Assessment of Heavy Metal Contamination in Soil in and around Sohar Industrial Port Area, Oman

Abstract

The increase in the number of heavy metal emitting sources in industrial areas is a serious issue in pollution science. Sohar Industrial Port (SIP) area is located in the northern part of Oman where different industrial activities like petrochemical production, metal processing, and waste disposal are prevalent. This study comprehensively identified the presence and quantities of heavy metals in the soils of Sohar Industrial Port area and traced their origin to geogenic or anthropogenic sources. Bulk geochemical and mineralogical analyses were carried out on all samples. Environmentally available and bioavailable heavy metals were extracted by diethylenetriaminepentaacetic acid (DTPA) and were finally analyzed using Inductively Coupled Plasma-Optical Emission spectrometry (ICP-OES). The environmentally available metals that showed higher concentrations when compared to international standards were Ni and Cd. The geochemical evidence showed a strong geochemical signature of the ophiolite rocks in the soils as indicated by the significant correlation between Cr and Ni (P< 0.05). In addition, the Cd content showed significant correlations with Ni and Cr (P< 0.05). Other metals like Pb and Zn, possibly also were geogenic in origin, but with significantly elevated concentrations in samples close to a national highway (P< 0.05). The present study demonstrated the significance of understanding the geological framework of an industrial area, which is already imposing high background concentrations of Cr, Ni and Cd, and also the possible anthropogenic impacts in the cases of Pb and Cd that exceeded internationally permissible limits.