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In most cases, in soils exposed to heavy metals accumulation, the highest content of heavy metals was noted in the surface layers of the soil profile. Accumulation of heavy metals may occur both as a result of natural processes as well as anthropogenic activities. The quality of the soil exposed to heavy metal contamination can be evaluated by indices of pollution. On the basis of determined heavy metals (Pb, Zn, Cu, Mn, Ni and Cr) in the soils of Roztocze National Park the following indices of pollution were calculated: Enrichment Factor ( EF ), Geoaccumulation Index (I geo ) , Nemerow Pollution Index ( PI Nemerow ) and Potential Ecological Risk ( RI ). Additionally, we introduced and calculated the Biogeochemical Index ( BGI ), which supports determination of the ability of the organic horizon to accumulate heavy metals. A tens of times higher content of Pb, Zn, Cu and Mn was found in the surface layers compared to their content in the parent material. This distribution of heavy metals in the studied soils was related to the influence of anthropogenic pollution (both local and distant sources of emission), as well as soil properties such as pH, organic carbon and total nitrogen content. [ABSTRACT FROM AUTHOR]

The study assessed the long-term effects of anthropogenic pressure of the sulfur industry on turf-covered soils located in the vicinity of the sulfur mine Grzybów. The study assumes that 20 years which elapsed since the end of the exploitation of sulfur is a period sufficiently long for the content of sulfur compounds in soils not to exceed the permissible level and that soil of the region can be classified as not contaminated. A part of the study involved identification of changes in the contents S tot. and S SO 4 2− in soils collected in the 1970s and early twenty-first century. It was also traced the relationship between the content of sulfur compounds and selected soil properties and estimated risk of soil environment pollution by heavy metals. Mean contents of trace elements studied amounted to 10.2–10.8 mg kg −1 for Pb, 14.3–39.4 mg kg −1 for Zn, 0.2–0.4 mg kg −1 for Cd, 3.8–32.2 mg kg −1 for Cr, 2.7–15.1 mg kg −1 for Cu and 2.9–18.7 mg kg −1 for Ni. Based on the results of S SO 4 2− content in soils collected at a distance of 1 km from the mine, it was found out that despite the passage of years, the amount of this type of sulfur still is increased and exceeds 0.14 g kg −1 . As the distance from the mine grew lower (from 0.017 to 0.03 g kg −1 ) average content of the sulfur form was observed. In the studied soil material we found generally positive, strong correlation between the S tot. and S SO 4 2− content and analyzed trace elements. The degree of contamination of examined soils with heavy metals was estimated on the basis of the integrated pollution index, which pointed to a moderate and low level of antropogenization of this area. In addition, the relationship between the determined characteristics of soils (C org. contents, the fraction <0.002 mm and pH) and heavy metals confirms that the trace elements present in soils do not occur in mobile forms in the soil solution. [ABSTRACT FROM AUTHOR]

Abstract: The aim of the research was to determine the level of accumulation of selected heavy metals (Pb, Cd, Hg, As) in meat and liver of sheep. The animals were divided into adequate age groups which allowed the analysis of statistical-mathematical correlations between the age of the animals and contamination of meat. Moreover there was determined the chemical composition of meat of animals of particular age groups. The research material for determining the content of heavy metals was taken from the longissimus muscle of back (m. longissimus dorsi), and samples of liver from the tail lobe. The analysis carried out results allows stating that together with age of sheep there decreases the content of water in meat and the content of protein, fat and ash increases. The contamination of meat and liver of sheep by Cd and Pb apparently depends on age of these animals. But there was a several times difference between the youngest and the oldest animals in the level of contamination of these tissues was. In muscles and in the liver of tested animals there was not stated the presence of arsenic over 0.001mg/kg. [Copyright &y& Elsevier]

The article shows the results of research on heavy metals (Cr, Zn, Ni, Cu, Pb, Cd) content in bottom sediments of two small storage reservoirs located in the south-eastern part of Poland. The analyses covered the top 10 cm layer of sediment samples taken in transects perpendicular to the shoreline, located in upper, central and lower sections of the studied reservoirs. The ordinary kriging method was applied to interpolate spatial distribution of heavy metals content in the sediments. The assessment of surface sediment contamination with heavy metals was based on a threshold effect level and probable effect level methods. In addition, the ecological risk was assessed on the basis of the indices: potential ecological risk index and toxic risk index. Moreover, the principal component analysis was carried out to find determinants for the distribution of the analyzed trace elements in reservoirs. The results of the completed analysis have proven that the highest concentrations of heavy metals (HM) are found in the vicinity of dams in both reservoirs. Calculated probable effects level values indicate a negative impact of Pb– Bliżyn Reservoir (BR) and Cd– Małoszówka Reservoir (MR) on aquatic biota. The analysis of heavy metal content and their interrelationships in surface sediments proves that Pb, Cu and Zn in the BR and Cd and Cr in the MR have anthropogenic origins. Moreover, the main determinants for HM distribution in the reservoir are hydromorphological parameters, which determine sediment grading and organic matter transport. [ABSTRACT FROM AUTHOR]

Detailed research on the content of heavy metals in ground and surface waters in the upper Sanna River catchment was initiated in 2013. The investigations were conducted in one of the most promising areas of potential shale gas extraction, in which the Frampol 1 test wellbore was drilled in 2012 (SE Poland, Roztocze Region). In the area of the wellbore, hydrochemical analyses of the waters of the river drainage zone were performed. Water was sampled from six objects representing soil water, porous groundwater, fissure-layer groundwater, and river water. The hydrological regime of groundwater and surface water was analysed based on data obtained from automatic recorders of water levels and results of periodic measurements of water flow. In 2013, water was sampled on a monthly basis for determination of the levels of Ba, Sr, Al, Fe, Mn, Zn, Cu, Cd, Co, Cr, Ni, As, V, Rb, Pb, Th, and U. The analysis results showed that the concentration of Sr was usually in the range of 100-400 µg/L, Fe 10-100 µg/L, Ba 10-40 µg/L, and Mn, Al, and Zn 1-10 µg/L. The concentration of the other metals generally did not exceed 1 µg/L. The concentrations of the elements analysed in the zone of drinking water intake were within the range specified by Polish and WHO standards. Significant differences were found in the metal content in the analysed waters; they were related to the water intake site, form of land management, and hydrometeorological conditions. The highest metal content was recorded in soil and river waters and the lowest in the spring waters of the main water-bearing horizon. At the current stage of the research, no impact of the Frampol 1 shale gas exploration wellbore on the metal content in the upper Sanna River catchment was found. [ABSTRACT FROM AUTHOR]

The aim of the study is to determine the concentration of selected heavy metals in soil contaminated with galvanising fume resulting from a fire in a galvanising plant. Surface horizon of soil exposed to contamination by toxic fumes due to the fire of a galvanising plant in Dębska Wola near Kielce (SE Poland) was analysed. Soil samples were collected in an agricultural area of 12 ha after the plant's failure in 2019 and three years after the fire in 2022. Grain-size distribution, pH and concentration of zinc, lead and cadmium were determined. The acceptable values of pollutants were significantly exceeded in soil (Znmax - 2007.3 mg·kg-1 DM, Pbmax - 509.5 mg·kg-1 DM, Cdmax - 17.1 mg·kg-1 DM in 0-5 cm horizon) and reduced in control samples (Znmax - 756.1 mg·kg-1 DM, Pbmax - 320.1 mg·kg-1 DM, Cdmax - 15 mg·kg-1 DM). In the organic-mineral horizon the concentrations declined by an average of Zn - 41.8%, Pb - 26.1% and Cd - 16.3%, while in the mineral horizon by 27.8% (Zn), 26.7% (Pb) and 15.6% (Cd). Industrial plants, in which thermal treatment of molten metals is conducted, pose a real threat to the environment in the case of a failure. In order to minimise the effects of potential leaks, their location should be thoroughly considered. The course and consequences of accidents should be monitored during the event (such as fire) and in the long term (e.g. with the use of bioindicators). [ABSTRACT FROM AUTHOR]

This study analysed forty-six soil samples from the top 15 cm (6 in.) of urban soil in Tripoli, Libya for heavy metal contamination using atomic absorption spectrometry. The metals assessed included cadmium (Cd), lead (Pb), zinc (Zn), copper (Cu), nickel (Ni), cobalt (Co), iron (Fe), manganese (Mn) and chromium (Cr), with average concentrations of 3.94±1.93, 38.17±11.67, 170.94±62.68, 29.67±8.00, 19.70±8.75, 30.38±10.68, 27.444.52±8, 739.15, 233.82±48.24 and 195.92±61.37 mg.kg-1.dwt (1.4E-4±7.0E-5, 1.35E-3±4.1E-4, 6.03E-3±2.21E-3, 1.05E-3±2.8E-4, 6.9E-4±3.1E-4, 1.07E-3±3.8E-4, 0.97±3.08E-1, 8.25E-3±1.7E-3 and 6.91E-3±2.16E-3 oz.lb.-1.dwt), respectively. Most of these levels exceeded the permissible limits set by the World Health Organization and typical background values. Pollution indices suggested that the soil ranged from unpolluted to moderately polluted, with Cd, Co, Cr, and Zn being of particular concern. Cd was found to be the primary contributor to ecological risk, mainly from anthropogenic sources. Principal component analysis identified four key components: PC1 was dominated by Cd, Pb, and Zn with moderate contributions from Cu, related to human activities; PC2 was dominated by Fe and Cr; PC3 by Ni and Mn; and PC4 by Co and Cu, primarily from natural sources. [ABSTRACT FROM AUTHOR]

The soil's biological quality and its functions are closely linked. They determine the ecological processes and ecosystem services. Therefore, the heavy metal contamination of forest soils, leading to their degradation, is a major international problem. Soil is a habitat for many organisms, and the strong correlations between soil properties, vegetation, and soil fauna are particularly evident in the rhizosphere. Therefore, comprehensive soil monitoring must take all these elements into account. In forest soils, Vaccinium myrtillus plays a vital role. Despite this, there is still a lack of information in the literature on the interrelationship between microarthropod biodiversity, including predatory soil mites, and heavy metals in the rhizosphere zone of blueberry plants. To fill this gap, we assessed the impact of the V. myrtillus rhizosphere on soil stability and biological quality using a bioindicator based on predatory mites. We conducted the study in Poland, on selected forest sites characterised by varying degrees of soil contamination. In our study, we used a combined analysis based on the following indicators: maturity index (MI), contamination factor (CF), pollution load index (PLI), and potential ecological risk index (PERI), which allowed us to determine the level of soil contamination. We extracted 4190 Gamasina mites from soil samples. We also investigated soil properties such as pH, organic matter content, total carbon, total nitrogen, C/N ratio, and heavy metal concentrations (Cd, Cu, Zn, Pb, and Ni). Our study proved that the rhizosphere zone significantly influences the stability of the predatory soil mite community, but this influence depends on the degree of soil contamination. We found that in unpolluted or moderately polluted soil, soil mites prefer habitats with less biological activity, i.e., non-rhizosphere zones. These main results are fascinating and indicate the need for further in-depth research. Our study's comprehensive combination of methods provides valuable information that can facilitate the interpretation of environmental results. In addition, our study can be a starting point for analysing the impact of the rhizosphere zones of many other plant species, especially those used in the reclamation or urban spaces. [ABSTRACT FROM AUTHOR]

Concentrations of trace elements such as Cr, Zn, Cd, Co, Mn, Cu, Ni, Pb, and Fe were investigated in water, bottom sediments, and macrophytes (Phragmites australis and Typha latifolia L.) collected from the Borków, Wilków, and Rejów water reservoirs in the Kielce Upland (Poland). The main objective of this study was to investigate the condition of water, bottom sediments, and macrophytes in selected three sedimentary basins of the Kielce Upland and to identify natural and anthropogenic factors influencing this condition. The secondary objectives were (i) to determine the contents of trace metals in water, bottom sediments, and macrophytes, (ii) to assess the quality of abiotic and biotic elements of the ecosystem based on selected criteria, (iii) to compare reservoirs in terms of pollution, and (iv) to determine the ability of macrophytes to be used as a bioindicator of water/sediment pollution. Field tests were conducted in 2021. The trace metals in water were determined by ETAAS (Cr, Cd, Mn, Cu, Ni, Pb) and FAAS (Zn), and spectrophotometry method (Fe). The trace metals in sediments and macrophytes, including Cr, Zn, Cd, Co, Mn, Cu, Ni, Pb, and Fe, were detected using ICP-OES method. Contamination of bottom sediments with potentially toxic metals was determined based on the geo-accumulation index (Igeo), contamination factor (CF), and pollutant load index (PLI). Statistical analyses were performed using the Statistica PL 13.1. The analyses showed that the accumulation of trace elements in the surface layer of the reservoir sediments increases as follows: in Borków, Cd < Co < Ni < Cu < Pb < Cr < Zn < Mn < Fe; in Wilków, Cd < Co < Cu < Ni < Pb < Cr < Zn < Mn < Fe; and in Rejow, Cd < Co = Cu = Ni = Pb < Zn < Cr < Mn < Fe. It was shown that the average distribution of metals in the bottom sediments of the studied reservoirs was as follows: Borków > Wilków > Rejów. Research has shown that the degree of trace metal accumulation increases as follows: water < sediments < macrophytes (except Pb from the reservoir in Borków). [ABSTRACT FROM AUTHOR]

Cadmium is one of the most important environmental contaminants. Animals grazing on natural pastures are particularly exposed to cadmium. Sheep are mostly reared in extensive and grazing systems. Therefore, sheep may accumulate larger amounts of cadmium compared to other ruminant species and are a good indicator of exposure to cadmium contamination in a given area. The determination of cadmium concentrations in the muscles, livers and kidneys of lambs and sheep was carried out in the Czech Republic during the period 2001--2022. The average cadmium content in the livers and kidneys of all the lambs was 0.037 ± 0.006 and 0.061 ± 0.013 mg.kg-1, respectively. The average cadmium content in the livers and kidneys of all the sheep was 0.319 ± 0.047 and 1.255 ± 0.204 mg.kg-1, respectively. The maximum limit for human consumption was not exceeded in any of the 24 samples in the lambs but was exceeded in 5 of 33 liver samples and 12 of 33 kidney samples in the adult sheep. The average value of cadmium in the muscles of the lambs and sheep was 0.004 ± 0.001 mg.kg-1. The maximum limit for human consumption was not exceeded in any muscle sample. The cadmium content in both the liver and in the kidney differs significantly between the lambs and sheep, being higher in the sheep (P < 0.001 for both comparisons). No statistically significant trend of a decrease in the cadmium content in the lamb and sheep tissues was found during the observed time (P > 0.05). We can sum up that there is an evident need for further monitoring of the cadmium concentration in lamb and sheep tissues in the Czech Republic. [ABSTRACT FROM AUTHOR]

The coal gangue dump may introduce heavy metal(oid)s (HMs) into surrounding agricultural soils, posing potential health risks to nearby communities. This study evaluated heavy metal(oid) pollution in agricultural soils adjacent to a gangue dump at an abandoned coal mine in Chongqing, Southwest China. The concentrations of HMs (As, Cd, Cr, Cu, Ni, Pb, and Zn) were quantified using ICP-MS, and the contamination status was assessed using the Geoaccumulation Index (Igeo), Contamination Factor (CF), Pollution Load Index (PLI), and Potential Ecological Risk Index (RI). Heavy metal(oid) contamination was detected in soils across a depth of 0–30 cm, particularly pronounced in the topsoil layer (0–10 cm and 10–20 cm depths). Cu emerged as the predominant contaminant across all examined depths, with average Igeo values of 1.20, 1.21, and 1.16 for the 0–10 cm, 10–20 cm, and 20–30 cm depths, respectively, indicating moderate contamination. The CF for Cu was 3.55, 3.55, and 3.50 for these respective depths, classifying it as considerable contamination. The PLI values ranged from 1.61 to 2.50, with a mean value of 2.12, indicating overall contamination. The ecological risk assessment indicated that the soil's ecological risk was low at all depths. Cd was the major contributor to the RI, accounting for 48%, 47%, and 42% at 0–10 cm, 10–20 cm, and 20–30 cm depths, respectively. Health risk assessments revealed significant non-carcinogenic risks to children (mean HI = 1.30) and unacceptable carcinogenic risks to both adults and children (mean TCR = 3.26 × 10–4 and 1.53 × 10–3, respectively). This study underscores the critical need for comprehensive risk assessments using multiple indicators to prioritize remediation efforts for HMs, providing a scientific basis for effective environmental management and public health protection in the Three Gorges Reservoir Area. [ABSTRACT FROM AUTHOR]

The soil environment plays an important role in urban ecosystems. To study the heavy metal contamination of soil in Beilun District, Ningbo, we collected soil samples from 60 points in urban and peri-urban areas of Beilun District and analyzed the spatiotemporal variation and sources of heavy metal pollution in various land-use types. The results shown that the heavy metal contents in 2015 and 2022 were higher than the background soil values of Ningbo city, and there was an accumulation of heavy metals over these 7 years. The contents of heavy metals in green belts and woodland in 2022 were higher than those in 2015, while there was no significant change in agricultural land. The heavy metal contents in both years were mainly in the order green belts > agricultural land > woodland. The spatiotemporal distribution of heavy metal content showed that heavy metal pollution in Beilun District was concentrated in five industrial areas, and there was a trend toward the disappearance of highly polluted points. But the single-factor pollution index, pollution load index (PLI), and geoaccumulation index (Igeo) indicated that there was no significant heavy metal pollution in Beilun District, and individual elements at specific points showed slight pollution. The source analysis results showed that the main source of Hg is chemical, As is mainly derived from agricultural, Cr, Ni and Cu are mainly derived from natural, the main sources of Zn and Cd are electroplating and machinery activities, and the main source of Pb is traffic. These results specify a reference for future investigation on urban soil heavy metals, and the source apportionment results provide a scientific foundation for subsequent soil heavy metal pollution treatment. [ABSTRACT FROM AUTHOR]

Heavy metal pollution in soils may have a significant impact on the environment and human health, disrupting the ecological balance in developing countries. This holds true for both industrial and agricultural endeavors. The study area, located in Vezirköprü district of Samsun province, consisted of 1664.9 hectares, from which 88 soil samples were collected from the surface (0–20 cm) depth. This study analyzed the physicochemical properties and heavy metal pollution indices, including the enrichment factor (EF), geo-accumulation index (I geo), pollution load index (PLI), contamination factor (Cf), potential ecological risk factor (Er), and potential ecological risk index (RI). In addition, the prediction accuracies of these indices were determined using artificial neural networks, considering pH, organic matter (OM), and clay contents, which affect the retention of heavy metals in soil. Based on the analysis results, the average concentration of copper (Cu) was 28.1 mg/kg, which exceeded the upper continental crust (UCC-28.0 mg/kg) and European mean soil value (ESA-17.3 mg/kg), but was below the world mean soil value (WSA) (38.9 mg/kg). The average concentration of nickel (Ni) was 40.3 mg/kg, which was higher than that of WSA (29 mg/kg), but lower than that of ESA (37 mg/kg) and UCC (47 mg/kg). The concentration of cadmium (Cd) exceeded the UCC value of 0.09 mg/kg by 0.19 mg/kg, but remained lower than the ESA and WSA values of 0.28 mg/kg and 0.41 mg/kg, respectively. The levels of other elements were found to be low compared with the UCC, WSA, and ESA results. The correlation values (R) between the actual and predicted values for PLI were higher than those for RI. During the training stage, the correlation values were 0.72 and 0.82 for RI and PLI, respectively. During the testing stage, the correlation values were 0.61 and 0.72, respectively. These results indicate that ANN can be used to predict the pollution status. [ABSTRACT FROM AUTHOR]

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The study specifically focused on the Hongliulin mining area, where a total of 40 soil samples were meticulously collected and analyzed from within a 1000 m radius extending from the tailings dam. The findings revealed that soil pH within the 0–1000 m range generally leaned towards the alkaline side. In terms of soil nutrient content, encompassing factors such as soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP), total potassium (TK), alkali nitrogen (AK), available phosphorus (AP), and quick-acting potassium (AK), the variations fell within the following ranges: 2.23–13.58 g/kg, 0.12–0.73 g/kg, 0.18–1.15 g/kg, 9.54–35.82 g/kg, 2.89–6.76 mg/kg, 3.45–11.25 mg/kg, and 5.86–130.9 mg/kg. Collectively, these values indicate relatively low levels of soil nutrients. Within the 0–500 m range of soil samples, the average concentrations of Cd, Hg, Pb, and As were 0.778, 0.198, 24.87, and 17.92 mg/kg, respectively. These concentrations exceeded the established soil background values of Shaanxi Province and emerged as the primary pollutants in the study area. Within this same range, the mean values of eight toxic metals (Pi) were ranked in the following descending order: 1.726 (Hg), 1.400 (As), 1.129 (Cr), 1.109 (Pb), 0.623 (Zn), 0.536 (Cd), 0.309 (Cu), and 0.289 (Ni). With the exception of Hg, As, Cr, and Pb, which exhibited slight pollution, the other toxic metals were found to be within acceptable pollution limits for this sampling range, in line with the results obtained using the geo-accumulation index method. The average potential ecological risk index for the eight toxic metals in the study area stood at 185.0, indicating a moderate overall pollution level. When assessing individual elements, the proportions of ecological risk attributed to Hg, As, Pb, and Cd were 34.57%, 27.44%, 25.11%, and 23.11%, respectively. This suggests that the primary potential ecological risk elements in the study area are Hg and As, followed by Cd and Pb. Notably, toxic metals Hg and Pb, as well as As and Pb, exhibited significant positive correlations within the sampling area, suggesting a common source. An analysis of the relationship between soil physicochemical properties and toxic metals indicated that soil pH, SOM, TN, and TP were closely linked to toxic metal concentrations. The toxic metal elements in the research area's soil exhibit moderate variability (0.16 < CV < 0.36) to high variability (CV > 0.36). Within the range of 0–200 m, the CV values for Cd and Hg exceed 1, indicating a high level of variability. The coefficient of variation for SOM, TP, AP, AK and TK is relatively high with the of 2.93, 2.36, 2.36, 21.01, 7.54. The soil in the sampling area has undergone significant disturbances due to human activities, resulting in toxic metal pollution and nutrient deficiencies. [ABSTRACT FROM AUTHOR]

Current industrial operations pollute the world's land, water, and air with heavy metals. Metals' environmental behaviour and geographical distribution near the industrial production. Heavy metal contamination potential was assessed using geoaccumulation index, enrichment factor, and other criteria. Heavy metal concentrations have increased due to industrial waste, geochemical shifts, agriculture, and mining. Modifying cell structure, heavy metals can harm and cause cancer. We need to develop and conduct comprehensive monitoring to determine if industrial production and mining is causing elevated heavy metal levels nearby area in the zone. This review shares contemporary heavy metal contamination on its nature, origin, and extent. [ABSTRACT FROM AUTHOR]

This study was carried out to determine the heavy metal pollution and possible sources of agricultural soils in Tavşanlı district, Which energy power plant is located. Total 83 soil samples were taken and 8 (Cu, Cr, Pb, Co, Fe, Mn, Ni, and Zn) heavy metals were analyzed in soil samples The mean concentration of heavy metals were determined as Cu (32.89 mg kg−1), Cr (285.69 mg kg−1), Co (36.37 mg kg−1), Mn (860.20 mg kg−1), Ni (457.59 mg kg−1), Pb (22.14 mg kg−1), Fe (30,250 mg kg−1) and Zn (65.05 mg kg−1), were determined. The mean concentrations of Cu, Cr Co, Mn and Ni found to be higher than both the upper continental crust values and the European soil mean values. Contamination factor Co (2.1), Cr (3.10) and Ni (9.73), enrichment factor Co (2.73), Cr (3.75) and Ni (11.42) and geoaccumulation index Co (0.18), Cr (0.50) and Ni (1.98) values showed that the soils were polluted by Co, Cr, and Ni. In addition, it was determined that Ni (48.65) poses a "moderate ecological risk" in the study area. Pearson correlation anaysis and principal component analysis determined that Cr, Co and Ni have both lithogenic and anthropogenic origin. [ABSTRACT FROM AUTHOR]

Understanding variations of heavy metals and their anthropogenic influence on wetland soils are very imperative and crucial for environmental planning and sustainability. To assess heavy metal contamination in Ibese wetland soils, Nigeria, 30 soil surface (0–20 cm) samples clustered around industrial effluents, were collected and analyzed with atomic absorption spectrophotometer for copper (Cu), zinc (Zn) and cadmium (Cd). Herein, the geo-accumulation (Igeo), and pollution index (PI), coupled with environmental (RS) remote sensing vegetation and water indices were employed as predictor models to assess heavy metals contamination of the area. The vegetation and water indices highlighted an intense decreasing vegetation trend and loss of waterbodies of the area, respectively. The results of the Igeo metals revealed that the wetland soils pollution ranged from uncontaminated to moderately contaminated, except Cd which ranged from moderately to heavy pollution. The PI shows a moderate significant pollution by Cu and Zn, except Cd which recorded considerable contamination. A very significant correlation was found between the metals and the spatial distribution pattern revealed that the contamination is related to the influence of uncontrolled human activities on soil properties like soil pH and organic carbon. The study suggested that adequate attention be directed to alert policymakers and stakeholders toward lessening the anthropogenic sources in the area for future control measures. [ABSTRACT FROM AUTHOR]

The present study highlights the occurrence and the temporal variations of physicochemical properties, and heavy metals in the sludge from sewage treatment plants (STPs) located in industrial (two sites) and non-industrial (one site) cities of Haryana, India. The sludge was acidic (5.59) to neutral (7.21) with a mean EC of 7.4 dS m−1. Prominent heavy metals present in the sewage sludge from industrial sites were Cd, Ni, and Cr with maximum values of 2.83, 1449.0, and 3918.5 mg kg−1, respectively. The contamination and enrichment factor better explained the buildup of Ni, Cr, and Cu in the sewage sludge from industrial sites. The pH, total carbon, phosphorus, and other water–soluble anions, viz. SO42−, Cl−, HCO3−, and PO43−, were the most important attributes of sludge controlling the binding and removal of the metals with particulate matters during the phase separation in STPs. These attributes explained about 90% of the variation in Cd, Ni, Cr, Cu, Mn, and Zn content of the sludge from different STPs. Sludge from the non-industrial site had a low potential ecological risk index of 74.0 compared to a very high-risk index of 2186.5 associated with the industrial sites. This study concludes that besides the concentration of the heavy metals, the enrichment factor coupled with geo-accumulation or ecological risk index can effectively categorize the sludge. However, these indices need to be linked with bioaccumulation, bioaccessibility, and biomass quality under different agroecologies for guiding the safer use of sewage sludge in agriculture. [ABSTRACT FROM AUTHOR]

Meat contamination is a problem that must be addressed since it can affect consumers' health. Standard acceptable limits for heavy metals in meat and organs have been established by many international organizations. Livestock including sheep, cattle, camels, and goats' side by side with other poultry species are the most significant sources of meat for protein. Heavy metal contamination in animal products may be harmful to people's health. The earth's crust naturally contains heavy metals, but uncontrolled human activity has significantly changed their geochemical cycles and biological equilibrium. This causes a buildup of metals in animal tissue that contain secondary metabolites, which gives rise to a specific pharmacological action. Humans can have negative health effects from prolonged exposure to heavy metals as lead, cadmium, arsenic, and mercury. This review showed that most of the studies conducted in different countries on heavy metals were mostly in red meat, and the research was few in the cases of domesticated birds and very rare in game birds, although it is considered a good example for investigating heavy metals in the environment. [ABSTRACT FROM AUTHOR]

Metals can accumulate in agricultural soils, presenting a serious threat to human health; therefore, it is important to analyze the quality of these soils to avoid possible harm related to their contamination in the future. Despite the importance of monitoring arable soil quality, few studies have examined the current state of Cu and Cd soil contamination through analysis of historical data and temporal trends in heavy metal content. Therefore, this study was aimed at analyzing the spatial variability of Cu and Cd content (expressed by toxicity indices) and assessing the level of contamination of arable soils in Poland over the last 25 years (1995–2020). The average Cu content in soil throughout the duration of the study was ~10 mg/kg. The average Cd content increased from 0.7 mg/kg (in 1995) to 3.4 mg/kg (in 2020). The evaluation of Cu and Cd soil contamination showed that soils contaminated with Cd and Cu constituted 1.4% and 2.3% of the total monitoring points, respectively. The geoaccumulation index and pollution index ranged for Cu from −5.23 to 3.09 (mean: −2.50) and from 0.02 to 6.40 (mean: 0.20), and for Cd from −5.23 to 6.92 (mean: −1.67) and from 0.01 to 60.58 (mean: 0.44). The soil was practically uncontaminated with Cu and Cd in 98.77%/98.92% and 93.44%/97.92% of cases, respectively. On a national scale, the contents of Cu and Cd in soils depend on soil properties (pH, C, OM, ST, and CM) to a very small extent. An assessment of the spatial distribution of Cu and Cd concentrations in Polish arable soils indicated regional differences related to the degree of industrialization/urbanization. The obtained results show the impact of human activity on the level of heavy metals present in soils. [ABSTRACT FROM AUTHOR]

This study aimed at investigating pollution sources and indicators in three study sites, namely, an industrial town (It), landfill (Lf), and wastewater treatment plant (WTP) in the vicinity of Ilam city, west of Iran. To achieve this objective, the sampling was performed from the topsoil (0–10 cm) of three sites (It, Lf, and WTP) with pollution potential. Some soil physico-chemical properties and total concentration of HMs including Cd, Pb, Ni, Cr, and Co, pollution indicators and sources of pollution were evaluated by statistical analysis. The results of the geoaccumulation index (Igeo), enrichment factor (EF), contamination factor (CF), and pollution load index (PLI) showed that the studied areas were contaminated with HMs. The highest average of Cd and Pb were 1.45 and 440.19 mg kg–1, respectively, in the Lf. Whereas, the highest average of Ni and Cr were 106.53 and 43.50 mg kg–1, respectively, in the IT, while the highest average of Co was 81.69 mg kg–1 in the WTP. According to the results of the principal components analysis (PCA) and clustering, a small part of the Pb, Ni, and Co amounts in the soils had the natural origin, while the results confirmed that a significant proportion of Pb, Cd, and Cr concentrations associated with human-caused hazards. Moreover, all areas (especially Lf and WTP sites) were highly contaminated with Cd. Due to the higher mobility of Cd and its human health hazards, this metal should be given more attention in the study sites of Ilam city. In general, based on our results, more paying attention needs to be considered by decision-makers and stakeholders to manage and control pollution production sources in the soils of the study sites. [ABSTRACT FROM AUTHOR]

To understand the impact of urbanization process on heavy metals (HMs) (distribution, sources and risks) in soil in different land-use types, we collected soil samples from 38 sites in Zhengzhou, China, and divided them into industrial, residential and agricultural areas. Various indices, including single factor pollution index (Pi), Nemerow pollution index (PN) and geo-accumulation index (Igeo) were used to analyze the pollution levels of HMs. The results showed that the average concentrations of Pb, Cd, Cu, Zn, Cr and Mn were 30.26 mg/kg, 0.31 mg/kg, 18.26 mg/kg, 85.85 mg/kg, 76.76 mg/kg and 211.13 mg/kg, respectively. Additionally, Pb, Zn and Cr were the main pollutants and showed serious pollution levels in three land-use types. Remarkably the pollution level of Pb was particularly prominent in industrial areas due to individual sampling points. Then, the principal component analysis (PCA) showed that Pb and Mn came from traffic and natural sources (34.14%), Cd and Zn from metal smelting (28.11%), Cr and Cu from the use of pesticides and fertilizers (17.57%). Furthermore, geographic information system (GIS) and potential ecological risk index ( E r i ) were employed to analyze the risk of HMs. Among them, the E r i value of Cd in the industrial area was shown to be 55.5, which reached moderate pollution. Moreover, Cd has the highest contribution to risk index (RI) among all soil types. The order of RI was industrial area > residential area > agricultural area, which would contribute to the future regional planning of Zhengzhou. [ABSTRACT FROM AUTHOR]

This work was carried out to monitor contamination levels of twelve heavy metals (HMs) in the agricultural soils of Kafr El-Zayat city in Egypt. The concentrations of Mg, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, and Pb were determined using inductively coupled plasma optical emission spectroscopy (ICP-OES). Contamination levels were estimated based on various geochemical parameters such as contamination factor (CF), enrichment factor (EF), geo-accumulation index (Igeo), degree of contamination (Cd), and pollution load index (PLI). The results showed that the majority of investigated soil samples were moderately contaminated (1 ≤ CF < 3) with V, Cr, Co, Cu, Zn, and Sr and had low contamination levels (CF <1) with Mg, Mn, Fe, Ni, and Pb. All investigated elements had geo-accumulation indices smaller than zero indicating uncontaminated soil samples except for V which showed (0 < Igeo < 1) indicating uncontaminated to moderate pollution levels. All soil samples were found to have deficient to minimal enrichment for all investigated HMs based on the average values of EF (EF < 2). Cluster analysis (CA) and principal component analysis (PCA) revealed that HMs were clustered into three groups compromising As and V; Ni, Cr, Mn, Co, Fe, and Mn; and Pb, Cu, Sr, and Zn, which suggests the presence of different sources of pollution. The contribution of anthropogenic sources to V, Cr, Co, Cu, Zn, As, and Sr was estimated to be 45, 30, 26, 11, 23, 27, and 13% of the total metal content, respectively. In general, the investigated agricultural soil samples could be classified as moderately contaminated and polluted based on the Cd factor (Cd = 13.7), and the PLI (PLI = 1.1), respectively. [ABSTRACT FROM AUTHOR]

This report presents the findings of the concentrations, distributions and health risks assessment of heavy metals (HMs) and volatile organic compounds (VOCs) in topsoils of two typical automobile mechanic villages (MVs) situated within Ogun State, Nigeria. One of the MVs is located in basement complex terrain (Abeokuta), while the second is in the sedimentary formation (Sagamu). Ten composite samples were collected at depth of 0–30 cm with the aid of soil auger from spent oil-contaminated spots within the two MVs. The chemical parameters of interest were Pb, Cd, benzene, ethylbenzene, toluene, total petroleum hydrocarbon (TPH) as well as oil and grease (O&G). In addition, soil pH, cation exchange capacity (CEC), electrical conductivity (EC) and particle size distribution were also evaluated in order to find out their impacts on assessed soil pollutants. Results revealed that the soils in both MVs are of sandy loam texture, slight acidic to neutral pH, mean CEC < 15 cmol/kg and mean EC > 100 μS/cm. The mean concentration of each of analyzed HMs and VOCs in soils from the two MVs was < 5 mg/kg, while the mean values of TPH and O&G content were > 50 mg/kg. The mean Cd values in soils of both MVs were higher than the national soil screening level of 0.8 mg/kg, but lower than the Canadian and Italian guidelines. There is no significant correlation between each of HMs/VOCs and any of assessed soil physicochemical variables. The non-cancer risk expressed in terms of hazard index (HI) was > 1 via oral ingestion route for adults and children at the two MVs, indicating adverse non-carcinogenic health risk. The HI > 1 value was obtained for adults only through the dermal absorption pathway in Abeokuta MV. However, HI values for the two age groups at the two MVs via inhalation route were < 1, indicating no likelihood of any non-carcinogenic effects via the breathing exposure. The potential of non-cancer risk via oral ingestion route in both MVs was derived from the contributive ratios of HMs and VOCs in the order: Cd > benzene > Pb > toluene. The carcinogenic risk (CR) values due to ingested Cd, benzene and Pb for both age groups at the two MVs exceed the safe limit range of 10–6 to 10–4. Cadmium, benzene and lead made considerable contributions to the estimation of CR through dermal exposure for adults only in Abeokuta MV. The CR values via inhalation pathway for adults and children in both MVs were within the threshold range. Artisans and children should circumvent accidental ingestion of contaminated soils in addition to wearing of protective clothes during routine vehicle maintenance activities. [ABSTRACT FROM AUTHOR]

This preliminary study focuses on three abandoned sites, located in the communes of Temuco, Villarrica, and Lonquimay, in the Araucanía Region, Chile. Two of the sites were classified as illegal landfills and one was a former landfill. Seventy-three surface samples were taken, of which 32 were from site S1, 20 were from site S2, and 21 were from site S3. The objectives of this study were (1) to establish the background values of trace metals present in soils through different statistical methods, (2) to determine the level of contamination and possible ecological risks in soils, and (3) to assess the health risk posed to children and adults from potentially hazardous elements (As, Ba, Cd, Co, Cr, Cu, Hg, Ni, Pb, V, and Zn). The data analyzed belong to a report presented by Chile's National Environmental Centre (CENMA). An evaluation was carried out through a multivariate statistical analysis to determine the type of origin and association of the trace elements, and spatial distribution maps were generated to establish the behavior of the contents of heavy metals present in the sites studied. The background values for sites S1, S2, and S3 were obtained by the median + 2MADdian absolute deviation) method. These values varied in the range of 14,702–41,785 mg kg−1 for Al, 0.83–8.9 mg kg−1 for As, 29.2–77.2 mg kg−1 for B, 59.2–143 mg kg−1 for Ba, 10.1–22.8 mg kg−1 for Cd, 18.4–51.2 mg kg−1 for Co, 12.3–38.0 mg kg−1 for Cr, 47.8–76.6 mg kg−1 for Cu, 36,230–64,274 mg kg−1 for Fe, 0.02–0.05 mg kg−1 for Hg, 482–4396 mg kg−1 for Mn, 16.7–19.3 mg kg−1 for Ni, 1.0–17.6 mg kg−1 for Pb, 1.4–28.2 mg kg−1 for Se, 108–258 mg kg−1 for V, and 68.1–145 mg kg−1 for Zn. In terms of ecological risk, the geoaccumulation index (Igeo), enrichment factor (EF), and contamination factor (Cf) values for As and Se at site S1, As at S2, and Pb with As at S3 were the main elements indicating the highest contamination levels, as well as a higher number of samples with contaminated content. The Potential Ecological Risk Index (PERI) revealed that on average, there was a moderate ecological risk for S1 and S2 and a considerable ecological risk for S3; the main contributions were generated by As and Hg in S1 and S2, while, in S3, they were produced by Pb and As. In terms of the risk to human health, the risk was higher in children than in adults, with the ingestion route as the main source of risk. For adults, it was found that there was no likelihood that they would develop any adverse non-carcinogenic or carcinogenic health effects. In contrast, children were found to be more likely to sustain adverse health effects. Regarding the non-carcinogenic risk to children, the Co and As samples at S1, S2, and S3, and the Pb at site S3 showed values exceeding the non-carcinogenic-risk limit. Regarding the carcinogenic risk, all three sites studied had Cd samples that indicated a likelihood of children developing cancer from this heavy metal. [ABSTRACT FROM AUTHOR]

Wadi Abu Subeira area contains many farms and houses and is one of the promising areas for iron mining. Therefore, 21 surface soil samples were collected and investigated for toxic heavy metals (Pb, Cr, Ni, Cu, Zn, Co, and As) using inductively coupled plasma (ICP) to establish a geochemical baseline for these metals during pre-mining conditions. To decipher the sources of these metals and their interrelationships, multivariate statistical analysis was applied, while to evaluate the degree of pollution and potential environmental risks the environmental indices were used. Abundances of Pb, Cr, Ni, Cu, Zn, Co, and As fluctuated from 17.72 to 0.06, 47.12 to 10.86, 47.88 to 9.25, 45.04 to 6.23, 51.93 to 17.82, 10.55 to 1.24, and 7.04 to 1.66 mg/kg, respectively, displaying a declining trend of Zn > Cr > Ni > Cu > As > Co > Pb. Additionally, the mean concentrations of all studied metals were found to be significantly lower than the selected international reference standards. Pearson correlation coefficient, principal component analysis, and cluster analysis revealed two geogenic geochemical associations for the studied toxic elements: (1) Zn-As-Ni-Cr-Cu-Co; and (2) Pb. Negative Igeo values were observed for all metals, which showed that the samples were uncontaminated and can be considered a geochemical baseline for the study area. Moreover, all CF values were lower than or close to 1, suggesting low contamination levels from all studied metals and supporting the association with natural geological processes. Similarly, Er and RI values of all metals were below 40 and 150, respectively, indicating a low-risk environment. Ultimately, the obtained levels of the studied metals can be used as a geochemical baseline for tracking the future changes in their accumulations in soil sediments considering the current assessment of the area as an environmentally safe area. [ABSTRACT FROM AUTHOR]

Soil microorganisms contribute substantially to a wide range of services and thereby improve recovery in ecosystem restoration. However, there is relatively limited information on how microbial communities respond to different land-use types with similar plant species and their potential roles in supporting soil restoration in mine tailings. To understand the importance of the response of soil microbial communities to the stress of tailings area in different soil habitats, this article selected three different land use types (Tailings area, Buffer zone and Vegetable field) as the variables in the Yanzibian tailings area in Ningqiang, Shaanxi Province, China. Soil physicochemical properties and heavy metal concentrations of the different land use types were compared. Illumina MiSeq. 2500 Sequencing Technology was used to analyze the abundance and structural diversity of the microbial community in soil samples. The results showed that most of the soil samples were unsafe with multiple metals. All soil samples in the buffer zone and tailings ponds were acidic. With the acidity decreased, bacterial community richness and diversity increased significantly. Briefly, different environmental factors and soil microbial communities were significantly distinct across different land-use types. Cu, Zn, Pb, pH, MC (Moisture content), TN (Total nitrogen), TP (Total phosphorus), and TK (Total potassium) were essential factors affecting the abundance and structural diversity of soil microbial communities across three different land-use types. As a result, Actinobacteria, Alphaproteobacteria, and Gammaproteobacteria were the top dominant classes in the buffer zone and Vegetable field soils, while Sulfobacillia dominated in tailings pond soils. Further, we found that with the continuous decline of the pH, the dominant genera transferred from norank_f__norank_o__Vicinamibacterales, Bacillus and Nocardioides to the norank_f__norank_o__Gaiellales and norank_f__norank_o__Acidobacteriales, then to Sulfobacillus. These confirmed that the responses of microbiota to heavy metals stress varied in different land-use types. Together, this study provides important information on the occurrence and distribution of soil microbiomes in tailings areas and their potentially beneficial roles in soil restoration. [ABSTRACT FROM AUTHOR]

The aim of this study is to evaluate the mobility/availability of potentially toxic elements in the soil of public parks to assess the environmental quality and potential health risks. The concentrations of 16 selected metals (Ca, Mg, Sr, K, Na, Li, Fe, Mn, Zn, Cu, Ag, Co, Ni, Cr, Cd and Pb) in the soil samples collected from 20 parks located in Lahore, Pakistan were measured by flame atomic absorption spectrometry using modified BCR sequential extraction during summer and winter season. In the exchangeable soil fraction, highest mean concentration was found for Ca, followed by Mg, K, Na and Mn, while in the reducible soil fraction, relatively higher mean levels were noted for Ca, Fe, Mg, K and Mn. In the case of oxidisable soil fraction, Fe, Mg, K, Na, Ca, Mn and Pb were the dominant contributors among the selected metals. Comparatively higher mobility and bioavailability in the soil was shown by Ca, Sr, Pb, Cd, Na, Ag, Co, Mn, and Zn while Cr, K, Li, Fe and Cu were found mainly in the residual fraction. Cluster analysis demonstrated anthropogenic intrusions of Cd, Pb, Co, Cr, Cu, Li, Zn and Na in the park soil. The pollution assessment revealed that the soil of the public parks was heavily to extremely polluted by Cd, followed by moderate to significant contamination for Pb and Zn. The modified degree of contamination (1.48 and 1.88 in summer and winter, respectively) exhibited an overall low degree of contamination. The health risk assessment showed that the calculated values were within the safe limit thereby indicating no significant non-carcinogenic or carcinogenic heath risk to the exposed population. The study offers more insights to control the environmental and human health risks of trace metals in public parks by reducing the soil pollution and it will provide critical information for policy makers to formulate effective pollution control strategies. [ABSTRACT FROM AUTHOR]

In this study, the contents of heavy metals (HMs) such as Al, Cd, Co, Cr, Cu Fe, Mn, Ni, Pb and Zn in soil samples collected from 403 sampling locations of the agricultural lands of Adıyaman Province (Türkiye) were determined by Inductively Coupled Plasma‒Optical Emission Spectrometry (ICP‒OES). The mean concentrations of Al, Cd, Co Cr, Cu Fe, Mn, Ni, Pb and Zn HMs were detected 28,986, 3.60, 15, 127, 52.67, 45,830, 817, 62.40, 10.75 and 66.25 mg kg−1, respectively. These results showed that the average concentrations of Cd, Cr, Cu, Fe, Mn and Ni exceeded the Upper continental crust average. To determine and to evaluate the contamination status and distribution of HMs in agricultural soils, metal pollution parameters such as enrichment factor (EF), geoaccumulation index (Igeo), contamination factor (Cf), pollution load index, potential ecological risk factor (Er), and potential ecological risk index (RI) were used. Factor analyses (FA) and principal component analyses (PCA) indicated that Cd, Cr and Ni levels were influenced by anthropogenic sources, Fe by both lithological and anthropogenic sources, and other HMs by lithogenic origins. For both children and adults, the hazard index (HI) and total hazard index (THI) values of HMs were < 1, suggesting that non-carcinogenic health risks to residents through ingestion, inhalation pathways, and dermal contact were currently absent. In addition, the cumulative carcinogenic risk (CCR) results were within the acceptable risk range (10–4 to 10–6). The results showed that children were more sensitive to the non-carcinogenic and carcinogenic effects of HMs. [ABSTRACT FROM AUTHOR]

Biochemical processes in the rhizosphere affect the availability and distribution of heavy metals (HMs) in various forms. Rhizosphere soil (RS) and non-rhizosphere soil (NRS) samples were collected from 10 fields under tarragon (Artemisiadracunculus L.) cultivation to investigate the release kinetics and distribution of HMs including cadmium (Cd), cobalt (Co), copper (Cu), iron (Fe), and zinc (Zn) in five fractions. The cumulative amounts of Cu and Fe released after 88 h were in the following ranges, respectively: 1.31–2.76 and 3.24–6.35 mg kg−1 in RS and 1.41–2.72 and 3.15–5.27 mg kg−1 in NRS. The parabolic diffusion and pseudo-second-order equations provided the best fit to the release kinetics data of Cu and Fe, respectively. The cation exchange model (CEM) based on Gaines–Thomas selectivity coefficients implemented in the PHREEQC program could well simulate the release of Cu and Fe suggesting that cation exchange was the dominant mechanism in the release of Fe and Cu from soils by 0.01 M CaCl2. Cadmium was predominantly found in fraction F2, while other HMs were mainly present in fraction F5. According to the risk assessment code, there was a very high risk for Cd, a medium risk for Co and Cu, a very low risk for Fe, and a low risk for Zn. Correlation analysis showed that soil physicochemical properties were effective in the distribution and transformation of HMs. Significant positive correlations between five fractions indicated that different forms of HMs can potentially transform into each other. [ABSTRACT FROM AUTHOR]

Concurrent exposure to cadmium (Cd) and lead (Pb) is prevalent in the environment, but information on the long-term impacts of complex Cd–Pb exposure on herbivorous insects, especially at low doses, is scant. We studied the effects of complex Cd–Pb exposure (4.06 mg/kg Cd and 12.5 mg/kg Pb) on the growth and food utilization of the herbivorous insect Spodoptera litura for 10 continuous generations. Cd or Pb ingestion, excretion and accumulation by insect at the different developmental stages was determined for ten generations. The weighted scores calculated by the analytic hierarchy process (AHP) on the basis of the parameters of survival, growth and food utilization indicated that complex Cd–Pb exposure had positive impacts on the insects, regardless of generations. Compared with Cd (4.06 mg/kg Cd) and Pb (12.5 mg/kg Pb) alone, complex Cd–Pb exposure showed antagonistic interactions. After exposure to complex Cd–Pb, although larvae significantly increased heavy metal uptake along with the elevated ECD and ECI, insects enhanced heavy metal excretion via the feces and puparium; consequently, heavy metal accumulation in the insect body significantly decreased. With increasing generations, the positive impacts of complex Cd–Pb stress on insects became increasingly obvious, and the uptake of Cd or Pb decreased while the excretion of Cd or Pb increased, which demonstrated that insect tolerance to Cd–Pb exposure at low concentrations increased over generations. [ABSTRACT FROM AUTHOR]

Heavy metal contamination in soils seriously threatens human health and aggravates the global pollution burden. In this study, we investigated the risk of heavy metal contamination in soils at a Zn-Pb mineral processing plant in Longnan, China, and the effects of different heavy metal contamination levels on diverse microbial communities. Statistical analysis showed that, except for Ni, the average content of all detected metals (Zn, Pb, As, Cu, Cd, Hg) in the soil was higher than the background value of soil in the study area, which was most seriously contaminated with Pb and As. Comparison of functional divisions showed that heavy metal soil contamination was most serious in the raw material stacking area and the production area. Interpolation analysis showed that areas closer to the wastewater discharge area had higher contents of each heavy metal and were more seriously polluted. From the point of pollution index, the risk of heavy metal soil pollution in the study area was very high (RI = 2845.24, i.e., > 600), with Cd and Hg being the most serious pollutants compared with other heavy metals. Microbial community abundance, diversity, and structure differed at different levels of heavy metal contamination. The community diversity of bacteria decreased with increasing heavy metal concentrations, while no significant change in fungi was observed. Evidence from variation redundancy analysis (RDA) and the Spearman correlation analysis showed that the leading factors affecting microbial community composition were Cu, Cd, Hg, and pH. Actinobacteria and Gemmatimonadetes at the uncontaminated level (CL) were significantly and negatively correlated with the concentrations of Cu, Zn, Cd, and Pb. Proteobacteria and Chloroflexi at the severely contaminated level (SL) were significantly correlated with pH and Hg. However, heavy metal contamination had less effect on most of the dominant fungi. In conclusion, microbial communities such as Proteobacteria, Actinobacteria, Chloroflexi, and Ascomycota showed greater tolerance to heavy metals. These results could be used as important references for the remediation of heavy metal-contaminated soils. [ABSTRACT FROM AUTHOR]

In recent years, many factors such as climate change and drought have changed the Zagros forests in western Iran. Also, unsuitable use of the forest is now threatening the long-term survival of Zagros forests by local natives. The municipal solid waste (MSW) disposal of Ilam city (in the west of Ilam province) is located in the Zagros forests. In this study, the effects of the Ilam landfill on soil and Oak tree (leaf) contamination with heavy metals (HMs) were investigated. 31 points around the landfill (at different distances from the landfill) were considered for sampling, and also 6 points were selected in forest areas that are far away from pollution sources as control areas. The forest soils and oak leaves were randomly collected from the control area and landfill. The soil and tree leaf samples were analyzed for cadmium, chromium, cobalt, copper, iron, lead, nickel, magnesium, and zinc using atomic absorption spectrophotometry. Several pollution indices, the Kriging method, and principal component analyses were applied for evaluating the contamination level spatial distribution, and possible sources of heavy metals. The concentrations of chromium, cobalt, and nickel in landfill soils were 531.6, 43.87, and 408.8, respectively, which were 5–10 times higher than the United States Environmental Protection Agency (USEPA) standards. The concentrations of chromium and nickel in oak leaves were 2.83 and 5.91, respectively, which are higher than the permissible limit. The results showed that there were statistically significant differences (p < 0.05) in metal soil concentrations between (lead, cobalt, zinc, and copper) the control area and landfill (with was 2 times higher than in the control). Higher values of soil pollution indices were obtained for the landfill sites than for the control sites. The findings of the spatial distribution confirmed that the heavy metals from the landfill significantly affected the soils of the Zagros forest. The presence of heavy metals in soil and leaf samples shows that contamination is due to leachate migration from an open dumping site. Regular monitoring around this non-engineered landfill is required. [ABSTRACT FROM AUTHOR]

Fifteen riparian populations of Lithuanian Lythrum salicaria were assessed for leaf macronutrient, micronutrient and non-essential element concentrations and compared to the former obtained molecular data at amplified fragment length polymorphism (PLP.AFLP) loci. Inductively coupled plasma mass spectrometry was used to profile the contents of 12 elements in the leaves. The leaf nutrient concentrations were within normal ranges for growth and development and heavy metal concentrations did not reach toxic levels. The concentrations of macroelements such as nitrogen, potassium, calcium and magnesium were in the range of 23,790–38,183; 7327–11,732; 7018–12,306; and 1377–3183 µg/g dry mass (d. m.), respectively; the concentrations of micronutrients such as sodium, iron, zinc and copper varied in the ranges of 536–6328; 24.7–167.1; 10.88–26.24; and 3.72–5.30 µg/g d. m., respectively, and the concentrations of non-essential elements such as lead, nickel, chromium, and cadmium were in the intervals of 0.136–0.940; 0.353–0.783; 0.207–0.467; and 0.012–0.028 µg/g d. m., respectively. When comparing the maximum and minimum values for site elements of L. salicaria, the concentration of N varied by 1.6, K—1.6, Ca—1.8, Mg—2.3, Na—6.1, Fe—6.8, Zn—2.4, Cu—1.5, Pb—6.9, Ni—2.2, Cr—2.2, and Cd—2.3 times. The coefficient of variation (CV) of element concentrations in sites was moderate to large: N—15.4%, K—14.3%, Ca—18.6%, Mg—24.8%, Na—50.7%, Fe—47.0%, Zn—24.9%, Cu—14.5%, Pb—57.1%, Ni—30.11%, Cr—26.0%, and Cd—38.6%. Lythrum salicaria populations growing near regulated riverbeds were characterized by significantly (p < 0.05) lower concentrations of Ca and Mg, and significantly (p < 0.05) higher concentrations of N, K, Fe, Na, Ni, Cr and Cd. The PLP.AFLP was negatively correlated with concentrations of N, Na, Fe, Ni, Cr, and Cd. The L. salicaria population with the lowest leaf N and Na concentration showed the highest genetic polymorphism (PLP.AFLP = 65.4%), while the least polymorphic population (PLP.AFLP = 35.0%) did not show extreme concentrations of either element. In conclusion, our elemental analysis of L. salicaria populations showed that ionomic parameters are related to genomic parameters, and some habitat differences are reflected in the ionomes of the populations. [ABSTRACT FROM AUTHOR]

Heavy metal contamination has occurred as a result of industrial civilization. Zinc, copper, chromium, and lead are the most prevalent heavy metal pollutants. Heavy metal contamination has arisen as a significant environmental issue on a global scale. Human and environmental health is at risk when soils are contaminated. as well as having poor engineering qualities. Solidification/Stabilization is a critical remediation strategy for polluted soils which is both efficient and cost-effective. The solidification/stabilization approach has been frequently used to rehabilitate heavy metal-contaminated areas. First, The use of gypsum to strengthen and leach polluted soils was reviewed. Also, cement/fly ash-solidified/stabilized soils have better engineering qualities. On the other hand, the global output of phosphogypsum surpasses 300 million tons, raising disposal and environmental problems every year. The efficiency of the phosphogypsum-based stabilization/solidification technique was investigated, and the methods employed biochar and chemical agents such as citric acid and FeCl3. This review examines various remediation options as well as innovative soil amendments. [ABSTRACT FROM AUTHOR]

Information on spatial distribution and potential sources of heavy metals in agricultural lands is very important for human health and food safety. In this study, pollution degree of lead (Pb), cadmium (Cd), and nickel (Ni) in Yüksekova Plain, located on the border in the southeastern part of Turkey, was evaluated by geoaccumulation index (Igeo), modified contamination factor (mCdeg), and Nemerow pollution index (PINemerow) combined with spatial autocorrelation using deep learning algorithms. A total of 304 soil samples were collected from two different depths (0–20 and 20–40 cm) in the study area, which covered 17.5 thousand ha land. Covariates were determined for spatial distribution models of Pb, Cd, and Ni by factor analysis (FA). Spatial distribution models for surface soils were developed using pedovariables (silt, sand, clay lime, organic matter, electrical conductivity, pH, Ca, and Na) determined by the FA and Igeo and mCdeg values by artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS) models. The estimation success of models for different depths was assessed by root mean square error (RMSE), mean absolute percent error (MAPE), and Taylor diagrams. The RMSE and MAPE values showed a strong correlation between heavy metal contents and the covariates. The RMSE values of ANN-Ni0-20, ANN-Ni20-40, ANN-Pb0-20, ANN-Cd0-20, and ANN-Cd20-40 models (0.01240, 0.07257, 0.0039, 0.00045, 0.00044, and 0.04607, respectively) confirmed the success of the models. Likewise, the MAPE values between 0.2 and 8.5% indicated that all models were very good predictors. In addition, the Taylor diagrams showed that the estimation performance of ANFIS and ANN models are compatible. The IgeoNi and IgeoPb values in both models at both depths indicated that strongly to extremely polluted (4–5) areas are quite high in the study area, while the IgeoCd values revealed that unpolluted areas are widespread. The mCdeg index value showed a moderate to high contamination at the first depth, while very high contamination at the second depth in most of the study area. Spatial distribution of PINemerow revealed that moderate pollution (2–3) is common in both soil depths of the study area. The PINemerow of subsurface layer was between 0.91 and 1 (warning limit class) in a small part of the study area. The results showed that vertical mobility of heavy metals is closely related to pedovariables. In addition, the ANN and ANFIS models are capable of exhibiting the heterogeneity in the spatial distribution pattern of high variation in the data. Thus, the locations with extreme contamination have been accurately determined. The pollution indices calculated considering the commonly used international reference values revealed that heavy metal pollution in some part of the study area reached the detrimental levels for human health and food safety. The results suggested that the pollution indices were more successful than simple heavy metal concentrations in interpreting the pollution risk levels. High-resolution spatial information reported in this study can help policy makers and authorities to reduce heavy metal emissions of pollutants or, if possible, to eliminate the pollution. [ABSTRACT FROM AUTHOR]

With the intensive urbanization and industrialization in recent years, lots of products containing heavy metals (HMs) have brought in severe environment problems. Yuqiao Reservoir (YQR) is an important drinking water source area in Tianjin of China, and the soil environmental quality of YQR is vital for human health. The goal of this study was to identify the priority control pollutants and hotspots of HMs contamination of YQR catchment. Thus, an integrated field investigation was conducted to analyze the major elements such as As, Cd, Cr, Cu, Hg, Ni, Pb and Zn in soils around YQR. Geoaccumulation index (Igeo), enrichment factor (EF) and potential ecological risk index (PERI) were employed to assess the contamination status of HMs. The average contents of these elements were given as follows: As 7.97 mg/kg, Cd 0.31 mg/kg, Cr 86.1 mg/kg, Cu 24.7 mg/kg, Hg 0.044 mg/kg, Ni 30.7 mg/kg, Pb 27.3 mg/kg and Zn 76.7 mg/kg. According to geoaccumulation index (Igeo) and enrichment factor (EF) values, Cd, Cr, Pb and As showed a prominent enrichment. The result of multivariate statistics showed that Cd, Cr, Cu, As, Ni, Pb and Zn concentrations were mainly affected by human activities, whereas Hg was mainly from natural release. The anthropogenic activities were the major sources with a contribution of 91.46%, while natural origins only contributed 8.54%. And agricultural fertilization, mining and traffic activities are the most probable sources of these heavy metals in the soil. The PERI values indicated that 65.7% of total HMs were at low risk, 22.5% in moderate risk and 11.8% in considerable risk. To ensure soil environmental quality and human health, cadmium should be listed as a priority control pollutant. Spatial maps of HMs and their integrated PERI provided clear hotspots that indicated lower risk in the region close to YQR but higher risk in the region far from YQR. [ABSTRACT FROM AUTHOR]

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Focused supervision and early warning of heavy metal (HM)-contaminated rice areas can effectively protect people's livelihood security and maintain social stability. To improve the accuracy of risk prediction, an Informer-based safety risk prediction model for HMs in rice is constructed in this paper. First, based on the national sampling data and residential consumption statistics of rice, we construct a dataset of evaluation indicators that can characterize the level of rice safety risk so as to form a safety risk space. Second, based on the K-medoids clustering algorithm, we classify the rice safety risk space into levels. Finally, we use the Informer neural network model to predict the safety risk indicators of rice in each province so as to predict the safety risk level. This study compares the prediction accuracy of a self-constructed dataset of rice safety risk assessment indicators. The experimental results show that the prediction precision of the method proposed in this paper reaches 99.17%, 91.77%, and 91.33% for low, medium, and high risk levels, respectively. The model provides technical support and a scientific basis for screening the time and area of HM contamination of rice, which needs focus. [ABSTRACT FROM AUTHOR]

The present study aimed to evaluate the potential toxic heavy metal (PTHM) concentrations and associated ecological and health risk of nearby inhabitants (child and adult populations) of the Bokaro thermal power station (BTPS), Jharkhand, India. The fly ash containing PTHMs is released from the thermal power plant and contaminates the soil of the nearby agricultural area, roadside area and residential area. Furthermore, PTHMs cause ecological risk as well as carcinogenic health effects in adults. Inhabitants are exposed to PTHMs through exposure pathways (for instance, direct ingestion, dermal contact and air inhalation), and PTHMs were examined in this study by calculating the estimated daily intake (EDI). The contamination factor (Cf) of Cd exceeded the threshold value throughout the study area, whereas the Cf of Hg was observed higher only in roadside soil (RSS). The geoaccumulation index (Igeo) of Cd was higher in the top soil of agricultural soil (AS) (7.39) and RSS (9.38). The level of PTHMs was monitored slightly higher in the topsoil of RSS. The ecological risk index (Eri) was detected to be the highest in RSS (1628.9). The permissible limit of Cd (0.05 mg kg−1) and Pb (0.1 mg kg−1) for all sampled vegetables and grain crops was surpassed. The transfer factor (TF) of the studied vegetables and grain crops was in the order of Cd > Cr > Pb > Hg > As. The results of the present study concluded that the hazard quotient (HQ) values for all PTHMs analysed in soil throughout the study area were < 1, which indicates that the child population was within the safe limit. However, the adult population was at a high risk of non-carcinogenic health effects due to increased permissible limits of Cd, Pb and Cr in vegetables and grain crops whereas the target carcinogenic risk (TCR) of Pb and Cr was higher and indicated that there may be a health risk of cancer in adults. [ABSTRACT FROM AUTHOR]

In the environment, heavy metal contamination is a well known problem due to its persistence and toxicity. Heavy metal pollution has significantly affected soil properties and functions, resulting in significantly increased land degradation as a result of anthropogenic interventions that include mining and various industrial and agriculture activities. While heavy metals pollution in soil have been studied very rarely in this District, this paper explores the current status of agricultural soil pollution by heavy metals in Raebareli. This study identifies heavy metals as well as their quantities in the soil and their spatial distribution; our study employed various pollutant indices and geographical information system (GIS) techniques. This research work evaluated the physiochemical properties, the pollution load index (PLI), contamination factor (CF) and the degree of contamination and geoaccumulation (Igeo) in sodic soils of the Raebareli District, Uttar Pradesh, India. Uchahaar site (US) has the most polluted soil, while the Bacharawa site (BS) has the least contaminated soil. The soil quality has degraded due to anthropogenic interventions at most sites. There is slight to moderate contamination by heavy metals at all sites. The Igeo values in subSites US1, US2 and US3 included high levels of Cu, Zn, Pb, Mn and Sr. SubSites BS2 and BS3 have high Sr levels and US1 has a high As level all these Subsites have high anthropogenic influences. The PLI values indicate that most of the study subSites come under a slightly polluted class, except US1 where the PLl was > 3 indicating severe heavy metal pollution at this site. All the pollution indices have then been utilized for building maps using the IDW method of interpolation. The spatial projection of PLI and ecological risk index (Er) values suggest that the northern part of Raebareli has a high pollution load and ecological risk in terms of heavy metal pollution. This study provide valuable information that policymakers could use to develop an appropriate plan to control pollution within the agricultural sector. [ABSTRACT FROM AUTHOR]

Heavy metal pollution in China's soil is very serious, and soil remediation is urgent. At present, most of the domestic and foreign research is aimed at one soil type for soil heavy metal pollution remediation. However, the distribution of heavy metals and the effect of remediation with chemical agents are different for different soils. This study is committed to investigating the effect of WTF on the remediation of heavy metal contamination in different soils based on the existing research in the laboratory. The influence of soil quality on remediation efficiency was analyzed by TCLP leaching of heavy metals, and different forms of heavy metals were extracted from the soil using the BCR method. The experimental results showed that the soil environment was alkaline, and the response to a low addition of WTF was more obvious. The Pearson correlation coefficient analysis yielded that the increase in the organic matter content led to an increase in the oxidizable Cd content. The WTF remediation did not change the overall acidity and alkalinity of the soil so that the overall soil environment remained stable; it increased the organic matter content and added fertility to the soil, and it increased the activity of most enzymes in the soil and promoted the circulation of the soil elements, making the soil fertile. [ABSTRACT FROM AUTHOR]

We examined the topsoil heavy metal concentration of four different urban functional areas (UFAs) in Nanjing, China: a heavy traffic area (HA), an industrial area (IA), a leisure area (LA), and a farmland area (FA). The purpose of the study is as follows: (i) to determine which heavy metal(s) were the primary pollutant(s) in the study area and the contamination status of five heavy metals (Cr, Ni, Cu, Zn and Pb) in the urban topsoil of Nanjing city, (ii) to assess the comprehensive pollution risk of heavy metals in UFAs using two methods: the ecological risk index and the fuzzy comprehensive evaluation based on Analytical Hierarchy Process (AHP). X-ray fluorescence (PXRF) was used to measure the soil heavy metal content, the potential ecological risk method was implemented to evaluate the risk level of each UFA, and the fuzzy comprehensive evaluation method was applied to assess the pollution degree of heavy metals in UFAs. PXRF analysis showed that Cr was the primary metal pollutant in the study area. There were also significant enrichments of Cu, Zn and Pb in collected soil samples. The four UFAs were ranked IA > HA > LA > FA in terms of the potential heavy metal ecological risk; the distribution pattern determined by the fuzzy comprehensive evaluation model followed the same order. Overall, 84.70%, 12.98% and 2.32% of the 647 sites were classified as class I (clean), class II (lightly polluted), and class III (heavily polluted), respectively, suggesting that most soil in Nanjing was clean. Based on the calculated weight matrices of the potential ecological risk results, the major pollutants were Cr and Zn. This investigation highlighted that most of the soil in the study area is clean, but certain sites are polluted to some degree, especially in the IA. The study area showed an overall moderate ecological risk for heavy metal pollutants, with Cu and Pb posing the greatest risk. [ABSTRACT FROM AUTHOR]

Recently sustainable and efficient land development and the potential reutilization values of abandoned mines (i.e., industrial, arable, and tourism) have been attracting worldwide attention. However, environmental impacts after rehabilitation practices are often ignored and field data are lacking. What remains unknown is an understanding how the risk of soil trace metal(loid)s (TMs) respond to short‐term rehabilitation of abandoned gold mines and the potential value for following targeted remediation. We found that a high level of TM cadmium (Cd) and arsenic (As)] contamination and significant health risk to humans, limited land reutilization in rehabilitation scenarios. Feedback from soil TMs to rehabilitation is of potential value for following targeted remediation. Specifically, (1) the major pollutants we studied were Cd and As. Cadmium poses a considerable ecological risk as evidenced by Igeo, contamination factor, Eri and risk assessment code, and a much higher bioavailability evidenced by non‐residual fractions (42.42%). Arsenic has the lowest environmental availability with 90.99% in residual fraction; (2) spatial distributions of TMs were similar. Sites with serious contamination were mainly located in the southwest of the study area, close to the abandoned mine; Results of principal component analysis suggested that mining activities were the main anthropogenic pollution sources; (3) there was no non‐carcinogenic risk and a higher carcinogenic risk was found in adults than in children. Targeted remediation techniques are needed to mitigate carcinogenic risks posed by As and Cr. This study emphasized the necessity of assessment of soil TMs risk in abandoned gold mines with short‐term rehabilitation and offered crucial data utilized to optimize time parameters (short‐term) towards sustainable and efficient land development. [ABSTRACT FROM AUTHOR]

Coal mining activities have a series of impacts on the local eco-environment, such as air pollution due to the release of toxic gases, contamination of soil with heavy metals, disturbance and contamination of surface and subsurface water, and damage to land resources with surface subsidence and accumulation of solid waste materials. This study investigated the distribution of heavy metals in mining sites by analyzing the heavy metal content in soil samples from different sites in the Dahuangshan mining area of the southern Junggar coalfield (Xinjiang, China). The results show that area C has the highest Cu content; and area B has the highest Mn content, the highest Zn content, the highest As content, and the highest Cd content, which indicate that area B underwent potential multiple heavy metal contamination. It also shows that the Cd is the major heavy metal for all three areas. The different eco-environmental indices, including the Nemerow comprehensive pollution index, the geo-accumulation index, and the potential ecological risk index, all show the same results, i.e., that Cd is the major potential contaminant in all three types of soil. [ABSTRACT FROM AUTHOR]