Heavy Metal Contamination Status Research Articles

Pollution Characteristics, Risk Assessment and Source Identification of Heavy Metals in Surface Sediments from the Cage Fish Farm of Poyang Lake, China

ABSTRACT With the development of cage culture, increasing heavy metals concentrations are being taken into sediments. The accumulation of heavy metals in sediments may cause long term environmental issues and pose threat to human health. Fourteen surface sediment samples were collected to assess the contamination status and potential ecological risk of heavy metals, and identify their potential sources from the cage fish farm of Poyang Lake. The concentrations of Cu, Pb, Zn, Cd, Cr, As and Ni in the sediments were measured by ICP-MS. The geo-accumulation index, enrichment factor and potential ecological risk index were implied to evaluate their pollution levels and ecological risk. The principal component analysis was used to identify their potential sources. The results showed that all of the examined heavy metals content exceeded their background values. These heavy metals (except Cd, Cr and As) presented moderately polluted level. Cu showed significant enrichment, Zn, Pb and Ni exhibited moderate enrichment, As and Cd presented minimal enrichment. Cu and Cd posed a moderate ecological risk, and the other heavy metals posed a low ecological risk. The comprehensive potential ecological risk was associated with considerable ecological risk. Cage culture, smelting, mining and agriculture activities were their primary pollution sources.

Response of benthic assemblages to heavy metal contamination from shipbreaking operations in a tropical coastal area

The response of macrobenthic communities to both environmental and anthropogenic pressures serves as a valuable indicator of ecosystem integrity. This study aimed to unravel the benthic community structure, examine the heavy metal contamination status, and explore the response of the microbenthic community to heavy metals in a tropical shipbreaking region. For this, sediment and benthos samples were taken from different sampling stations of the shipbreaking area and the non-shipbreaking sites. The results showed the benthic community consisted of 23 taxa, including Polychaeta, Oligochaeta, Amphipoda, Decapoda, Gastropoda, Bivalvia, and Priapulida, with polychaetes being the predominant group. The benthic community and diversity values were significantly varied between the two sampling sites (p <0.05). Taxa richness was lower in the shipbreaking area, primarily characterized by the dominance of opportunistic benthic groups, particularly Capitella sp. The concentrations of heavy metals (µg. g−1) in the sediment varied within the following ranges: 35.54–258.021 for Zn, 4.84–132.08 for Pb, 22.82–75.25 for Cu, 198.74–764.16 for Mn, 14.57–42.13 for Cr, 4.03–42.23 for Ni, and 3.82–14.85 for Co. Based on concentration levels, Zn, Pb, and Cu were identified as major contaminants with moderate to high potential for adverse effects, particularly evident in the shipbreaking area compared to non-shipbreaking areas. Pollution indices, including enrichment factors and contamination factors, also highlighted contamination by Zn, Pb, and Cu. Among the benthic taxa, Polychaeta demonstrated a high degree of tolerance to elevated concentrations of these heavy metals. Amphipoda density was significantly negatively correlated with Zn, Pb, and Cu concentrations, with significant coefficients of determination (r2= 0.38, p <0.10; r2= 0.64, p <0.01 and r2 = 0.63, p <0.01, respectively). Multivariate analyses (cluster analyses, MDS and CCA) demonstrated both positive and negative relationships among heavy metals and benthic groups. Canonical Correspondence Analysis (CCA) showed the benthic community was negatively correlated with Zn, Pb, and Cu. This finding provided critical insights into the ecological health of aquatic ecosystems, aiding in the development of informed conservation and management strategies.

Determination and contamination status of mercury and other heavy metals in artisanal and small-scale gold mining at Banyumas region, Central Java, Indonesia, using ICP-OES

ABSTRACT The determination of mercury and other heavy metals (As, Cd, Cr, Ni, and Pb) has been carried out as toxic metals for the human body. Sample preparation was carried out by the microwave digested assist. The determination of heavy metals was carried out using the ICP-OES. The validation parameters used were linearity, Limit of Detection (LoD), Limit of Quantitation (LoQ), precision, and accuracy. Mercury, Arsen, Cadmium, Chromium, Nickel, and Lead average content in sediment gold ore processing waste was 1617.64, 5525.09, 20.24, 484.96, 259.67, and 1210.27 μg/kg, respectively. Linearity used a standard solution of 10–1000 μg/kg, and it produced a regression equation with r2 > 0.9992. The Limit of Detection (LoD) and the Limit of Quantitation (LoQ) was below 1.56 μg/kg and 6.27 μg/kg, respectively. The precision was calculated by the repeatability method, with a result of %RSD below 2.30%. Accuracy was obtained by recovering a spiked standard. The recovery value was found to be between 83% and 118%. Geoaccumulation Index (Igeo), Metal Pollution Index (MPI), Degree of Contamination (Cdeg), and Potential Ecological Risk Index (PERI) in this study was −8.62–1.43, 0.02–5.33, 8.80, and 168.59, respectively. The waste processing site at Artisanal and Small-Scale Gold Mining is generally contaminated by mercury and other heavy metals. All the validation parameters of the method are in the acceptability range, so the method can be used as a routine method for determining mercury and other heavy metals (As, Cd, Cr, Ni, and Pb) levels in gold ore processing waste.

Ecological and human health risk assessment of heavy metal contamination in soils of major industrial estates of Tamil Nadu, India

ABSTRACT This study endeavoured to determine the current status of heavy metal contamination in soils around leather industrial areas of Tamil Nadu and the associated environmental and human health risks. Accordingly, 31 soil samples were examined using the total reflection X-ray fluorescence (TXRF) spectroscopy technique. From TXRF results, the mean concentrations of heavy metals (mg kg−1, dry weight) were obtained in the trend of Fe (9234.03) > Al (592.00) > Cr (194.99) > Sr (148.76) > Mn (137.61) > Cl (81.79) > Zn (38.97) > Cu (38.33) > V (36.78) > Pb (31.18) > Ni (9.81) > As (1.12). The pollution indices such as geo-accumulation index (Igeo), contamination factor (CF), and enrichment factor (EF) revealed the significant contaminants in the study area. The hazard index (HI) indicated that non-carcinogenic risk (NCR) due to heavy metals were negligible for both adults and children (HI < 1). In addition, total cancer risk (TCR) showed carcinogenic risk (CR) for adults (TCR = 1.38 × 10−4) and children (TCR = 1.27 × 10−3) are moderate and higher, respectively. Multivariate statistical analyses such as Pearson correlation analysis (CA), hierarchical cluster analysis (HCA), and factor analysis (FA) revealed that the heavy metals derived from various sources such as lithogenic and anthropogenic. Overall, special concern is advised to the inhabitants, especially with regard to children, in the study area about the health risks due to the anthropogenic inputs.

Heavy Metals In Bivalves From Coastal Municipalities Of C apiz,P hilippines

This research study is based on the current status of heavy metal contamination in bivalves within the coastal areas of Capiz, Philippines, drawing insights from accessible data. The findings shed light on the contamination’s extent, potential threats to human health, and the pollution’s origins. The researchers acknowledge the study’s limitations. As per the findings, elevated levels of heavy metals, such as lead, mercury, cadmium, arsenic, and chromium, in bivalves collected from Capiz’s coastal regions. Variations in metal concentrations are observed among different bivalve species and sampling sites, with identified geographical distribution patterns and potential contamination hotspots. An assessment of conformity to regulatory limits and guidance for heavy metal levels in shellfish consumption is conducted, identifying any exceedances or areas of concern. The research aims to establish the extent to which bivalves from Capiz aligns with legal requirements. Potential health risks allied to the bivalve consumption are evaluated based on the detected heavy metal levels, considering various exposure routes, population characteristics, and toxicity reference values. The research scrutinizes the impact of human activities, including industrial discharges, agricultural practices, and urban runoff, on heavy metal contamination in coastal ecosystems. The ongoing discussion underscores the need for further investigation and underscores the importance of addressing the issue to ensure the environmental sustainability and safety of coastal resources in Capiz.

Contamination status, risk assessment, and control measures of heavy metals in tuber crops

Tuber crops (TCs) are an important food source for people; however, the contamination of TCs by heavy metals (HMs) has not received sufficient attention. In this study, 253 batches of TCs samples containing HMs (Pb, Cd, Cr, Hg, As) were collected to investigate the contamination status and health risks. The results showed that different TCs contained different concentrations of HMs, while cassava exhibited the highest levels of each HM. In terms of health risks, the non-carcinogenic and carcinogenic risks associated with TCs consumption were in the “Negligible risk”, “Cautionary risk”, respectively. On the economic and age scales, the health risk concerning TCs consumption varied. The health risks increased when cassava was included in the diet. Field experiments were conducted to explore the factors influencing the accumulation of HMs and propose measures to control HMs contamination. When measures were taken to intervene in the factors (soil HMs, soil organic matter, soil pH and cassava variety) affecting the HMs content in cassava, the health risks were significantly reduced, with a maximum reduction of 43.71% and 17.50% in non-carcinogenic and carcinogenic risks, respectively. This study provides ideas for the pollution management of HMs in TCs.

Heavy metal contamination in Shanghai agricultural soil

As heavy metals in soil could enrich in biomass and pose health risk to human, it is vital to monitor their contaminations to ensure qualified agricultural production. In this study, we collected >4000 soil samples from agricultural fields in Shanghai during 2010∼2020, and unveiled heavy metal contamination status in this metropolitan. We found that although Shanghai has a long industrialization history, the heavy metal levels in agricultural soil are within safe ranges according to national standard. Specifically, the median levels of Cd, Hg, As, Pb, Cr and Cu are 0.11, 0.13, 7.47, 23.80, 41.00 and 28.30 mg/kg, respectively, which are as good as, or even better than national averages. However, there are spatial and temporal heterogeneities for heavy metal contaminations in Shanghai. For example, the levels of Cd, Hg and Cr are relatively higher in some districts with high industry density, which should be further monitored in the future. Moreover, while the levels for Cd, Cr and Pb have decreased, the level for Hg has mildly increased during this period which needs counteractive measures. Correlation analysis of heavy metal levels and soil fertility parameters suggested overuse of fertilizers may be related to heavy metal contamination in some regions. In summary, our study present by far the largest and most comprehensive landscape of heavy metal contamination in Shanghai agricultural soil, which will be useful for future policy-design and land use planning to ensure safe agricultural production.

Assessment of Soil Properties and Heavy Metal Contamination Status in Vegetable Farms along River Sauna

Assessment of Soil Properties and Heavy Metal Contamination Status in Vegetable Farms along River Sauna

Characteristics and Potential Ecological Risks of Heavy Metal Content in the Soil of a Plateau Alpine Mining Area in the Qilian Mountains

In recent years, the ecological and environmental problems caused by mining in the Qilian Mountains have attracted considerable attention, and the government has carried out a number of comprehensive ecological environment remediation projects there, among which ecological restoration in the Qilian Mountain alpine mining area is an essential task. As a result, heavy metals have been studied in the soil of the Qilian Mountain alpine mining area. This can provide a scientific basis and data support for the establishment of a demonstration index for monitoring ecological environmental restoration in mining areas. In order to understand the content and contamination status of heavy metals in the soil surrounding the alpine mining area of Qilian Mountain, 56 soil samples were collected to determine the levels of eight heavy metals, including Cd, Hg, As, Pb, Cr, Cu, Zn, and Ni. The spatial distribution of heavy metals in the soil of the study area was analyzed based on a statistical approach. The single-factor pollution index (Pi), Nemerow comprehensive pollution index (PN), geoaccumulation index (Igeo), and potential ecological risk index (RI) were used to evaluate soil heavy metal pollution and potential ecological risk. Principal component analysis (PCA), positive matrix factorization (PMF) models, and geostatistical analysis were also used to investigate the source of heavy metals. The results show that the average Cd, As, Cr, Cu, Zn, and Ni content of the grassland soil around the mining area exceeds the soil background values in both Qinghai Lake Basin and Qinghai Province. The spatial distribution of the eight heavy metal elements in soil showed an island-like pattern, with high-value areas of each metal element appearing, indicating that human activities in the study area had negative effects on the soil environment. The value of the single pollution index showed that levels of Ni, Cd, Cu, Cr, Hg, and As pollution were low, while there was no Pb or Zn pollution. The Nemerow integrated pollution index had an average value of 1.39, indicating a slight pollution trend. The average values of Cr and Zn in the geoaccumulation index ranged from 0 to 1, indicating mild to moderate contamination in the studied region. The average value of the integrated ecological risk index in the study area was 135.43, which is in the intermediate ecological risk range. In descending order of size, the average ecological risk index of each heavy metal element was Hg &gt; Cd&gt; As &gt; Ni &gt; Cu &gt; Pb &gt; Cr &gt; Zn. From the perspective of the spatial distribution pattern of ecological risk, the two high-value discriminants were in the western part of the study area, close to the mining area. Zn, Cu, Pb, and Cd in soils were mainly affected by human activity, while Cr and Ni were mainly affected by soil geochemistry. Cd is the main contaminant in the study area, and soil Cd contamination of the grassland in the study area must be considered.

Ecological and health risk assessment of heavy metals in roadside soil, dust and water of three economic zone in Enugu, Nigeria

Heavy metals posed threat to humans and environment. Spatial distribution/source identifications of heavy metals in soil, dust and water along major road of three economic zone of Enugu: Enugu/PH road (Industrial area), Agbani Road (Residential) and Ogui New Layout Road (Commercial) were evaluated. Soil and dust samples were collected at 15 cm depth and 1 m from roads, underground water at 65 m from roadside between December 2020–April 2021. Heavy metals were quantified by AAS. Heavy metals (mg/kg) in roadside soil varied from 0.00 to 0.05 (Cr), 1.50–4.00 (As), 0.08–6.93 (Ni), 4.98–7.86 (Cu), 0.00–0.03 (Hg), 213.95–274.79 (Fe), 1.25–4.16 (Pb) and 8.49–16.23 (Mn) for Enugu/PH; 0.00–0.20 (Cr), 2.75–3.13 (As), 0.25–4.94 (Ni), 3.65–11.73 (Cu), 0.00–0.00 (Hg), 159.87–233.65 (Fe), 2.08–4.54 (Pb), 6.18–17.15 (Mn) for Agbani; 0.00–0.13 (Cr), 1.48–3.70 (As), 0.03–1.50 (Ni), 3.13–5.54 (Cu), 0.00–0.00 (Hg), 138.06–189.51 (Fe), 0.58–1.38 (Pb), 9.75–21.75 (Mn) for Ogui. The level of heavy metals (mg/kg) in roadside dust ranged from 0.00 to 0.18 (Cr), 0.00–2.33 (As), 0.85–2.05 (Ni), 4.54–16.93 (Cu), 0.00–0.00 (Hg), 137.36–247.03 (Fe), 0.88–4.99 (Pb), 17.65–26.43 (Mn) for Enugu/PH; 0.00–0.00 (Cr), 0.00–2.85 (As), 0.71–4.68 (Ni), 4.94–121.85 (Cu), 0.00–0.00 (Hg), 159.23–203.70 (Fe), 0.59–14.63 (Pb), 15.05–23.44 (Mn) for Agbani; 0.00–0.14 (Cr), 0.00–2.33 (As), 1.08–4.45 (Ni), 4.25–6.95 (Cu), 0.00–0.00 (Hg), 152.84–207.66 (Fe), 1.00–3.41 (Pb), 14.13–23.18 (Mn) for Ogui. As in water Enugu/PH (0.081 mg/L), Agbani (0.079 mg/L) and Ogui (0.150 mg/L). Principal component analysis indicated that Cr, As, Ni, Cu, Hg, Pb Fe and Mn distributions were affected by traffic, industrial release and natural sources, ecological analysis showed low to moderate pollution. Risk assessment (children/adults) via each pathway were HI <1. Estimated cancer risk of 75% heavy metals via CRing/inh/der (soil, dust water) below 1× 10−6 - 1 × 10−4, total cancer risk shows high probability of carcinogenic risk via ingestion as children > adult susceptibility on prolonged exposure to vehicular activity, hence alarming contamination status of heavy metals in Enugu and associated health risk.

Evaluation of the Effects of Heavy Metals on Sediments and Rainwater Samples Due to Gas Flaring in the South Eastern Nigeria

This study evaluates the concentrations of heavy metals in sediment and rainwater samples of Ibeno, south eastern Nigeria due to gas flaring. Surface sediment samples were collected randomly in six different sites during the dry season in the intertidal zone at extremely low tide from the flare point to a distance of about 250m away from the flare site. Rainwater samples were collected with the use of pre-clean basins at an open space in three selected communities of Ibeno and were transferred into different sterilized plastic rubbers with their labels. These samples were transported to the laboratory for analysis of heavy metals concentrations using a particle induced x-ray emission (PIXE) technique. Heavy metals such as Titanium (Ti), Chromium (Cr), Manganese (Mn), Iron (Fe), Copper (Cu), Zinc (Zn), Rubidium (Rb), Strontium (Sr), Zirconium (Zr) and Lead (Pb) were analyzed in sediments while Vanadium (V), Arsenic (As), Nickel (Ni), Lead (Pb), Iron (Fe), Copper (Cu), Zinc (Zn), Chromium (Cr), Manganese (Mn) and Cadmium (Cd) were obtained in rainwater. The concentrations of Iron (Fe) in sediments are higher at the study area than every other elements but Manganese (Mn) poses more negative effects than others. The four pollution indices such as enrichment factor (EF), geo-accumulation index (Igeo), contamination factor (CF) and pollution load index (PLI) were employed to assess the contamination status of heavy metals in sediment samples of the study area. The results revealed the elemental trend to be in descending order in each area of this study, which followed the sequence Mn&gt; Zn&gt; Pb&gt; Cu&gt; Fe&gt; Sr&gt; Rb&gt; Cr&gt; Ti &gt;Zr, while PLI revealed the extent of pollution in each site which ranged from 1.44 to 1.94. Most of the heavy metals concentrations in sediments such as Mn, Zn, Pb, Cu and Fe were far above the permissible limits, while in rainwater samples Pb, Cd, Ni, Fe and Mn were far above the permissible limits by WHO, 2008 and NSDWQ, 2007. This revealed that the rainwater in the study area were not free from toxicity and are unfit for drinking. Analysis of multi-variant statistics such as Pearson’s correlation coefficient and cluster analysis were also applied to ascertain the relationship and sources of investigated heavy metals. Both positive and negative correlations were observed among some heavy metals at 0.01 and 0.05 levels, while the cluster analysis revealed four main clusters. The study revealed that the ecosystems in the studied areas were vulnerable to bioaccumulation of heavy metals in that soil which could be of hazard effect to the ecosystem.

Heavy Metal Contamination Status of Water, Agricultural Soil, and Plant in the Semiarid Region of Kandahar, Afghanistan

Agricultural irrigation using wastewater containing heavy metals (HM) might impose risks in bioaccumulation in foods. The current study was performed to assess the status of HM in terms of water-soil–plant systems in Kandahar, Afghanistan, where industrial and domestic wastewater was partially reused for irrigation. Water, soil, and plant samples were collected from wastewater sites in Haji-Arab (HA), Bala-Karz (BKZ), and Mahal-e-Nejat (MN) in comparison with those from a freshwater-irrigated site in Char-Bagh (CB). The HM levels in unfiltered water samples remained lower than the World Health Organization (WHO) and Food and Agriculture Organization (FAO) permissible values, but the HM concentrations in soil and crops were higher at the HA, BKZ, and MN (wastewater-irrigated sites) than those at the CB site (freshwater-irrigated site). Lead (Pb) levels were high in soils (43–83 mg/kg) and crops (18–36 mg/kg) and extremely exceeded the safe limits even for those crop samples cultivated in the freshwater-irrigated site. Continuous wastewater irrigation increased the HM concentration in water, soil, and plants, but the Pb pollution was found to be ascribed to the minerals in that area since the underground water was showing high Pb levels. The bioaccumulation of HM in the studied sites was related to the cultivated crops and correlated with the land use in the watershed area. This study is important in understanding the risks associated with HM and exercising prudence when applying various irrigation resources in Afghanistan.

Ecological risk assessment of aquatic organisms induced by heavy metals in the estuarine waters of the Pearl River

With the rapid economic development of China's coastal areas and the growth of industry and population, the problem of heavy metal contamination in estuarine waters is increasing in sensitivity and seriousness. In order to accurately and quantitatively describe the current status of heavy metal contamination and identify sensitive aquatic organisms with high ecological risks, five heavy metals in eight estuaries of the Pearl River were monitored at monthly intervals from January to December in 2020, and the ecological risks of aquatic organisms induced by heavy metals were evaluated using Risk quotients (RQ) and species sensitivity distributions (SSD) methods. The results showed that the concentrations of As, Cu, Pb, Hg and Zn in estuaries of the Pearl River were (0.65–9.25) μg/L, (0.07–11.57) μg/L, (0.05–9.09) μg/L, (< 0.40) μg/L and (0.67–86.12) μg/L, respectively. With the exception of Hg in Jiaomen water, the other heavy metals in each sampling site met or exceed the water quality standard of Grade II. The aquatic ecological risks of As, Pb and Hg were generally low in the waters of the Pearl River estuary, but individual aquatic organisms are subject to elevated ecological risks due to Cu and Zn. The content of Zn has a lethal effect on the crustaceans Temora Stylifera, and the content of Cu has a serious impact on the mollusks Corbicula Fluminea and has a certain impact on the crustaceans Corophium sp. and the fish Sparus aurata. Heavy metal levels and joint ecological risks (msPAF) in the Humen, Jiaomen, Hongqimen, and Hengmen estuaries were slightly higher than in other estuaries, and the Yamen estuary had the lowest contration of heavy metals and ecological risk. Research findings can serve as a basis for formulating water quality standards for heavy metals and for protecting aquatic biodiversity in the Pearl River Estuary.

Vertical distribution, contamination status and ecological risk assessment of heavy metals in core sediments from a mangrove-dominated tropical river

Understanding the vertical distribution of heavy metals aids in tracing the contamination history, however, it is limited for mangrove-dominated river. Thus, this study aimed to assess the vertical distribution of nine heavy metals and their possible ecological risk in several layers of core sediments from a mangrove-dominated river inside the Sundarban mangrove forest (World heritage and Ramsar site), Bangladesh. 45 core samples from five stations were analyzed using Flame Atomic Absorption Spectrophotometer (FAAS). The findings showed that, with the exception of Fe, Ni, and Cu, which suggested increased metal release in recent times, higher metal levels were recorded in the surface layer (0–10 cm), followed by the middle layer (10–20 cm), and inner layer (20–30 cm) of sediment cores. When compared to non-industrial forest sediment, core sediment from industrial sites contained noticeably more metals (p < 0.05). Overall, the mean metal concentration (mg/kg) followed the increasing order of Cd < As < Pb < Cu < Cr < Zn < Ni < Mn < Fe. Among the studied metals, the levels of Cd and Ni exceeded the average shale value. Contamination indices such as enrichment factor (EF), contamination factor (CF), and geo-accumulation index (Igeo) showed that the studied sediments were only contaminated by Cd. Ecological risk assessed by ecological risk factor (Eri) and risk index (RI) suggested that the analyzed heavy metals, with the exception of Cd, posed no significant ecological threats. All of the heavy metals analyzed might have originated from similar anthropogenic sources, according to the correlation matrix, cluster analysis (CA), and principal component analysis (PCA).

Ecological and Human Health Risk Assessment of Heavy Metal in Sediment and Demersal Fish Species in Western Offshore Nigeria, Gulf of Guinea

This study was focused to assess the contamination status of heavy metals in sediments, and human health risks associated with fish consumption from western Nigeria offshore in the Gulf of Guinea. Triplicate samples of demersal marine fish species and sediments were collected from five stations (fishing ground) and analysed for heavy metals [mercury (Hg), cadmium (Cd), and lead (Pb)] and metalloid [arsenic (As)] using ICP-OES (inductively coupled plasma optical emission spectrometry) adopted USEPA 200.7 standard method. The metals/metalloid concentrations in demersal fish species and sediment fell below the FAO/WHO permissible limits and sediment quality guidelines (SQG) [probable effect level (PEL) and threshold effect level (TEL)]. The ecological indices [probable contamination index (PCI), mean effect level quotients, newly modified hazard quotient (mHQ), and hazard quotient (HQ)] revealed low contamination level of heavy metals in sediment. The hazard index (HI) of metals in fish species associated with human health fell below the recommended threshold of 1 with no significant health risk to the consumers. The target cancer risk (TCR) of Cd and Pb in the fish species were below the regulation range of 1.0 × 10−6 to 1.0 × 10−4 set by the USEPA. The cluster analysis revealed two clusters. Cluster 1 (C1) showed that Cd was significantly accumulated in the sediment. Cluster 2 (C2) showed significantly low bioaccumulation of Hg, Cd, Pb, and As in fish species across all stations. The ecological and health risk assessment indices generally established low potential adverse effect on demersal marine fish species due to the overall low ecological severity risk associated with heavy metals/metalloids in sediment. Hence, consumers of fisheries resources from western off Nigeria coast are relatively safe from being exposed to any non-carcinogenic and carcinogenic health risk.

Distribution of Cr, Cd, Cu, Pb and Zn in organs of three selected local fish species of Turag river, Bangladesh and impact assessment on human health

The current study estimates the contamination status of heavy metals in fish organs of three local fish species including Amblypharyngodon microlepis (Mola), Trichogaster chuna (Chuna Khalisha) and Annaldale Loach (Gutum fish) which were collected from Turag river during the months from January to March 2022. The heavy metal concentrations of river water and fish organs were assessed through Atomic Absorption Spectrophotometer (AAS). Heavy metals in river water was detected in the order of Ni > Zn > Cu > Cd > Pb > Cr while metal accumulation in the fish organs were detected in the order of Zn > Cr > Cu > Pb > Cd, Zn > Cu > Cr > Pb > Cd and Zn > Cu > Cr > Pb > Cd for Trichogaster chuna, Amblypharyngodon microlepis and Annaldale Loach respectively. Among the detected heavy metals, highest contamination factor (CF) of Zn (1.104198) in intestine and lowest CF of Cu (0.00315) was detected in muscle of Amblypharyngodon microlepis (Mola). On the other hand, highest CF of Cd (1.072772) in liver and lowest CF of Zn (0.0225016) in gill of Trichogaster chuna (Chuna Khalisha) was detected. In case of Annaldale Loach (Gutum fish), highest CF of Cu (0.304122) in liver and lowest CF of Zn (0.002593) in intestine was detected. The total target hazard quotients (TTHQ) values of Amblypharyngodon microlepis in liver (1.18816) exceeded allowable threshold of 1 while TTHQ values in the muscle (1.8862) and liver (1.03995) of Annaldale Loach (Gutum fish) surpassed the acceptable standard limit as well. The TTHQ values (Gill- 0.18764, Muscle- 2.1633, Intestine- 1.68741, liver- 1.03995, kidney- 1.82188) for all of the organs of Trichogaster chuna (Chuna Khalisha) exceeded the acceptable standard limit which indicated possible non-cancer risk for all consumers and some of the fishes found unsafe if they are consumed for a longer time. However, the target cancer risk (TCR) values indicated no potential cancer risks by consumption of those fishes. The regulatory authorities should pay more attention to reduce the river water contamination through industrial effluents which might affect public health.

Contamination Status and Health Risk Assessment of Soil Heavy Metals in the Northern Slope of Eastern Tianshan Mountains Industrial Belt in Xinjiang, Northwest China

In recent years, soil heavy metal pollution has become an important issue of general concern because it is an important factor that threatens the soil environment. To assess the risk of the human health of the people living in the economic belt on the northern slope of the eastern Tianshan Mountains, and provide guidance for pollution control and risk prevention, the northern slope of the eastern Tianshan Mountains was selected as the study area, and six heavy metals (i.e., Zn, Cu, Cr, Pb, and Hg) were measured. The results revealed that the Cu, Pb, Hg, and As contents of the soil exceeded the soil background value of Xinjiang by 1.02, 4.10, 1.76, and 7.98 times, respectively. The Zn and Cr contents were lower than the limits of regional soil standards. Based on the pollution assessment using the pollution index (PI), values indicate that the levels of Zn and Cr pollution were low, those of Cu and Hg pollution were moderate, and those of Pb and As pollution were high. The health risk assessment results revealed that there are non-carcinogenic risks to children. The carcinogenic health risks posed by the heavy metals in this region are higher than the threshold (10−4), indicating that they pose a hazard to human health. The results of this research provide a theoretical basis and reference for soil heavy metal pollution control and human health risk management in this area.

Ecological Risk Assessment of Heavy Metals and Environmental Quality of Tunisian Harbours

Harbours are one of the most disturbed coastal ecosystems due to intensive anthropogenic pressures. This study aimed for the first time to compare anthropogenic impacts in three harbours from the central coast of Tunisia (Mediterranean Sea) employing analysis of heavy metal contamination and ecological quality status (EcoQS). Sampling was carried out in spring 2019 in the fishing harbour of Teboulba, the marina of Monastir, and the commercial harbour of Sousse. The high levels of concentration in heavy metals and organic matter were closely related to the fine-grained fraction of the sediment in the fishing and commercial harbours. A total of 94 macrobenthic species, including five nonindigenous species, were identified belonging to six zoological groups. Multivariate analyses highlighted a strong influence of the harbour activity on the diversity of macrozoobenthic communities. Three benthic assemblages were identified according to their environmental characteristics such as sediment type, organic matter content, and heavy metal contamination. Benthic and biotic indices (H′, J′, AMBI, and BO2A) showed that the EcoQS varied from poor (commercial harbour) to good (marina), and was significantly influenced by harbour activity, organic matter, and heavy metal contamination of the sediment. The present work could be considered as providing important baseline data for the implementation of national environmental policies and management plans in the future.

Heavy metal contamination assessment and probabilistic health risks in soil and maize near coal mines.

ObjectiveCoal mining activities have continuously introduced heavy metals into the soil–crop system, causing increasing damage to crops. This study integrated the analysis of the heavy metal contamination status and human health risk in soil and maize near coal mines to help formulate control strategies for soil quality, maize production, and safe consumption.MethodThis study was carried out on maize agricultural land near a coal mining plant. Heavy metal contamination was assessed by the geo-accumulation index (Igeo), enrichment factor (EF), and bioaccumulation factor (BCF). The Monte Carlo simulation was used to estimate the probabilistic health risk of heavy metals exposure in soil and maize. The relationship between the concentration of heavy metal in the soil and that in maize was further visualized by correlation analysis and random forest analysis.ResultsThe results revealed that the mean concentrations of soil Ni, Cu, As, Cd, Sn, Zn, Pb, and Hg were all above the local background level. Ni was the most severely polluted heavy metal in maize and had a concentration higher than the risk control standard for corn in China (NY 861-2004). The Igeo values of all heavy metals were low, and EF values showed enrichment in V, Cr, Ti, Ni, and As. The assessment of probabilistic health risk exposed by heavy metals in soil and maize indicated that 1.16 and 1.46% of residents exceeded the carcinogenic risk level due to heavy metal exposure from soil and maize, respectively. Children were the most sensitive to maize and soil heavy metal exposure in the contaminated area. Ingestion of heavy metals was associated with the highest health risk to residents, followed by dermal contact and inhalation. As and Cr in soil and Cr and Ni in maize had the greatest impact on human health risk. Furthermore, maize heavy metals were affected the most by soil Cr, Cd, and V.ConclusionThese results may provide useful information for human carcinogenic risk associated with soil and maize heavy metal exposure due to coal mining activities.

Heavy metal contamination status in the soil-water-rice system near coal-fired power plants in Cilacap, Indonesia

Indonesia is intensively developing plenty of coal-fired power plants to support electricity demand growth. Some research showed the utilization of coal as an electrical energy source may produce anthropogenic contaminants (ACs) that can bioaccumulate in plants. This research was carried out to investigate the severity of the heavy metals contamination problem, for instance, arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) in soil, water, rice, and rice bran using ICP-MS and ICP-OES. This research demonstrated the metal contamination levels of arsenic, cadmium, mercury, and lead in the soil, water, rice, and rice bran were below the maximum limit, according to SNI, Codex, and FAO/WHO. However, only a rice sample showed the lead (Pb) level above the safe limit. Coal-fired power plant activities in Cilacap did not indicate clear evidence of soil, water, rice, and bran heavy metal contamination. Therefore, transformation to green energy (e.g., solar and geothermal) is highly recommended to minimize the potential health risks of environmental pollution due to the coal-fired power plant's by-product activities.