Assessment of sediment quality using different pollution indicators and statistical analyses, Hurghada area, Red Sea coast, Egypt

Assessment of contamination, mobility and application of selected technology-critical elements as indicators of anthropogenic pollution of bottom sediments

The study investigates the potential of technology-critical elements (TCEs) in the bottom sediments of the Biała Przemsza River as indicators of anthropogenic activities. The mass fractions of TCEs: Ge, Ga, In, Tl, Sb and Te (and other elements) in the sediment were analysed by inductively coupled plasma mass spectrometry with the maximum mass fractions: 2.46, 25.6, 0.528, 27.7, 12.5 and 0.293 mg/kg, respectively. Distribution and identification of TCE sources were supported by statistical analysis (principal component analysis coupled with varimax rotation and hierarchical cluster analysis). Assessments of TCE contamination using the geoaccumulation index, pollution index, contamination factor, enrichment factor and the antimony-to-arsenic ratio highlighted the high contamination of bottom sediments by Sb, Ga, Tl, Cd, As, Zn, Pb and moderate contamination by Co, In and V. Distinct behaviour patterns were observed among TCEs, revealing Sb and Tl as potential indicators of Zn-Pb ore mining activities. Co, V, Ge and, to a lesser extent, Te emerged as promising indicators of coal and coal fly ash effluents. Sequential chemical extraction of TCEs showed that Sb, In and Tl had the highest mobility from sediments. The Risk Assessment Code calculations suggest, that in the Biała Przemsza River bottom sediments, there is an average risk of contamination by As, Tl and Mn. Soluble forms of Tl, Ge, Sb, Te and In were identified in descending order, indicating their bioavailability.

A comparative study of the risk assessment and heavy metal contamination of coastal sediments in the Red sea, Egypt, between the cities of El-Quseir and Safaga

This study aimed to assess the influence of pollution on the quality of sediments and the risks associated with El-Qusier and Safaga Cities, Red Sea, Egypt, during 2021, divided into four sectors, using multiple pollution indices. To achieve that, we evaluated the metal pollution index (MPI), contamination factor (Cf), pollution load index (PLI), contamination security index (CSI), and anthropogenicity (Anp%). Moreover, carcinogenic and non-carcinogenic risks are used for human health hazards. Results indicated that Mn and Fe recorded the highest concentrations, whereas Cd had the lowest. El-Quseir City sediments were found the following metal ions: Fe > Mn > Ni > Zn > Cu > Co > Pb > Cd, where the order in the Safaga City was: Fe > Mn > Zn > Ni > Cu > Pb > Co > Cd. MPI > 1, this is alarming in the study area due to heavy metal pollution. In addition, Cf < 1 in all metals except Cd with contamination degree CD ranged from low to considerable contamination in El-Qusier city. In contrast, contamination ranged from significant to very high in Safaga city. PLI < 1 is lower than the reference at all monitored stations. CSI values ranged from relatively low to moderate. Besides Cd, data reflect each element's low environmental danger (EriMe40). This study's risk index (RI) is low to moderate in Sector 1 and high to extremely high in Sector 2. HQ and HI index < 1 means it is safe for human health in order: HI ingestion > HI dermal. CSR for different pathways was recorded as dermal > ingestion, in which total CSR for all paths is considered harmful, and the cancer risk is troublesome and higher than the reference ranges of 1 × 10-6-1 × 10-4. In conclusion, the examined heavy metals provide environmental hazards across the assessed locations.

Potential contamination and health risk assessment of heavy metals in Hurghada coastal sediments, Northwestern Red Sea

Throughout the year, people flock to the Red Sea's shoreline for tourism and fishing. The current study aims to document heavy metal contamination and human health assessment in 30 surface sediment samples collected along the Hurghada shoreline in Egypt. To estimate sediment contamination, the pollution index (PI), pollution load index (PLI), degree of contamination (Cdeg), and Nemerow integrated pollution index (NIPI) were calculated, while the chronic daily intake (CDI), hazard index (HI), cancer risk (CR), and total lifetime cancer risk (LCR) were determined on both adults and children via ingestion, dermal, and inhalation pathways. The HM averages (μg/g dry weight) were in the following order: Fe (345.70) > Mn (49.36) > Pb (41.98) > Zn (7.47) > Ni (1.73) > Cu (1.23) > Co (1.09) > Cd (0.14). Pollution indices found that Hurghada coastal sediments were moderately polluted with Pb but not with the other HMs. The average CDI values were in the descending order of ingestion > dermal > inhalation pathways, and the average CDI values on children were higher than those on adults. The hazard index (HI) for adults and children was Pb > Ni > Cd > Fe > Mn > Co > Cu > Zn, and all values were <1.0, showing that these HMs had no substantial non-carcinogenic impacts on the human body. LCR results show that children have greater values than adults. LCR values in adults were lower than 1 × 10-6, indicating no substantial health concerns, while in children they ranged from 1 × 10-6 to 1 × 10-4, indicating no significant risk to human health.

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, I_geo, 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.

Contamination assessment and spatial distribution of heavy metals in the Sefidrud Delta coastal lagoons, Caspian Sea, N Iran

Three coastal lagoons on the Sefidrud Delta, Caspian Sea, were investigated to evaluate heavy metal pollution in sediments. Amirkola Lagoon is located in the eastern part of the delta (abandoned delta lobe) and is aged more than 500 years, whereas Kiashahr and Zibakenar lagoons are in the western or active part delta lobe and formed in the last decades. One hundred six sediment samples and three sediment cores were taken from studied lagoons. The samples were analyzed by ICP-OES. Geo-accumulation index (I_geo), contamination factor (CF), degree of contamination (C_deg), pollution load index (PLI), and Potential ecological risk index (RI) were employed to determine heavy metal pollution for Co, Cr, Cu, Ni, Pb, V and Zn. Nonparametric statistical analysis (Two-step cluster analysis, analysis of variance, and T-test technique) was used to discriminate the pollution sources. Based on contamination indices, the Kiashahr and Zibakenar lagoons show significant to moderate contamination with Co, Cu, Pb, Zn, and V, whereas the Amirkola Lagoon samples show the lowest metal contamination. PLI values demonstrated metal contamination in the Kiashahr and Zibakenar lagoons but no contamination in the Amirkola Lagoon. Although there was a notable rise in RI values from Amirkola to two other lagoons, all indicated low ecological risk. Statistical methods designated the unique interpretation of contaminant sources. Although the same geogenic origin of sediments in the Sefidrud Delta and lagoons deposits, Co, Zn, and Pb show anthropogenic sources in the newly-formed Kiashahr and Zibakenar lagoons.

Risks Assessment of Potentially Toxic Elements’ Contamination in the Egyptian Red Sea Surficial Sediments

The potential impact of tourism, industrial, and urban activities on Egypt’s Red Sea coastline, which is well-known for its economic and environmental importance, was investigated at fifteen coastal sites. In the present study, the concentration of cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) in marine sediments from these sites, was determined using Inductively Coupled Plasma Mass Spectrometers (ICP-MS). In detail, various pollution indices, statistical analyses, and spatial distribution patterns were used to assess the pollution status, impacts of human activities, ecological risks, and sources of potentially toxic elements (PTEs) in surface marine sediment. A detailed comparison with up-to-date data was conducted. These sediments were composed predominantly of fine and very fine sands. Mean grain size distribution typically depends on the source of the sediment from the following two prime sources: terrigenous (autochthonous) and biogenic (allochthonous). The detected PTE mean concentrations were as follows: Fe > Mn > Zn > Cr > Ni > Pb > Co > Cu > Cd. Multivariate statistical analysis results revealed their close distribution and association. Cd and Pb levels in the studied area have been slightly impacted by anthropogenic inputs. According to the calculated pollution indices, although a minimal or moderate contamination degree was detected in the study area, it was determined that there was a low to moderate ecological risk. The slightly high degree of contamination and risk centered in the middle of the study area around phosphate mining and related activities. More attention should be given to the concentrations and sources of Cd, Ni, and Pb as the main pollution factors.

Toxic metal pollution and ecological risk assessment in water and sediment at ship breaking sites in the Bay of Bengal Coast, Bangladesh

Quantification of four toxic metals (As, Cr, Cd, and Pb) in water and sediments at the Sitakunda ship breaking area in Bangladesh was studied. Along with this, sediment quality and ecological risk were evaluated for the metal intrusion to the study area. A total sample number of 120 (water; n = 60 and sediment; n = 60) were analyzed for both winter and summer seasons using atomic absorption spectrophotometer (AAS). The trace metal concentration in both water and sediment showed decreasing trend as follows; Cr (mean-W: 0.118 mg/L; mean-S:121.87 mg/kg) > Pb (mean-W: 0.064 mg/L; mean-S: 65.31 mg/kg) > As (mean-W: 0.03 mg/L; mean-S: 32.53 mg/kg) > Cd (mean-W: 0.004 mg/L; mean-S: 4.81 mg/kg). However, in both segments, the concentrations of the toxic metals exceeded the recommended acceptable limits. As and Cd showed significant variation (water and sediment) between the seasons, while Pb and Cr had no seasonal impact. Metal pollution index (MPI) and contamination factor (CF) was evaluated and revealed that the study area exhibited the critical score of water quality (MPI > 100). The cumulative effect of the metal concentrations was high (CI > 3). The assessed mean geoaccumulaiton index (I_geo) revealed that the study area was moderate to strongly polluted except for Cr. According to the contamination factor (CF), the sediment samples were moderate to highly contaminated by Cd, Pb, and As. Moreover, the explored range of pollution load index (PLI) in all sampling sites in the ship breaking region was from 1.75 to 3.10, suggesting that the sediment in the study area was highly polluted by heavy metals (PLI > 1). The risk index and the potential ecological risk index (PERI) suggested that the study area was at high risk due to metals pollution. Therefore, it is obligatory to maintain some crucial efforts for the betterment of the surrounding environment near the investigated sites.

Trace Metal Contamination of Bottom Sediments: A Review of Assessment Measures and Geochemical Background Determination Methods

This paper provides an overview of different methods of assessing the trace metal (TM) contamination status of sediments affected by anthropogenic interference. The geochemical background determination methods are also described. A total of 25 papers covering rivers, lakes, and retention tanks sediments in areas subjected to anthropogenic pressure from the last three years (2019, 2020, and 2021) were analysed to support our examination of the assessment measures. Geochemical and ecotoxicological classifications are presented that may prove useful for sediment evaluation. Among the geochemical indices, several individual pollution indices (CF, Igeo, EF, Pi (SPI), PTT), complex pollution indices (PLI, Cdeg, mCdeg, Pisum, PIAvg, PIaAvg, PIN, PIProd, PIapProd, PIvectorM, PINemerow, IntPI, MPI), and geochemical classifications are compared. The ecotoxicological assessment includes an overview of Sediment Quality Guidelines (SQG) and classifications introduced nationally (as LAWA or modified LAWA). The ecotoxicological indices presented in this review cover individual (ERi) and complex indices (CSI, SPI, RAC, PERI, MERMQ). Biomonitoring of contaminated sites based on plant bioindicators is extensively explored as an indirect method for evaluating pollution sites. The most commonly used indices in the reviewed papers were Igeo, EF, and CF. Many authors referred to ecotoxicological assessment via SQG. Moreover, PERI, which includes the toxic response index, was just as popular. The most recognised bioindicators include the Phragmites and Salix species. Phragmites can be considered for Fe, Cu, Cd, and Ni bioindication in sites, while Salix hybrid cultivars such as Klara may be considered for phytostabilisation and rhizofiltration due to higher Cu, Zn, and Ni accumulation in roots. Vetiveria zizanoides demonstrated resistance to As stress and feasibility for the remediation of As. Moreover, bioindicators offer a feasible tool for recovering valuable elements for the development of a circular economy (e.g., rare earth elements).

A Review of Heavy Metals in Coastal Surface Sediments from the Red Sea: Health-Ecological Risk Assessments

The heavy metal (HM) pollution in sediment is of serious concern, particularly in the Red Sea environment. This study aimed to review and compile data on the concentrations of four HMs (Cd, Cu, Pb, and Zn) in the coastal surface sediments from the Red Sea, mainly from Saudi Arabia, Egypt, and Yemen, published in the literature from 1992 to 2021. The coastal sediments included those from mangrove, estuaries, and intertidal ecosystems. It was found that the mean values of Cd, Cu, Pb, and Zn in coastal Red Sea sediments were elevated and localized in high human activity sites in comparison to the earth upper continental crust and to reference values for marine sediments. From the potential ecological risk index (PERI) aspect, 32 reports (47.1%) were categorized as ‘considerable ecological risk’ and 23 reports (33.8%) as ‘very high ecological risk’. From the human health risk assessment (HHRA) aspect, the non-carcinogenic risk (NCR) values (HI values < 1.0) of Cd, Cu, Pb, and Zn represented no NCR for the ingestion and the dermal contact routes for sediments from the Red Sea countries. The reassessment of the HM data cited in the literature allowed integrative and accurate comparisons of the PERI and HHRA data, which would be useful in the management and sustainable development of the Red Sea area, besides being a helpful database for future use. This warrants extensive and continuous monitoring studies to understand the current and the projected HM pollution situation and to propose possible protective and conservative measures in the future for the resource-rich Red Sea ecosystem.

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

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.

Data Analysis of Beach Sands’ Chemical Analysis Using Multivariate Statistical Methods and Heavy Metal Distribution Maps: The Case of Moonlight Beach Sands, Kemer, Antalya, Turkey

Multivariate statistical methods are widely used in several disciplines of fundamental sciences. In the present study, the data analysis of the chemical analysis of the sands of Moonlight Beach in the Kemer region was examined using multivariate statistical methods. This study consists of three parts. The multivariate statistical analysis tests were described in the first part, then the pollution indexes were studied in the second part. Finally, the distribution maps of the chemical analyses and pollution indexes were generated using the obtained data. The heavy metals were mostly observed in location K1, while they were sorted as follows based on their concentrations: Mg > Fe > Al > Ti > Sr > Mn > Cr > Ni > Zn > Zr > Cu > Rb. Also, strong positive correlations were found between Si, Fe, Al, K, Ti, P. According to the results of factor analysis, it was found that four factors explained 83.5% of the total variance. On the other hand, the coefficient of determination (R2) was calculated as 63.6% in the regression model. Each unit increase in the value of Ti leads to an increase of 0.022 units in the value of Si. Potential Ecological Risk Index analysis results (RI < 150) revealed that the study area had no risk. However, the locations around Moonlight Beach are under risk in terms of Enrichment Factor and Contamination Factor values. The index values of heavy metals in the anomaly maps and their densities were found to be successful; and higher densities were observed based on heavy metal anomalies.

Comprehensive pollution monitoring of the Egyptian Red Sea coast by using the environmental indicators

The environmental pollution indicators and multivariate statistical analysis were used to evaluate the potential ecological risk and the contamination of Fe, Mn, Zn, Ni, Pb, Cu, Cd, and Co in surface sediments of the Egyptian Red Sea coast. The results revealed that the studied area suffers from high contamination of certain metals such as the Hurghada area (Pb, Cd, Zn, Ni, and Cu), Quseir City area (Cd, Co, Pb, and Ni), and Safaga and Marsa Alam areas (Cd and Pb). Enrichment factor and principal components analysis reported that the pollution sources of Fe, Mn, and Co are related to natural weathering process while Cu, Zn, Ni, and Pb are related to anthropogenic sources as landfill, plastic rubbish, fishing boats, phosphate operations, and tourist activities. Moreover, Co and Cd metals can come from both of natural and anthropogenic sources. The average concentrations of Cd, Cu, Zn, Pb, Ni, and Co in sediments of the Egyptian Red Sea coast are higher than those in the coasts of the Red Sea (Saudi Arabia), Mediterranean Sea (Egypt and Libya), Bengal bay (India), and the Caspian Sea (Russia). However, the studied metal content is lower than the sediment quality guideline values except for Cd.

Distribution and accumulation ability of heavy metals in bivalve shells and associated sediment from Red Sea coast, Egypt

Concentrations of Fe, Mn, Cu, Zn, Pb, Ni, Cd, and Co in molluscan shells and associated surface sediments from four sites on the Gulf of Aqaba and Red Sea coasts, Egypt, were measured by using atomic absorption spectrophotometer. The results revealed an apparent difference in the ability of each species regarding accumulating heavy metals in its shell. These results showed that Tridacna squamosa has the highest accumulation ability for Pb, Ni, and Zn, and Chama pacifica has the highest accumulation capability for Co and Cd, whereas Periglypta reticulata has the highest accumulation ability for Cu. The results also showed that there is a positive correlation between the concentration of Cu, Zn, Pb, and Ni and the size of shell. Simultaneously, there is a negative correlation with Fe, Mn, Co, and Cd. The results of bio-accumulation of molluscan species were consistent with the enrichment factors for sediments, where the Hurghada site was extremely enriched with Pb and very enriched with Cu, Zn, and Ni. Moreover, the Quseir site was extremely enriched with Cd and very enriched with Pb. The Um al-Sid site was severe enriched with Cd and Pb. Meanwhile, the Ras Mohamed site was severe enriched with Pb and nearly unpolluted with other metals. Heavy metals can enter the studied ecosystem by terrigenous and anthropogenic sources as a weathering process of the nearby beaches and mountains, ship maintenance, industrial activities, wastewater, and traffic exhaust.

Contamination and ecological risk assessment of the Red Sea coastal sediments, southwest Saudi Arabia

The level of heavy metals (HMs) in coastal sediments has attracted the environmental researchers due to their persistence, abundance, biomagnification and toxicity. The present study was conducted to assess the contamination and ecological risk assessment of HMs in Jazan coastal sediments, Red Sea, Saudi Arabia utilizing pollution indices and multivariate statistical analyses. A total of 32 surface samples were collected for Cu, Sb, Zn, Cr, Cd, Pb, Fe, Co, Ni, Al, and total organic matter analysis using an atomic absorption spectrophotometer. The results indicate the following descending order of metal concentrations: Al > Fe > Cr > Cu > Zn > Ni > Co > Pb > Cd > Sb. Average level of Cd is significantly higher than those from many neighboring and worldwide coastal sediments; and recorded very severe enrichment, severe contamination and very high risk in the investigated sediments. The pollution indices and statistical analyses revealed that proportion of Zn, Fe, Ni, Cr, Al, Cu, Sb and Pb were formed from lithogenic sources of weathering Quaternary units and atmospheric deposition. Most of the Cd, Sb, and Pb levels were derived from anthropogenic sources of industrial, agricultural, and fishing activities. The higher contribution of organic matter may be attributed to the mangrove roots and organic fertilizers; and played a key role in adsorbing, transferring and accumulating of elements.

Distribution and metal contamination in core sediments from the North Al-Wajh area, Red Sea, Saudi Arabia

Forty-one bottom sediment samples were collected from three cores at the mouth of Wadi Haramel, Wadi Antar, Wadi Dumaygh, north of Al-Wajh, Red Sea, Saudi Arabia, to evaluate the levels of heavy metal contamination, using the enrichment factor (EF), geoaccumulation index (Igeo), contamination factor (Cf), soil pollution index (SPI), and multivariate statistical analysis (hierarchical cluster analysis and principal component analysis). Fe, Al, Pb, Mn, Cu, Ni, Co, Cd, Sr, V, Hg, and Total Organic Matter (TOM%) were quantified by Atomic Absorption Spectrophotometer. The vertical distribution of the heavy metals concentrations increased upwards indicating high heavy metals input. The results of enrichment factor and soil pollution index calculations indicate a strong anthropogenic supply of Cd and Sr (SPI = 1.10, 2.70, EF = 18.25, 17.99 respectively) while Cu and Ni show moderate anthropogenic input from urban, industrial activities and some new projects in the northern coast of Saudi Arabia.

Distribution, ecological risk, and source analysis of heavy metals in recent beach sediments of Sharm El-Sheikh, Egypt

To study the distribution of the concentrations and the sources of pollutants and their environmental assessment in the Sharm El-Sheikh coastal area, Fe, Mn, Cu, Zn, Pb, Ni, Cd, and Co concentrations were analyzed in the beach sediments of Sharm El-Sheikh harbor and Sharm El-Maya bay by the atomic absorption spectrophotometer. The results revealed that Sharm El-Sheikh harbor has higher concentrations of Fe, Mn, Ni, and Cd than in Sharm El-Maya bay. Meanwhile, the environmental pollution indicators as enrichment factors, metal pollution index, contamination factors, sediments pollution index, geo-accumulation index, ecological risk factor, and the potential contamination index reported that Sharm El-Sheikh harbor has a higher degree of pollution (MPI = 43.4) than Sharm El-Maya bay (MPI = 38.2). Moreover, both of the studied areas have shown very high contamination of Cd and moderate to high contamination of Pb, Mn, Cu, and Zn. Furthermore, the concentrations of Mn, Cu, Ni, and Cd in the studied area are higher than those in the coasts of Hurghada, Shalateen, Red Sea of Saudi Arabia, and the Russian Caspian Sea. The main sources of the metals in the studied area are the human impacts as tourist activities, boat navigation, large numbers of anchored tourist boats, diving operations, and car fuel combustion products. In addition, the natural weathering of Gabal El-Safra and basement rocks can be counted as natural sources of metals.

Contamination and ecological risk assessment of heavy metals pollution from the Shalateen coastal sediments, Red Sea, Egypt

To assess the contamination and ecological risk assessment of the Shalateen coastal sediments, Red Sea, Egypt, 35 samples were collected to analyze Cu, Sr, Zn, Cd, Pb, Fe, Co, Ni, Mn, and total organic matter with an atomic absorption spectrophotometer. Several indices were calculated to estimate the contamination levels. The results indicated the following order of metal concentrations: Fe > Sr > Mn > Zn > Ni > Pb > Cu > Co > Cd, and revealed that the investigated sediments are highly enriched and contaminated with Sr, Cd, Pb and Zn. Statistical analyses subdivided the elements into Fe and Mn from natural sources, Sr, Cd, Pb and Zn from anthropogenic sources, and Ni, Cu and Co from combined natural and anthropogenic sources. The average Pb and Cd concentrations are considerably higher compared to the Caspian Sea, Indian Ocean, northern Red Sea, background shale, and continental crust. Possible sources of pollutants are fishing operations, antifouling paints, runoff, desalination plants, industries and dissolution of carbonate sediments.

Heavy Metals in Sediments of Urban Streams: Contamination and Health Risk Assessment of Influencing Factors

Sediments of two urban streams in northern Poland outflowing to the Baltic Sea were assessed to explain the spatial variation in relation to urbanization level of the catchment, the role of retention tanks (RTs) and identification of pollution level. During the 3 month period of investigation sediment samples were collected from the inflow (IN) and outflow (OUT) of six RTs located on streams for flood protection. Six heavy metals (HMs) were investigated: Cu, Pb, Zn, Cd, Ni, Cr. The assessment of four geochemical enrichment indices used to quantify contamination of HMs in the sediments at IN and OUT samples was carried out. Contamination factor (CF), pollution load index (PLI), geoaccumulation index (Igeo) and potential ecological risk (RI) were calculated and the indices usefulness was assessed. Also, the hazard quotient (HQ) was calculated to assess health risk associated with dredging works. In sediments from RTs where paved surfaces constituted more than 70% of the catchment the HMs concentrations were from one to three times higher for Ni and from two to 143 times higher for Cu in comparison to soft catchment results. The extremely high Cu concentration (1114 mg/kg d.w.) found in sediments at RT Orłowska IN was most likely associated with large area of roofs covered with copper sheet. Calculation of CF, PLI, Igeo, RI, HQ indicators allows for a complex and multi-dimensional assessment of sediment status. Among these, CF and PLI classified the analyzed sediments as most polluted. Basing on the sedimentary HMs concentrations the health risk level via dermal exposure pathway was assessed as low.

Spatial distribution and ecological risk assessment of the coastal surface sediments from the Red Sea, northwest Saudi Arabia

To assess the spatial distribution and ecological risk assessment along the Red Sea coast, Saudi Arabia, 30 samples were collected for aluminum, chromium, copper, zinc, cadmium, lead, mercury, iron, cobalt, nickel and organic matter analysis. The descending order of metal concentrations was Al > Fe > Cr > Cu > Zn > Ni > Co > Pb > Hg > Cd. Average values of enrichment factor of Hg, Cd, Cu, Co, Cr, Ni, Pb and Zn were higher than 2 (209.50, 25.52, 20.36, 9.62, 7.28, 6.52, 6.21 and 6.07 respectively), which means anthropogenic sources of these metals. The average levels most of the studied metals were lower than those of the background shale and the earth crust and those recorded along most worldwide coasts, while the average values of zinc, copper, cobalt and nickel were higher than the values recorded from the Red Sea coast, the Gulf of Aqaba and some Caspian Sea coasts. The Duba bulk plant-Saudi Aramco, Duba refinery station and the tourist resort were the possible anthropogenic sources of pollutants in the southern part of the study area; and the landfilling, cement factory and Duba port and shipment operations in the central part, while the landfilling resulting from construction of the green Duba power plant and crowded fish boats were the possible sources in the northern part.