Environmental assessment of toxic heavy metals in bottom sediments of the Sharm Obhur, Jeddah, Saudi Arabia.

The concentrations, spatial distributions, pollution level, and health risks of heavy metals in sediments of the Sharm Obhur, Northern Jeddah, Saudi Arabia were evaluated. Average concentrations were found to be: Cr > Zn > Ni > Cu > As>Pb with the highest concentrations found near the head of the sharm, and decreasing towards the mouth. Environmental indices, together with the statistical analyses, showed that the sharm experiences a low to moderate degree of pollution. Sampling sites with heavy metal contamination are concentrated near the head and the southern coast of the sharm, where intensive human activities associated with a boat dock, construction, and recreation are common. The mean carcinogenic risk (CR) values of As, Cr and Ni are at permissible level suggesting unlikely adverse impacts of heavy metals on human health. Despite acceptable CR values; however, serious non-carcinogenic and carcinogenic health threats from metals may yet be an issue particularly for sensitive populations such as children.

Benthic foraminifera as bioindicators for the heavy metals in the severely polluted Hurghada Bay, Red Sea coast, Egypt.

Twenty-nine sediment samples were collected from the Hurghada Bay, a heavily polluted bay on the Red Sea of Egypt, to inspect the environmental quality status and anthropogenic consequences on benthic foraminifera. Some foraminiferal species showed deformations in their apertures and coiling directions as a response to environmental stresses. In addition, the FoRAM index, an index used for evaluating the growth of coral reefs, indicated a hazard in the proximity of nearshore stations. To elucidate the relationships between the biological response and chemistry of sediments, eight heavy metals concentrations (Cu, Cd, Zn, Pb, As, Cr, Ni, and Mn) were analyzed using inductively coupled plasma-atomic emission spectrometers (ICP-AES). Interestingly, two groups of benthic foraminiferal associations were illustrated using multivariate statistical analyses. Group I have extremely high heavy metal concentrations, an enriched total organic matter (TOM)%, high deformation percentages, and mud content. Moreover, it is dominated by Ammonia tepida which is regarded as an opportunistic species. Group II includes low to moderately polluted stations, highly enriched living foraminiferal assemblages, and is dominated by the sensitive rotaliids Neorotalia calcar and Amphistegina lobifera. Alternatively, four geochemical indices, EF, CF, Igeo, and PLI, are used to assess the contamination level that shown ominous spots for the nearshore stations of the Hurghada Bay. The pollution indices (HQ and HI) were also conducted to evaluate the risks of carcinogenic heavy metals on human health. Our findings demonstrated that ingestion and dermal exposure have greater carcinogenic hazards for adults and children than inhalation. The lifetime carcinogenic risk (LCR) is significantly higher than the permissible limit and follows this order: Pb > As > Cr > Cd > Ni. To that end, developing strategies to lessen the negative impact of pollution on human health and/or the Red Sea's biodiversity is an inevitable issue in the present day and future.

Benthic ostracods (crustacean) as a nearshore pollution bio-monitor: examples from the Red Sea Coast of Egypt.

Benthic ostracods are deemed as one of the most useful micro-fauna for biomonitoring in shallow marine ecosystem, which are sensitive to environmental changes that can be reflected by their diversity and abundances. The pollution leads to high dominance index and low abundance ostracod communities. Therefore, eighteen sediment samples were collected from Ras Gharib and Quseir sites, along the Red Sea coast, to assess the ostracods response toward the anthropogenic environmental disturbances. Jugosocythereis borchersi, Alocopocythere reticulata, and Loxocorniculum ghardaqensis are the most abundant ostracods in the study localities. To evaluate the linkage between ostracods and contaminated sediments, metal concentrations in the sediments were measured using inductively coupled plasma optical-emission spectrometry (ICP-OES). We observed a significant spatial difference in elemental distribution in sediment samples, and some elements are of higher contributions than the average marine sediment composition. The quantitative analysis of benthic ostracod associations was processed statistically with geochemical data and differentiated the study area into two environments, based on the degrees of contamination. Quseir is encompassing the most contaminated stations. It is characterized by sediments richer in heavy metals, higher silt, and higher organic matter contents. Contaminated environments favor the presence of pollution-tolerant species (e.g., J. borchersi, C. torosa, L. ghardaqensis, G. triebeli, M. striata, A. reticulata, and partly, C. dimorpha). Conversely, Ras Gharib is less polluted with metals and organic matter, and is characterized by pollution-sensitive species (X. rhomboidea). Noteworthy, a low density of ostracods was observed at the expense of the diversity around contaminated stations of the Quseir site.