Metal Contamination In Surface Sediments Research Articles

Assessment of Heavy Metal Contamination in the Sediments and Soils in the City of Dubai based on the Geoaccumulation Index

This research assesses heavy metal contamination in surface sediments and soils in Dubai using the geoaccumulation index model. Soil and sediment samples were collected from 19 sites across Dubai, with sampling conducted twice to detect variations in heavy metal concentrations. Eight heavy metals—Silver (Ag), Cadmium (Cd), Chromium (Cr), Copper (Cu), Manganese (Mn), Nickel (Ni), Lead (Pb), and Zinc (Zn)—were analyzed for their environmental impact and abundance.Results showed that the soil was highly polluted with Silver (Ag). Nickel (Ni) concentrations ranged from Unpolluted to Moderately Polluted. Chromium (Cr) levels indicated Unpolluted to Moderately Polluted status, except in Al-Marmoum Heritage Village, Jumeirah Lakes, Al-Mamzar Open Beach, and Remram, which showed higher contamination. Cadmium (Cd) levels varied, with some sites Unpolluted and others Unpolluted to Moderately Polluted. Copper (Cu), Manganese (Mn), Lead (Pb), and Zinc (Zn) levels indicated unpolluted status.Area-wise, Jumeirah Lakes, excluding silver contamination, was generally Unpolluted. Dubai Creek exhibited the highest geoaccumulation index for several metals, including Silver, Cadmium, Chromium, Nickel, and Zinc.

Identification of toxic metal contamination in surface sediments of the Xiaoqing River under a long-term perspective (1996–2020): Risks, sources and driving factors

The contamination of sediments by toxic metals poses a significant threat to both river ecosystems and human health. In this study, the geo-accumulation index (Igeo), biotoxicity evaluation method, and potential ecological risk index (RI) were employed to analyze the contamination level, biotoxicity risk, and potential ecological risk of toxic metals in surface sediments of the Xiaoqing River. To identify toxic metal sources, Spearman correlation and principal component analysis with multiple linear regression analysis (PCA−MLR) were employed. Additionally, redundancy analysis (RDA) was utilized to investigate potential driving factors affecting toxic metal accumulation in sediments. The results revealed that the levels of the five investigated metals (Cr, Pb, As, Hg, and Cd) showed constant fluctuations during the period 1996–2020. The midstream was found to be more polluted than the upstream and downstream. In the research area, Hg was identified as the primary contaminant with high levels of contamination, posing a biotoxicity risk and potential ecological risk. Pollution sources were identified for two periods: A (1996–2010) and B (2011–2020), with industrial, agricultural, traffic, and natural sources being the main contributors. During period A, industrial sources accounted for the highest proportion (40.8%), followed by agricultural sources (36.6%), and geological natural sources (22.6%). During period B, agricultural sources accounted for the highest proportion (42%), followed by industrial and traffic sources (32.4%), and geological natural sources (25.6%). The distribution of toxic metals in the basin was significantly influenced by water pH, sediment organic matter, population density, and per capita GDP. The study results provide fundamental data for preventing pollution and managing water resources contaminated with toxic metals in the sediments of the Xiaoqing River in Jinan. Additionally, it serves as a reference for analyzing related ecological and environmental issues in the basin.

Evaluation of metal contamination in surface sediments and macroalgae in mangrove and port complex ecosystems on the Brazilian equatorial margin.

This study evaluated metal contamination in surface sediments and macroalgae of mangroves and port complexes on the Brazilian equatorial margin. Samples were collected between August 2020 and February 2021 at seven points in a mangrove swamp under the influence of port activity and at two points without port activity. Metal concentrations in the macroalgae and sediments were determined using inductively coupled plasma‒optical emission spectrometry. All macroalgal species bioaccumulated metals, as demonstrated by their bioaccumulation factors. The geochemical contamination indices indicated that the estuarine complex was influenced by port activity as moderately contaminated by Pb, Cr, Mn, and Fe and considerably contaminated by Zn and Cu. The enrichment factor confirmed significant mineral enrichment of Zn and Cu in this environment. The concentrations of the metals in the sediment followed the order Fe > Mn > Cr > Zn > Cu > Pb at most sampling points. Cladophoropsis membranacea recorded the highest bioaccumulation values for Pb (0.44), Rhizoclonium africanum for Zn (1.08), Cr (0.55), and Fe (0.30), and Bostrychia radicans for Mn (2.22). The bioaccumulation pattern of metals in the most abundant macroalgal species followed the order Bostrychia radicans (Mn > Zn > Cu > Cr > Pb > Fe) and Rhizoclonium africanum (Zn > Mn > Cr > Cu > Pb > Fe).

Heavy metal contamination in surface sediments of the Upper Bhima Basin, Maharashtra, India

Heavy metal contamination in surface sediments of the Upper Bhima Basin, Maharashtra, India

Multi-index assessment of heavy metal contamination in surface sediments of the Pearl River estuary intertidal zone

Surface sediments from 21 stations within the Pearl River estuary (PRE) intertidal zone were sampled for heavy metal contamination analysis. Average heavy metal concentrations (mg/kg) in the PRE intertidal zone were 118.5 (Cr), 860.4 (Mn), 19.5 (Co), 72.5 (Ni), 128.1 (Cu), 198.5 (Zn), and 73.0 (Pb), with the concentrations of Mn, Co, Ni, Cu, and Zn being significantly higher than their corresponding background values. The enrichment factor (EF) and geo-accumulation index (Igeo) reveal the same contamination status, with Pb, Ni, Co, Mn, and Cu showing slight to moderate contamination. Overall, the combined heavy metal concentration in the PRE intertidal surface sediments had a 24.7 % probability of toxic effects on aquatic biota based on the joint probabilistic risk (JPR) approach. Principal component analysis (PCA) coupled with the correlation analysis (CA) revealed that the heavy metal contamination in the PRE intertidal zone might originate from natural and anthropogenic sources.

Assessment of heavy metal contamination in surface sediments off the Dongying coast, Bohai Sea

In this study, 214 surface sediment samples were collected from the offshore area of the Dongying coast and were analysed for heavy metals; particularly, their concentrations and pollution status were evaluated. The copper (Cu) and chromium (Cr) distributions were similar, their concentrations were the highest in the northeast areas and the Xiaoqing River estuary, where dominated by fine-grained sediments. Higher concentrations of lead (Pb), zinc (Zn), cadmium (Cd), and arsenic (As) were generally found in the offshore area of the study location, and the highest Cd concentration was observed in the Xiaoqing River estuary. The sediments were not polluted by Cu, Pb, Zn, and Cr; they were not polluted or moderately polluted by Cd and As. Results of the principal component analysis indicated that Cu, Pb, Zn, and Cr were derived from natural sources and Cd and As were derived from anthropogenic sources.

An Eco-Environmental Risk Assessment of Heavy Metal Contamination in Surface Sediments of Lake Yangzong, Southwestern China

An Eco-Environmental Risk Assessment of Heavy Metal Contamination in Surface Sediments of Lake Yangzong, Southwestern China

Analysis of heavy metal contamination in surface sediments of Iskenderun Bay, Turkey

Abstract The ecological risk resulting from the accumulation of some heavy metals in the sediments of Iskenderun Bay was assessed using the following measures: enrichment and contamination factor, pollution load index (PLI), and potential ecological risk index (RI). The concentrations of the studied heavy metals were in the following order: Fe > Ni > Mn > Cr > Zn > Cu > As > Pb > Cd > Hg. Ni and As had the highest EF values. This situation is most likely due to the presence of iron, pesticide, and fertilizer plants in the region. According to the United States Environmental Protection Agency, Ni, As, Mn, and Cr may have harmful effects on faunal communities in sediments. According to the RI, Site 4 was more contaminated and toxic than the other seven study sites, with “moderate” ecological risk. Pearson’s correlation coefficient was determined by multivariate methods – cluster and principal component analysis. As can be inferred from the RI values, the potential toxic effect of As and Ni in the sediments is moderate.

The spatial distribution of benthic foraminifera in the Pearl River Estuary, South China and its environmental significance

Thirty surface sediment samples were collected from the Pearl River Estuary, South China, and benthic foraminifera were analyzed in order to understand the relationship between foraminiferal assemblages and environmental parameters. Multivariate analyses showed that the foraminferal assemblages (i.e., abundance and diversity) are correlated with the hydro-sedimentary gradients within the estuary. In addition, the dominant faunal composition seems to be largely influenced by food availability and trace metal contamination in surface sediments. A comparison with historical data from 1980s demonstrated that the foraminiferal abundance and diversity in the lower estuary have dramatically decreased over the last three decades, together with a significant shift in the dominant species. This is most likely due to the cumulative impacts of eutrophication and Cu contamination caused by human activities in the Pearl River basin. This work confirms the value of benthic foraminifera as bio-indicators in polluted estuarine environments.

Heavy metal contamination in surface sediments from lakes and their surrounding topsoils of China.

Due to rapid urbanization, industrialization, agricultural development, and mining activities, soil heavy metal pollution has become a severe issue in China. To explore the regional heavy metal ecological risk of lake sediment and surrounding topsoil, we analyzed 237 lakes, with 1797 lake sediment sampling points and 1164 surrounding topsoil sampling points. Lower mean concentrations were detected for most heavy metals in soils than sediment (except for Hg). Cd and Hg in sediments and soils showed a more significant variation, with the coefficient of variation exceeding 110%. Linear regressions and Pearson's correlation analyses demonstrated that sediments and soils exhibited significant positive correlations. The principal heavy metals exceeding the Agricultural Soil Control Standard (ASCS) in sediments and soils were As and Cd, respectively. The Yunnan-Guizhou Plateau Lake Region (YGPLR) was the most seriously affected, exceeding the ASCS for Cd. The lakes with the most severe pollution were located in YGPLR impacted by the high background concentration of heavy metals in soil and mineral development activities. The Eastern Plain Lake Region, the Southeast Lake Region, and the Northeast Plain and Mountain Lake Region showed a clear anthropogenic impact. Lakes in the Inner Mongolia-Xinjiang Lake Region and the Tibetan Plateau Lake Region were estimated to have relatively low ecological risks due to their sparse population and slight environmental disturbance. The impact of geochemical factors on the ecological risk of heavy metals in lake sediments is more substantial than that of human activities at the regional scale.

Assessment of heavy metal contamination in surface sediments in the western Taiwan Strait

The concentrations of the heavy metals Cu, Pb, Zn, As, Cr, Co, and Ni of a total of 187 surface sediment samples collected from the western Taiwan Strait were analyzed. The distribution characteristics and degree of contamination of these elements were investigated. The mean concentrations of Cu, Pb, Zn, As, Cr, Co, and Ni in the surface sediments of the study area were 10.2 mg/kg, 18.3 mg/kg, 51.7 mg/kg, 7.5 mg/kg, 38.7 mg/kg, 8.0 mg/kg, and 16.5 mg/kg, respectively. The heavy metals in the study area were mainly from natural sources. The regional pollution load index (PLIzone) was 0.64, indicating that there was no contamination, and an area with a relatively high PLIzone was found in the northern part of the study area. Furthermore, the impacts of the rapid development of Fujian's marine economy on the marine environment in the past decade should be further compared and analyzed.

Potential Ecological Risk Assessment of Heavy Metals Contamination in Surface Sediments of Ikpoba River, Southern Nigeria

The potential ecological risk assessment of heavy metals contamination in surface sediments of Ikpoba River, Edo State was estimated in this study after assessment of heavy metal concentrations in surface sediments from seven stations of the study area. Heavy metals were analyzed in the sediments using Atomic Absorption Spectrophotometer. The index of geo-accumulation for the metals (Lead (Pb); Iron (Fe); Nickel (Ni) and Copper (Cu)) studied were less than zero showing that the stations sampled were unpolluted with heavy metals. Contamination factor followed same pattern. Generally, there was a low potential ecological risk for heavy metal contamination to sediment dwelling organisms. However, station 4 (Capitol) was moderately contaminated and extremely enriched with Cu. Heavy metal values in this study were below the EPA limits for sediments except station 4 which was heavily polluted with Cu following the EPA guidelines. Regular monitoring and assessment of pollution load of Ikpoba River is recommended.

Environmental pollution assessment of Al-Musk Lake, Jeddah, Saudi Arabia

Jeddah represents the second largest city in Saudi Arabia and has more than 3.5 million residents. The daily estimated water used per capita is 200 L. The absence of a well-done network of sewage in some places especially in south Jeddah (Old Jeddah) considered a serious environment. In Jeddah, the potable water used for municipal purposes is mostly returning to the surrounding environments as wastewater (e.g., Al-Musk Lake). The site Al-Musk Lake uses as sewage dumping lake without any purification processes till the year 2010. The wastewater of this lake caused various environmental dangers owing to heavy metal contamination of surface sediments, groundwater, soil and air. Its areal distribution has been increased during last 17 years (2000–2017). Its surface fine-grained sediments are including a huge amount of heavy metals and organic contaminants owing to accumulation of sewage water during the last two decades. The climate of the Saudi Arabia is mostly dry hot continental condition so that, the topmost clayey sediments of this lake are enriched in pollutants. That means, wind will carry these pollutants directly to Jeddah and the surrounding regions and are inhaled by residing citizens in these regions during respiration and thus could cause a variety of respiratory diseases or other infections. Owing to accumulation of sewage water-bearing organic materials during last 17 years, Al-Musk Lake subsurface sediments contain considerable amounts of heavy metals (Pb, Cd, As, Cu, Co and Hg) and organic materials. The organic matter content (OMC) of the studied surface soil samples varies from 4.2 to 11.3%. The OMC has a significant strong relationship with both silt and clay contents of the studied soil samples.

Heavy metal contamination in surface sediments: A comprehensive, large-scale evaluation for the Bohai Sea, China

Heavy metal contamination in the Bohai Sea (China) has been the focus of many studies, but most of them only focused on local pollution levels and thus lacked high spatial resolution for the whole sea. In this study, heavy metals (i.e., As, Cr, Cu, Cd, Pb, Zn, and Fe) in surface sediments were analyzed to assess the spatio-temporal pollution conditions of the Bohai Sea, an important coastal environment consisting of Bohai Bay, Laizhou Bay, and Liaodong Bay. The results indicated that the heavy metal concentration in the sediments was in the range of 6.43–32.18 mg/kg for As, 14.90–58.07 mg/kg for Cr, 3.90–27.19 mg/kg for Cu, 0.04–0.27 mg/kg for Cd, 11.09–30.95 mg/kg for Pb, 18.76–65.58 mg/kg for Zn, and 0.78%–2.55% for Fe. The distribution of heavy metals revealed that the concentrations were relatively low in Laizhou Bay, very high in the northwest coastal region of the Bohai Sea, and decreased from near-shore to off-shore areas. Moreover, both the enrichment factor and geo-accumulation index demonstrated that there was no contamination to be found for Cr, Cu, Zn in the region and a slight to moderate pollution of As, Cd, and Pb. Cd and As presented considerable potential ecological risk as a result of their high toxicity. The potential ecological risk index (RI) suggested that a third of the areas (northwest coastal area of the Bohai Sea) has moderate ecological risk. The risk area was generally decreased as offshore distance increased, which suggested that the contamination and risk of heavy metals are influenced by anthropogenic activities.

Assessment of nutrient and heavy metal contamination in surface sediments of the Xiashan stream, eastern Guangdong Province, China.

In this study, nutrient and heavy metal contamination in surface sediments of the Xiashan stream were investigated. Determining pollution degree of nutrient and heavy metal were the main objectives of this investigation. For this reason, the concentrations of total nitrogen (TN), total phosphorus (TP), seven heavy metals (Cu, Zn, Pb, Cd, Cr, Ni, Hg), and metalloid (As) were analyzed at 55 sampling sites. The mean TN concentration in surface sediments was 5.007 g/kg, while the mean TP concentration was 0.385 g/kg. Based on the sediment quality guideline (SQGs) and background values of Chinese soil and sediment, the majority of the mean TN concentrations in surface sediments were higher than their background values, while the TP concentrations were different from those observed for TN. For heavy metal concentrations in surface sediments, most of sampling stations were higher than their background values. The mean geo-accumulation (Igeo) indices for heavy metals were ranked as follows: Cd > Hg > Cu > Zn > Pb > Ni > Cr > As. The potential ecological risk index (RI) indicated heavy metal contamination level in Xiashan stream was very high ecological risk. According to Igeo and RI values, heavy metals especially Cd and Hg are influenced significantly by anthropogenic activities. Cd and Hg are not only as pollutant but also considerable contributor to ecological risk. Multivariate statistical investigations showed that there is a significant and positive correlation between Pb, As, and Cd. Cu, Ni, and Cr have similar characteristic and therefore probably originated from the same sources. Suggested by the results, it is necessary to control nitrogen and heavy metal contamination caused by human activities in the study area.

Bioavailability and Assessment of Metal Contamination in Surface Sediments of Rades-Hamam Lif Coast, around Meliane River (Gulf of Tunis, Tunisia, Mediterranean Sea)

The total concentration and the speciation of heavy metals (Pb, Cd, Cu, Zn, Ni, and Cr) in surface sediments of Rades-Hamam Lif coast were determined, with particular focus on the effect that urban and industrial waste in the Meliane river has on the estuary and coastal surface sediments of the Rades-Hamam Lif coast, off the Mediterranean Sea. Several geochemical indices were applied to assess the risk of contamination and the environmental risks of heavy metals on surface sediments. The total concentrations of these heavy metals are influenced by runoff, industrial, and urban wastewater. The Cd, Pb, Zn, and Ni are affected by anthropogenic sources, especially at the mouth of the Meliane river. The sequential extraction of Cd was presented dominantly in the exchangeable fraction and thus the high potential bioavailability. In contrast, Cr and Cu were mostly bound to the residual fraction indicating their low toxicity and bioavailability. The order of migration and transformation sequence was Cd > Pb > Ni > Zn > Cr > Cu, and the degree of pollution was Cd > Pb > Ni > Zn > Cr > Cu.

Assessment of heavy metals contamination in surface sediments of Sabratha, Northwest Libya

In order to assess the effect of sewage on surface sediments of Sabratha area, seven heavy metals were analyzed by Atomic Absorption Spectrophotometer in 40 sediment samples collected from the vicinity area of a sewage station. Environmental pollution indicators as an enrichment factor (EF), potential contamination index (Cp), soil pollution index (SPI), potential ecological risk index (PERI), correlation coefficient, and cluster analysis (Pearson’s method) were used. The results illustrated that the studied sediments are extremely severe with Cd (EF > 50; Cp > 3; SPI > 3; 160 ≤ PERI 320) and severe enrichment with Pb and Co (EF = 10–25; 1 < SPI ≤ 3). The potential sources of metal pollution in the study area are anthropogenic sources such as sewage, traffic exhaust, agricultural activities, and landfills. These results are very distinct in the samples near to the sewage station, indicating that they may be the most significant reason for the increasing metal concentrations in the study area. These results show that the average concentration of Cd and Pb is higher than the permissible level relative to those recorded in many world localities.

Assessment of heavy metal contamination in surface sediments along the Mediterranean coast of Morocco.

In this paper, heavy metal contamination in surface sediments along the Mediterranean coast of Morocco was investigated. Determining pollution degree as well as heavy metal origins were the main objectives of this investigation. For this reason, concentrations of nine heavy metals (Cd, Cu, Cr, Ni, Pb, Zn, Hg, Fe, and Mn) were analyzed at ten stations sampled during three different periods. The obtained concentrations showed significant variation between sampling periods, which was controlled by several environmental and chemical processes. According to contamination indices results using pollution load index (PLI), modified contamination degree (mCd), geoaccumulation index (Igeo), enrichment factor (EF), and potential ecological risk index (RI), sampling stations were classified between uncontaminated and strongly contaminated without detecting any intense heavy metal pollution in surface sediment. Likewise, the EF values were comprised between no enrichment and moderate to severe enrichment. According to sediment quality guidelines, the calculated M-ERM-Q indicated that heavy metal mixtures have between 9 and 49% probability for being toxic. This result revealed lowest to medium-low potential of adverse effects to biota populations. Regarding heavy metal origins, multivariate statistical investigation showed that Cd, Cu, Hg, Pb, and Zn are derived mainly from anthropogenic activities, while Fe, Mn, Cr, and Ni were derived from natural sources. Despite Cd is considered as a typical anthropogenic metal, the very low concentrations obtained in this study support the involvement of natural factor in the enrichment with this metal. Therefore, the surface sediments contamination along the Mediterranean coasts of Morocco is particularly caused by a combination of anthropogenic and natural factors. As a result, the study area can be considered as not significantly enriched by human activities.

Application of Pollution Indices in the Assessment of Heavy Metal Contamination of Surface Sediments of River Bonsa, Ghana

Heavy metal contamination of sediments is a major risk to ecological systems and human health. Not only do sediments influence the quality of the water column, but can be transferred to micro biota and fishes, ultimately ending up at higher trophic levels in the food chain though biomagnification. This study was carried out to assess the contamination levels of heavy metals in the sediments of river Bonsa. Ten sediment samples were taken along the river and analyzed for Copper (Cu), Lead (Pb), Manganese (Mn), Iron (Fe), Zinc (Zn), Cadmium (Cd), Chromium (Cr), Cobalt (Co), and Nickel (Ni) using Atomic Absorption Spectroscopy (AAS). Data analysis was accomplished by comparing the measured heavy metal concentrations to Australian and New Zealand Environment and Conservation Council (ANZECC) and National Oceanic and Atmospheric Administration (NOAA) fresh water sediment quality guidelines and by the computation of geo-accumulation indices and enrichment factors. The results show that apart from Ni which had two of its sample concentrations (at BS1 21.167 mg/kg and at BS2 29.374 mg/kg) exceeding the ANZECC lower limit (21 mg/kg) guideline for fresh water sediment, all other heavy metals recorded concentrations below the lower limits of their respective ANZECC standards. Out of the 10 samples analyzed, 7 recorded Mn concentrations above the NOAA ARC TEL. A one-sample t-test also showed that the mean concentrations of Cu, Pb, Cd, Zn, Ni, and Cr were significantly lower than their respective ANZECC threshold values and Fe concentration was also significantly lower than the NOAA threshold; however, there was no significant difference between Mn mean value and the corresponding NOAA guideline value. The assessment of heavy metal pollution was derived using the Enrichment Factor (EF) and geo-accumulation indices (I-geo). The computed enrichment factors indicated that all the heavy metals except Ni are from natural sources (i.e., EF < 1.5) signifying a degree of heavy metal depletion rather than enrichment. The sources of Ni were attributed to domestic waste disposal into the river at sampling points BS1 and BS2 as well as run offs from a nearby auto mechanic workshop. All the metals had I-geo values between 0 and 1 (0 < I-geo < 1) denoting unpolluted to moderately polluted sediments. Thus, in terms of heavy metals, the river is unpolluted. These findings are very important as it shows that river Bonsa has not yet been impacted as far as heavy metals are concerned and the data gathered may serve as baseline for future studies.

Mineralogy, composition and heavy metals’ concentration, distribution and source identification of surface sediments from the saline Maharlou Lake (Fars Province, Iran)

This study concerns the mineralogy, spatial distribution and sources of nine heavy metals in surface sediments of the Maharlou saline lake, close to the Shiraz metropolis in southern Iran. The sources for these sediments were studied by comparing the mineralogy and the distribution of heavy metals, using multivariate statistical analysis (correlation analysis and principal component analysis). The geochemical indices, including geo-accumulation index (Igeo), contamination factor (CF) and pollution load index (PLI), were used to assess the degree of heavy metal contamination in surface sediments. Sediment quality guidelines (SQGs) have also been applied to assess its toxicity. The XRD analysis shows that the main minerals of the surface sediments are aragonite, calcite, halite and quartz, with small amounts of montmorillonite, dolomite and sepiolite. The total heavy metal contents in surface sediments decrease in order of Sr > Ni > Cr > Zn > Cu > Co > Pb > As > Cd and the average concentrations of Sr, Ni and As exceeded more than 10, 5 and 3 times, respectively, by comparing with the normalized upper continental crust (UCC) values. The results of pollution indices (Igeo, CF and PLI) revealed that strontium (Sr), nickel (Ni) and arsenic (As) were significantly enriched in those sediments. Based on the sediment quality guidelines (SQGs), Ni would infrequently cause toxicity. Multivariate statistical analysis indicated that the Ni, Co and Cr came mainly from natural geological background sources, while Cd, Cu, Pb, and Zn were derived from urban effluents (especially traffic emissions) and As originated from agriculture activities. Significant relationships of Sr with S, CaO and MgO in sediments suggest that Sr was derived from carbonate- and gypsum-bearing catchment source host rocks.