Average Metal Concentrations Research Articles

Introducing bio-indicator fish of the Persian Gulf based on health risk assessment of 27 commercial species

BackgroundThe increasing consumption of seafood may bring health risks. It will be especially important for the people living along the coasts who are highly dependent on seafood for food and income. MethodsIn this research, a comprehensive health risk assessment was performed on 27 species of high-consumption commercial fish sampled from stations located in Hormozgan province within the Northeast Persian Gulf. Concentrations of trace metals and their health risk were investigated. ResultsSpatial distribution of trace metals in commercial fish showed central stations including Kong and Greater Tonb have higher concentrations of all trace metals except Pb. Some metals showed a significant correlation between concentrations. Our finding indicated the average concentration of all trace metals except Ni in all species was below the concentrations proposed by WHO/FAO/USEPA. EDI for all metals in all species in both adult and child age groups was lower than its RfD (oral reference dose of trace metal) showing the daily consumption of these fish does not pose any health risk and implicates seafood consumption guidelines or policies. Values of THQ for each metal and HI for all metals were lower than 1 in all commercial fish indicating the lack of non-cancerous health risk through the long-term consumption of these fish. The research found potential health risks associated with the consumption of these fish, specifically related to the metals Cr, Ni, and Cd. ConclusionIn total, health risk indices proposed eight fish as bio-indicator species of the Persian Gulf. The findings emphasize the risk management of commercial fish consumption, especially bio-indicator species, in Hormozgan province, the Northeast Persian Gulf.

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.

Impacts of land use/cover and slope on the spatial distribution and ecological risk of trace metals in soils affected by smelting emissions.

The soil contamination around smelting sites shows high spatial heterogeneity. This study investigated the impacts of distance, land use/cover types, land slopes, wind direction, and soil properties on the distribution and ecological risk of trace metals in the soil around a copper smelter. The results demonstrated that the average concentrations of As, Cd, Cu, Pb, and Zn were 248.0, 16.8, 502.4, 885.6, and 250.2 g mg kg-1, respectively, higher than their background values. The hotspots of trace metals were primarily distributed in the soil of smelting production areas, runoff pollution areas, and areas in the dominant wind direction. The concentrations of trace metals decreased with the distance to the smelting production area. An exponential decay regression revealed that, depending on the metal species, the influence distances of smelting emissions on trace metals in soil ranged from 450 to 1000 m. Land use/cover types and land slopes significantly affected trace element concentrations in the soil around the smelter. High concentrations of trace metals were observed in farmland, grassland, and flatland areas. The average concentrations of trace metals in the soil decreased in the order of flat land > gentle slope > steep slope. Soil pH values were significantly positively correlated with Cd, Cu, Pb, Zn, and As, and SOM was significantly positively correlated with Cd, Pb, and Zn in the soil. Trace metals in the soil of the study area posed a significant ecological risk. The primary factors influencing the distribution of ecological risk, as determined by the Ctree analysis, were land slope, soil pH, and distance to the source. These results can support the rapid identification of high-risk sites and facilitate risk prevention and control around smelting sites.

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.

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).

Spatiotemporal distribution and potential risks of metals and total petroleum hydrocarbons (TPHs) in seawater from the Zhifu Bay and its surrounding areas, Yellow Sea, China (2015–2019)

To investigate the concentrations, spatiotemporal distribution, correlation with environmental factors, and potential risks of four metals (Hg, Cu, Pb, and Cd) and total petroleum hydrocarbons (TPHs) in seawater from the Zhifu Bay and its surrounding areas, surface seawater samples were collected from 10 stations in spring, summer, and autumn of 2015–2019. Compared with values from other regions, the average concentrations of metals and TPHs were in the low and medium levels, respectively. Concentrations of all the study pollutants decreased in the offshore direction, suggesting that most of these pollutants are from land and nearshore sources. Annual variation patterns indicated decreasing trends of Cu and TPHs, and due to the seasonal differences in river discharges, rainfalls, and human activities, wet seasons (summer and/or autumn) exhibited higher concentrations of Hg, Cu, and TPHs than dry season (spring). The potential ecological risk of Cu and carcinogenic health risk of Cd suggest that the discharge of metals from the sea should be more strictly controlled.

To the study of the features of the heavy metals deposition in the mosses of the Samara region

The features of the deposition of heavy metals by mosses from the atmosphere in the identified background area (Krasnosamarsky forest) for the Samara region were studied. Pleurozium schreberi showed the highest metal accumulating capacity, Brachythecium salebrosum - average, Dicranum polysetum - the lowest. Climacium dendroides showed high species specificity in the accumulation of heavy metals among the studied species, which may be related to its water regime. A comparative analysis of the chemical “fingerprint” of the average content of heavy metals for the mosses of the Krasnosamarsky forest area according to to Markert revealed a negative deviation from the average content of heavy metals in the bryophytes of the Samara region, which meant that there were no atmospheric sources of heavy metal pollution in the study area. Mosses growing in the Krasnosamarksky forest can be used as reference species for the region. The revealed increased level of accumulation of a number of elements (Cr, V, Co, Ni, As, Fe, Zn) demonstrated the biogeochemical features of the Samara region in comparison with the reference moss species Pleurozium schreberi in Western Europe. This also indicates the need to use indicators of species growing in the region as reference values.

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).
 The enrichment factor (EF), contamination factor (CF), géoaccumulation index (Igeo) and pollution load index (PLI) were determined from the metal concentrations obtained.
 The average concentrations of heavy metals vary as follows:
 Cd > Co > Cr > Zn > Ni > Cu > Hg > Pb > As.
 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.
 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.
 The EF values show very severe enrichment for cobalt (Co), followed by overall extremely severe enrichment for cadmium (Cd) and mercury (Hg).
 The calculated Igeo indicates extreme cadmium, mercury and cobalt contamination.
 The calculated PLI values are all greater than one. These results show that all the soils are polluted.
 The index determination approach makes it possible to predict the extent of soil pollution by the heavy metals considered in our study.

Koncentracija teških metala u tkivu oslića Merluccius merluccius (Linnaeus, 1758) iz Oranskog zaljeva (Sredozemno more)

To evaluate the potential human health risk to hake consumers, the bioaccumulation of heavy metals (Cd, Pb, and Zn) was measured in the edible tissues of hake Merluccius merluccius (Linnaeus, 1758) caught from Oran Bay on the western Algerian Mediterranean coast. Results revealed that the average metal concentrations varied significantly among sex and in target organs. The concentrations of metal accumulation take place preferentially in the liver compared to the muscle of hake species, with the highest levels found for Zn, followed by Pb and Cd. The Estimated daily intake (EDI) of each trace metal did not exceed the tolerable daily intake (TDI). Human health risk assessment from heavy metal exposure through fish consumption from Oran Bay for adults showed no significant non-carcinogenic adverse health risk since all calculated values for Target Hazard Quotient (THQ) and Total Target Hazard Quotient (TTHQ) were <1.

Spatial distribution of heavy metals, source identification, risk assessment and particulate matter in the M4 motorway.

Metal-containing dust is a potential severe environmental and human health threat. Metals present in dust may originate from car exhausts, tear and wear of tires, and vehicular emissions, which are less manageable. Metal-containing dust from roads can contaminate the soils, and crops alongside motorway. This study aimed to investigate the Pb Cd, Cu, Ni, and Zn concentrations in dust, soil, and vegetation collected from the M4 motorway Faisalabad. The results indicated that average metal concentrations in dust from all sites varies (Pb) 44.01mgkg-1, (Cd) 1.22mgkg-1, (Cu) 49.5mgkg-1, (Ni) 28.3mgkg-1, and (Zn) 113.7mgkg-1. The pollution assessment indices CF and PLI of Industrial city and Painsra had comparatively maximum levels of environmental pollution. Moreover, the geo-accumulation index (Igeo) of metals was high at Chak 115 and Painsra, while Igeo at ten sites was in the following descending order: Cd > Pb > Cu > Ni > Zn. Furthermore, it was identified that the maximum ecological risk index (Eir) was in declining order, i.e., Cd > Pb > Cu > Ni > Zn, at all sites. The potential ecological risk was categorized as high risk in all respective sites. The particulate matter fractions PM2.5 and PM10 represented the maximum risk at the Industrial city site, which was unhealthy, although the Painsra site had poor air quality. The total suspended particulate was classified as hazardous at FDA city and Painsra. In contrast, food crops (maize, sugar cane, and sesame) and soil along the M4 motorway have similar Pb, Cd, Cu, Ni, and Zn contamination patterns like dust. However, two crops, maize and sugarcane, along the M4 motorway were found to be more polluted. The level of metals contamination through dust disposition was consistently higher adjacent to roads, possibly indicating depraved impacts on food crops.

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).

Status, Source, and Risk Assessment of Heavy Metal(Loid)s and Polycyclic Aromatic Hydrocarbons (PAHs) in the Street Dust of Ilam, Iran

A total of 25 Ilam street dust specimens were sampled to investigate the possible ecological and health risks of heavy metal(loid)s and polycyclic aromatic hydrocarbons (PAHs). We found that the average concentrations of heavy metal(loid)s, namely Pb, Zn, Cu, Cr, Cd, Ni, V, and As, were 52, 213, 63, 46, 0.4, 44, 31, and 5 mg/kg, respectively. The average concentration of all heavy metal(loid)s except for Cr and V was several times higher than the baseline values. We evaluated Zn and Pb in the region using the average enrichment factor (EF) and pollution index (PI); the Nemerow integrated pollution index (NIPI) indicated that 76% of the samples had high degrees of pollution. According to principal component analysis (PCA), three principle components are involved in the heavy metal(loid) pollution of Ilam street dust. For example, the pollution sources of Cu, Cr, Cd, and Ni likely originated from anthropogenetic origins, including traffic, tire depreciation, and gasoline use. The sources of Pb and Zn were other anthropogenic activities, such as metal corroding and the combustion of garbage and gases from industries, while V and As were probably from natural sources. The range of sum over 11 PAHs was 167–11,497 μg/kg with a mean of 2242 μg/kg. The concentration of low molecular weight (LMW) PAHs averaged 1471 μg/kg, accounting for 66% of the total PAHs; their sources were mainly associated with combustion and pyrogenic emissions. The PCA also revealed that PAHs mainly originated from burning fossil fuels. The values of RQ∑PAHs (MPCs) and RQ∑PAHs (NCs) were respectively >1 and ≥800, indicating a high ecosystem risk for PAHs. Mean values for RQ∑PAHs (MPCs) and RQ∑PAHs (NCs) were 4 and 1021, respectively, implying that Ilam street dust poses a relatively high ecosystem risk of PAHs. Street dust PAHs’ toxic equivalency quotient (TEQ) varied from 26 to 199 μg/kg. The total cancer risk was 3.92 × 10−4 and 4.06 × 10−4 for adults and children, respectively, indicating that the potential for cancer risk is very high through dust dermal contact and ingestion.

Evaluation of the generation of reactive oxygen species and antibacterial activity of honey as a function of its phenolic and mineral composition.

The antibacterial activity (ABA) of honey is associated with the generation of reactive oxygen species (ROS), where polyphenols (PFs) play a key role due to their pro-oxidant action modulated by metallic cations. In this work, the contents of PFs, H2O2, OH radicals, Cu, Fe, Mn, Zn, and ABA against Staphylococcus epidermidis and Pseudomonas aeruginosa were determined in honeys from central Chile. Then, their relationships were evaluated through partial least squares regression. The average contents of phenolic acids, flavonoids and metals in honey ranged from 0.4 to 4μg/g, 0.3-1.5μg/g and 3-6μg/g, respectively. All honeys showed accumulation of H2O2 (1-35μg/g) and OH radicals. The PLS showed that gallic acid, p-coumaric acid, chrysin, kaempferol, Fe, and Mn stimulate the generation of ROS. Quercetin, Cu, and Zn showed marginal antioxidant effects. PFs favor the ABA of honey against both bacteria and H2O2 against S. epidermidis.

Ecological and human health risk assessment of heavy metals in sewage sludge produced in Silesian Voivodeship, Poland: a case study

This study aimed to assess the potential risks posed by heavy metals in sewage sludge (SS) produced by municipal wastewater treatment plants (WWTPs) in the most industrialized region in Poland, the Silesian Voivodeship. The ecological risk was assessed using three indices: the Geoaccumulation Index (Igeo), Potential Ecological Risk Factor (ER), and Risk Assessment Code (RAC), while the health risk was estimated by using carcinogenic and non-carcinogenic risk indices. The average concentrations of metals in the sludge samples were determined revealing that Zn was the predominant element, whereas Cd and Hg were present in the lowest concentrations. The study showed that the processes used in wastewater treatment plants influenced the overall metal content and chemical speciation. According to Igeo values, the dewatered sludge samples exhibited higher contamination levels of Cd and Zn, while Cu and Pb were upon to a lesser extent. The ER values suggest that Cd and Hg present the highest ecological risk. Considering the chemical forms and RAC values, Ni (26.8–37.2%) and Zn (19.8–27.0%) were identified to cause the most significant risks. The non-carcinogenic risk for adults and children was below acceptable levels. However, the carcinogenic risk associated with Ni (WWTP1) for both demographic groups and Cr and Cd (WWTP2), specifically for children, exceeded the acceptable threshold. Ingestion was the primary route of exposure. Although the dewatered SS met the standards for agricultural use, there is still a risk of secondary pollution to the environment and possible adverse health effects.

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.

Investigating PM2.5 toxicity in highly polluted urban and industrial areas in the Middle East: human health risk assessment and spatial distribution

Exposure to particulate matter (PM) can be considered as a factor affecting human health. The aim of this study was to investigate the concentration of PM2.5 and heavy metals and their influence on survival of A549 human lung cells in exposure to PM2.5 breathing air of Ahvaz city. In order to assess the levels of PM2.5 and heavy metals, air samples were collected from 14 sampling stations positioned across Ahvaz city during both winter and summer seasons. The concentration of heavy metals was determined using ICP OES. Next, the MTT assay [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] was employed to ascertain the survival rate of A549 cells. The findings from this research demonstrated that average PM2.5 of the study period was (149.5 μg/m3). Also, the average concentration of PM2.5 in the urban area in winter and summer was (153.3- and 106.9 μg/m3) and in the industrial area this parameter was (191.6 and 158.3 μg/m3). The average concentration of metals (ng/m3) of urban areas against industrial, Al (493 vs. 485), Fe (536 vs. 612), Cu (198 vs. 212), Ni (128 vs. 129), Cr (48.5 vs. 54), Cd (118 vs. 124), Mn (120 vs. 119), As (51 vs. 67), Hg (37 vs. 50), Zn (302 vs. 332) and Pb (266 vs. 351) were obtained. The results of the MTT assay showed that the highest percentage of cell survival according to the exposure concentration was 25 > 50 > 100 > 200. Also, the lowest percentage of survival (58.8%) was observed in the winter season and in industrial areas with a concentration of 200 μg/ml. The carcinogenic risk assessment of heavy metals indicated that except for Cr, whose carcinogenicity was 1.32E−03, other metals were in the safe range (10–4–10–6) for human health. The high concentration of PM2.5 and heavy metals can increase respiratory and cardiovascular diseases and reduce the public health level of Ahvaz citizens.

Heavy Metals Contamination of Surface Water of Mini WHUO Stream in Port Harcourt, Rivers State, Nigeria

The level of heavy metals in the Mini Whuo Stream in Port Harcourt, Rivers State, Nigeria was assessed. The heavy metals’ analysis was performed after due digestion by the use of a Thermo Atomic Elemental Absorption Spectrophotometer. The average concentrations of the heavy metals studied in the stream were Pb; 2.594±0.76 mg/L, Cu; 1.90±0.60 mg/L, Zn; 2.50±0.74 mg/L, Cd; 0.472±0.17 mg/L, Ni; 2.785±0.87 mg/L, Cr; 4.484±0.76 mg/L, Co; 0.228±0.13 mg/L, Fe; 1.779±0.46 mg/L and As; 0.059±0.02 mg/L.The concentration of the heavy metals in the stream occurred in the order Cr &gt; Ni &gt;Pb&gt; Zn &gt; Cu &gt; Fe &gt; Cd &gt; Co &gt;&gt;As.The pollution assessment indices used in the evaluation of the anthropogenic activities has influenced the concentration of heavy metals in the stream using WHO maximum limit as basis of decision were, contamination factor, pollution load index, contamination degree and modified contamination degree. These four indices indicated that the studied heavy metals have contaminated the stream to a high level that it was no more suitable for domestic use.

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.

Contamination Characteristics and Source Apportionment of Potentially Toxic Elements in Soil around the Coal-fired Power Plant Using APCS-MLR and PMF Models

To investigate the characteristics and sources of potentially toxic elemental contamination in soils around the coal-fired power plant, we selected the soil around the Jingyuan power plant as the object of investigation. Thirty-six and 27 soil samples collected from the urban and farmland areas were analyzed for PTEs (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn), respectively. We employed the geoaccumulation index, single-factor pollution index, and improved Nemerow integrated pollution index to evaluate the contamination characteristics of PTEs, and combined correlation analysis with absolute principal component scores-multiple linear regression (APCS-MLR) and positive matrix factorization (PMF) receptor models were used to quantitatively analyze the pollution sources of PTEs. The results revealed that all the average concentrations of other soil metals around Jingyuan power plant exceeded their corresponding background values of Gansu Province, except for As, in agricultural soil, and Hg exhibited significant spatial non-homogeneity, and thus it was visibly affected by anthropogenic activities. The values of the single-factor pollution and geoaccumulation indices indicated that the soils of both sites were mainly contaminated with Cd, Cr, Ni, and Pb, and Hg contamination was reflected in wide areas for both sites. Additionally, the results of the improved Nemerow index demonstrated that the investigated soil was between moderately contaminated and heavily contaminated. Further, the comprehensive pollution degree of urban soil was higher than that of agricultural soil. Moreover, source apportionment revealed that PTEs in urban soil were derived from mixed sources of traffic activities and coal combustion, mixed sources of traffic activities and industrial and mining activities, and atmospheric deposition from industrial activities, with contribution rates of APCS-MLR of 35.2%, 25.1%, and 23.4%, respectively. The PMF contribution rates were 40.2%, 12.4%, and 47.7%, respectively. PTEs in agricultural soil were from one mixture source of industrial, mining, agricultural, and traffic sources, and the other mixed source was of traffic activities and coal combustion, with a APCS-MLR contribution rate of 40.3% and 35.9% and a contribution rate of PMF of 36.2% and 18.0%, respectively. In addition, another mixed source of agricultural activities and coal combustion was obtained using the PMF model, with a contribution rate of 48.5%.