Evaluation of coastal sediments for heavy metal contamination, Yanbu area, Red Sea coast, Saudi Arabia

Abstract

To evaluate the heavy metal contamination, ecological risk and possible sources at Saudi Yanbu coastline, 30 sediment samples were collected for Fe, Pb, Ni, As, Zn, Cu, Cr, Co, Al, Sb, Cd, and TOC analyses using ICP-MS. The potential ecological risk index (PERI), enrichment factor (EF), contamination factor (CF), potential contamination index (Cp), geoaccumulation index (Igeo), soil pollution index (SPI) were calculated and interpreted, and multivariate analyses were applied. The results indicated the following order for metal averages: Al (8573 μg/g) > Fe (5895 μg/g) > Mn (192 μg/g) > Zn (80.4 μg/g) > Cu (35.87 μg/g) > Cr (27.11 μg/g) > Ni (23.5 μg/g) > Co (8.29 μg/g) > Pb (7.72 μg/g) > As (6.83 μg/g) > Sb (0.50 μg/g) > Hg (0.33 μg/g) > Cd (0.30 μg/g). Average levels of As, Ni, Zn, Co, Cd, and Pb values were greater than those reported from many coastal sediments from the Red Sea, Gulf of Aqaba, Arabian Gulf and Mediterranean Sea, as well as the sediment quality guidelines. The results of potential ecological risk revealed very high risk for Cd, high risk for Hg, considerable risk for Cu, Sb, and As, moderate risk for Pb and Ni, and no to low risk for Zn and Cr. The moderately severe enriched HMs (Cd, Zn, Cu, Hg) and the moderate enriched ones (Pb, Co, As) were originated mostly from anthropogenic sources related to industrial, agricultural, urbanization and fishing activities. The no and minor enriched HMs (Fe, Al, Ni, Cr, Sb) were mostly related to lithogenic factors related to rock weathering and atmospheric inputs.