Average Concentrations Of Heavy Metals Research Articles

Geospatial evaluation and bio-remediation of heavy metal-contaminated soils in arid zones

Introduction: Soil pollution directly impacts food quality and the lives of both humans and animals. The concentration of heavy metals in Egypt’s drain-side soils is rising, which is detrimental to the quality of the soil and crops. The key to reducing the detrimental effects on the ecosystem is having accurate maps of the spatial distribution of heavy metals and the subsequent use of environmentally sustainable remediation approaches. The objective of this work is to assess soil contamination utilizing spatial mapping of heavy metals, determine contamination levels using Principal Component Analysis (PCA), and calculate both the contamination severity and the potential for bioremediation in the soils surrounding the main drain of Bahr El-Baqar. Furthermore, evaluating the capacity of microorganisms (bacteria, fungi, and “Actinomycetes) to degrade heavy elements in the soil.Methodology: 146 soil sample locations were randomly selected near the Bahr El-Baqar drain to examine the degree of soil pollution Ordinary Kriging (OK), method was used to map and analyze the spatial distribution of soil contamination by seven heavy metals (Cr, Fe, Zn, Cd, Pb, As, and Ni). Modified contamination degree (mCd) and PCA were used to assess the research area’s soil pollution levels. The process involved isolating, identifying, and classifying the microorganisms present in the soil of the study area. The study findings showed that variography suggested the Stable model effectively matched pH, SOM, and Cd values. Furthermore, the exponential model proved suitable for predicting Fe, Pb and Ni, while the spherical model was appropriate for Ni, Cr, and Zn.Results: The study revealed three levels of contamination, with an extremely high degree (EHDC) affecting approximately 97.49% of the area. The EHDC exhibited average concentrations of heavy metals: 79.23 ± 17.81 for Cr, 20,014.08 ± 4545.91 for Fe, 201.31 ± 112.97 for Zn, 1.33 ± 1.37 for Cd, 40.96 ± 26.36 for Pb, 211.47 ± 13.96 for As, and 46.15 ± 9.72 for Ni. Isolation and identification of microorganisms showed a significant influence on the breakdown of both organic and inorganic pollutants in the environment. The study demonstrated exceptionally high removal efficiency for As and Cr, with a removal efficiency reached 100%, achieved by Rhizopus oryzae, Pseudomonas aeruginosa, and Bacillus thuringiensis.Conclusion: This study has designated management zones for soil contamination by mapping soil pollutants, geo-identified them, and found potential microorganisms that could significantly reduce soil pollution levels.

Source-specific probabilistic health risk assessment of heavy metals in surface water of the Yangtze River Basin

The detrimental effects of heavy metal accumulation on both ecosystems and public health have raised widespread concern. Source-specific risk assessment is crucial for developing effective strategies to prevent and control heavy metal contamination in surface water. This study aims to investigate the contamination characteristics of heavy metals in the Yangtze River Basin, identifying the pollution sources, assessing the risk levels, and further evaluating the health risks to humans. The results indicated that the average concentrations of heavy metals were ranked as follows: zinc (Zn) > arsenic (As) > copper (Cu) > chromium (Cr) > cadmium (Cd) > nickel (Ni) > lead (Pb), with average concentrations of 38.02 μg/L, 4.34 μg/L, 2.53 μg/L, 2.10 μg/L, 1.17 μg/L, 0.84 μg/L, and 0.32 μg/L, respectively, all below the WHO 2017 standards for safe drinking water. The distribution trend indicates higher concentrations in the upper and lower reaches and lower concentrations in the mid-reaches of the river. By integrating the Absolute Principal Component Scores-Multiple Linear Regression (APCS-MLR) receptor model and Positive Matrix Factorization (PMF) model, the main sources of heavy metals were identified as industrial activities (APCS-MLR: 41.3 %; PMF: 42.1 %), agricultural activities (APCS-MLR: 30.1 %; PMF: 27.4 %), and unknown mix sources (APCS-MLR: 29.1 %; PMF: 30.4 %). The calculation of the hazard index (HI) for both children and adults was <1, indicating no non-carcinogenic or carcinogenic risks. Based on the source-specific risk assessment, agricultural activities contribute the most to non-carcinogenic risks, while industrial activities pose the greatest contribution to carcinogenic risks. This study offers a reference for monitoring heavy metals and controlling health risks to residents, and provides crucial evidence for the utilization and protection of surface water in the Yangtze River Basin.

Proximate analysis, levels of trace heavy metals and associated human health risk assessments of Ethiopian white sugars

In this study, white sugar samples collected from five Ethiopian sugar manufacturing plants were analyzed for their proximate composition, and trace heavy metals level (Fe, Co, Ni, Mn, Zn, Cr, Cd, and Pb). Human health risk assessments associated with heavy metals exposure from white sugar ingestion were also assessed. Proximate analysis was conducted according to AOAC methods. For heavy metals determination, the sugar samples were digested using a mixture of HNO3, HClO4 and H2O2 (4:3:1) at 250 °C for 3 h prior to FAAS analysis. The measured mean values (%) of proximate parameters including moisture, ash, fiber, protein, fat and carbohydrate were found in the range of 0.07–0.61, 2.56–4.33, 0.06–0.24, 0.78–1.49, 1.16–1.89 and 92.13–95.03, respectively. The average concentration of heavy metals found in the sugar samples were ranged as 1.366–12.502, 0.107–0.268, 0.099–0.842, 0.458–1.000, 10.140–25.480, 0.053–0.322, 0.427–0.827 and 0.074–0.528 in mg/kg for Fe, Mn, Ni, Co, Zn, Cr, Cd and Pb, respectively. All the studied metals are below FAO/WHO permissible limit except Cd and Pb in Kessem, Fincha'a and Metahara samples. The target hazard quotient (THQ) and hazard index (HI) values are <1, indicating no non-carcinogenic risks of the heavy metals to an adult population via consumption of white sugar. However, the single element incremental lifetime cancer risk (ILCR) occurrence is probable from Ni for samples obtained from Kessem sugar factory (ILCR>1.0 × 10−4). The cumulative ILCR of heavy metals (Ni, Cr, Cd and Pb) resulting from consumption of white sugar by an adult person reveal a potential adverse cancer risk (ILCR>1.0 × 10−4) for all the studied samples except for sugar samples obtained from Wonji sugar factory. Therefore, continuous monitoring of these toxic metals should be made mainly by sugar industries and responsible government regulatory bodies to avert heavy metal toxicity associated with white sugar consumption in Ethiopia.

Association between exposure to heavy metals in atmospheric particulate matter and sleep quality: A nationwide data linkage study

BackgroundRecent studies have demonstrated that long-term exposure to particulate matter (PM) is associated with poor sleep quality. However, no studies have linked PM constituents, particularly heavy metals, to sleep quality. ObjectiveThis study investigated the association between exposure to heavy metals in PM and sleep quality. MethodsWe obtained nationwide data from the Korean Community Health Survey conducted in 2018 among adults aged 19–80 years. Sleep quality was evaluated using Pittsburgh Sleep Quality Index (PSQI). Poor sleep quality was defined as PSQI ≥5. One-year and three-month average concentrations of heavy metals (lead, manganese, cadmium, and aluminum) in PM with diameter ≤10 μm were obtained from nationwide air quality monitoring data and linked to the survey data based on individual district-level residential addresses. Logistic regression analyses were performed after adjusting for age, gender, education level, marital status, smoking status, alcohol consumption, history of hypertension, and history of diabetes mellitus. ResultsOf 32,050 participants, 17,082 (53.3%) reported poor sleep quality. Increases in log-transformed one-year average lead (odds ratio, 1.14; 95% confidence interval, 1.08−1.20), manganese (1.31; 1.25−1.37), cadmium (1.03; 1.00−1.05), and aluminum concentrations (1.17; 1.10−1.25) were associated with poor sleep quality. Increases in log-transformed three-month average manganese (odds ratio, 1.13; 95% confidence interval, 1.09−1.17) and aluminum concentrations (1.28; 1.21−1.35) were associated with poor sleep quality. ConclusionWe showed for the first time that exposure to airborne lead, manganese, cadmium, and aluminum were associated with poor sleep quality. This study may be limited by self-reported sleep quality and district-level exposure data.

Assessment of heavy metals at mangrove ecosystem, applying multiple approaches using in-situ and remote sensing techniques, Red Sea, Egypt.

Mangrove areas are considered the most retention zone for heavy metal pollution as it work as an edge that aggregates land and sea sediments. This study aims to examine if the heavy metals' existence in the mangrove sediment is related to contamination or natural resources. In addition, it gives an interpretation of the origin of these metals along the Egyptian Red Sea coast. Twenty-two samples of mangrove sediments were collected and then, analyzed for metals (Mn, Ni, Cu, Fe, Cd, Ag, and Pb) using inductively coupled plasma mass spectroscopy (ICP-MS). Integration between the in-situ data, contamination indices, and remote sensing and geographical information science (GIS), and multivariate statistical analysis techniques (PCA) were analyzed to assess and clarify the spatial origin of heavy metals in sediment at a regional scale. The average concentration of heavy metals from mangrove sediments were shown to be substantially lower than the referenced value, ranging from moderate to significant except the levels of Ag were very high. The heavy metals concentrations were expected to be naturally origin rather than anthropogenic and that be confirmed by mapping of Red Sea alteration zones spots. These alteration zones are parallel to mangrove sites and rich by several mineralization types including heavy metals that are carried by flooding to the coastline. Remote sensing and GIS techniques successfully contributed to interpreting the pattern of the origin of heavy metals and discharging systems that control the heavy metals concentration along the Red Sea coast.

Risk assessment of heavy metals in the freshwater lake sediments around Eppawala phosphate deposit, Sri Lanka

The Eppawala area in Sri Lanka has an agricultural-based economy. As a result, the recent agricultural intensification could increase the risk of heavy metal contamination in lakes in the area as the main water canal in the area, i.e., Jaya Ganga, flows across these lakes. Therefore, this study focuses on the risk assessment of heavy metals in the freshwater lake sediments in the Eppawala area and the identification of potential sources for heavy metal contamination in the lakes. Nine heavy metals (Cr, Mn, Co, Ni, Cu, Zn, As, Cd, and Pb) were investigated in surface sediments (n = 22) of the upstream and downstream lakes of the Eppawala Phosphate Deposit (EPD). The average heavy metal concentrations in the upstream lake sediments were higher than those downstream. Eppawala lake sediments were heavily polluted by As along with moderate to high Cr pollution. However, only As and Cd indicated considerable to moderate ecological risk levels to the local environment. The downstream lake sediments showed lower heavy metal contents compared to those upstream and had negative correlations between heavy metals and P2O5 contents. This reveals that the EPD does not contribute to the heavy metal contamination in the Eppawala lake sediments. However, the statistical analysis showed that heavy metals were mostly derived from similar pollution sources. Agrochemicals used in paddy cultivation in the vicinity might be a potential source of heavy metals. This study highlights the importance of implementing remediation to control the heavy metal pollution prevailing in the Eppawala lakes. 

Analysis of the Source Apportionment and Pathways of Heavy Metals in Soil in a Coal Mining Area Based on Machine Learning and an APCS-MLR Model

Long-term coal mining activities have led to severe heavy metal pollution in the soil environment of coal mining areas, posing significant threats to both ecological environments and human health. In this study, surface soil samples were collected from the overlying soil of coal gangue and the surrounding areas of the Panyi coal mine in Huainan. The concentrations of Cd, Zn, Cu, Ni, and Pb elements were determined. A self-organizing map (SOM) and an absolute principal component score multiple linear regression (APCS-MLR) receptor model were employed for the quantitative analysis of the soil’s heavy metal pollution sources and contributions. Additionally, this study focused on the analysis of the pathways of the relatively serious pollution of Cd. The results revealed that the average concentrations of heavy metals (Cd, Pb, Zn, Cu, Cr, and Ni) in the study area were 4.55, 0.59, 1.54, 0.69, 0.59, and 0.71 times the local soil background values, respectively. The concentrations of Cd and Zn exceeded the risk screening values at some sampling points, with exceedance rates of 44% and 8%, respectively, indicating a relatively serious Cd contamination. The sources of heavy metals in the soil in the study area were classified into four categories: mining activities, agricultural activities, weathering of natural matrices, and other unknown sources, with average contributions of 55.48 percent, 24.44 percent, 8.91 percent and 11.86 percent, respectively. Based on the spatial distribution of Cd, it was inferred that atmospheric deposition is one of the important pollution pathways of Cd in the study area. Cd profile distribution patterns and a surface water pollution survey showed that the farmland areas were affected by the irrigation water pathway to some extent. The vertical distribution of heavy metal content in the forest area showed a strong disorder, which was related to the absorption function of plant roots. The results of this study can help to improve the environmental management of heavy metal pollution so as to protect the ecological environment and human health.

Proximate Composition, Trace and Macro Element, and Heavy Metal Content of Edible Seaweed Solieria robusta in Tawi-Tawi, Philippines

Solieria robusta is a red seaweed consumed widely by the local population in the southern Philippines. However, current information regarding its proximate composition, trace and macro element, and heavy metal content is lacking. This study marks the first attempt in the Philippines to ascertain the proximate composition, trace and macro element, and heavy metal content of edible seaweed S. robusta. Our findings revealed that S. robusta primarily consists of ash content, measuring 44.30 ± 0.4 g/100 g, followed by carbohydrates at 32.96 ± 0.45 g/100 g. The moisture content of dried S. robusta was 16.91±0.04 g/100 g. The crude protein content of this edible seaweed was determined to be 5.61 ± 0.05 g/100 g, with total fat noted at 0.22 ± 0.01 g/100 g. The average concentration of trace elements (Zn, Fe, Mg, and Cu), macro element (K), and heavy metals (Pb and Cd) followed the order of Zn &gt; Fe &gt; K &gt; Mg &gt; Pb &gt; Cu &gt; Cd. Notably, three essential minerals -Zn, Fe, and K- were present in significant quantities in S. robusta, with concentrations of 219±8.70, 209±5.75, and 9.83±0.22 mg/kg, respectively. However, one trace element, Zn, and one heavy metal, Pb, exceeded the permissible values, and the rest were within the safe limits. This study constitutes a significant contribution to the comprehension of the nutritional profile and mineral composition of S. robusta, emphasizing its potential as a valuable dietary resource.

Size-classified aerosol-bound heavy metals and their effects on human health risks in industrial and remote areas in Japan

Airborne aerosols were collected in six size classes (PM<0.1, PM0.1–0.5, PM0.5–1, PM1–2.5, PM2.5–10 and PM>10) to investigate aerosol health risks in remote and industrial areas in Japan. We focused on heavy metals and their water-dispersed fractions. The average concentration of heavy metals was 18 ± 25–86 ± 48 ngm−3 for PM<0.1, 46 ± 19–154 ± 80 for PM0.5–1 ngm−3, 98 ± 49–422 ± 186 ngm−3 for PM1–2.5, 321 ± 305–1288 ± 727 ngm−3 for PM2.5–10 and 65 ± 52–914 ± 339 ngm−3 or PM>10, and these concentrations were higher in industrial areas. Heavy metals emitted from domestic anthropogenic sources were added to the long-range transport component of the aerosols. The water-dispersed fraction of heavy metals contained 3.3–40.1% of the total heavy metals in each size class. The relative contribution of Zn and other species (As, Cd, Cr, Ni, Pb, Mn, V and Cu) increased in the water-dispersed fraction. Smaller particles contained greater proportions of the water-dispersed heavy metal fraction. Carcinogenic risk (CR) and the hazard index (HI) were estimated for each size class. The CR of carcinogens was at acceptable levels (<1 ×10−6) for five particle size fractions. The HI values for carcinogens and noncarcinogens were also below acceptable levels (<1) for the same five size fractions. The estimated CR and HI values were dominated by contributions from the inhalation process.

Assessment of heavy metals contamination of agricultural soils using pollution indicators in Thi-Qar governorate, Southern Iraq

This study aims to assess the levels of contamination of agricultural soils with heavy elements (cobalt, copper, iron, nickel, cadmium, and lead) in three regions in Thi-Qar Governorate, Southern Iraq. These three regions are Al-Gharraf, Al-Islah, and Al-Batha. The study was done by using the pollution indicators, which are geographical pollution index (Igeo), contamination degree (Cd), contamination factor (Cf), pollution load index (PLI), potential ecological risk factor (Er), and finally, risk index (RI). From each region, four soil samples were collected from holes 25 cm deep, separated by a distance of 500 meters. After the digestion process of the samples, the concentrations of the studied elements were measured by flam atomic absorption spectrometer (FAAS). The results showed that the average heavy metal concentrations for all samples were (365.810, 96.424, 41.36, 11.919, 5.194 and 0.352 mg/kg). They were in the following order Fe &gt; Ni &gt; Cu &gt;Co &gt; Pb &gt; Cd, respectively. The concentrations of heavy metals in the study areas were all within the limits allowed by the World Health Organization (WHO) except for 8.3% of the studied areas that were beyond the permissible limits for cadmium only. The reason for the increase in cadmium concentrations in some areas could be due to sewage, industrial emissions and agricultural practices. According to the Igeo values, the levels of minerals studied for the three regions followed the following order Cd &gt; Cu &gt; Co &gt; Pb &gt; N i&gt; Fe.

Assessment of contamination and potential ecological risks of heavy metals in riverine sediments from gold mining and pristine areas in Ghana

This study explore the characteristics of heavy metal pollution, contamination levels, and potential ecological risks in riverine sediments found in both gold mining and pristine areas. Such investigations are vital for the ongoing monitoring and preservation of water bodies and overall ecosystem health. In total, 44 composite sediment samples were collected from seven pristine environments and four mining sites. These samples underwent preparation, digestion, and analysis for heavy metal content, utilizing the inductively coupled plasma emission mass spectrometer (ICP-MS). Various tools and models, including the geo-accumulation index, enrichment factor, and degree of contamination, were employed to assess the impact of pollution on the environment. Modified ecological risk index were also used to evaluate potential ecological risks. The average concentrations of heavy metals in pristine sites spanned from 0.01±0.01 (Cd) to 73,753.64 ± 388.15 mgkg−1 (Fe), while in mining sites, they ranged from 0.04±0.02 (Cd) to 56,394.25±400.66 mgkg−1 (Fe). Comparing these concentrations against the USEPA Ecological Screening Values, Mean Shales levels, and the Canadian ISQG, it became evident that Pb, Cd, Zn, Ni, Co, and Mn concentrations generally remained below the recommended guideline values in both pristine and mining areas. However, concentrations of Cr, As, Cu, and Hg exceeded the prescribed threshold limits, particularly in the mining regions. Through Principal Component Analysis (PCA) and Geometrical Analysis for Interactive Aid (GAIA) modeling, two primary sources of heavy metals were identified: anthropogenic-related and geogenic-related. GAIA and PCA together explained 78.53 % and 79.40 % of the total variability in heavy metal concentrations, respectively. Overall, the pollution and ecological risk assessment indicated low to moderate contamination levels, with a notable exception of high arsenic contamination in the Nyam river. The findings of this study hold significance for assessing sediment conditions and river quality in mining communities within Ghana and globally. They also provide empirical data to recommend measures for mitigating water contamination in such communities.

Oral and dermal exposure to natural radionuclides and heavy metals in water and sediments of Nile River, Qena, southern Egypt

This study assessed the levels of natural radionuclides (226Ra, 232Th, and 40K) and heavy metals (Hg, Fe, Cr, As, Zn, Cu, Cd, and Pb) in surface water and sediment samples from the Nile River in Qena Governorate, southern Egypt, using a gamma-ray spectrometer, 3ʺ NaI (Tl) scintillation detector coupled with 1024 multi-channel analyzer, and an atomic absorption spectrometer. In surface water and sediments, the average activity concentrations of natural radionuclides were 40K (4.73 Bq L−1; 395.76 Bq kg−1) > 226Ra (0.41 Bq L−1; 18.14 Bq kg−1) > 232Th (0.30 Bq L−1; 17.98 Bq kg−1). The average heavy metal concentrations in surface water in µg L−1 were Fe (121.0) > Zn (33.80) > Cr (28.0) > Cu (8.62) > Pb (8.35) > As (1.19) > Hg (0.81) > Cd (0.12). In Nile sediments the concentrations in mg kg−1 were Fe (1670.0) > Zn (207.0) > Cr (29.40) > Cu (16.20) > Pb (4.32) > Hg (0.41) > Cd (0.31) > As (0.14). The heavy metal evaluation index (HMEI) calculations for water samples revealed that 31% of the samples were suitable for domestic use, while 69% were not. The geo-accumulation index, enrichment factor, and ecological risk factor for sediments were estimated, showing extreme enrichment for Hg and Zn with high ecological risk for Hg. Health risks for adults were evaluated due to oral and dermal exposure to Nile surface water and sediments from the study area, indicating minimal radiological risks and potential carcinogenic and non-carcinogenic risks from the metals.

Feasibility study of concentration of chemical and physical parameters in excavated water coal mining as a cage fishing destination

A research was carried out on the feasibility of chemical and physical concentrations in coal mine excavation water for use in cage fisheries. This research aims to analyze the concentration conditions of chemical parameters (NH3, pH, Cu and Fe) and physical parameters (DO, temperature and turbidity) in water originating from coal excavations which are already in the form of lakes. Samples were prepared before analysis by adding concentrated nitric acid. Analysis of Cu and Fe concentrations was carried out using an Atomic Absorption Spectrophotometer (AAS), ammonia using a UV-Vis Spectrophotometer, DO concentrations were analyzed using the titration method, turbidity analysis using a nephelometer, temperature using a thermometer and pH using a pH meter. From the research results, it was found that the physical parameters of lake water from former coal mine excavations were pH, temperature, DO, NH3 and turbidity is suitable because it has not yet passed the quality standards for designation as a cage for cultivating freshwater fish. The concentration of the heavy metal Cu in coal excavation water has exceeded the quality standards set for cultivating freshwater fish and the metal concentration Fe has not exceeded the quality standards set. Research analysis of the average concentrations of heavy metals in water samples from former coal mining pools, namely Cu (0.166; 0.278; 0.284 mg/L), and Fe (0.020; 0.029; 0.023 mg/kg).

Assessment of Soil Pollution by Heavy Metals in the Market Gardening Areas of Korsimoro

The aim of this study was to assess heavy metal soil pollution in market garden areas in the commune of Korsimoro. The analysis focused mainly on zinc (Zn), nickel (Ni), chromium (Cr), copper (Cu), lead (Pb), cadmium (Cd), cobalt (Co), arsenic (As) and mercury (Hg). Composite samples of soil labels s1 to s21 were taken from the market garden site around the dam at a depth of 0-20 cm. A total of 21 soil samples were taken. The soil samples were analysed using inductively coupled plasma mass spectrometry (ICP/MS) at the Bureau of Mines and Geology of Burkina Faso laboratory (BUMIGEB).&#x0D; The enrichment factor (EF), contamination factor (CF), géoaccumulation index (Igeo) and pollution load index (PLI) were determined from the metal concentrations obtained.&#x0D; The average concentrations of heavy metals vary as follows:&#x0D; Cd &gt; Co &gt; Cr &gt; Zn &gt; Ni &gt; Cu &gt; Hg &gt; Pb &gt; As.&#x0D; The average concentrations of cadmium (587.039mg/kg±20.546), mercury (29.048mg/kg±20,647), nickel (60.037 mg/kg±14,615) and cobalt (575.956mg/kg±66,693) exceed the WHO limit values for agricultural soils.&#x0D; The calculated CF values show very high contamination of Co, Cd and Hg, considerable contamination of Cu, Cr, Zn, Ni and As, and no contamination of Pb.&#x0D; The EF values show very severe enrichment for cobalt (Co), followed by overall extremely severe enrichment for cadmium (Cd) and mercury (Hg).&#x0D; The calculated Igeo indicates extreme cadmium, mercury and cobalt contamination.&#x0D; The calculated PLI values are all greater than one. These results show that all the soils are polluted.&#x0D; The index determination approach makes it possible to predict the extent of soil pollution by the heavy metals considered in our study.

Heavy metal concentrations in surface waters of Hurghada and environs, Red Sea Coast, Egypt, and their correlation with sediment distribution

This study investigates the properties and chemistry of surface water in Hurghada and its adjacent areas, with a focus on assessing the potential impact of human activities on water quality by measuring the concentrations of heavy metals in surface water samples. A total of fifty-nine surface water samples were collected and analyzed for various heavy metals, including manganese (Mn), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), cadmium (Cd), mercury (Hg), and lead (Pb) using the AAS technique.The results indicate that at the Desert Rose Resort transect, the average total concentrations of heavy metals were within the following ranges: Fe (average of 26.96 μg/L), Cu (average of 0.61 μg/L), Zn (average of 6.31 μg/L), and Pb (average of 0.75 μg/L). Conversely, at the Abu-Shaar transect, Ni (0.87 μg/L) and Cd (average of 0.02 μg/L) were the dominant heavy metals, while Mn exhibited the highest mean value (1.80 μg/L) at the El-Samaka Village transect. Notably, Hg was not detected in any of the samples within the study areas.Comparative analysis of heavy metal concentrations in Hurghada's surface waters with data from the Red Sea coast and other global regions reveals that the study areas maintain heavy metal concentrations well below the maximum permissible values for the marine environment. These findings suggest that human activities have not significantly impacted heavy metal levels in the region's surface waters.Additionally, statistical assessments, such as correlation coefficients (r), were employed to explore the relationships between heavy metal concentrations in water and sediment. These relationships provide valuable insights into the dynamic balance of elements within the sediment and their potential direct or indirect transfer into the water.

Assessment of heavy metal content and ecological risk in offshore surface sediments of the Northern Persian Gulf: Implications for environmental management

Offshore surface sediment samples from fifty-five stations in the northern parts of the Persian Gulf and the Strait of Hormuz were examined to evaluate the content and ecological risk of heavy metals. The physicochemical characteristics of both surface water and deep water were measured using probes and CTD. To determine the source of pollution and assess the ecological risk, various indicators were used, including contamination factor (CF), contamination degree (CD), enrichment factor (EF), pollution load index (PLI), and risk index (RI). The average concentrations of heavy metals in sediment samples were Fe: 1.4 (0.2–2.7%), Cr: 72.9 (8−127), Ni: 59.8 (14−113), V: 43.4 (7−77), Zn: 35.7 (3−58), Cu: 17.5 (2−29), Pb: 12.1 (5−48), Co: 9.4 (1−17), As: 3.9 (1.7–7.2) ppm. Ni and Cr concentrations in almost all Persian Gulf stations especially in shallower parts were higher than their threshold effect level, while Pb, As, Zn, and Cu concentrations were below the threshold values in all stations. The results revealed that EF for all investigated metals in all stations was less than 1.5, which indicates that the studied region had low enrichment and the origin of the heavy metals is natural. However, human activities have contributed to Ni enrichment in the Jask and Bandar Abbas coasts. CD values varied between 11.7 and 14.6, exhibiting the range of moderate pollution to lowest possible pollution category. The PLI for all samples was in the range of 1.2–2.2, which demonstrates advanced pollution load. RI (=∑Eij) varied between 34 and 89, indicating a low ecological risk (IR<110).

Geochemical contamination of heavy metals and health risk assessment of coastal sediments along the North Chennai to Pondicherry, India using total reflection X-ray fluorescence spectroscopy (TXRF)

The present work aimed to assess the contamination and human health risk assessment of heavy metals (HMs) in 21 sediment samples collected from the North Chennai to Pondicherry coastal area of Tamil Nadu using total reflection X-ray fluorescence spectroscopy (TXRF). Enrichment factor (EF), contamination factor (CF), and geo-accumulation index (Igeo) were calculated to estimate sediment contamination. The average concentrations of HMs (mg kg−1 dry weight) were: Al (4305.12), V (25.77), Cr (15.08), Mn (83.39), Fe (4539.77), Ni (2.89), Cu (2.67), Zn (9.46), As (2.81), Hg (0.05), and Pb (0.92). Results of EF indicated no enrichment with Al, Ni, and Pb, moderate enrichment with V, and severe enrichment with As and Hg. Based on Igeo, all sediment samples showed unpolluted with HMs (except As and Hg). Based on total lifetime cancer risk (LCR), there are no significant health risks for people in the study area from carcinogenic Cr, As, and Pb.

Assessment of heavy metal pollution in surface water of Bangladesh

Industrial discharge of heavy metals severely deteriorates surface water quality in many parts of the world, particularly in lower-middle-income countries like Bangladesh. This study collected published data from 30 different surface water bodies in Bangladesh, including rivers, lakes, freshwater wetlands (Haors), and river estuaries, on mean concentrations of 12 heavy metals (Cd, Pb, Cr, Hg, Zn, Cu, Ni, Al, Fe, Mn, As, and Co) in surface water bodies from 2010 to 2022. The study aimed to explore the pollution source and levels of heavy metals in the surface water of Bangladesh. The water quality status and correlations between variables were assessed using the heavy metal pollution index (HPI), heavy metal evaluation index (HEI), and principal component analysis (PCA). The analysis results showed that the average heavy metal concentrations in the surface water of Bangladesh were in the order of Fe>Al>Mn>Cr>Zn>Cu>As>Ni>Pb>Co>Cd>Hg in the range of 3.98 ppm to 0.004 ppm. It also showed that Dhaka, Chittagong, Mymensingh divisions, and Bogra city of Rajshahi division are the most polluted areas of Bangladesh in terms of heavy metal concentration, whereas Khulna and Sylhet divisions are moderately polluted. The results showed that about 83.3 % of water bodies have HPI values greater than 100, which is considered unsafe for consumption. However, the HEI analysis revealed that about 46.7 % of water bodies were in the high pollution category (HEI > 20). The correlation matrix of heavy metals illustrated strong positive linear relationships between Cr and Co, Cu and As, Cu and Cd, and As and Cd. The principal component analysis suggested that the most contributing sources of pollution in the studied area are related to different anthropogenic activities, such as municipal waste and industrial effluent discharge, including tanneries, textile and dyeing industries, shipbreaking yards, and gas production plants, as well as agricultural runoff.

Risk Assessment and Determination of Arsenic and Heavy Metals in Fishery Products in Korea.

The purpose of this study is to quantify several heavy metals (Pb, Cd, Hg, Me-Hg, and metalloid arsenic) contained in Korean fishery products (seven categories, 1186 samples) and assess their health risk. Heavy metals quantification was conducted using inductively coupled plasma mass spectrometry (ICP-MS) and a direct mercury analysis (DMA). The good linearity (R2 > 0.999), limits of detection (1.0-3.2 µg/kg), limits of quantification (3.1-9.6 µg/kg), accuracy (88.14-113.80%), and precision (0.07-6.02%) of the five heavy metals were obtained, and these results meet the criteria recommended by the AOAC. The average heavy metal concentrations of fishery products were in the following order: As > Cd > Pb > Hg > Me-Hg for sea algae, crustaceans, mollusks, and echinoderms, As > Hg > Me-Hg > Pb > Cd for freshwater fish and marine fish, and As > Pb > Cd > Hg > Me-Hg for tunicates. Heavy metal concentrations were lower than MFDS, EU, CODEX, and CFDA standards. In addition, the exposure, non-carcinogenic, and carcinogenic evaluation results, considering the intake of aquatic products for Koreans, were very low. It was concluded that this study will provide basic data for food safety and risk assessment.

Analysis of heavy metal, rare, precious, and metallic element content in bottom ash from municipal solid waste incineration in Tehran based on particle size

Waste incineration is increasingly used worldwide for better municipal solid waste management and energy recovery. However, residues resulting from waste incineration, such as Bottom Ash (BA) and Fly Ash (FA), can pose environmental and human health risks due to their physicochemical properties if not managed appropriately. On the other hand, with proper utilization, these residues can be turned into valuable Municipal metal mines. In this study, BA was granulated in various size ranges (< 0.075 mm, 0.075–0.125 mm, 0.125–0.5 mm, 0.5–1 mm, 1–2 mm, 2–4 mm, 4–16 mm, and > 16 mm). The physicochemical properties, heavy metal elements, environmental hazards, and other rare and precious metal elements in each Granulated Bottom Ash (GBA) group from Tehran's waste incineration were examined using ICP-MASS. Additionally, each GBA group's mineralogical properties and elemental composition were determined using X-ray fluorescence (XRF) and X-ray diffraction (XRD). The results showed that the average concentration of heavy metals in GBA, including Zn (1974 mg/kg), Cu, and Ba (790 mg/kg), Pb (145 mg/kg), Cr (106 mg/kg), Ni (25 mg/kg), Sn (24 mg/kg), V (25 mg/kg), As (11 mg/kg), and Sb (29 mg/kg), was higher in particles smaller than 4 mm. Precious metals such as gold (average 0.3 mg/kg) and silver (average 11 mg/kg) were significantly higher in GBA particles smaller than 0.5 mm, making their extraction economically feasible. Moreover, rare metals such as Ce, Nd, La, and Y were detected in GBA, with average concentrations of 24, 8, 11, and 7 mg/kg, respectively. The results of this study indicated that BA contains environmentally concerning metals, as well as rare and precious metals, with high concentrations, especially in particles smaller than 4 mm. This highlights the need for proper pre-treatment before using these materials in civil and municipal applications or even landfilling.