Persistent organic pollutants, heavy metals and radioactivity in the urban soil of Priština City, Kosovo and Metohija

Assessment of coastal river water quality in Bangladesh: Implications for drinking and irrigation purposes

Saltwater intrusion in the coastal areas of Bangladesh is a prevalent phenomenon. However, it is not conducive to activities such as irrigation, navigation, fish spawning and shelter, and industrial usage. The present study analyzed 45 water samples collected from 15 locations in coastal areas during three seasons: monsoon, pre-monsoon, and post-monsoon. The aim was to comprehend the seasonal variation in physicochemical parameters, including water temperature, pH, electrical conductivity (EC), salinity, total dissolved solids (TDS), hardness, and concentrations of Na+, K+, Mg2+, Ca2+, Fe2+, HCO3-, PO43-, SO42-, and Cl-. Additionally, parameters essential for agriculture, such as soluble sodium percentage (SSP), sodium absorption ratio (SAR), magnesium absorption ratio (MAR), residual sodium carbonate (RSC), Kelly's ratio (KR), and permeability index (PI), were examined. Their respective values were found to be 63%, 16.83 mg/L, 34.92 mg/L, 145.44 mg/L, 1.28 mg/L, and 89.29%. The integrated water quality index was determined using entropy theory and principal component analysis (PCA). The resulting entropy water quality index (EWQI) and SAR of 49.56% and 63%, respectively, indicated that the samples are suitable for drinking but unsuitable for irrigation. These findings can assist policymakers in implementing the Bangladesh Deltaplan-2100, focusing on sustainable land management, fish cultivation, agricultural production, environmental preservation, water resource management, and environmental protection in the deltaic areas of Bangladesh. This research contributes to a deeper understanding of seasonal variations in the hydrochemistry and water quality of coastal rivers, aiding in the comprehension of salinity intrusion origins, mechanisms, and causes.

Endophytic Bacillus sp. R1 and Its Roles in Assisting Phytoremediation and Alleviating the Toxicity of Aluminum Combined Phenanthrene Contaminations in Brassica napus

The release of organic and inorganic contaminants into soil from industry, agriculture, and urbanization has become a major issue of international concern, particularly the heavy metals such as aluminum (Al) and the chemical phenanthrene (PHE). Due to their potential toxicity and non-biodegrade in the environment, efficient remediation methods are urgently needed. Recently, research has comprehensively discussed using plants and their endophytes in bioremediation efforts. Endophytic Bacillus sp. R1, isolated from Brassica napus permanently contaminated with Al and PHE, has growth-promoting properties and can efficiently detoxify these contaminants. The pot experiment indicated that compared to the Al combined PHE contaminated soil alone treatment, the R1 treatment led to increased Al accumulation in canola roots across different levels of PHE, Al, and combined PHE and Al contamination. However, Al accumulation in canola shoots and seeds remained unchanged for all treatments. Moreover, PHE in canola roots and shoots was decreased by R1 inoculation and thereby reducing 26.12-60.61% PHE translocated into canola seeds. Additionally, R1 inoculation significantly increased the proportion of extractable Al and, decreased the proportion of acid-soluble inorganic Al and humic-acid Al, but did not affect the concentration of organically complexed Al. In summary, endophyte R1 can degrade PHE, improve canola roots' Al uptake by increasing soil available Al, and scavenge the reactive oxygen species through production of antioxidant enzymes to help alleviate the toxicity of canola co-contaminated with aluminum and phenanthrene.

Identification of possible sources for potentially toxic elements and polycyclic aromatic hydrocarbons and their spatially varying relationships in urban soils of Dublin, Ireland

Potentially toxic elements (PTEs) and polycyclic aromatic hydrocarbons (PAHs) harm the ecosystem and human health, especially in urban areas. Identifying and understanding their potential sources and underlying interactions in urban soils are critical for informed management and risk assessment. This study investigated the potential sources and the spatially varying relationships between 9 PTEs and PAHs in the topsoil of Dublin by combining positive matrix factorisation (PMF) and geographically weighted regression (GWR). The PMF model allocated four possible sources based on species concentrations and uncertainties. The factor profiles indicated the associations with high-temperature combustion (PAHs), natural lithologic factors (As, Cd, Co, Cr, Ni), mineralisation and mining (Zn), as well as anthropogenic inputs (Cu, Hg, Pb), respectively. In addition, selected representative elements Cr, Zn, and Pb showed distinct spatial interactions with PAHs in the GWR model. Negative relationships between PAHs and Cr were observed in all samples, suggesting the control of Cr concentrations by natural factors. Negative relationships between PAHs and Zn in the eastern and north-eastern regions were related to mineralisation and anthropogenic Zn-Pb mining. In contrast, the surrounding regions exhibited a natural relationship between these two variables with positive coefficients. Increasing positive coefficients from west to east were observed between PAHs and Pb in the study area. This special pattern was consistent with prevailing south-westerly wind direction in Dublin, highlighting the predominant influences on PAHs and Pb concentrations from vehicle and coal combustion through atmospheric deposition. Our results provided a better understanding of geochemical features for PTEs and PAHs in the topsoil of Dublin, demonstrating the efficiency of combined approaches of receptor models and spatial analysis in environmental studies.

Heavy metal contamination levels, source distribution, and risk assessment in fine sand of urban surface deposited sediments of Ekaterinburg, Russia

Urban surface deposited sediments (USDS) are unique indicators of local pollution that pose a potential threat to the living environment and human health. Ekaterinburg is a highly populated metropolitan area in Russia with rapid urbanization and industrialization activities. In Ekaterinburg's residential areas, about 35, 12, and 16 samples are represented by green zones, roads, driveways, and sidewalks, respectively. The total concentrations of heavy metals was detected using a chemical analyzer inductively coupled plasma mass spectrometry (ICP-MS). Zn, Sn, Sb, and Pb have the highest concentrations in the green zone, while V, Fe, Co, and Cu represent the utmost values on roads. Moreover, Mn and Ni are the prevailing metals in the fine sand fraction of driveways along with sidewalks. Broadly, the high pollution in the studied zones is generated by anthropogenic activities and traffic emissions. The potential ecological risk (RI) was observed in high risk (IR > 600), even though the results of all heavy metals reveal no adverse health effects from the considered noncarcinogenic metal for adults and children by different exposure pathways except the children's exposure to Co in case of the dermal contact, where the HI values of Co for children in the studied zones are higher than the proposed level (> 1). In all urban zones, the total carcinogenic risk (TLCR) values are predicted as a high potential inhalation exposure.

Environmental and biological monitoring of organochlorine pesticides in the city of Salamanca, Mexico

The former Tekchem Industrial Unit located in the city of Salamanca, Mexico, constitutes an environmental liability in which the presence of high levels of organochlorine pesticides (OCPs) has been reported. In the present study, levels of OCPs were quantified using gas chromatography-mass spectrometry in 52 soil samples and in 88 blood samples from school-age children in the city of Salamanca. A median concentration of 70.6 ng/g (6.93-3299) was obtained for total OCPs in soil, while for the total sum of dichlorodiphenyltrichloroethane (DDT) the value was 49.6 ng/g (6.93-3276). In children, the median level of the total sum of OCPs was 390 ng/g lipid (7.34-14,895), and for the total sum of DDT was 175 ng/g lipid (< LOD-14,802). The OCPs that resulted in highest concentrations in soil were DDT and its metabolites, as well as aldrin and heptachlor epoxide, while in blood the highest levels corresponded to 4,4'-dichlorodiphenyltrichloroethane (4,4'-DDT) and its metabolites, followed by heptachlor and heptachlor epoxide. The spatial distribution of the concentrations of OCPs in soil shows that the facilities of Tekchem may be a significant potential source for the dispersion of these compounds toward the metropolitan area of Salamanca. The results obtained in the present study demonstrate the presence of OCPs in soil and in child population, providing important bases to study the problem from a broader perspective, while reiterating the importance of continuing efforts to generate resolute and precautionary measures with respect to the environmental liability of Tekchem.

Spatial characteristics, sources and exposure risk of polychlorinated biphenyls in dusts and soils from an urban environment in the Niger Delta of Nigeria

Chlorinated organic compounds, such as polychlorinated biphenyls (PCBs), are a threat to both humans and the environment because of their toxicity, persistence, and capacity for long-range atmospheric transport. The concentrations of 28 PCB congeners, including 12 dioxin-like and seven indicator PCBs, were investigated in soils, and indoor and outdoor dusts from Port Harcourt city, Nigeria, in order to evaluate the characteristic distribution patterns in these media, their sources, and possible risk. The PCB concentrations varied from 4.59 to 116 ng g^-1 for soils, and from 1.80 to 23.0 ng g^-1 and 2.73 to 57.4 ng g^-1 for indoor and outdoor dusts respectively. The sequence of PCB concentrations in these matrices was soil > outdoor dust > indoor dust. The composition of PCBs in these matrices indicated the prevalence of lower chlorinated PCBs in indoor and outdoor dusts, while the higher chlorinated congeners were dominant in soils. Di-PCBs were the predominant homologues in indoor dusts, while deca-PCBs were the most prevalent homologues in outdoor dusts and soils. The TEQ values of dioxin-like PCBs in 60 % of the soils, 100 % of the indoor dust, and 30 % of the outdoor dust were above the indicative value of 4 pg TEQ g^-1 established by the Canadian authority. The hazard index (HI) values for exposure of adults and children to PCBs in these media were mostly greater than one, while the total cancer risk (TCR) values exceeded the acceptable risk value of 10^-6, which indicate probable non-carcinogenic and carcinogenic risks resulting from exposure to PCBs in these media. Source analysis for PCBs in these matrices shows that they originated from diverse sources.

Combined pollution of heavy metals and polycyclic aromatic hydrocarbons in the soil in Shenfu Region, China: a case of three different cities

It is a challenging issue to investigate the combined pollution of heavy metals and polycyclic aromatic hydrocarbons (PAHs) in urban soils. The purpose of this study was to determine the concentrations of these two pollutants in soils in Shenyang, Fushun, and Fushun New District, to analyze their distribution, their interaction, and co-contamination levels. The concentrations of heavy metals were measured by inductively coupled plasma mass spectrometry (ICP-MS), while the concentrations of 21 kinds of PAH were analyzed by gas chromatography-mass spectrometry (GC-MS). Based on the analysis of pollution concentrations and distribution patterns, the intrinsic links between heavy metals and PAHs in three different cities were assessed using a variety of multivariate analysis methods. Compared to Shenfu New District, the concentration of pollutants in Shenyang and Fushun shows a higher level. Moreover, the results of redundancy analysis (RDA) of samples may quantify the possibility of combined pollution of different heavy metal elements and PAHs. This study also affirms the important role of multivariate analysis in being used to reveal the complex interactions and spatial distribution of different pollutants.

Potentially harmful elements in urban surface deposited sediment of Ekaterinburg, Russia: Occurrence, source appointment and risk assessment

In this study, the human health risks of potentially harmful elements (PHEs) in urban surface deposited sediments (USDS) were examined by collecting urban dust samples, measuring their PHE concentrations, and using index evaluation. About 35, 12 and 16 samples are represented a green zones, roads, driveways and sidewalks in residential areas of Ekaterinburg, respectively. The dust fraction (0.002-0.1 mm) was obtained by sieving, filtration, and decantation process. Total concentrations of 10 PHEs were measured using inductively coupled plasma mass spectrometry. The highest concentrations of Pb were found in USDS from green zones, while Fe, V, Mn, Co, Ni, Sn, and Sb on roads, Cu and Zn on driveways and sidewalks. The contamination levels in the investigated land-use areas were studied, where the highest contamination was contributed from Sb in the driveways and sidewalk. Moreover, the pollution in the studied zones was a high load, contributing to anthropogenic activities and traffic emissions. No non-cancerogenic risk was attributed from the PHEs based on the results of health indices (HI < 1) for both adult and children, except Co and Ni which has HI > 1 for children. The total carcinogenic risk (TLCR) in all urban landscape areas is defined as a high potential inhalation exposure and a low potential ingestion and dermal exposure.

Sustainable Strategies for the Agricultural Development of Shaanxi Province Based on the Risk Assessment of Heavy Metal Pollution

Heavy metal elements in farmland soil can be absorbed by crops and endanger food security. To assess the risk of heavy metal elements in farmland soil to crops in Shaanxi Province, we collected 693 soil samples and analyzed the concentrations of nine heavy metals (As, Hg, Pb, Cd, Cr, Mn, Cu, Zn, and Ni). According to the National Standard (GB 15619-2018) of the People’s Republic of China, the proportions of soil sample points in which the concentration of heavy metals was higher than the risk screening value were 2.02% (Cd), 0.29% (Cr), 0.29% (Zn), 2.31% (Cu), 1.15% (Ni), and 0.14% (Pb). The proportions of areas in which the concentration of heavy metal was higher than the background value were as follows, from largest to smallest: Zn (53.20%) > Mn (49.86%) > Cd (29.51%) > Hg (26.77%) > As (26.58%) > Ni (14.95%) > Cu (13.90%) > Pb (6.49%) > Cr (1.40%). The assessment of the risk of heavy metal exposure (geo-accumulation index (Igeo), pollution load index (PLI), and potential ecological risk index (RI)) determined that Hg was the most concerning heavy metal in the farmland soil of Shaanxi Province. Moreover, 11.56% of these areas had Hg contamination, and they were mainly distributed in the western Guanzhong region. The farmland soil in the Guanzhong region was the most contaminated, followed by the southern Shaanxi region and then the northern Shaanxi region. The main sources of heavy metal contamination causing large-scale farmland soil pollution are agricultural production activities, transportation, and air pollution caused by coal combustion in Shaanxi Province. Therefore, sustainable strategies for the prevention and control of heavy metal pollution and agricultural development must be applied in different regions. Heavy metal pollution should be managed, and relevant policies should be created and enforced, such as the standardization of the use of qualified pesticides and fertilizers, improved treatment of livestock and poultry manure, development of the clean energy industry structure, and promotion of renewable energy vehicles. In terms of the high-quality development of agriculture, developing modern and local agriculture in different regions should be based on local geographical, climatic, and economic conditions.

Spatial clustering and source-specific risk of combined pollutants in soils from an industrial area in Shanxi Province, China

Heavy metal (loid)s (HMs) and polycyclic aromatic hydrocarbons (PAHs) in soils from a typical industrial county of Shanxi were synchronously measured to determine the spatial clustering of combined HMs and PAHs pollution, and the resulting source-specific health risks. The spatial interaction of HMs and PAHs was determined by the Moran's I index, and a bivariate local indicators of spatial association (LISA) analysis showed that the high HMs-high PAHs clusters were mainly distributed in Fencheng and Xijia towns, as well as the main urban areas of Xiangfen County. The spatial clusters of high naphthalene (Nap)-high HMs were more obvious than those of high benzo(a)pyrene (Bap)-high HMs. Based on positive matrix factorization (PMF), four sources were identified for both HMs and PAHs, with coal consumption and industrial emission identified as common sources of both pollutants. The source-oriented health risk was determined using an improved health risk assessment model. The cancer risk from the combined pollution industrial emissions was relatively serious for both adults and children, with the risk value exceeding 10^-6. Therefore, special attention should be paid to emission control. Based on spatial clustering and source-specific health risk assessment, the largest risk areas and pollutant sources were in the main urban areas of Fencheng and Xijia towns. The spatial interaction patterns and source-specific HMs and PAHs pollution concentrations provide a basis for effective pollution management and control. Finally, a systematic framework for reference was proposed for risk area identification and analysis of the source-oriented health risks of combined HMs and PAHs pollution.

Pollution Assessment and Source Apportionment of Soil Heavy Metals in a Coastal Industrial City, Zhejiang, Southeastern China

In this research, Ningbo City, a typical industrial city in southeastern China, was selected as the study area, and the concentrations of 12 heavy metals (Cd, Cr, Ni, Pb, Zn, Cu, Hg, As, Co, V, Se, and Mn) were measured at 248 sampling points. Pollution index methods were used to assess the status of soil heavy metal contamination, and the Positive Matrix Factorization (PMF) model and Unmix model were integrated to identify and apportion the sources of heavy metal contamination. The results indicated that nearly 70% of the study area was polluted by heavy metals, and that Ni, Cr, and Zn were the main enriched heavy metals. The five sources identified using the PMF model were a geological source, an atmospheric deposition source, a transportation emissions source, a mixed source of agriculture and industry, and a mixed source of geology and industry. The four sources identified using the Unmix model were a mixed source of geology, agriculture, and industry (14.27%); a transportation emissions source (4.76%); a geological source (14.7%); and a mixed source of geology and industry (66.28%). These results have practical significance, as they can help to carry out pollution source risk assessment and give priority to the management of pollution source control.

Gross alpha activity in urban sediments as an important indicator of urban environmental processes on the example of three Russian cities

The protection of the urban environment from radioactive wastes (including technologically enhanced natural radionuclides) and potentially harmful elements have recently become very critical. Thus, the present study aimed to assess the radioactive levels in low-volume samples of dust and fine sand fractions of the urban surface deposited sediments (USDS) collected in three Russian cities. The detection was conducted via CR-39 and LR-115 type II solid-state nuclear track detectors (SSNTDs) have been used to detect gross alpha activity concentrations. A statistically significant difference was observed between the average gross alpha activity concentrations in the dust fraction and the fine sand fraction in each city. The obtained results also illustrate the gross alpha activity concentration in the dust fraction is higher than in the fine sand fraction. This is consistent with the results of the chemical and mineralogical analysis. The dust fraction size has a higher gross alpha activity concentration than the fine sand fraction due to the natural partitioning of the main minerals constituting USDS with trace uranium and thorium content (feldspar, plagioclase, amphibole and others) and negligible uranium and thorium content (quartz). In some cases, USDS radioactivity is associated with monazite and zircon. A good correlation (0.58) was found between the gross alpha activity concentration and the effective content of uranium and thorium. Finally, an assessment of the gross alpha activity concentrations in the USDS size fractions was considered an essential indicator of environmental processes that are significant in terms of their impact on human health.

A novel method to analyze the spatial distribution and potential sources of pollutant combinations in the soil of Beijing urban parks

Organic and inorganic pollutants are often co-sedimentary in soils and have the same sources in the urban environment. The identification of the sources and distribution of combined pollutants is a basic step in risk management. In this study, the levels of polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) were measured in urban park soils in Beijing. Bivariate local Moran's I and positive matrix factorization (PMF) source apportionment were used to identify the spatial clustering patterns and potential sources of PAHs and HMs, as well as to ultimately define a pollution risk control area. The results revealed an obvious clustered distribution of PAHs and HMs in the park soils. High-high areas were defined as sites containing a complex mixture of pollutants, which were mainly located in the center and north of Beijing. High-low and low-high areas were located outside the city center but had the potential for combined pollution, and therefore require continuous attention. Bivariate local indicators of spatial association (LISA) enabled a more accurate analyses of the mechanism controlling the spatial distribution of PAH and HM combinations in urban parks. The source apportionment indicated that industrial and traffic emissions were the most important sources of the pollutant combinations in urban parks, with traffic emissions accounting for most of the pollution.

A critical review on the formation, fate and degradation of the persistent organic pollutant hexachlorocyclohexane in water systems and waste streams

The environmental impacts of persistent organic pollutants (POPs) is an increasingly prominent topic in the scientific community. POPs are stable chemicals that are accumulated in living beings and can act as endocrine disruptors or carcinogens on prolonged exposure. Although efforts have been taken to minimize or ban the use of certain POPs, their use is still widespread due to their importance in several industries. As a result, it is imperative that POPs in the ecosystem are degraded efficiently and safely in order to avoid long-lasting environmental damage. This review focuses on the degradation techniques of hexachlorocyclohexane (HCH), a pollutant that has strong adverse effects on a variety of organisms. Different technologies such as adsorption, bioremediation and advanced oxidation process have been critically analyzed in this study. All 3 techniques have exhibited near complete removal of HCH under ideal conditions, and the median removal efficiency values for adsorption, bioremediation and advanced oxidation process were found to be 80%, 93% and 82% respectively. However, it must be noted that there is no ideal HCH removal technique and the selection of removal method depends on several factors. Furthermore, the fates of HCH in the environment and challenges faced by HCH degradation have also been explained in this study. The future scope for research in this field has also received attention.

Heavy Metals Contamination of Urban Soils—A Decade Study in the City of Lisbon, Portugal

There is an intense and continuous growth of the world population living in cities. This increase in population means an increase in car traffic, an increase in new constructions and an increase in the production of waste that translates into an intensive use of land, particularly in terms of soil contaminants. Among other environmental contaminants, toxic metals, such as lead (Pb), cadmium (Cd), nickel (Ni) and chromium (Cr) represent a public health problem. In this study the content of toxic metals in Lisbon’s (Portugal) soils was determined. The study was conducted over approximately a decade in six city locations, with a total of about 700 samples. Each site has different urban characteristics: traffic zone, residential area, urban park and mixed areas. The study allowed to verify the heterogeneity of metal content values in the city soils and their dependence on local traffic. Metal contents were determined by graphite furnace atomic absorption spectroscopy (GFAAS). For each site the geo-accumulation index, pollution factor, degree of contamination, pollution load index and ecological risk factor were calculated. The mean concentrations of Cd, Cr, Ni and Pb in soils were 0.463, 44.0, 46.6 and 5.73 mg/kg of dry soil, respectively. In the last year of the study the values were 0.417, 51.5, 62.4 and 8.49 mg/kg of dry soil, respectively. Cd and Ni exceeded the typical content values of these metals in the earth’s crust, indicating their anthropogenic origin. The correlation analysis revealed a significant correlation between Cr and Ni, Cd and Ni and Cd and Pb contents in the city soils. Regarding the results obtained in this long monitoring campaign, Lisbon’s soils can be considered as having low levels of pollution by these metals.

Multi-metal tolerance of DHHC palmitoyl transferase-like protein isolated from metal contaminated soil

The microbiota inhabiting in metal polluted environment develops strong defense mechanisms to combat pollution and sustain life. Investigating the functional genes of the eukaryotic microbiota inhabiting in these environments by using metatranscriptomics approach was the focus of this study. Size fractionated eukaryotic cDNA libraries (library A, < 0.5 kb, library B, 0.5-1.0 kb, and library C, > 1.0 kb) were constructed from RNA isolated from the metal contaminated soil. The library C was screened for Cadmium (Cd) tolerant genes by using Cd sensitive yeast mutant ycf1^Δ by functional complementation assay, which yielded various clones capable of growing in Cd amended media. One of the Cd tolerant clones, PLCg39 was selected because of its ability to grow at high concentrations of Cd. Sequence analysis of PLCg39 showed homology with DHHC palmitoyl transferases, which are responsible for addition of palmitoyl groups to proteins and usually possess metal coordination domains. The cDNA PLCg39 was able to confer tolerance to Cd-sensitive (ycf1^Δ), Copper-sensitive (cup1^Δ) and Zn-sensitive (zrc1^Δ) yeast mutants when grown at different concentrations of Cd (40-100 μM), Cu (150-1000 μM) and Zn (10-13 mM), respectively. The DHHC mutant akr1^Δ transformed with PLCg39 rescued from the metal sensitivity indicating the role of DHHC palmitoyl transferase in metal tolerance. This study demonstrated that PLCg39 acts as a potential metal tolerant gene which could be used in bioremediation, biosensing and other biotechnological fields.

Potentially toxic elements in the Middle East oldest oil refinery zone soils: source apportionment, speciation, bioaccessibility and human health risk assessment

In this research, fifteen potentially toxic elements (PTEs) (Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, Sc and Zn) were analysed and quantified in samples collected at 44 sites in an urban area of Iran. Sources were apportioned using enrichment factors (EFs), modified pollution index (MPI), principal component analysis (PCA), multivariate linear regression of absolute principal component scores (MLR-APCS) and speciation, with a focus on anthropogenic PTEs in the urban and industrial soils of the Arvand Free Zone area, an oil-rich zone in the country. Furthermore, the bioaccessibility and the human health risks of PTEs were investigated. The EF revealed a significant enrichment for elements such as Cd, Cu, Hg, Mo, Pb, Sb and Zn. Values of MPI showed that Abadan industrial district and Abadan petrochemical complex are the most polluted sites in the study area.The PCA/MLR analysis revealed four main sources: natural sources, fossil fuel combustion, traffic and oil derivatives and petroleum waste. The relative contribution of each source to PTE concentration varied from 32.3% of the natural sources to 30.6% of traffic and from 20.1% of petroleum waste to 17% of fossil fuel combustion. The source apportionment of metals generated using MLR-APCS receptor modelling revealed that 85.0% of Hg was generated by oil products. Chemical speciation results were compatible with the results obtained from PCA. Bioaccessibility of PTEs decreased from gastric to intestinal phase except Mo and Sb due to their different geochemical characteristics. Hazard index (HI) for non-cancer risk of PTEs for both children and adults based on total element concentrations was estimated to range from 2-fold to more than 10-fold higher than that of bioaccessible phases.

Beta radioactivity of urban surface-deposited sediment in three Russian cities

Study of gross beta activity was conducted in Russian cities Ekaterinburg, Rostov-on-Don, and Nizhny Novgorod. The cities were characterized by continental climate, although they are located in different geographical zones. The bulk urban samples were fractionated with three size fractions: dust (0.002-0.1 mm), fine sand (0.1-1 mm), and coarse sand (> 1 mm). Measurement setup equipped with beta radiometer BDPB-01 was designed to measure the low levels of gross beta-activity in a small amount of the obtained size-fractionated samples. According to the results of the study, the gross beta activity depends on the size fraction and the city. The highest beta activity concentration was found in the dust fraction which is about the same in all cities 0.8-0.9 Bq g^-1. In size fractions of fine sand and coarse sand, the beta activity depends on the city. Among other cities, the highest average beta concentration was found in Ekaterinburg (0.8 and 0.6 Bq g^-1 in fine and coarse sand fractions, respectively), while the lowest is 0.28 and 0.44 Bq g^-1, respectively. The relationship of beta activity concentration with mineral and chemical composition is studied. Average beta activity in the different fractions of the surface-deposited sediment correlates with uranium, thorium, and organic matter concentration. The gross beta activity may be considered an indicator of high contribution of dust and high pollution with Pb, Cu, and Zn in the urban environment.

Comprehensive Evaluation of Metal Pollution in Urban Soils of a Post-Industrial City-A Case of Łódź, Poland

The pollution of urban soils by metals is a global problem. Prolonged exposure of habitants who are in contact with metals retained in soil poses a health risk. This particularly applies to industrialized cities with developed transport networks. The aim of the study was to determine the content and spatial distribution of mobile metal fractions in soils of the city of Łódź and to identify their load and sources. Multivariate statistical analysis (principal component analysis (PCA), cluster analysis (CA)), combined with GIS, were used to make a comprehensive evaluation of the soil contamination. Hot-spots and differences between urban and suburban areas were also investigated. Metals were determined by atomic absorption spectrometry (AAS) after soil extraction with 1 mol L^-1 HCl. In most sites, the metal content changes in the following order: Zn > Pb > Cu > Ni > Cd. About one-third of the samples are considerably (or very highly) contaminated, (contamination factor, CF > 3) with Cu, Pb, or Zn. In almost 40% of the samples, contaminated soils were found (pollution load index, PLI > 1). All metals have a strong influence on the first principal component (PC1), whereas second principal component (PC2) is related to pH. Polluted soils are located in the downtown, in the south and east part of the city. The distribution of contamination coincides with the urban layout, low emission sources and former industrial areas of Łódź.

In Vitro Bioadsorption of Cd2+ Ions: Adsorption Isotherms, Mechanism, and an Insight to Mycoremediation

The objective of this paper is to establish the significance of the mycoremediation of contaminants such as Cd2+ to achieve sustainable and eco-friendly remediation methods. Industries such as electroplating, paint, leather tanning, etc. release an enormous amount of Cd2+ in wastewater, which can drastically affect our flora and fauna. Herein, we report on the in vitro bioadsorption of Cd2+ ions using fungal isolates obtained from different contaminated industrial sites. The detailed studies revealed that two fungal species, i.e., Trichoderma fasciculatum and Trichoderma longibrachiatum, were found to be most effective against the removal of Cd2+ when screened for Cd2+ tolerance on potato dextrose agar (PDA) in different concentrations. Detailed adsorption studies were conducted by exploring various experimental factors such as incubation time, temperature, pH, inoculum size, and Cd2+ salt concentrations. Based on optimum experimental conditions, T. fasciculatum exhibited approximately 67.10% removal, while T. longibrachiatum shows 76.25% removal of Cd2+ ions at pH 5.0, 120 h incubation time, at 30°C. The inoculum sizes for T. fasciculatum and T. longibrachiatum were 2.5% and 2.0%, respectively. Finally, the morphological changes due to Cd2+ accumulation were examined using scanning electron microscopy (SEM). Further, Fourier transform infrared spectroscopy (FTIR) spectroscopy reveals the presence of various functional groups (-CH, –C=O, NH and –OH), which seem to be responsible for the efficient binding of Cd2+ ions over the fungal surfaces.

Spa environments in central Serbia: Geothermal potential, radioactivity, heavy metals and PAHs

This study aims to estimate geothermal potential, radioactivity levels, and environmental pollution of six most popular spas in Central Serbia (Ovčar, Gornja Trepča, Vrnjačka, Mataruška, Bogutovačka and Sokobanja), as well as to evaluate potential exposure and health risks for living and visiting population. Thermal possibilities of the studied spas showed medium and low geothermal potential with total thermal power of 0.025 MW. Gamma dose rates in air varied from 63 to 178 nSv h^-1. Specific activities of natural radionuclides (²²⁶Ra, ²³²Th and ⁴⁰K) and ¹³⁷Cs in soil were measured; annual effective doses and excess lifetime cancer risk from radionuclides were calculated. Radon concentration in thermal-mineral waters from the spas ranged between 1.5 and 60.7 Bq L^-1 (the highest values were measured in Sokobanja). The annual effective dose from radon due to water ingestion was calculated. The analyzed soils had a clay loam texture. The presence of As, Cr, Cu, Fe, Mn, Ni, Pb, Cd, Zn, and Hg in soil was investigated. The concentrations of As, Cr, Ni, and Hg exceeded the regulatory limits in many samples. Soil samples from Mataruška spa were generally the most contaminated with heavy metals, while the lowest heavy metal concentrations were observed in Sokobanja. Health effects of exposure to heavy metals in soil were estimated by non-carcinogenic risk and carcinogenic risk assessment. Total carcinogenic risk ranged between 6 × 10^-4 and 137 × 10^-4 for children and between 0.1 × 10^-4 and 2.2 × 10^-4 for adults. The sum of 16 PAHs analyzed in soil samples varied from 92 to 854 μg kg^-1.

Ecological risk of combined pollution on soil ecosystem functions: Insight from the functional sensitivity and stability

Assessing the ecological risk of combined pollution, especially from a holistic perspective with the consideration of the overarching functions of soil ecosystem, is crucial and beneficial to the improvement of ecological risk assessment (ERA) framework. In this study, four soils with similar physicochemical properties but contrasting heavy metals contamination levels were selected to explore changes in the integrated functional sensitivity (MSI), resistance (MRS) and resilience (MRL) of soil microbial communities subjected to herbicide siduron, based on which the ecological risk of the accumulation of siduron in the four studied soils were evaluated. The results suggested that the microbial biomass carbon, activity of denitrification enzyme and nitrogenase were indicative of MSI and MRS, and the same three parameters plus soil basal respiration were indicative of MRL. Significant dose-effect relationships between siduron residues in soils and MSI, MRS and MRL under combined pollution were observed. Heavy metal polluted soils showed higher sensitivity and lower resistance to the additional disturbance of herbicide siduron due to the lower microbial biomass, while the resilience of heavy metal polluted soils was much higher due to the pre-adaption to the chemical stresses. The quantifiable indicator microbial functional stability was incorporated in the framework of ERA and the results showed that the accumulation of siduron in the studied soils could exhibit potential harm to the integrated functional stability of soil microbial community. Thus, this work provides insights into the application of integrated function of soil microbial community into the framework of ERA.

Occurrence, source apportionment, and potential human health risks of metal(loid)s and PAHs in dusts from driving school campuses in an urban area of Henan, China

Concentrations, health risks, and sources of 9 metal(loid)s (As, Cd, Co, Cr, Cu, Hg, Ni, Pb, and Zn) and 16 PAHs in dusts collected from the 29 driving school campuses in the urban area of Kaifeng, Henan Province, China, were evaluated. The health risks due to exposure to these pollutants in dusts were assessed under three different scenarios (working for 10 years, 20 years, and 30 years in driving schools), using the health risk assessment model developed by US EPA. The results indicated that the mean concentrations for As, Cd, Cr, Cu, Hg, Pb, and Zn were higher than the local dust background except Co and Ni. The total PAH concentrations ranged from 198.21 to 3 400.89 μg kg^-1, with a mean value of 908.72 μg kg^-1. The dominant components were the two and three member-ring PAHs, accounting for 55.79% of the ∑PAHs, while PAHs with four to six member-rings accounted for 44.21% of total PAHs. The non-cancer risks of metal(loid)s in most samples were within the safe range except for two samples, with Pb as the major non-carcinogenic risk factor. The cancer risks of As, Cd, Cr, and Ni were also within the currently acceptable range except for one sample under two scenarios (working for 20a and 30a in a driving school). The cancer risks of PAHs in most samples were within the safe range except for one sample under scenario 3. The source identification results demonstrated that Pb, Zn, Cu, and Cd in the driving school dusts are mainly affected by the emission of driving-school vehicles. For PAHs, the typical driving school vehicle emissions were predominated by Phe and Ant, followed by Flu, Pyr, BkF, and Nap. The concentrations and health risks of the metal(loid)s and PAHs in the dusts were not significantly related to the driving school operation time or vehicle density, but closely related to the surrounding environments and the historical land uses of driving schools.

Source apportionment of soil PAHs and human health exposure risks quantification from sources: the Yulin National Energy and Chemical Industry Base, China as case study

The Yulin National Energy and Chemical Industry Base is widely known for its rich mineral resources and multi-type fossil chemical industry, yet little is known regarding the level of contaminants. Therefore, this study investigates the spatial distributions and potential exposure risk of ubiquitous polycyclic aromatic hydrocarbons (PAHs) contamination in this region and apportions PAHs source and source-oriented risk using two mathematical models, principal component analysis-multiple linear regression (PCA-MLR) model and positive matrix factorization (PMF) model coupling human health exposure risk. Results showed that ∑₁₆PAHs concentrations ranged from 110 to 4934 μg/kg dw in 38 soil sampling sites. Compared with PCA-MLR model, PMF model is preferred method for source apportionment. Source apportionment results derived from PMF model indicated that the dominant contribution to ∑₁₆PAHs was from coal-derived sources (34% for coke oven emissions and 33% coal combustion source), followed by wood combustion (22%) and vehicular emission (11%). The human health exposure risk of each source category was quantitatively calculated for three exposure routes by combining the total carcinogenic risk (Total-CR) and total hazard index (Total-HI) values with identified source contributions. The results showed that increased Total-CR was highly apportioned from coke oven emissions source and coal combustion was identified as the major cause of increased Total-HI, even though it was less contributed to ∑₁₆PAHs. Moreover, the distributions of Total-CR and Total-HI apportionment for each source were significantly influenced by land utilization types.

Improving risk management by using the spatial interaction relationship of heavy metals and PAHs in urban soil

Identifying combined pollution risk areas is difficult because of the complex pollutant sources and heterogeneous soil properties in urban systems. This study used bivariate local Moran's I to analyze the spatial interaction between heavy metals and PAHs, revealed the causes of spatial interaction patterns through PMF, and proposed a risk zoning approach for combined pollution in urban areas. The results showed that both heavy metals and PAHs had high spatial heterogeneity in urban soil. Bivariate LISA maps revealed the spatial interactions between heavy metals and PAHs. The historical area was the hotspot of combined pollution. The overlay of pollutant sources and sinks was responsible for the spatial interaction patterns of combined organic and inorganic pollution. Coal consumption was the main emission source for heavy metal and PAHs pollution, accounting for 31% and 21%, respectively. We used bivariate LISA as the auxiliary variable to reduce the uncertainty of identification combined pollution risk zones. More than 11% of the total area clustered significantly where concentration of both heavy metals and PAHs ware in excess of the risk threshold. This study indicates that we can provide better decision-making support for soil risk management based on the knowledge derived from spatial interaction analysis.

Quantitative contributions of the major sources of heavy metals in soils to ecosystem and human health risks: A case study of Yulin, China

Quantifying source-oriented risk can identify primary pollution sources to help alleviate risks to ecosystems and human health posed by soil heavy metals. Taking Yulin National Energy and Chemical Industry Base as an example, ecosystem and human health risk assessments of each identified source category were quantitatively calculated by combining the Potential Ecological Risk (RI) and Total Carcinogenic Risk (Total-CR)/Total Hazard Index (Total-HI) assessment models with the positive matrix factorization (PMF) receptor model. In this work, an analysis of the Geoaccumulation Index (I_geo), Contamination Index (P_i), RI, CR and HI of heavy metals (As, Cr, Cu, Zn, Cd, Pb, Hg and Mn) identified universal ecosystem risks and both carcinogenic and noncarcinogenic health risks in most sites. Source apportionment results indicated that the dominant source of heavy metals in the soil was coal-related activities (52.5%), followed by industrial activities (22.0%), traffic activities (13.2%) and agricultural activities (12.3%). The source-oriented quantitative risk assessment results showed that coal-related activities are the greatest contributor to RI and Total-HI, while industrial activities are the largest source of Total-CR, which should be controlled, to reduce the carcinogenic health risk posed by exposure to heavy metals.

Occurrence and risk assessment of potentially toxic elements and typical organic pollutants in contaminated rural soils

The residual levels and risk assessment of several potentially toxic elements (PTEs), phthalate esters (PAEs) and polycyclic aromatic hydrocarbons (PAHs) in rural soils near different types of pollution sources in Tianjin, China, were studied. The soils were found to be polluted to different extents with PTEs, PAEs and PAHs from different pollution sources. The soil concentrations of chromium (Cr), nickel (Ni), di-n-butyl phthalate (DnBP), acenaphthylene (Any) and acenaphthene (Ane) were higher than their corresponding regulatory reference limits. The health risk assessment model used to calculate human exposure indicates that both non-carcinogenic and carcinogenic risks from selected pollutants were generally acceptable or close to acceptable. Different types of pollution sources and soil physicochemical properties substantially affected the soil residual concentrations of and risks from these pollutants. PTEs in soils collected from agricultural lands around industrial and residential areas and organic pollutants (PAEs and PAHs) in soils collected from agricultural areas around livestock breeding were higher than those from other types of pollution sources and merit long-term monitoring.

Seasonal variation and health risk assessment of organochlorine compounds in urban soils of Novi Sad, Serbia

The aim of this paper was to determine spatial and seasonal variation of 6 indicator polychlorinated biphenyls (PCBs) and 18 organochlorine pesticides (OCPs) in urban soils of Novi Sad, Serbia. Sixty surface soil samples were collected during both winter and summer season, from different types of locations: schools, recreational areas, residential and industrial zones. Samples were treated using the method of accelerated solvent extraction, which allows simultaneous extraction and clean up of PCBs and OCPs. Targeted compounds were analyzed by GC-μECD and confirmed by GC-MS. The total concentrations of studied PCBs varied from <LOD to 18.9 ng g^-1 (mean 2.84 ng g^-1 and median value of 1.21 ng g^-1) in winter and from <LOD to 24.6 ng g^-1 (mean 3.27 ng g^-1 and median value of 1.60 ng g^-1) in summer. Regarding the OCPs analyzed, dichlorodiphenyltrichloroethanes (DDTs) were only detected in both seasons. The total concentration of DDTs ranging from <LOD to 86.3 ng g^-1 (mean 7.57 ng g^-1 and median value of 1.87 ng g^-1) in summer and from <LOD to 182 ng g^-1 (mean 15.6 ng g^-1 and median value of 3.15 ng g^-1) in winter. There were no significant difference between seasons for studied PCBs and DDTs. Spatial distribution of PCBs and DDTs were also evaluated using Arc GIS. Additional, principle component analysis was performed to evaluate relationships between PCBs, DDTs and soil characteristics. Positive correlation was observed among p,p'-DDE, p,p'-DDD and organic matter. The total lifetime carcinogenic risk indicated that the lifetime cancer risk was acceptable.

Assessment of Radioactive Materials and Heavy Metals in the Surface Soil around the Bayanwula Prospective Uranium Mining Area in China

The present work is the first systematic and large scale study on radioactive materials and heavy metals in surface soil around the Bayanwula prospective uranium mining area in China. In this work, both natural and anthropogenic radionuclides and heavy metals in 48 surface soil samples were analyzed using High Purity Germanium (HPGe) γ spectrometry and inductively coupled plasma-mass spectrometry (ICP-MS). The obtained mean activity concentrations of ²³⁸U, ²²⁶Ra, ²³²Th, ⁴⁰K, and ¹³⁷Cs were 25.81 ± 9.58, 24.85 ± 2.77, 29.40 ± 3.14, 923.0 ± 47.2, and 5.64 ± 4.56 Bq/kg, respectively. The estimated average absorbed dose rate and annual effective dose rate were 76.7 ± 3.1 nGy/h and 83.1 ± 3.8 μSv, respectively. The radium equivalent activity, external hazard index, and internal hazard index were also calculated, and their mean values were within the acceptable limits. The estimated lifetime cancer risk was 3.2 × 10⁻⁴/Sv. The heavy metal contents of Cr, Ni, Cu, Zn, As, Cd, and Pb from the surface soil samples were measured and their health risks were then assessed. The concentrations of all heavy metals were much lower than the average backgrounds in China except for lead which was about three times higher than that of China’s mean. The non-cancer and cancer risks from the heavy metals were estimated, which are all within the acceptable ranges. In addition, the correlations between the radionuclides and the heavy metals in surface soil samples were determined by the Pearson linear coefficient. Strong positive correlations between radionuclides and the heavy metals at the 0.01 significance level were found. In conclusion, the contents of radionuclides and heavy metals in surface soil around the Bayanwula prospective uranium mining area are at a normal level.