Lead Concentrations In Soil Research Articles

Occurrence and Uptake of Heavy Metals in Soil and Plant (Tomato) Associated with Crude Oil Contamination

The general increase of heavy metal content in the soil has been largely caused by crude oil spillage. This study investigates the possibility of tomato (Lycopersicon esculentum Miller) to sorb heavy metals present in crude oil. Crude oil of 0 mL (control), 75 and 150 mL were mixed thoroughly with 15 kg of loamy soil (dry weight) in perforated plastic buckets, as the experimental pots and left for 4 days before transplanting tomato seedlings. After 12 weeks of transplanting, heavy metals analysis was carried out on plant’s fruits, leaves, stems and roots. Physicochemical analyses show that control soil had the lowest organic carbon (3.07 %) while 150 mL had the highest mean organic carbon content (8.24 %). The silt, clay and sand constituents were not significantly different (p > 0.05) in both treated and untreated soil. The control had the least pH value (6.1) while the lead (Pb) content in soil was highest in 150 mL (0.33 mg/kg) but was not significantly different (p > 0.05) from control (0.26 ) and 75 mL (0.30 mg/kg). Lead (Pb) and Cadmium (Cd) were not detected in leaves and fruits. However, bioaccumulation factor (BAF) of Cd and Ni in stem were greater than 1. Although, the concentrations of these heavy metals falls below toxic levels, its consumption could lead to adverse health effects in both man and animals through bioaccumulation or biomagnification.
 HIGHLIGHTS
 
 Countries with poor hydrocarbon pollution regulation are more challenging with oil spills, either through accidental discharges or indiscriminate disposal of hydrocarbon waste
 Plants essentially need some metals such as iron, copper among others, for their growth and other metabolic activities. However, at excess of specific limits, these metals adversely affect plant growth
 In this study, bioaccumulation factors (BAF) of Cd and Ni in the stem were greater than 1, this shows that the tomato plant is a hyperaccumulator of Cd and Ni from the soil
 
 GRAPHICAL ABSTRACT

The impact of the mountain barrier on the spread of heavy metal pollution on the example of Gorce Mountains, Southern Poland

The main objective of this study was to determine the content, mobility, and the variability of concentration of zinc, lead, and cadmium in soils from the Gorce Mountains (south Poland), located over 100 km south-east from the potential industrial sources of contamination—zinc-lead sulfide ore mine and smelter in Bukowno, as well as hard coal mines of Silesia region and Kraków Nowa-Huta steelwork. The abovementioned problem is crucial in the context of the traditional mountain farming still extant in the region, as well as intensively developing tourism. The geoaccumulation index and potential ecological risk index were adopted to evaluate soil pollution in the study area and the BCR sequential extraction technique to assess mobility of the abovementioned elements. The obtained results clearly show that the pollution from distant industrial sources in the mountains is detectable. Apart from the increased concentrations of the tested metals in the soil (especially available forms), there is also a strong correlation between the concentrations of lead, zinc, and cadmium, which proves their common source of origin. The main evidence is the fact that differences in the concentrations of the tested metals on the windward and leeward sides were statistically significant. This also means that the studied mountain area, despite relatively low altitudes (up to 1310 m above sea level), constitutes a measurable barrier to the spread of atmospheric pollutants.

Degradation Reduces Microbial Richness and Alters Microbial Functions in an Australian Peatland

Peatland ecosystems cover only 3% of the world’s land area; however, they store one-third of the global soil carbon (C). Microbial communities are the main drivers of C decomposition in peatlands, yet we have limited knowledge of their structure and function. While the microbial communities in the Northern Hemisphere peatlands are well documented, we have limited understanding of microbial community composition and function in the Southern Hemisphere peatlands, especially in Australia. We investigated the vertical stratification of prokaryote and fungal communities from Wellington Plains peatland in the Australian Alps. Within the peatland complex, bog peat was sampled from the intact peatland and dried peat from the degraded peatland along a vertical soil depth gradient (i.e., acrotelm, mesotelm, and catotelm). We analyzed the prokaryote and fungal community structure, predicted functional profiles of prokaryotes using PICRUSt, and assigned soil fungal guilds using FUNGuild. We found that the structure and function of prokaryotes were vertically stratified in the intact bog. Soil carbon, manganese, nitrogen, lead, and sodium content best explained the prokaryote composition. Prokaryote richness was significantly higher in the intact bog acrotelm compared to degraded bog acrotelm. Fungal composition remained similar across the soil depth gradient; however, there was a considerable increase in saprotroph abundance and decrease in endophyte abundance along the vertical soil depth gradient. The abundance of saprotrophs and plant pathogens was two-fold higher in the degraded bog acrotelm. Soil manganese and nitrogen content, electrical conductivity, and water table level (cm) best explained the fungal composition. Our results demonstrate that both fungal and prokaryote communities are shaped by soil abiotic factors and that peatland degradation reduces microbial richness and alters microbial functions. Thus, current and future changes to the environmental conditions in these peatlands may lead to altered microbial community structures and associated functions which may have implications for broader ecosystem function changes in peatlands.

Accumulation of lead radionuclides in 18 leaf vegetable types in Viet Nam

Studying the concentration of radioactive lead in soil and plants, and using plants for phytoremediation are important for the environment and human health protection. In this study, we used gamma spectrometry to determine activity concentration in soil - plants, transfer factor. The average activity concentration of lead radionuclides in soil and plants were in the following order of 210Pb > 214Pb > 212Pb. The average activity ratio of 214Pb and 212Pb to 210Pb in soil were 0.70 and 0.59 and in plants were 0.69 and 0.14, respectively. The results showed that there was not much difference between the ratio of radioactive 214Pb and 210Pb concentrations in vegetable and plant samples. Ming aralia (Polyscias fruticose) and lettuce (Lactuca sativa) contained the highest concentrations of 210Pb, and Malabar spinach (Basella alba) contained the lowest concentration. Ming aralia could be used for the radioactive decontamination of 210Pb. There vegetable samples from Ho Chi Minh City were considered safe for human consumption in the aspect of lead radionuclides.

Study of the Effect of Mercury Salt on the Presence of Annelida (Lumbricus terrestris) in Soil and the Histological Changes on the Skin Tissue

The earthworm is the most beneficial organism for assessing metallic contamination due to the fact that critical high-quality correlations have been determined between earthworm steel concentrations and soil cadmium, copper, lead, zinc, and mercury concentrations. The mercury compounds are very poisonous for most organisms. Here, we investigated the ability of earthworms (Lumbricus terrestris) to HgCl2 (below laboratory conditions). A study of the effect of five different salt concentrations of mercury chloride (HgCl2) 1 ppm, 5 ppm, 10 ppm, 50 ppm, and 100 ppm was studied on worm survival and calculation of the concentration required to destroy half the number of worms (LC50). The results showed that there is an inverse relationship between these salt concentrations and the time required to perish 100% of worms. It was found that the concentration of 100 ppm is the lethal concentration of half the number (LC50) of the earthworm (Lumbricus terrestris). The effects of the salt concentrations used confirmed their effect on the experimental worm weights as well, so the concentration of 50 ppm was the most influential on earthworm weights of the type of Lumbricus terrestris, as it caused a reduction 12% of worm weights with a significant difference, while the concentrations 1 ppm and 100 ppm were the least effective, as they caused the worms to decrease by only (5%), while the remaining two concentrations 5 ppm and 10 ppm caused their effect to decrease by 7% only. Thus, it can be concluded that lower worm weights have nothing to do with the lethal concentrations of the heavy metal salt (HgCl2). The histological study also showed that low concentrations of mercury chloride salt have less effect on earthworms’ skin tissue compared to higher concentrations.

Change in the content of Pb and Cd mobile compounds in sod-podzolic soil at application increasing doses of mineral fertilizers

Results are presented of study of seasonal dynamics of lead and cadmium mobile compounds content in arable sod-podzolic soils of long stationary trial on application of increasing doses of mineral fertilizers. The studies revealed that the concentrations of mobile compounds of elements in the soil are insignificant and do not exceed MAC and background concentrations; this fact indicates the absence of anthropogenic contamination of the studied arable soils. During the growing seasons of two years of observation, the content of mobile Pb changed from 0.08 to 1.03 mg/kg in the first year and from 1.34 to 3.10 mg/kg in the second. The content of mobile Cd was from 0.04 to 0.10 mg/kg in the first and from 0.02 to 0.05 mg/kg in the second year of observation, respectively. During the growing season, the content of mobile forms of elements was very dynamic. The maximum content of mobile lead was characteristic of the initial phase of the growing season (end of May - June) at the most favorable combination of hydrothermal factors. Clear reliable patterns in changing the content of mobile forms of cadmium during the season were not revealed. The application of increasing doses of fertilizers leads to an increase in the acidity (decrease in pH) of the arable layer of soils. However, the influence of this factor on the dynamics and content of lead and cadmium was ambiguous, which indicates a complex influence of other unaccounted soil factors.

Influence of Silicon on Translocation, Compartmentation and Uptake of Lead in Leafy Vegetables

Lead (Pb) has phytotoxic and toxic effects on plants and animals. Leafy vegetables accumulate this element resulting in enrichment along the food chain. Silicon has beneficial effects in enhancing plants’ tolerance to biotic and abiotic stresses including heavy metals such as Pb. The study was carried out under greenhouse and field conditions aiming at determining the effects of silicon on transfer, mobility, and uptake of lead by leafy vegetables (spinach, kale, and amaranths). The greenhouse experiment was carried out as a split-plot arranged in Completely Randomized Design (CRD). The vegetable species were allocated to the main plots whereas the treatments (Pb, Pb+Si, Si, and Control) were assigned to the subplots. The field experiment was sited in polluted soils, and treatment included control and Si, applied to spinach, kale, and amaranths. Data was collected on Pb concentrations in roots, stems, and leaves, transfer factor, mobility index, and uptake of lead by leafy vegetables. Lead concentration was highest in roots, intermediate in stems, and least in leaves. Silicon application reduced concentration, transfer factor, mobility, and uptake of lead by 20, 40, 15, and 24%, respectively. The lead transfer factor and translocation index was less than one. Pearson correlation coefficient indicated a strong positive correlation between lead concentrations in soils and plant tissues of leafy vegetables. Application of silicon on polluted soils reduced transfer and mobility of lead in edible tissues of leafy vegetables. The study recommends silicon application to reduce the concentration of lead on vegetable tissues, however, it recommends against vegetable production for human consumption on polluted soils.

Estimation of soil lead content based on GF-5 hyperspectral images, considering the influence of soil environmental factors

Estimation of soil lead content based on GF-5 hyperspectral images, considering the influence of soil environmental factors

Spatial distribution of lead (Pb) in soil: a case study in a contaminated area of the Czech Republic

For decades, the Příbram district in the Czech Republic has been affected by industrial and mining activities, which are the main sources of heavy metal pollutants and negatively affect soil quality. A recent study examined visible–near-infrared (VNIR), shortwave-infrared (SWIR), and X-ray fluorescence (XRF) spectroscopy to model soil lead (Pb) content in a selected area located in Příbram. Following that study, and using the data, we examined the spatial distribution of Pb content in the soil, with a combination of traditional techniques (Moran’s I, hotspot analysis, and Kriging). One of the novel points of this work is the use of the Getis–Ord hotspot analysis before the execution of Kriging interpolation to better emphasize clustering patterns. The results indicated that Pb was a spatially dependent soil property and through extensive in-situ sampling, it was possible to generate an accurate interpolation model. The high-Pb hotspots coincided with topographic obstacles that were modeled using topographic profiles extracted from Google Earth, indicating that Pb content does not always exhibit a direct relationship with topographic height as a result of runoff, due to the contribution of topographic steps. This observation provides a new perspective on the relationship between Pb content and topographic patterns. Highlights Different spatial analyses were executed to examine the spatial distribution of Pb Extensive in-situ sampling provided an accurate Kriging interpolation model of Pb Pb hotspots with field soil data were mapped with a high degree of certainty The Pb hotspots coincided with topographic obstacles modeled using Google Earth

ОЦЕНКА ЗАГРЯЗНЕНИЯ ТЯЖЕЛЫМИ МЕТАЛЛАМИ ПОЧВ ГОРОДА ПЕТРОПАВЛОВСКА-КАМЧАТСКОГО, КАМЧАТСКИЙ КРАЙ

The results of determining the gross content of zinc, copper and lead in the surface soil layer, collected in Petropavlovsk-Kamchatsky, are presented in the paper. Based on them the heavy metal pollution degree assessment in different places of the city during 2017–2020 is given. It was found that almost everywhere the lead content in soils corresponded to a very high or high degree of contamination. According to the concentration of copper and zinc, the soils were classified as low and medium polluted. During 2017–2020 an increase of copper and zinc concentration in soils was registered. The dynamics of changes in lead concentration, on the contrary, was poorly expressed during 2017–2018. In 2020 a decrease in its content was found in all observed areas. According to the integrated pollution indexes PLI and NPI, the most polluted soils were identified in such areas as ‟Hospital” (2017),‟Botanicheskiy Pereulok” (2018), ‟Stadium Spartak” (2020). All city soils were characterized by a weak degree of potential environmental risk resulting from heavy metal pollution. The obtained data can be used to monitor heavy metal contamination of urbanized territories soils in Kamchatka Territory.

Phytoremediation of Lead Contaminated Land Using Vetiver zizanoides and Citric Acid as Chelating Agent

Environmental pollution due to hazardous waste in Karangdawa, Margasari, Tegal has an impact on soil and groundwater quality. Lead found in the soil exceeds the permissible standards. It is necessary to recover soil from Lead because it can enter food crops and accumulate in the human body. Phytoremediation is commonly used in land remediation because it’s economical and doesn’t cause secondary environmental problems. One of the ways to optimize Phytoremediation is by using chelating agents. The purpose of the study was to analyze the ability of Vetiver zizanoides and analyze the most optimum dose variation of Citric acid to uptake Lead to the plant. The ability of Vetiver zizanoides and Citric acid as metal chelators in Pb uptake was investigated for 28 days with Citric acid doses of 0.5 g/kg, 1 g/kg, and 2 g/kg. Analysis of Lead concentration in roots, stems, and soil using AAS. From the results of the study, Vetiver zizanoides was able to survive from Lead exposure up to 4979.8 ppm. Application 1 g/kg of Citric acid in the soil, increased the bioconcentration, and bioaccumulation compared to control plants. The results indicated that the addition of Citric acid as a chelating agent could increase the function of Vetiver zizanoides as a phytoremediation agent.

Fungal Population and Physicochemical Characteristics of Abattoir-Impacted Soil in Iwofe, Rivers State

Aim: To determine the fungal population and physicochemistry of abattoir impacted soil in Iwofe, Rivers State.
 Study Design: This study focused on Abattoir impacted soil. Statistical analysis of data and interpretation was carried out.
 Place and Duration of Study: Abattoir impacted soil was collected from three points in an abattoir located in Iwofe, Rivers State while the unpolluted soil which served as control was collected from the Rivers State University, Port Harcourt in January, 2021.
 Methodology: Standard microbiological techniques were used: the fungal population was determined by inoculating aliquots of an appropriate dilution resulting from a ten-fold serial dilution on prepared Sabouraud dextrose agar plates in duplicates. Plates were later incubated for 3-5 days after which colonies were enumerated and used in obtaining the fungal population in the soil samples while distinct colonies were subcultured for macroscopic and microscopic identification of fungi. The physicochemical parameters and heavy metals were analyzed using standard methods.
 Results: Fungal load in the control and abattoir impacted soil were 1.09×105 and 3.9×104 CFU/g, respectively. The fungal load of the control soil was significantly higher (P˂0.05) than the abattoir impacted soil. The fungal isolates identified in the abattoir impacted soil were Microsporium sp, Aspergillus niger and Candida sp while Aspergillus niger, Aspergillus flavus, Fusarium sp, Penicillium sp, Mucor sp and Rhizopus sp were identified from the control soil. The pH, temperature, nitrate and phosphate of the abattoir soil were 6.7, 28.33℃, 27.83(mgKg-1) and 1055(mgKg-1), respectively. The concentrations of Cadmium, Iron and Lead in the abattoir Impacted soil and control soil were 0.81, 563.35 and 7.12 mgKg-1, 0.51, 582.0 and 3.18 mgKg-1, respectively. The physico chemistry and heavy metals in the abattoir soil were within acceptable limits.
 Discussion and Conclusion: The findings from this study showed that heavy metals in abattoir impacted soil had an impact in the fungal population which led to the isolation of only three fungal isolates belonging to Microsporium sp, Candida sp and Aspergillus niger. More so, despite the presence of heavy metals in the abattoir impacted soil, the metals were all within permissible limits. Thus, the abattoir impacted soil was not heavily polluted.

Determination of Heavy Metals in Soil around Amasoma Community in Bayelsa State, Nigeria

Aims: Anthropogenic activities such as crude oil exploration and exploitation has led to the suspicion of heavy metals contamination in the study area. This study investigated the concentration of zinc, nickel, lead and cadmium in the soil extracted from the area where Scent Leaf (Ocimum gratissimum) and Pawpaw tree (Carica papaya) are grown in Amassoma community, Bayelsa State, Nigeria.
 Study Design: Scent leaf (Ocimum gratissimum) and Pawpaw tree (Carica papaya) soils from where these plants are grown were randomly collected for heavy metal analysis from within Amassoma community in Southern Ijaw Local Government Area of Bayelsa State, Nigeria
 Place and Duration of Study: This study was carried out in Biological Sciences, Faculty of Science, Niger Delta University, Wilberforce Island, Amassoma, Bayelsa State between March 2019 to September 2019
 Methodology: Scent leaf (Ocimum gratissimum) and Pawpaw tree (Carica papaya) soils were digested and analyzed for heavy metals using Atomic Absorption Spectrophotometer (AAS, model S471096). The method used was wet-ashing method for the analysis.
 Results: the concentrations of Lead (Pb), Nickel (Ni), Cadmium (Cd), and Zinc (Zn), in pawpaw soil and scent leaf soil. From the sample data analysis, the average lead (Pb) contents in pawpaw soil and scent leaf soil were 1.283 mg/kg and 1.44 mg/kg respectively. The average Cadmium (Cd) in pawpaw soil and scent leaf soil were 0.256 mg/kg and 0.256 mg/kg respectively. The average Nickel (Ni) compositions in pawpaw soil and scent leaf soil were 4.71 mg/kg and 5.09 mg/kg respectively. While the Average Zinc (Zn) in pawpaw soil and scent leaf soil is 2.280 mg/kg and 2.160 mg/kg respectively. The soil analyzed for heavy metals were below the threshold target values recommended by the WHO.
 Conclusion: The Scent leaf (Ocimum gratissimum) and Pawpaw tree (Carica papaya) soils analyzed for heavy metals were below the permissible limit recommended by WHO for soil safety. The result from the present study revealed that there may not be soil contamination as a result of the selected heavy metals, however, It is recommended that caution should be taken in regulating the anthropogenic activities that may tend to elevate the level of heavy metals in the surrounding to prevent contamination of soil over time which could be detrimental to the health of the populace.

Lead content in soil, plants, rodents, and amphibians in the vicinity of a heating plant's ash waste.

This study supplements previous research focused on environmental condition in the vicinity of waste ash material. The main aim of our study was the comparative analysis of lead levels in soil, plant, and animal organisms in the area of the tailings pond and surroundings, using x-ray. Findings confirm that the level of Pb in the top layer of soil is in the range of 20-135ppm. Lead content in Calamagrostis plant tissues was confirmed only at the tailings pond area, with the highest lead concentrations measured in above-ground components; stems with blooms followed by roots and ground floor sheats. The livers, kidneys, and hearts of Apodemus flavicollis were examined, with findings of higher values in the tailings pond area than in the reference site, and average values of 14.5ppm for livers, 16.0ppm for kidneys, and 16.6ppm for hearts. No significant differences were discovered based on sex and body length/body weight of A. flavicollis individuals. Values for Bombina variegata liver tissue reached an average of 12.3ppm for individuals caught in a water reservoir without ash sediments, versus 15.7ppm in those trapped by the edge of then tailings pond area. Females had lower concentrations of lead than males, but with no statistically significant differences found. Despite lower lead levels in soil and ash than expected, concentrations in mammalian and amphibian organs suggest a possible transition of this element into the food chain, and therefore further research in this area is recommended.

Lead, Soils, and Children: An Ecological Analysis of Lead Contamination in Parks and Elevated Blood Lead Levels in Brooklyn, New York.

Although the prevalence of elevated childhood blood lead levels (BLLs) has been declining, there are still an estimated 500,000 children (1 to 5years) with BLLs above the CDC's reference value (≥ 5μg/dL). The objective of this study was to evaluate the ecological association between soil lead (Pb) concentrations in greenspaces in Brooklyn, NY and elevated BLLs of children aged 1 to 5years old. Soil samples (n = 1504) were collected from a wide variety of parks within 43 neighborhood tabulation areas (NTAs) located in Brooklyn, NY, analyzed with a portable XRF with a subset (n = 350), and also analyzed by ICP-MS. Lead concentrations were right skewed with a mean of 160.4ppm and a median of 113.1ppm. The Pb concentration range spanned three orders of magnitude with most samples (66.7%) ≥ 80ppm and 6.7% of samples ≥ 400ppm. Elevated BLL (≥ 5ug/dL) data on children 1 to 5years were obtained from the New York City Department of Health and Mental Hygiene (2011-2015). Weighted median soil Pb concentrations were calculated for each NTA and stratified into quartiles. The overall median rate of children from 1 to 5years old with BLLs ≥ 5µg/dL was 28.6 per 1000; the median rate was highest (p = 0.070) in the fourth quartile (Pb concentrations ≥ 150ppm) compared to the first quartile (Pb concentrations < 88ppm), 37.2 vs. 28.3 per 1000, respectively. We then used multivariable linear regression to determine the ecological association between BLL rates and soil Pb concentrations. In the final stepwise multivariable regression model, controlling for known risk factors, there was a significant positive association between soil Pb concentrations and increased childhood BLL rates (beta = 0.0008; p = 0.004). Our findings suggest that thereis an ecological association between high soil Pb levels and increased rates of elevated childhood BLLs.

Prediction of Soil Heavy Metal Distribution Using Geographically Weighted Regression Kriging.

Both soil heavy metals and the influencing factors are related to spatial location and are spatially heterogeneous. However, the global linear regression model assumes the regression coefficients to be spatially stationary throughout the study region and is unable to account for the spatially varying relationships between soil heavy metals and influencing factors. Thus, the objectives of this study were to estimate the spatial distribution of soil heavy metals using a geographically weighted regression kriging (GWRK) approach, and compare the GWRK results with those obtained from ordinary kriging (OK) and regression kriging (RK). A dataset of soil lead (Pb) concentrations in Daye city, China, that was sampled in 2019 was used. According to the results of spatial smoothness, variability, and interpolation accuracy, GWRK was the best method and could provide the most reasonable spatial distribution pattern and the highest spatial interpolation accuracy in comparison with OK and RK.

Manage the environmental risks of perovskites

Manage the environmental risks of perovskites

Radon potential mapping in Jangsu-gun, South Korea using probabilistic and deep learning algorithms

The adverse health effects associated with the inhalation and ingestion of naturally occurring radon gas produced during the uranium decay chain mean that there is a need to identify high-risk areas. This study detected radon-prone areas using a geographic information system (GIS)-based probabilistic and machine learning methods, including the frequency ratio (FR) model and a convolutional neural network (CNN). Ten influencing factors, namely elevation, slope, the topographic wetness index (TWI), valley depth, fault density, lithology, and the average soil copper (Cu), calcium oxide (Cao), ferric oxide (Fe2O3), and lead (Pb) concentrations, were analyzed. In total, 27 rock samples with high activity concentration index values were divided randomly into training and validation datasets (70:30 ratio) to train the models. Areas were categorized as very high, high, moderate, low, and very low radon areas. According to the models, approximately 40% of the study area was classified as very high or high risk. Finally, the radon potential maps were validated using the area under the receiver operating characteristic curve (AUC) analysis. This showed that the CNN algorithm was superior to the FR method; for the former, AUC values of 0.844 and 0.840 were obtained using the training and validation datasets, respectively. However, both algorithms had high predictive power. Slope, lithology, and TWI were the best predictors of radon-affected areas. These results provide new information regarding the spatial distribution of radon, and could inform the development of new residential areas. Radon screening is important to reduce public exposure to high levels of naturally occurring radiation.

Green remediation of high-lead contaminated soil by stabilization/solidification with insoluble humin: Long-term leaching and mechanical characteristics

High concentrations of lead in soil will greatly weaken the stabilization/solidification effect. Humin (HM) is expected to improve this process because it is a neutral, insoluble, porous and green material as well as an eco-friendly adsorbent extracted from natural peat soil. However, HM has not been studied with respect to the stabilization/solidification (S/S) characteristics of potentially toxic element (PTE)-contaminated soil due to its different extraction sources and methods, as well as complex properties. To study these effects, insoluble HM was extracted for treatment of high-lead contaminated soil by cement-based S/S. The experimental results show that HM has a strong adsorption capacity for lead with a maximum adsorption capacity of 200.2 mg kg−1. The negative influence of a high content of lead on the compressive strength over a 0–90-day period is weakened after adding HM to the soil, wherein a competitive mechanism between HM and a high concentration of lead is proposed. The lead leaching concentration of stabilized soil is significantly decreased under different leaching methods from 0 to 60 days and then decreases slowly. The lead speciation results for the stabilized soil determined through the Tessier sequential extraction method show that HM promotes the gradual chemical transformation of lead from exchangeable and carbonate-bound fractions to a more stable state, with respective decreases of 27.5% and 15.1%. In addition, SEM-EDS images show that HM with a high porosity and specific surface area coexists well with cement, which promotes the stabilization of lead. In conclusion, HM contributes to decreasing the mobility and bioavailability of lead and achieving environmental remediation.

Evaluation of lead (Pb) concentration in animal tissue, soil, and water samples from grazing pasture near mining industry in southern part of Mongolia

Lead (Pb) is a substance that can cause serious damage to the brain and kidneys, soften bones, adverse effect to the reproductive system, and can be fatal. Long-term exposure to the substance can damage not only children, but also adults' nervous systems. Lead does not belong into the category of toxic substances due to its effects on the human body. It is considered as a harmful substance. In this study, we analyzed lead concentration in liver and kidney of cattle, horse, sheep, and goat from the mining areas located in the Ulaanbadrakh, Zuunbayan, and Airag soums of Dornogovi province. As a result, the level of lead in the liver of sheep and goat Zuunbayan soum of Dornogovi province was slightly higher than in other soums. The content of heavy metals in water and soil samples did not exceed the international standard average.