Heavy metal concentrations in the surface sediments of the northwestern Arabian Gulf, Kuwait

The present work is primarily discussing the investigation of sediment samples collected from 21 stations throughout Kuwait’s marine environment. The study was assessing the concentration of heavy metals (Co, Cr, Cu, Ni, Pb, and Zn), its grain size, total organic carbon content, and carbonate content. Microwave digestion method followed by ICP-MS analysis was performed to assess the heavy metal concentration. The average heavy metal abundance was in the sequence of Pb˃ Co˃ Cu˃ Zn˃ Cr˃ Ni. Grain size analysis showed that most of the locations of the study area contained a predominantly silt fraction, with a mean value of 81.2% silt and 12.62% sand, and the lowest mean value was found for clay at 6.23%. TOC analysis showed a mean value of 1.53%; whereas the carbonate showed a mean value of 30.0% calcium carbonate. The geo-accumulation index (I_geo), in turn, suggested that sediment samples were not contaminated by Co, Cr, Cu, Ni, Pb, or Zn. This study showed that the total concentrations of Cu, Pb, and Zn in the sediment samples were well below the national sediment quality guidelines. However, the maximum total concentrations of Cr and Ni were above some of the national sediment quality guidelines, warranting them being considered as a potential contamination hazard.