within standard values. For soil samples, the mean levels of metals, except Pb, were lower than maximum permissible levels. Among these, Cd and Zn showed the lowest and highest level, respectively. The results showed that the mean levels of chromium in surface water, groundwater and soil surrounding Moghan’s tannery were high due to the pollution generated by the factory which necessitates the greater attention and implementation more pollution preventive procedures by environmental professionals and decision-makers.