The contents of the potentially harmful elements in the arable soils of southern Poland, with the assessment of ecological and health risks: a case study

Distribution and biotransfer of potentially toxic elements in a terrestrial ecosystem from an abandoned realgar mine

The present study was conducted to examine the trophic transfer of potentially toxic elements (PTEs) in a closed arsenic mine. Eight PTEs in a soil-plant-leaf litter-earthworm-top predators (free-range local chicken and wild passerine bird) system were analyzed for nitrogen and carbon stable isotopes, PTE concentrations, bioaccumulation factors (BAFs), and transfer factors (TFs). The PTE concentrations in soils from mining areas were generally higher than a adjacent controlled area, with As and Cd in soils showing the prominent compared to other six PTEs, as seen for the indices of geo-accumulation index (Igeo), pollution index (PI) and potential ecological risk index (RI). The relatively high BAF and TF values suggested a distinct biotransfer of PTEs along the soil-plant-leaf litter-earthworm system. BAFs were mostly <1 except in earthworms, indicating that earthworms had a strong capacity to take up these metals. The TFs varied both among PTEs and organism's species, e.g., the transfer capacities of As in Pteris vittata and Pteris cretica, Cd in Miscanthus sinensis, and Pb, Cr and Mn in moss were the highest. For local free-range chicken and wild passerine bird, the concentrations of PTEs were higher in gastric contents and feather than in internal tissue (stomach, liver and heart), with lower contents in muscle and egg. Bioaccumulation of PTEs generally decreased from decomposer earthworms, to primary producer plants, to top predator, indicating a potential bio-dilution tendency in higher trophic levels in the terrestrial food chain.

The spatial distribution of potentially toxic elements in the mountain forest topsoils (the Silesian Beskids, southern Poland)

Progressive industrialisation and urbanisation in recent decades have dramatically affected the soil cover and led to significant changes in its properties, which inevitably affect the functioning of other components of the forest ecosystems. The total content of Pb, Cd, Zn, Fe, Cr, Cu, Ni, As, and Hg was studied in twenty-five plots at different heights in the topsoil (organic and humus horizons) formed from the Carpathian flysch in the area of the Silesian Beskids (Western Carpathians). The aim of this article is to analyse the spatial distribution of potentially toxic elements in the mountain forest topsoil in different types of plant communities and to determine the relationship between altitude and potentially toxic elements contamination. The soils studied are acidic or very acidic, with an average range of 3.8 (H2O) and 2.9 (KCl). Concentrations of the metals Cd, Zn, Fe, Cr, Cu, Ni, and Hg on the plots that were analysed are within the range of permissible standards for forest ecosystems in Poland, while Pb and As exceed the permissible standards for this type of ecosystem. Spearman's rank correlation coefficient showed a high correlation between Fe-Cr (r(32) = 0.879, Pb-Hg r(32) = 0.772, Ni-Cr r(32) = 0.738, Zn-Cd r(32) = 0.734, and Cu-Hg r(32) = 0.743, and a moderate statistically significant positive correlation between Cu-Pb r(32) = 0.667 and As-Pb r(32) = 0.557. No correlation was found between altitude and the occurrence of potentially toxic elements. The geo-accumulation index (Igeo) index, on the other hand, indicates that Pb, As, and Cd have the highest impact on soil contamination in all study plots: it classifies soils from moderately to strongly polluted. The enrichment factor (EF) obtained for As and Hg indicates significant-to-very high enrichment in all areas studied. The potential ecological risk index (PLI) calculated for the sites indicates the existence of pollution in all areas examined. The highest risk categories (considerable to very high) are associated with cadmium and mercury.

Mobility, bioaccumulation in plants, and risk assessment of metals in soils

Heavy metal contamination of soils is one of the main factors contributing to soil quality decline and loss of biodiversity, which is also associated with plant contamination, as metals accumulate in the surface layer of soils and then enter the trophic chain. The aims of the study were to assess the mobility and bioavailability of metals in soils to plants, and to estimate the ecological and health risks associated with heavy metal content in soils. 320 topsoil and 206 plant samples were collected. Fractional analysis showed that for most of the samples, there was no or low risk associated with the mobility of Cr, Pb, Cu, Ni, Zn, and low and medium for Cd. High and very high metal release risk was only shown for Cd (28 % of samples), and Zn and Pb (2 % of samples). The bioaccumulation factor found moderate levels of accumulation for Cd, Zn, Cu, Ni. High accumulation of Cd and Zn was found in 38 % and 15 % of plant samples. Alivibrio fischeri proved to be a more sensitive indicator of soil ecotoxicity compared to Sinapis alba. In the 81 % of the soil samples found a low probability of adverse effects on ecological receptors associated with exposure to soilborne metals. In the case of human health risk, no harmful health effects were observed due to accidental ingestion of metal-containing soils in the study area. In assessing metal risks, the choice of indicators is crucial. Moreover, the properties of soils have a significant impact on the mobility of metals and their bioaccumulation by plants. This means that the more varied the choice of indicators, the more comprehensive, reliable and close to reality the risk assessment of heavy metals in soils will be.

Prediction of the concentration of antimony in agricultural soil using data fusion, terrain attributes combined with regression kriging

Potentially toxic elements in agricultural soils are primarily derived from anthropogenic and geogenic sources. This study aims to predict and map antimony (Sb) concentration in soil using multiple regression kriging in two distinct modeling approaches, namely Sb prediction using data fusion coupled with regression kriging (scenario 1) and Sb prediction using data fusion, terrain attributes, and regression kriging (scenario 2). Cubist regression kriging (cubist_RK), conditional inference forest regression kriging (CIF_RK), extreme gradient boosting regression kriging (EGB_RK) and random forest regression kriging (RF_RK) were the modeling techniques used in the estimation of Sb concentration in agricultural soil. The validation results suggested that in scenario 1, EGB_RK was the optimal modeling approach for Sb prediction in agricultural soil with root mean square error (RMSE) = 1.31 and mean absolute error (MAE) = 0.61, bias = 0.37, and high coefficient of determination R² = 0.81. Similarly, the EGB_RK was also the optimal modeling approach in scenario 2, with the highest R² = 0.76, RMSE = 0.90, bias = 0.06, and MAE = 0.48 values than the other regression kriging modeling approaches. The cumulative assessment suggested that the EGB_RK in scenario 2 yielded optimal results compared to the respective modeling approach in scenario 1. The uncertainty propagated by the modeling approaches in both scenarios indicated that the degree of uncertainty during the modeling process was distributed across the study area from a low to a moderate uncertainty level. However, cubist_RK in scenario 2 exhibited some elevated spots of uncertainty levels. As a result, the combination of data fusion, terrain attributes, and regression kriging modeling approaches produces optimal results with a high R² value, minimal errors as well as bias. Furthermore, combining terrain attributes with data fusion is promising for reducing model error, bias and yielding high-accuracy predictions.

Metal contamination in sediments of dam reservoirs: A multi-facetted generic risk assessment

The quality of bottom sediments is a key factor for many functions of dam reservoirs, which include water supply, flood control and recreation. The aim of the study was to combine different pollution indices in a critical generic risk assessment of metal contamination of bottom sediments. Both geochemical and ecological indices reflected that sediment contamination was dominated by Zn, Pb and Cd. The ecological risk indices suggested a high riks for all three metals, whereas human health risks were high for Pb and Cd. An occasional local contamination of sediments with Cr and Ni was revealed, although at levels not expected to cause concerns about potential ecological or health risk. Sediments from the Rybnik reservoir for Cu only revealed a high potential ecological risk. EF turned to be as being the most useful, whereas TRI (∑TRI) was the most important ecological index. All multi-element indices suggested similar trends, indicating that Zn, Pb and Cd taken altogether had the greatest impact on the level of sediment contamination and posed the greatest potential ecological and health risks to organisms. The use of sequential BCR extraction and ecotoxicity analyses allowed for a multi-facetted generic risk assessment of metals in sediments of dam reservoirs.

The evaluation of Hudson River sediment as a growth substrate - Microbial activity, PCB-degradation potential and risk assessment

The potential use of growth substrates prepared with an admixture of 10% to 75% Hudson River sediments was evaluated by analysis of changes in microbial activity (measured using Biolog Ecoplates) and molecular markers (presence of degradative tceA1 and bphA genes) as well as potential risks toward humans and the environment (health and environmental risk quotients). The highest microbial activity was found in growth substrate with 25% Hudson River sediments compared to unamended control soil. Significant differences were observed between samples amended with lower (0-10%) and higher (25-75%) proportion of sediment. Microbial activity increased with the proportion of sediment amendment (≥25% sediment); however, this increase in microbial activity was not affected by increasing pollutant concentrations (PCBs, Pb, Cr Ni and Zn) nor decreasing TOC content. The growth substrate amended with Hudson River sediments demonstrated a potential for PCB degradation, as evidenced by the presence of tceA1 and bphA genes responsible, respectively, for reductive dehalogenation and oxidation of a range of aromatic organic compounds including PCBs. An assessment of risk quotients showed that the growth substrates containing lower doses of Hudson River sediments (10-50%) meet the international requirements for use in agriculture/horticulture for the production of non-food crops. Nevertheless, due to the elevated content of some toxic metals and PCBs, the growth substrate prepared with the highest proportion of sediments (75%) was not suitable for agricultural/horticultural use.

The Properties of Black Locust Robinia pseudoacacia L. to Selectively Accumulate Chemical Elements from Soils of Ecologically Transformed Areas

The black locust Robinia pseudoacacia L. is a common species that originated from North America. In Europe, it is an invasive and introduced plant. Due to its low habitat requirements and ecological plasticity, this species colonizes new anthropogenically transformed areas quickly. This study investigated the chemical composition of selected tissues of Robinia pseudoacacia L. in five various habitats with different levels of anthropopression conditions in southern Poland. The presented research aimed to compare the chemical composition of black locust parts tissues (leaves, branches, and seeds) and the soil under its canopy. To determine the heavy metal contamination and enrichment in soil, the geoaccumulation index, enrichment factor, contamination factor, pollution load index, and potential ecological risk index were calculated. The results showed that all examined soils are considerably or very highly contaminated and the main heavy metals, which pollute the studied samples, are cadmium (1.3–3.91 ppm), lead (78.17–157.99 ppm), and zinc (129.77–543.97 ppm). Conducted research indicates that R. pseudoacacia leaves are the primary carrier of potentially toxic elements. Due to low bioaccumulation factor (BAF) values, it is clear that black locusts do not accumulate contaminants in such amounts that it would pose risk to its use in degraded area reclamation. The obtained results showed that R. pseudoacacia is able to grow in a wide range of habitats and could be applied for greening urban habitats and disturbed ecosystems caused by industry.

Human risk associated with the ingestion of artichokes grown in soils irrigated with water contaminated by potentially toxic elements, Junin, Peru

The contamination of water, air and soil with potentially toxic elements (PTE) compromises the supply of contaminant free food. Vegetables grown in contaminated soils can absorb and accumulate PTE at concentrations that are toxic to human health. In this context, the human risk associated with the intake of artichokes grown in soils irrigated with PTE contaminated water was assessed. 120 samples of surface soil and artichoke heads were collected and the concentrations of Cu, Fe, Pb, Zn and As were determined. The results showed that the concentrations of Cu, Fe and Zn in soil did not exceed the standards of the Ministry of Environment of Peru, but they did exceed those of Pb (125.45 mg kg^-1) and As (28.70 mg kg^-1). The decreasing order of mean PTE concentration in artichoke heads was Fe > Zn > Cu > Pb > As, exceeding the permissible levels of FAO/WHO CODEX Alimentarius. However, the concentrations of As comply with the maximum limits of inorganic contaminants in vegetables (0.3 mg kg^-1) established in the MERCOSUR regulations. The non-carcinogenic and carcinogenic risk of Pb and As indicated that the ingestion of artichoke heads does not represent a health risk.

Characteristics of Potentially Toxic Elements, Risk Assessments, and Isotopic Compositions (Cu-Zn-Pb) in the PM10 Fraction of Road Dust in Busan, South Korea

The pollution status of ten potentially toxic elements (PTEs), isotopic compositions (Cu, Zn, Pb), and the potential ecological risk posed by them were investigated in the PM10 fraction of road dust in Busan Metropolitan city, South Korea. Enrichment factors revealed extremely to strongly polluted levels of Sb, Cd, Zn, Pb, and Cu in the PM10 fraction of road dust, with Sb levels being the highest. Statistical analyses showed that the major cause for contamination with PTEs was non-exhaust traffic emissions such as tire and brake wear. Cu and Zn isotopic compositions of road dust were related to traffic-related emission sources such as brake and tires. Pb isotopic compositions were close to that of road paint, indicating that Pb was a different source from Cu and Zn in this study. No significant health risk was posed by the PTEs. Taking into account the total length of road in Busan, a high quantity of PTEs in road dust (PM10) can have serious deleterious effects on the atmospheric environment and ecosystems. The results of metal concentrations and isotopic compositions in road dust will help identify and manage atmospheric fine particle and coastal metal contamination derived from fine road dust.

Ecological and Health Risk Assessments of an Abandoned Gold Mine (Remance, Panama): Complex Scenarios Need a Combination of Indices

The derelict Remance gold mine is a possible source of pollution with potentially toxic elements (PTEs). In the study area, diverse mine waste has been left behind and exposed to weather conditions, and poses risks for soil, plants and water bodies, and also for the health of local inhabitants. This study sought to perform an ecological and health risk assessment of derelict gold mining areas with incomplete remediation, including: (i) characterizing the geochemical distribution of PTEs; (ii) assessing ecological risk by estimating the pollution load index (PLI) and potential ecological risk index (RI); (iii) assessing soil health by dehydrogenase activity; and iv) establishing non-carcinogenic (HI) and carcinogenic risks (CR) for local inhabitants. Soil health seems to depend on not only PTE concentrations, but also on organic matter (OM). Both indexes (PLI and RI) ranged from high to extreme near mining and waste accumulation sites. As indicated by both the HI and CR results, the mining area poses a health risk for local inhabitants and particularly for children. For this reason, it will be necessary to set up environmental management programs in the areas that are most affected (tailings and surrounding areas) and accordingly establish the best remediation strategies to minimize risks for the local population.

Potentially toxic elements' occurrence and risk assessment through water and soil of Chitral urban environment, Pakistan: a case study

This study investigated the concentrations of potentially toxic elements (PTE) including copper (Cu), chromium (Cr), cobalt (Co), cadmium (Cd), nickel (Ni), iron (Fe), zinc (Zn), lead (Pb), molybdenum (Mo) and manganese (Mn) in water and soil of the Chitral city, Pakistan. For this purpose, water (n = 66) and soil (n = 48) samples were collected from various locations of the Chitral city and analyzed for the PTE concentrations. Determined PTE concentrations were evaluated for the human and ecological potential risk. Results revealed that hazard quotient through water consumption was less than the threshold limit (1). However, for soil, the Fe mean hazard index (HI > 1) value for children only surpassed the threshold limits. The mean cancer risk index values via soil exposure were higher (RI > 1 × 10^-4) through consumption of Co, Ni and Cd for children and only Co for adults. Contamination factor (CF) values for Mo, Cd and Fe were found very high, considerable and moderate for 79%, 8% and 77% of sampling sites, respectively. Geoaccumulation index (I_geo) showed that soils were moderately-heavily polluted due to Mo. Potential ecological risk index (PERI) values exhibited considerable risk with an average risk index value in the range 190 < RI < 380. Higher values of CF, I_geo and PERI revealed the presence of pollution and pose risk to ecological environment.

Pollution, Sources and Human Health Risk Assessment of Potentially Toxic Elements in Different Land Use Types under the Background of Industrial Cities

Residents in industrial cities may be exposed to potentially toxic elements (PTEs) in soil that increase chronic disease risks. In this study, six types of PTEs (Zn, As, Cr, Ni, Cu, and Pb) in 112 surface soil samples from three land use types—industrial land, residential land, and farmland—in Tonghua City, Jilin Province were measured. The geological accumulation index and pollution load index were calculated to assess the pollution level of metal. Meanwhile, the potential ecological risk index, hazard index, and carcinogenic risk were calculated to assess the environmental risks. The spatial distribution map was determined by the ordinary kriging method, and the sources of PTEs were identified by factor analysis and cluster analysis. The average concentrations of Zn, As, Cr, Ni, Cu, and Pb were 266.57, 15.72, 72.41, 15.04, 20.52, and 16.30 mg/kg, respectively. The results of the geological accumulation index demonstrated the following: Zn pollution was present in all three land use types, As pollution in industrial land cannot be neglected, Cr pollution in farmland was higher than that in the other two land use types. The pollution load index decreased in the order of industrial land > farmland > residential land. Multivariate statistical analysis divided the six PTEs into three groups by source: Zn and As both originated from industrial activities; vehicle emissions were the main source of Pb; and Ni and Cu were derived from natural parent materials. Meanwhile, Cr was found to come from a mixture of artificial and natural sources. The soil environment in the study area faced ecological risk from moderate pollution levels mainly contributed by As. PTEs did not pose a non-carcinogenic risk to humans; however, residents of the three land use types all faced estimated carcinogenic risks caused by Cr, and As in industrial land also posed high estimated carcinogenic risk to human health. The conclusion of this article provides corresponding data support to the government’s policy formulation of remediating different types of land and preventing exposure and related environmental risks.

Human Health Risk Assessment and Potentially Harmful Element Contents in the Cereals Cultivated on Agricultural Soils

Potentially harmful element (PHE) contents were investigated in six species of cereals in southern Poland, with human health risk implications assessed afterwards. The PHE contents belonged to the following ranges (mg/kg wet weight): As below the limit of detection ( oat (HQ = 0.38) > maize (HQ = 0.02). The total non-carcinogenic risk value of the statistical daily consumption of cereals was acceptable low (HQ = 0.58). The acceptable cancer risk (CR) level of 1.0 × 10-5 investigated only for As was not exceeded under any of the intake scenarios. Concerning the mean As content in cereals consumed daily in statistical amounts the CR value was equal to 5.1 × 10-8. The health risk value according to the Pb content in cereals using the margin of exposure (MOE) approach was equal to 1.27, indicating an acceptable low risk.

Human Health Risk Assessment and Potentially Harmful Element Contents in the Fruits Cultivated in the Southern Poland

The presence of potentially harmful elements (PHEs) in popularly consumed fruits in Poland was determined by inductively coupled plasma mass spectrometry. The As, Cd, Co, Cr, Cu, Hg, Ni, Pb, Se, Sb, Tl, and Zn contents were investigated in 21 fruit species grouped as berry, pome, stone, and shell fruits. The PHE contents belonged to the following ranges (mg/kg wet weight): Cd < limit of detection (LOD)-0.116, Co < LOD-0.062, Cu < LOD-15.5, Ni < LOD-2.23, Pb < LOD-2.07, Sb < LOD-0.240, Tl < LOD-0.110, and Zn 0.37-37.7. Their concentrations exceeded the maximum allowable concentration (MAC) set by European Union regulation for Pb only. Bioconcentration coefficient (BC) values, calculated in accordance to the PHE contents in exchangeable and acid soluble forms in soil after first step of the Community Bureau of Reference (BCR) sequential extraction procedure, revealed that berry fruits had potential for accumulation of Cu, Ni, Sb, and Tl; stone fruits-Cu, Sb, and Tl; pome fruits-Cu, Ni, and Sb, and shell fruit (walnut)-Cu. Human health risk assessment associated with the intake of PHEs in fruits was evaluated in terms of daily intake rates (DIR), and carcinogenic and non-carcinogenic risk by cancer risk (CR) and hazard quotient (HQ), respectively. For Pb margin of exposure (MOE) approach was used for health risk evaluation. Daily intake rates for all PHEs were below the provisional maximum tolerable daily intake (PMTDI) values. The mean total non-carcinogenic risk values were the following: berry fruits HQ = 0.47, pome fruits HQ = 0.36, stone fruits HQ = 0.42, and shell fruits (walnut) HQ = 0.22, indicating no health hazards. The carcinogenic risk for As in walnut only under an adult intake scenario (CR = 1.98 × 10-6) was found to be above the acceptable risk level. The mean Pb health risk, according to Polish statistical intake rates, was acceptable low as the MOE value was equal to 15.7 for adults. In reference to the intake rates recommended by United States Environmental Protection Agency (USEPA), MOE values for Pb indicated acceptable low risk both for adults (MOE = 14.0) and children (MOE = 1.64). In general, the finding of this research revealed no health risk arising from PHE consumption with fruits for the population of Poland.

Geochemical Fractions of the Agricultural Soils of Southern Poland and the Assessment of the Potentially Harmful Element Mobility

Surface samples (0–25 cm each) of agricultural soils were investigated in five Regions (voivodeships) of southern Poland. The mean Potentially Harmful Element (PHE) pseudototal content ranges were as follows (mg/kg): As 5.19–10.9, Cd 0.34–1.56, Co 1.92–6.70, Cr 9.05–25.7, Cu 8.74–69.4, Hg 0.001–0.08, Ni 3.93–19.9, Pb 20.3–183, Sb 0.80–1.42, Tl 0.04–0.17, and Zn 61.3–422. The PHE availability depended on pH, the organic carbon (Corg) content, and the pseudototal PHE content in soils. Exchangeable and acid soluble PHE contents (BCRF1) determined in the Community Bureau of Reference (BCR) three-step sequential extraction procedure decreased in this order: Cd > Zn > Co > Ni = Sb > Cu > Tl > As > Cr = Pb. Actually available PHE contents in pore water (0.01 mol/dm3 CaCl2) ranged as follows: Cd 0.81–17%, Cr 0–0.25%, Cu 0.01–2.31%, Ni 0.16–2%, Pb 0.2–0.49%, and Zn 0.25–2.12%. The potential soluble total content of PHEs in pore water (0.05 mol/dm3 Na2EDTA) ranged as follows: Cd 27–91%, Cr 0.7–7.1%, Cu 6.7–98%, Ni 3.6–41%, Pb 15–41%, and Zn 3–34%. The mobility factor (MF) values indicated Cd (31.6%) and Zn (21.0%) as the most mobile elements in soil. Other PHEs followed the order of Co > Ni > Tl > As > Sb > Cu > Cr > Pb, with the MF values <10%. The risk assessment code (RAC) values revealed a very high ecological risk of Cd and Zn in the Podkarpackie Region and a high ecological risk of Cd in the Regions of Opolskie, Śląskie, Małopolskie, and Podkarpackie, and the same of Zn in the Opolskie and Śląskie. The modified risk assessment code (mRAC) index pointed a very high potential of adverse effects in soils in the Podkarpackie and a medium potential in the Opolskie, Śląskie, Małopolskie, and Świętokrzyskie. The potential adverse effect risk, described by the individual contamination factor (ICF) factor, was the following in the Regions, in the decreasing order: Cd > Pb > Sb > Zn > Co > Cu > Ni > Tl > As > Cr, and the same as described by the global contamination factor (GCF) values: Opolskie > Podkarpackie > Świętokrzyskie > Śląskie > Małopolskie.

Potentially Harmful Element Concentrations in the Vegetables Cultivated on Arable Soils, with Human Health-Risk Implications

Potentially harmful elements (PHEs) were investigated in eight groups of vegetables cultivated in southern Poland and the relevant health-risk implications were assessed. The PHE contents belonged to the following ranges (mg/kg wet weight) in edible parts: As < limit of detection (LOD)-0.056, Cd < LOD-0.375, Co < LOD-0.029, Cu < LOD-7.638, Hg < LOD-0.163, Ni < LOD-0.299, Pb < LOD-0.580, Sb < LOD-0.163, Tl < LOD-0.128, and Zn 1.23-34.9. The PHE concentrations decreased in the following order: Zn > Cu > Ni > Cd > Pb > Sb > Hg > Tl > As > Co. The concentrations of essential PHEs decreased as follows: root > leaf > seed > tuber > legume > inflorescence > shoot > fruit, while the unnecessary PHEs followed this sequence: leaf > root > tuber > legume > inflorescence > seed > shoot > fruit. Soil-to-plant transfer factors revealed capacities to adsorb Cd, Hg, and Tl in roots; Cd, Hg, Tl, and Zn in leaves; Cd, Hg, and Sb in tubers; and Cu, Sb, and Zn in legumes and seeds. The daily intake rates, as a percentage of permissible maximum tolerable daily intake, amounted to the following proportions: Cd 23%, Tl 13%, Hg 5.0%, Ni 3.1%, Pb 2.6%, and As 0.4%. Non-carcinogenic risk described as hazard quotient (HQ) was exceeded in root (HQ = 12.1), leafy (HQ = 2.1), and tuber (HQ = 1.4) vegetables. The carcinogenic risk of As (CR = 8.54 × 10-5) was found unacceptable. The margins of exposure for adults (MOE = 3.1) and children (MOE = 1.6), respectively, indicated a low health risk of Pb in consumed vegetables.