International Journal of Marine Science, 2017, Vol.7, No.13, 114-124
114
Research Article Open Access
Effects of Urbanization on the Heavy Metal Concentrations in the Red Sea
Coastal Sediments, Egypt
Mohamed E.A. El-Metwally, Ahmed S. Abouhend, Mahmoud A. Dar, Khalid M. El-Moselhy
Division of Marine Environment, National Institute of Oceanography and Fisheries, Egypt
Corresponding email
International Journal of Marine Science, 2017, Vol.7, No. 13 doi
Received: 20 Mar., 2017
Accepted: 14 Apr., 2017
Published: 04 May, 2017
Copyright © 2017
El-Metwally et al., This is an open access article published under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article
:
El-Metwally M.E.A., Abouhend A.S., Dar M.A., and El-Moselhy K.M., 2017, Effects of urbanization on the heavy metal concentrations in the Red Sea coastal
sediments, Egypt, International Journal of Marine Science, 7(13): 114-124 (doi
Abstract
The total concentrations of heavy metals (Cu, Zn, Pb, Cd, Fe, Mn, Ni and Co) were determined in surface sediments from
the coastal area of the Red Sea in four cities (Ras-Gharib, Hurghada, Safaga, and Qusier). In all sediment samples, the mean
concentration ranges in (µg/g) of the studied metals were 11.2-145.3, 14.2-225.5, 18.5-90.8, 1.4-5.6, 1373-31,089, 72.5-758.5,
15.3-65.7 and 10.2-26.3, respectively. The effects of population pressure and different activities on metal contamination were
evaluated, and metals were grouped according to sources of contamination using Principal Component Analysis (PCA). Maritime
activities in Hurghada showed highest risk of contamination with Cu, Zn and Pb, while the sediments of Safaga City showed highest
contaminated with Fe and Mn. The sediments quality and ecological risk of heavy metals were assessed relating to the sediments
background levels of metals and calculating contamination factor (CF), metal pollution load index (MPI), enrichment factor (EF) and
geo-accumulation index (I
geo
). Average values of EF showed that Pb and Cd were highly enriched from anthropogenic contamination.
The recorded (I
geo
) values of Co and Cd were categorized as moderately polluted, while Pb was strongly effective pollutant in the
studied sediments.
Keywords
Heavy metals; Pollution; Red Sea; Sediments; Ecological risk
Introduction
Marine coastal areas experience active land-ocean interactions. One of the important problems of this interaction
is the ecotoxicological effect of heavy metals contamination in the coastal sediments (Amin et al., 2009). Most of
the heavy metals discharged into coastal environment are deposited due to strong affinities for sediments particles
(Abu-Hilal and Badran, 1990). Therefore, marine sediments are recognized as the ultimate reservoir for heavy
metals in aquatic system (Gargouri et al., 2011). Enriched sediments with heavy metals pose a complex
environmental problem; they can directly endanger marine organisms and human health through accumulation in
food chain. Furthermore, when the environmental condition changes, metals could be released into water column
again to cause secondary pollution (Hu et al
.
, 2011).
Most tropical near-shore marine habitats have become under increasing pressure due to urban and industrial
wastes, coastal constructions and recreational activities (McClanahan et al., 2000). The Red Sea is not exception;
its environment has been considered for long time unpolluted, however due to rapid recreational and tourism
activities in the last three decades, there is evidence of increased pollution in various locations (Hanna and Muir,
1990; El-Moselhy et al., 2014). Coastal regions, particularly, lagoons and tidal flat play major biological and
environmental role for marine life and fisheries. However this zone is typically frail and sensitive to
contamination. Increasing population, urban and industrial expands adjacent to these areas usually associated with
higher threat from chemical contaminants on tropical marine ecosystem (Peters et al., 1997).
Although large parts of the Red Sea coastline are still undeveloped, other areas are facing increasing hazard from
industrial and urban development. Principal anthropogenic pressure in coastal cities originated from oil production,
desalination plants, untreated sewage, land reclamation and dredging and ship traffic (McClanahan et al., 2000;
Bruckner et al., 2011). Evaluating the effects of anthropogenic influence is crucial for protection and sustainable
management of the fragile aquatic system in the Red Sea. The concentrations of heavy metals in surface sediments
