Discriminant analysis of concentrations of trace elements in Ulaanbaatar soil

The compositional profiles and health risks of polybrominated diphenyl ethers (PBDEs) were analyzed with urban surface dust and soil samples from industrial, traffic and green areas in Shanghai. The total concentration of ∑8PBDE in urban surface dust ranged from 1.90 to 162 ng/g with a mean value of 29.6 ng/g, while the total concentration of ∑8PBDE in urban surface soil ranged from 1.09 to 39.9 ng/g with a mean value of 9.46 ng/g. ∑PBDEs have a higher concentration in urban dust samples as compared to urban soil samples. Cancer risks were calculated by Average Daily Dose (ADD) for human exposure to urban surface dust and soil containing PBDEs. Concentrations in Shanghai were 3.66×10-4 and 5.85×10-5 for children, and 1.58×10-4 and 6.44×10-5 for adults. Meanwhile, the health risk assessment has indicated that the intake of PBDEs via ingestion and dermal contact were higher than that via inhalation.

Soil heavy metals in karst areas have obvious high background value characteristics. Conducting county-level soil heavy metal ecological risk assessment and identifying heavy metal sources in karst areas are of great significance for soil pollution control and land resource management. Taking Pingguo City, a typical karst county in Guangxi Province, as the study object, 3 151 surface and deep soil samples were collected using the grid method and combined to form 785 analytical samples. The contents of eight heavy metal elements, including As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn, were determined. The content characteristics and sources of heavy metals were analyzed using statistical analysis, interpolation analysis, factor analysis, and the absolute principal component-multiple linear regression model （APCS-MLR）. Using the content of heavy metal elements in deep soil （150-200 cm） as background values, the ecological risk assessment of heavy metals in surface soil （0-20 cm） in the study area was conducted using the geo-accumulation index （Igeo） and potential ecological risk index （RI） methods. The results showed that the average content of heavy metal elements in the deep soil of the study area was significantly higher than the background value of the C layer soil in Guangxi Province, and the average content of heavy metal elements in the surface soil was significantly higher than the background value of the A layer soil in Guangxi Province. The spatial distribution of soil heavy metal element content generally showed the characteristics of high in karst areas and low in non-karst areas. The main sources of As, Cr, Ni, Pb, and Zn were soil parent materials, with contribution rates of 74.36%, 84.59%, 93.69%, 79.67%, and 78.17%, respectively. The main sources of Cd were soil parent material sources and unknown sources, with contribution rates of 37.33% and 31.05%, respectively. The main sources of Cu were soil parent materials and unknown sources, with contribution rates of 59.07% and 40.23%, respectively. The main sources of Hg were tectonic activity and mineralization, as well as unknown sources, with contribution rates of 52.49% and 30.65%, respectively. The geo-accumulation index （Igeo） showed that the surface soil was mainly polluted by Cd, with mild or above pollution accounting for 47.78%. The potential ecological risk index （RI） showed that the proportion of surface soil heavy metal comprehensive potential ecological hazards with mild, moderate, strong, and very strong levels was 80.78%, 14.97%, 2.51%, and 1.64%, respectively.

<p>The <sup>137</sup>Cs (t<sub>1/2</sub> =30 years) is a principal radioisotope that was artificially introduced into the environment through the atmospheric bomb tests took place from the middle of the 1940s to the 1980s and from the major nuclear accidents (i.e., Chernobyl, 1986 and Fukushima, 2011). From the atmosphere, <sup>137</sup>Cs easily adsorbs to particles and it returns to lithosphere (pedosphere) by wet and dry deposition as a radioactive fallout component. Due to the Chernobyl nuclear accident, the released contaminated air mass, containing Cs-137, largely propagated, deposited, and distributed across several European countries in the ambient environment (Balonov et al., 1996). These particles also reached houses (e.g. through open windows, cracks, and vents) in an urban environment and deposited inside resulting in the exposition of the habitants to <sup>137</sup>Cs, especially in areas that are not accessible for a regular cleaning like attics. Following the nuclear accidents, primary attention was drawn to agricultural areas and less attention was paid to urban environments. Accordingly, the goal of this study is to compare the <sup>137</sup>Cs activity in attic dust as undisturbed samples, and urban soils as disturbed environmental materials to determine the <sup>137</sup>Cs distribution in urban environment. </p><p>Attic dust (AD) samples were collected from 14 houses, which were built between 1900 and 1990 14 urban soil (US) samples were collected nearby the houses at a depth of 0-15 cm in Salgótarján, a former industrial city. To obtain a representative local undisturbed soil sample, a forest soil sample was collected from the upwind direction (NW) of the city. To check the <sup>137</sup>Cs content of the local industrial waste material, we also collected fly-ash slag sample from a waste dump.   AD and US samples were analyzed by a well-type HPGe and with an n-type coaxial HPGe detector in a low background iron chamber, respectively.</p><p>Cs-137 activity in the studied AD ranges from 5.51±0.9 to 165.9±3.6 Bq kg<sup>-1, </sup>with a mean value of 75.4±2.5 Bq kg<sup>-1 </sup>(decay corrected in 2016). In contrast, US samples show <sup>137</sup>Cs activity ranging between 2.3±0.4 and 13.6±0.6 Bq kg<sup>-1</sup>.  The brown forest soil sample has elevated <sup>137</sup>Cs activity concentration (18.5<strong>±</strong>0.6 Bq kg<sup>-1</sup>), compared to the urban soils. The fly-ash slags activity is below the detection limit (0.7±0.5 Bq kg<sup>-1</sup>).</p><p>The average <sup>137</sup>Cs activity in AD is ~15 times higher than that of US. This result clearly indicates that attic area provides a protected (hardly or unchanged) environment, therefore physical condition of the dust remains constant in time, and there is a small chance for chemical reaction. Forest soil proves that US were highly disturbed by anthropogenic activity. This is supported by fly-ash slag activity results.  Whereas, <sup>137</sup>Cs activity concentration of the AD samples shows significantly higher than that of the studied soils in Hungary. This confirms again US cannot show the historical atmospheric <sup>137</sup>Cs pollution such as attic dust. A statistically significant relationship (p=0.003, r<sup>2</sup>=0.05) were found between the AD and US samples. Therefore, it can be considered that attic dust remained undisturbed for decades and preserve past record of components of atmospheric pollution.</p><p> </p><p> </p>

Distribution and impacts of contamination by natural and artificial radionuclides in attic dust and urban soil samples from a former industrial Hungarian city: A case study from Salgótarján

The background concentration of potentially toxic elements (PTE) in soils is influenced by the parent material composition and soil forming processes. The soil natural concentration of PTE is a first step to establish regulatory levels for the monitoring of these elements in soils suspected of contamination. In the present study, we performed a natural background concentration survey of PTE in soils of the Piauí state, Brazil. The study provides the basis for establishing soil quality reference values (QRVs) for a large area (over 251,000km2) with different pedological features. A total of 262 geo-referenced soil samples (0.0-0.2m) were collected in areas relatively undisturbed by human activity. The concentrations of Ba, Cd, Co, Cr, Cu, Fe, Mo, Ni, Pb, Sb, V, and Zn were determined by ICP-OES. Univariate statistical methods and multivariate exploratory techniques were used to understand the relationship between soil characteristics, geological features, and PTE concentrations in soils. The mean background concentrations of PTE in the soils were generally lower than those reported in other countries and/or other Brazilian states, and followed the order: Fe > Ba > V > Cr > Cu > Pb > Zn > Ni > Pb > Co > Mo > Sb > Cd. The main factors governing the concentrations of PTE in soils were the parent material and the soil texture. The different geological features in the study area influenced the spatial distribution of PTE and divided the state into three regions presenting low, high, and intermediate values. Given this geological and pedological complexity, we proposed establishing three sets of QRV rather than a single QRV for the whole state to avoid misinterpretation regarding the investigation of areas suspected of contamination. This background concentration survey contains a wealth of information that provides the basis for the soil guideline values in the state and supports future research on the impact of anthropogenic activities in soil contamination.

With increasing urban area and population, global cities are playing a more important role in the alteration of the global biogeochemical cycles. The aims of this study are to understand the concentrations and stoichiometric relations of biogenic elements (C, N, and P) in urban soils, further to reveal the effects of C, N, and P accumulation on the urban environment. We collected 317 surface (0–10 cm) soil samples taken from Nanjing, China, a typical city with more than 2000 years of history. These soil samples were located in different urban zones of Nanjing with different land use histories. The soil C, N, and P concentrations were determined. The stoichiometric relations of soil C, N, and P were investigated in urban soils. Meanwhile, some studies on sources of C, N, and P in diverse urban settings from literature were combined to explore the universal rule of C, N, and P cycling and their ecological and environmental effects in urban area. Compared to rural soils, more C, N, and P are accumulated in the urban soils, which also change their stoichiometric relations. The concentrations of OC, TN, and TP in urban top soils are 17.0 ± 9.69 g kg−1, 1.53 ± 0.92 g kg−1, and 1.31 ± 0.67 g kg−1, respectively. The mean atomic ratio of C:N:P is 37:3:1 in the surface of urban soils that strictly differs from natural soils in China and the whole world. The mean of C:N ratio in urban soils is similar to that of agriculture, grassland, and forest soils. However, the ratios of C:P and N:P in urban soils are much lower than that in agricultural, forest, and grassland soils. This implies that P is extremely enriched in the urban soils. The high C in urban soils are considered coming from natural and anthropogenic sources. The high N and P mainly come from anthropogenic sources. The well-constrained C:N:P ratio in rural soils does not apply for urban soils. The abnormal C:N:P ratio of urban soils is the result of unbalanced accumulation of C, N, and P from human activities. Urban soils are already an important storage of carbon. High N and P in urban soils may bring threat of surface water eutrophication and ground water contamination. These effects are expected to increase with the city development time.

This study evaluates the status of soil contamination by potentially toxic elements (PTEs)—Cr, Co, Ni, Cu, Zn, As, Mo, Cd, Sn, Ba, Pb in agricultural and urban areas in the Lesser Poland Voivodeship in light of applicable regulations. The method validation was performed, and the uncertainty of the analytical process, including the sampling stage, was estimated. Soil samples collected by the doubling method were acid-mineralized and then analyzed by inductively coupled plasma mass spectrometry. Validation was performed with reference materials, and process uncertainty was determined by analysis of variance in the ROBAN programme. PCA analysis was also used to determine correlations between PTEs. The results for Zn, Sn, and Cu in agricultural soils, as well as Cu in urban soils, were below the limit of quantification. For Mo, Cd, and Pb in agricultural soil, and Zn and As in urban soil, the estimation was rejected due to inconclusive results. In agricultural and urban soil samples, the average Ba content was respectively 209.27% and 114.72% of the limit value standard, indicating high Ba levels. In urban soil, the Cd concentration reached 292% of the limit value. The method validation was successful, confirming the accuracy of the analysis. Exceeding the maximum limit value for Ba and Cd in soil samples can have a negative impact on the environment and pose a threat to soil and human health. More research is required to monitor the environmental risk and identify sources of hazardous metal emissions.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-20680-9.

The relationship between historical development and potentially toxic element concentrations in urban soils

The effect of sewage sludge fertilization on the concentration of PAHs in urban soils

Accumulation of potentially toxic elements in the body tissues of sheep grazed on grassland given repeated applications of sewage sludge

Due to their low tolerance to pollutants and hand-to-mouth pathways the health risk is very high in children's population. The aim of this study was to evaluate risk to children's health based on the content of heavy metals in urban soil samples from Podgorica, Montenegro. This study included the investigation of several toxic metals such as Pb, Cd, Cu and Zn in soil samples from public parks and playgrounds. Sampling was conducted in a period October-November, 2012. Based on cluster analysis, soil samples were divided into two groups related to similarity of metal content at examinated locations: the group I--near by recreational or residential areas of the city, and the group II--near traffic roads. Concentration of toxic metals, in urban soil samples were determined by a graphite furnace atomic absorption spectrometry (Pb and Cd) and by inductively coupled plasma optical emission spectrometry technique after microwave digestion. Due to exposure to urban soil, non-cancerogenic index hazardous index (HI) for children was estimated using 95th percentile values of total metal concentration. The value of the total (ingestion, dermal and inhalation) HI is calculated for maximum, minimum and the average concentration of metals for children. Mean concentrations of Pb, Cd, Cu and Zn in the surface layer of the studied urban soils were 85.91 mg/kg, 2.8 mg/kg and 52.9 mg/kg and 112.5 mg/kg, respectively. Samples from group II showed higher metal content compared to group I. Urbanization and traffic are the main sources of pollution of the urban soils of Podgorica. Most of the samples (93.5%) had a high Pb content, 12.9% of the samples had a higher content of Cd, while Cu and Zn were within the limits prescribed by national legislation. At one location the level of security for lead is HI = 0.8 and very closed to maximum acceptable value of 1. It is probably the result of intensive traffic near by. All metals investigated showed relatively higher concentrations at sites that were close to industrial places and high ways. The mean concentrations of Pb and Zn and maximum concentrations of Pb, Cd, and Zn were higher than presented values in the National Regulation.

The definition of urban soil is descriptive, a description of a state, not a taxonomic classification. There are no physical or chemical property lists for it as for general soils’ definition. “Urban soil” is a generic term and can be interpreted in many ways, but it refers to soils affected by urbanization. Urban soils supply environmental services and support the urban vegetation communities, despite being essentially different from natural soils. The main goals of this paper were to characterize urban soils in open green undisturbed patches and find a feature that will identify urban soils, not directly affected by urbanization process, like construction, residential, and transportation development. Seventy soil samples were collected from Mount Carmel National Park, city of Haifa’s remnant patches and disturbed sites. The samples were taken from horizon A, after the coarse organic particles or trash residues were removed. Two non-distractive spectral methods across visible and near, shortwave, and mid-infrared (VNIR-SWIR-MIR) spectral regions were used to characterize the soil minerology and total carbon content (0.35–25 μm) and analyzed by previously published top-down spectral unmixing method. The urban soils from all the city sites were found to be a combination of anthropogenic residue, contaminants alien like actinolite and chrysotile traces, local clay, and silicate minerals, while the park’s soils contained none. Furthermore, the average total carbon content found in urban soils was significantly lower than the amount found in the park’s samples. The results of the spectroscopy and analytical chemical analysis could not set apart the urban soils; all samples contained materials from anthropogenic origin. Yet, urban soil samples and park soil samples had different spectra features, which set the two soils significantly apart. The spectra of urban soil samples contain high absorption features at the VNIR and very few and much less information at the MIR wavelength. This fundamental difference can define urban-affected soils. The spectral feature found in this study may be useful for creating a non-destructive method to trace the urbanization changes in rapid acquisition of soil information at quantitative and qualitative levels.

采用调查分析方法,研究长沙城市森林土壤Zn、Cu、Ni、Pb、As、Cd、Hg7种重金属含量,并以长沙市土壤背景值和湖南省土壤背景值为参比值,采用Hakanson潜在生态危害指数法评价不同城市化梯度森林土壤重金属潜在生态风险。结果表明:7种重金属的平均含量均随着城市化程度提高而增加,Pb增幅最大,As增幅最小。同一城市化梯度森林土壤均以Zn平均含量最高,Cd最低,但均未超过土壤环境质量标准(GB15618-1995)Ⅱ级标准值。在城市中心区,桂花树林、樟树+桂花树混交林土壤Zn、Cu、Pb、As、Hg平均含量普遍较高,而樟树+马尾松混交林、桂花树+杜英混交林土壤Cu、Ni、As、Cd、Hg平均含量普遍较低,Pb、Zn空间分布差异明显,Cd、Ni、As空间分布比较均匀,Cu、Ni、Pb、As、Cd、Hg之间(除Cd与As、Ni之间外)均存在显著(<em>P</em>＜0.05)或极显著(<em>P</em>＜0.01)的相关性,与土壤有机质之间也呈显著(<em>P</em>＜0.05)或极显著(<em>P</em>＜0.01)的相关性,Zn、Cu、Ni、Pb、As、Cd、Hg主要是人为输入;中心区森林土壤重金属的潜在生态危害已达到中等生态危害程度,边缘区接近中等生态危害程度,郊区为轻微生态危害程度,Zn、Cu、Ni、Pb、As均为轻微生态危害程度,Cd、Hg已达到中等生态危害程度以上。;In order to understand the influence of urbanization on distribution of heavy metals in soils, concentrations characteristics of 7 heavy metals (Zn, Cu, Ni, Pb, As, Cd, and Hg) in various forest types were investigated along an urban gradient in Changsha, a capital city of Hunan Province, China. The concentrations and potential ecological risk of heavy metals in the urban soils was assessed when compared to the background values of heavy metals in soils in both Changsha city and Hunan Province. A total nineteen major forest types were selected at three locations (namely urban district location, urban fringe location, and suburban location) along the urban gradient degree in urban forests soil in the Changsha city. Two forest plots (each with the size of 20m × 20m) were built in each forest types. Three subplots were (each with an area of 1 m²) were set up in each of the plots. Five soil samples (from 0-20 cm depth) were randomly taken within each subplot and pooled to a soil sample for heavy metals chemical analysis, 0-20cm soil samples were collected from different urban gradient (urban district, urban fringe, suburban) forest to analyze the concentrations of Zn, Cu, Ni, Pb, As, Cd, and Hg, and the potential ecological hazard assessment indices by Hakanson was used to assess the soil heavy metals potential ecological risk degree in urban forest, based on the background values of soil in Changsha City and in Hunan Province. Results showed that the average concentration of the same heavy metal elements in urban forest soils tended to increase with degree of urbanization. Pb had the maximum increasing value and As the minimum. In the same urbanization location degree, Zn had the highest average concentration and Cd had the lowest one among the studied of all test heavy metals., On average, while the average the concentrations of all examined heavy metals them in study sites were lower than those in the Environmental Quality Standard for Soil (Ⅱgrade) in China.,. The heavy metals whose concentrations were higher than the background values in Changsha cite and the accumulation tendency of test heavy metals in urban forest were as in the order as of Cd＞Hg＞As＞Pb＞Cu (Ni)＞Zn in the study sites. The concentration of re existed some differences in the same heavy metal element varied concentration with among different types forest types in the city, The average concentrations of Zn, Cu, Pb, As, and Hg were as higher in <em>Osmanthus fragrans</em> forests and, <em>Cinnamomum camphora Presl.</em> and<em> Osmanthus fragrans </em>mixed forests, but that of Cu, Ni, As, Cd, and Hg were found to be was low concentrations in<em> Cinnamomum camphora Presl.+ Pinus massoniana </em>mixed forests and, <em>Osmanthus fragrans +Elaeocarpus sylvestris Poir </em>mixed forests, the spatial distribution patterns of Pb and Zn was significant different in the study area, while Cd, Ni and As were more evenly distributed. Significant correlations were found among Zn, Cu, Ni, Pb, As, Cd, and Hg concentrations in soils (<em>P</em>< 0.05), except the relationships between Cd and As, and Ni. The 7 heavy metals had positively significant correlations with soil organ matter. It was found that Zn, Cu, Ni, Pb, As, Cd and Hg mainly came form the anthropogenic inputs in the urban district forests. Based on potential ecological risk assessment, the situation of heavy metals was in the medium ecological risk level in urban district locations, was in closing to the medium level in urban fringe locations, and was in a slight level in suburban locations in Changsha cite. Among the studied heavy metals, Zn, Cu, Ni, Pb, and As were in a slight risk level, while Cd and Hg were in medium or strong ecological risk level. Our study provided scientific reference to estimate and evaluate the impact of urbanization on heavy metals in Southern China.

Quantities and associations of lead, zinc, cadmium, manganese, chromium, nickel, vanadium, and copper in fresh Mississippi delta alluvium and New Orleans alluvial soils

Concentrations of major and trace elements in soil and grass at Shimba Hills National Reserve, Kenya