Distribution Of Metals In Soils Research Articles

Mapping soil trace metal distribution using remote sensing and multivariate analysis.

Trace metal soil contamination poses significant risks to human health and ecosystems, necessitating thorough investigation and management strategies. Researchers have increasingly utilized advanced techniques like remote sensing (RS), geographic information systems (GIS), geostatistical analysis, and multivariate analysis to address this issue. RS tools play a crucial role in collecting spectral data aiding in the analysis of trace metal distribution in soil. Spectroscopy offers an effective understanding of environmental contamination by analyzing trace metal distribution in soil. The spatial distribution of trace metals in soil has been a key focus of these studies, with factors influencing this distribution identified as soil type, pH levels, organic matter content, land use patterns, and concentrations of trace metals. While progress has been made, further research is needed to fully recognize the potential of integrated geospatial imaging spectroscopy and multivariate statistical analysis for assessing trace metal distribution in soils. Future directions include mapping multivariate results in GIS, identifying specific anthropogenic sources, analyzing temporal trends, and exploring alternative multivariate analysis tools. In conclusion, this review highlights the significance of integrated GIS and multivariate analysis in addressing trace metal contamination in soils, advocating for continued research to enhance assessment and management strategies.

Effects of drip and flood irrigation on soil heavy metal migration and associated risks in China

BackgroundDifferent irrigation methods have variable effects on the physiochemical properties of soils. The predicted widespread replacement of flood irrigation with drip irrigation will alter the micro-environment of the associated soils in terms of migration, transformation, morphology, and toxicology of heavy metals and pesticides. The dynamics of heavy metals in soil under drip irrigation have only been investigated with regard to the use of sewage and reclaimed water; studies comparing these patterns across different irrigation methods are scarce. PurposeHere, we aimed to investigate the effects of drip and flood irrigation on heavy metal distribution in soil and the related risks in three typical agricultural systems in China. MethodsWe used fixed-point sampling, digestion analytical methods, descriptive analyses, one-way analysis of variance (ANOVA), Nemerow pollution index analyses, and correlation analyses to investigate the different effects of drip and flood irrigation on heavy metals (Cd, Cr, Cu, Pb, and Zn) in soils from Hebei, Xinjiang, and Ningxia Provinces, China. Results and DiscussionAnalyses of soil samples collected from drip-irrigated fields revealed significant differences in the concentrations of soil heavy metals at depths of 0–60 cm. Drip irrigation had a greater effect on heavy metal content in the soil surface than flood irrigation. In addition, heavy metals likely accumulated at the edges of the wetting fronts following prolonged irrigation. In comparison to drip irrigation, flood irrigation elevated pollution levels in the soil. The amount of fertiliser affected the leaching and migration of heavy metals in the soils by altering the physiochemical characteristics of the drip irrigation solution. ConclusionDrip irrigation alters the dynamics of heavy metals in soil by influencing their migration and accumulation patterns. This effect can be attributed to the methods of adding water and fertilisers to the soil under drip irrigation. Altering these variables can impact the level of heavy metals that bioaccumulate in crops. This study provides a scientific basis for reducing heavy metal pollution under drip irrigation.

Risk Assessment of Heavy Metal Distribution in Soil of a Typical Tourist Island in South China

Risk Assessment of Heavy Metal Distribution in Soil of a Typical Tourist Island in South China

Assessment of depth wise distribution, enrichment, contamination, ecological risk and sources of soil heavy metals over an Industrial area in Southern India

Assessing the depth-wise distribution of heavy metals in soil can provide valuable insights into the extent of enrichment, contamination, and the possible sources of pollutants. A study was conducted in parts of Patancheru Industrial areas of Hyderabad, India to assess the vertical distribution of heavy metal content in soil, focusing on enrichment, contamination, and pollutant sources. Sixty soil samples from 15 sites, spanning four depths (0–15 cm, 15–30 cm, 30–50 cm, 50–100 cm) were analyzed for total Fe, Mn, Zn, Cu, Pb, Cr, Co and Ni concentrations. The concentrations of Fe, Mn, Zn, Cu, Pb, Cr, Co, and Ni, regardless of the study depths and sites, range from 2570–10,667, 22.5–439, 11.6–47.2, 3.47–14.2, 5.53–31.7, 36.0–63.1, 2.99–17.5 to 10.5–47.3 mg kg−1respectively. The mean concentrations of all the measured heavy metals showed minor variation across depths, except for Zn and Pb. Moreover, the mean concentration of all the measured heavy metals at various soil depths was within the threshold or target limits except for total Ni. At certain sampling depths and locations, Ni content exceeded the permissible threshold of 35 mg kg−1 in the soil. Surface soils (0–15 cm) exhibited moderate to significant enrichment of Pb, Zn, Cr, and Co. The enrichment factor for the overall Pb concentration varies from 3.02 to 24.73, indicating a range of moderate to very high enrichment throughout the soil depths. Following Pb, Cr exhibits enrichment levels ranging from 2.31 to 9.35, while Co ranges from 1.07 to 5.58.The sites within the study area varied in contamination levels, spanning from moderate contamination to a slight degree of pollution, as assessed by the contamination/pollution index of each element. Principle component analysis and enrichment factor values show that Cu originated primarily from natural sources; while Pb and Cr were likely to be anthropogenic to purely anthropogenic and Zn, Mn, Ni, and Co had both crustal and like to be anthropogenic origins. The maximum and minimum ecological risk index (ERI) values were recorded for Pb and Zn content, respectively. The maximum PERI value of 15.8 was recorded in the study area, indicating a low ecological risk level. However regular monitoring of the heavy metal concentration in soils is recommended over the study area to maintain a low level of ecological risk via reclamation interventions.

Spatial distribution prediction of soil heavy metals based on sparse sampling and multi-source environmental data

Predicting the precise spatial distribution of heavy metals in soil is crucial, especially in the fields of environmental management and remediation. However, achieving accurate spatial predictions of soil heavy metals becomes quite challenging when the number of soil sampling points is relatively limited. To address this challenge, this study proposes a hybrid approach, namely, Light Gradient Boosting Machine plus Ordinary Kriging (LGBK), for predicting the spatial distribution of soil heavy metals. A total of 137 soil samples were collected from the Shengli Coal-mine Base in Inner Mongolia, China, and their heavy metal concentrations were measured. Leveraging environmental covariates and soil heavy metal data, we constructed the predictive model. Experimental results demonstrate that, in comparison to traditional models, LGBK exhibits superior predictive performance. For copper (Cu), zinc (Zn), chromium (Cr), and arsenic (As), the coefficients of determination (R²) from the cross-validation results are 0.65, 0.52, 0.57, and 0.63, respectively. Moreover, the LGBK model excels in capturing intricate spatial features in heavy metal distribution. It accurately forecasts trends in heavy metal distribution that closely align with actual measurements. Environmental ImplicationThis study introduces a novel method, LGBK, for predicting the spatial distribution of soil heavy metals. This method yields higher-precision predictions even with a limited number of sampling points. Furthermore, the study analyzes the spatial distribution characteristics of Cu, Zn, Cr, and As in the grassland coal-mine base, along with the key environmental factors influencing their spatial distribution. This research holds significant importance for the environmental regulation and remediation of heavy metal pollution.

Assessment of iron and heavy metals accumulation in the soils of the combat zone

The object of the study is soils in areas with active military operations. The study is dedicated to assessing the environmental impact of military operations through forecasting. The paper highlights the impact of military conflict on the distribution of heavy metals in soils. An analysis of the distribution and interaction of heavy metals in soil is carried out, which helps to understand the dynamics of pollution in the context of military conflict, and allows to understand the complex processes of the impact of military operations on the environment and the state of soil resources. The complex interrelationships between military operations and environmental pollution are revealed, with an emphasis on the importance of studying the distribution and immobilization of iron and heavy metals in the current conditions of the risk of military operations. It is shown that the most rapidly distributed metals in the soil are: iron (Fe), zinc (Zn), cadmium (Cd), antimony (Sb); the slowest: arsenic (As), lead (Pb), copper (Cu), nickel (Ni), mercury (Hg), manganese (Mn), vanadium (V). It was found that loams and chernozems are more prone to the accumulation of heavy metals and iron than sandy soils. Compared to sandy soil, the rate of metal release in loam decreases from 16.7 % to 69.7 %. In comparison of chernozem to loam, the release rate slows down from 17.85 % to 32.08 %. It was found that the rate of spreading of barium, cobalt, arsenic, lead, mercury, manganese, strontium and titanium does not depend on the type and mechanical parameters of the soil. The practical use of the results will help to predict the mechanism of pollution spread and help to identify the highest risk areas. The results of the study indicate the need to develop scientifically sound strategies for environmental protection and promotion of sustainable development in the area affected by military events

Spatial distribution of heavy metals in soils around cement factory and health risk assessment: a case study of Canakkale-Ezine (NW Turkey).

Sustainable use of agricultural land plays a crucial role in ensuring food security. For sustainable use of soils, it is very important to focus on the pollution status. This study was conducted on the soils in the northern part of the Ezine district in northwestern Turkey. The study aimed to determine the physicochemical properties of the soils in the vicinity of the cement plant, the concentrations of heavy metals, the spatial distribution of heavy metals, and their impact on the health of the local human population. Soil samples were collected from the cement plant in different directions (S,W, N, E, NE, SW) and at different distances (1, 3, 5, and 7km) from 0-10cm depth with three replicates. The soil samples were analyzed for texture, pH, electrical conductivity, lime, and heavy metals such as Cd, Co, Cu, Fe, Mn, Ni, Pb, and Zn. The soils had different textures (loam, sandy clay loam, loam, sandy loam), slightly alkaline pH, low lime content, and moderate organic matter content. Except for Cd and Pb, the average values of the other heavy metals (Co = 1.18 < 19 mg kg-1,Cr = 50.92 < 90 mg kg-1, Cu = 31.21 < 45 mg kg-1, Fe = 16,007 < 47,200 mg kg-1, Mn = 499.68 < 850 mg kg-1, Ni = 41.17 < 68 mg kg-1, Zn = 50.91 < 95 mg kg-1) in the soils were below the normal background level. The heavy metal contents of the soils in the study area are influenced by various sources (geological structure, agrochemicals used in agricultural activities, and vehicle traffic). The prevailing wind direction did not influence the local distribution of heavy metals in soils in the study area. The health risk assessment model studies showed that the hazard quotient values of less than 1 for adults and children indicate that the noncarcinogenic risks were insignificant. People exposed to heavy metals in the soils of the study area contaminated from various sources for a long time could be at carcinogenic risk. Since Cr and Pb exceed the acceptable risk range in children and Cr exceeds the acceptable risk range in adults, geochemical monitoring of soils should be conducted periodically by authorized institutions in the study area.

Elevated temperature induces contrasting transformation of exogenous copper to soil solution and solid phases in an arable soil

Heavy metal contamination of soils has been a global environmental issue over the past decades, threatening food security and human health. Understanding the migration and transformation of heavy metals in soils is critical for restoring an impaired environment and developing sustainable agriculture, particularly in the face of global warming. However, little effort has been devoted to investigating the impact of elevated temperatures on the migration and distribution of exogenous heavy metals in soils. This study experimented with a 180-day incubation at 15 °C, 30 °C, and 45 °C with an arable soil (Alfisol) of Huang-Huai-Hai River Basin, China, which was initially spiked with copper (Cu). A comparison of the results revealed that the percentage of soil water-soluble Cu doubled at 45 °C compared with 15 °C. The percentage of protein-like substances in dissolved organic matter (DOM) was the highest at 45 °C, suggesting that proteinaceous components play a more significant role in controlling the dissolution of Cu into DOM. Moreover, by sequential extraction and micro-X-ray fluorescence (μ-XRF), Cu was facilitatively transformed from exchangeable, and specifically adsorbed fractions, to iron (Fe)/manganese (Mn) oxides bound species by 7.75%23.63% with the elevation of temperature from 15 °C to 45 °C. The conversion of Cu speciation is attributed to the significant release of organic carbon from Fe/Mn oxides, especially the Mn oxide components, which are available for Cu binding. The findings of this work will provide an in-depth understanding of the fate of Cu in soils, which is fundamental for the risk assessment and remediation of Cu-polluted soils in the Huang-Huai-Hai River Basin under the context of global warming.

Enrichment Characteristics, Source Apportionment, and Risk Assessment of Heavy Metals in the Industrial and Mining Area of Northern Guangdong Province

In order to understand the heavy metal pollution of the industrial and mining area in northern Guangdong Province, topsoil samples (0-20 cm) from 209 sites in study area were collected, and the concentrations of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn were analyzed. The source and distribution characteristics of Cd, Cr, Hg, Ni, Pb, As, Cu, and Zn in soil samples were analyzed using the geographic information system (GIS) and principal component analysis (PCA), and the geo-accumulation index and potential ecological hazard index were used to evaluate their pollution status and ecological risk. The results showed that:① Except Ni, all seven heavy metal elements exceeded the national soil background value but were below the pollution risk screening value. The soil environment as a whole was relatively clean. ② The spatial distribution of heavy metals in soil differed. The contents of As and Pb showed northwest-southeast zonal distribution. The contents of Cd, Cu, Hg, and Zn generally decreased from the middle to the surrounding, which was consistent with the industrial and mining enterprise locations. However, the spatial distribution of Cr and Ni had no direct relationship with the location of pollution sources such as industrial enterprises. ③ The eight heavy metals could be identified as three principal components (PCs). PC1 (Cd, Cu, Pb, and Zn) was mainly affected by human activities such as lead-zinc deposit dressing, traffic emissions, and agricultural production. However, PC2 (Cr and Ni) was a natural source, mainly affected by soil parent material. In addition, PC3 (As and Hg) was mainly affected by industrial activities such as non-ferrous metal smelting and thermal power generation. ④ According to the geo-accumulation index method, the risk degree of the eight heavy metals was:Cd>As>Zn>Hg>Pb>Cu>Cr=Ni. The contents of Cr and Ni in soil were at a no-risk level; the contents of As, Cu, Hg, Pb, and Zn were at a low-risk level; and the content of Cd was at a high-risk level. Most potential ecological hazards for single elements in the study area were at a mild risk level. In contrast, a small proportion of the surface soils in areas of intense industrial activity were subject to substantial levels of heavy metal stress and require further attention.

Polypropylene microplastics affect the distribution and bioavailability of cadmium by changing soil components during soil aging.

Compared with the widespread and serious heavy metal contamination in soils, microplastic pollution has gained attention only recently. Little is known about how microplastics affect the distribution of heavy metals in soils, especially across soil components level. In this study, a 180-day soil aging experiment and soil density fractionation were performed to investigate the effect of polypropylene (PP) microplastics on the binding behavior of cadmium (Cd) to solid components, i.e. particulate organic matter, organo-mineral complexes (OMC), and mineral. Results showed addition of 2-10% microplastics in soils induced the decomposition of OMC fraction by 10.88-23.10%. Compared to the control, the content of dissolved organic carbon increased, and pH, humic substances, and soil organic matter decreased with microplastics. After 180d of aging, the content of Cd in OMC fraction increased by 17.92%, while microplastics made Cd contents decline by 10.01-19.75%. The impacts strongly depended on the dose and surface characteristic of microplastics. Overall, PP microplastics increased the concentration of bioavailable Cd in soils via decreasing soil retention of Cd by the OMC fraction. These findings based on the solid components level will provide a new perspective for understanding microplastics effects on soil systems and pollutants.

Accumulation and distribution of heavy metals in soil and food crops in the Pb–Zn mine environ. Case study: Region of Probištip, North Macedonia

The aim of the study was to investigate the exploration and distribution of various chemical elements in soils and vegetables from gardens in the region of Probištip, North Macedonia. This region was exposed to heavy metals pollution from Pb–Zn mining and flotation tailings landfill near the town of Probištip for 70 years. A total of 38 samples of various crops and vegetable products from 19 gardens were analyzed. The analyzes were carried out by ICP-AES (Al, Ba, Ca, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, P, Pb, Sr, V, and Zn) and by ICP-MS (As, Cd, Co, Cr, and Pb). It was found that the content of some potentially toxic elements (As, Cd, Cu, Pb, and Zn) in the soil samples from the gardens, exceeded the target values. From these results, it is clear that the contamination of the soils in this area is due to mining activities and the distribution of flotation wastes from the nearby flotation dump. It was also found that the contaminated soils lead to elevated levels of these elements in some vegetables from the gardens, especially those near the Zletovska River and the flotation waste landfill, exceeding the nationally permissible food content.

Long-term wetland reclamation affects the accumulation and profile distribution of heavy metals in soils

Long-term wetland reclamation affects the accumulation and profile distribution of heavy metals in soils

Peculiarities of profile distribution of metals in soils of geochemically conjugated landscapes of Chelyabinsk city

The article discusses the results of soil-geochemical studies carried out on the territory of the Chelyabinsk urban district. The features of the profile distribution of pollutants within the landscape catena are established. The maximum concentrations of heavy metals are confined to the upper soil horizons of the eluvial position under forest vegetation. The soils of the superaquatic position under moist meadow and swamp vegetation are less polluted. The most polluted soil layer is located at a depth of 4-10 cm from the surface. This may be due to a decrease in heterogeneous emissions from the city’s metallurgical enterprises over the past 30 years.

Distribution of Heavy Metals in Soil of the Temporary Municipal Solid Waste Landfills in the City of Botosani, Romania

Distribution of Heavy Metals in Soil of the Temporary Municipal Solid Waste Landfills in the City of Botosani, Romania

Analysis of driving factors of spatial distribution of heavy metals in soil of non-ferrous metal smelting sites: Screening the geodetector calculation results combined with correlation analysis

Heavy metals (HMs) discharged from smelting production may pose a major threat to human health and soil ecosystems. In this study, the spatial distribution characteristics of HMs in the soil of a non-ferrous metal smelting site were assessed. This study employed the geodetector (GD) by optimizing the classification condition and supplementing the correlation analysis (CA). The contribution of driving factors, such as production workshop distributions, hydrogeological conditions, and soil physicochemical properties, to the distribution of HMs in soil in the horizontal and vertical dimensions was assessed. The results showed that the main factors underlying the spatial distribution of As, Cd, Hg, Pb, Sb, and Zn in the horizontal direction were the distance from the sintering workshop (the maximum q value of that factor, q=0.28), raw material yard (q=0.14), and electrolyzer (q=0.29), while those in the vertical direction were the soil moisture content (q=0.17), formation lithology (q=0.12), and soil pH (q=0.06). The findings revealed that the CA is a simple and effective method to supplement the GD analysis underlying the spatial distribution characteristics of HMs at site scale. This study provides useful suggestions for environmental management to prevent HMs pollution and control HMs in the soil of non-ferrous metal smelting sites.

Application of individual and integrated pollution indices of trace elements to evaluate the noise barrier impact on the soil environment in Wrocław (Poland)

Trace elements emitted by road transport cause long-term contamination of road soils. This study showed the effect of the noise barrier on the spatial distribution of metals in soils at the City Centre Ring Road in Wrocław (Poland). Samples were taken along the barrier every 150 m and across the screen at distances of 0.5, 2.5, 5 (only on the left side), 10, 20, and 50 m from the noise screen on both sides of road no. 5. The contamination of soils was assessed with the use of commonly used individual pollution indices, integrated pollution indices based on the PI index or metal concentrations, and a potential ecological risk index (RI). The geoaccumulation index (Igeo) and the single pollution index (PI) indicate moderate contamination of soils by Cu, Pb, and Zn at most measuring points. The significant risk was reported from Cd in all samples. Integrated pollution indices, especially the PI_Nemerow, PI_avg, and RI confirm the poor quality of studied soils. The presence of elements in soil is related to anthropogenic factors. The spatial distribution of pollution indices and results of statistical analysis (HCA) indicate that Cr and Ni are of natural origin. Remaining elements (Cd, Pb, Cu, Zn) are of mixed origin with a large share from car transport (the significant Spearman’s correlation coefficients). In the case of cadmium, dendograms suggest the existence of an additional anthropogenic source, which is also confirmed by moderately strong correlations of this element with other metals.

Source identification and spatial distribution of heavy metals in soil of central urban area of Chongqing, China

ABSTRACT To understand the characteristics of heavy metal pollution in soil and identify the source of heavy metals, 342 surface soil samples were collected in Chongqing, China. The contents of 11 heavy metals (i.e., arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), copper (Cu), zinc (Zn), nickel (Ni), mercury (Hg), antimony (Sb), manganese (Mn), and molybdenum (Mo)) were determined. The Principal Component analysis/absolute Principal component fraction (PCA/APCS) receptor model, the classified regression (CATREG) model, and the hot spot model were employed to analyze the data. The contents of As, Cd, Cr, Pb, Cu, Zn, Ni, Hg, Sb, Mn, and Mo in soil were 5.80, 0.13, 76.56, 25.55, 23.99, 75.58, 30.50, 0.05, 0.64, 573.32, and 0.56 mg·kg−1, respectively. The results of principal component analysis showed that the main heavy metal elements under the first principal component load were Cu, Ni, Zn, Mn, Cr, Pb, and Cd. The second principal component is mainly loaded with Mo, As, Hg, and Sb. The results of classified regression analysis showed that population density mainly affected Cu (0.54), soil mainly affected Ni (0.41), Sb (0.49), Zn (0.47), and Mn (0.21), and water quality mainly affected As (0.45) and Mo (0.37). Air quality mainly affected Cd (0.33) and Cr (0.37), traffic activity mainly affected Hg (0.31), and slope mainly affected Pb (0.31). The research results can be used to trace the environmental sources of soil heavy metals, fundamentally prevent and repair soil heavy metal pollution, and protect urban soil environmental quality.

Cadmium (Cd) and Copper (Cu) Exposure and Bioaccumulation Arrays in Farm Ruminants: Impact of Forage Ecotypes, Ecological Sites and Body Organs

Copper (Cu) and cadmium (Cd) metal distribution in soil–plant ecosystems and their public health risk impact on ruminants (cows, buffalo, and sheep) are explored in the present investigation. Five different forage crops were selected, and the foraging responses of three types of ruminants (cows, buffalo, and sheep) at three ecological sites were evaluated. The soil of these three ecological sites was metal polluted (due to wastewater irrigation) and was studied to evaluate the metal contamination and pollution load index. For the assessment of Cd and Cu, soil, vegetation, blood, hair, and feces samples were collected and analysed using an atomic absorption spectrophotometer. High consumption of fodder crops (Sorghum bicolor Kuntze, Sesbania bispinosa (Jacq.) W. Wight, Cynodon dactylon (L.) Pers., Suaeda fruticosa (L.) Forssk., and Tribulus terrestris L.) by cows and buffalo at site-III resulted in an increase in daily Cu and Cd intake. The pollution load index was higher at site-II and site-III, indicating a severe health risk scenario for local inhabitants. Cd and Cu were at their maximum levels in fodder crops. A significant increase in the concentrations of Cd and Cu was found in the blood, hair, and feces of cows and buffalo at site-III. Ecological indicators such as the bioaccumulation factor, the pollution load index, and the enrichment factor were found to be higher in buffalo than cows. The Cd level in forages was highest at the site-III Cd level and in the order of S. bispinosa &gt; S. fruticosa &gt; T. terresteris &gt; C. dactylon &gt; S. bicolor. Although these levels were lower than the permissible maximum limit, they were generally higher in the forage crops. Exposure of local inhabitants to the consumption of milk and meat from these cattle showed the serious health risks consequences. This situation can be properly managed by general monitoring of soil and vegetation pollution, avoiding metal contamination in the soil and food chain components, and using treated waste water and other alternate water sources for forage irrigation.

A statistical approach to study the spatial heavy metal distribution in soils in the Kushk Mine, Iran

AbstractThe present study was conducted for the spatial distribution and concentration evaluation of heavy metals, including Cu, Cd, Mn, Fe, Zn, and Pb, within 102 soil samples collected from Kushk Mine in Bafgh, Iran. This work employed hierarchical clustering analysis (HCA), principal component analysis (PCA), and spatial distribution patterns, to perform element distribution evaluation within the area. The distributions of heavy metals in the entire area were exhibited in the form of maps. The average concentrations of Cd, Cu, Mn, Fe, Zn, and Pb were found to be 0.39, 0.26, 5.3, 4.1, 51.9, and 40.9 mg.kg−1, respectively. Based on the PCA and HCA findings, the heavy metals were divided into two groups. The first group included Pb, Cd, Zn, and Cu. In the first group, altered threshold‐surpassing anthropogenic and lithogenic pollution was found to be the main factor accounting for Pb and Zn. The second group involved Fe and Mn, which could be impacted by either anthropogenic and lithogenic factors. Furthermore, the geo‐statistical results demonstrated higher contents of the heavy metals in the south of the mine and in the vicinity of the mine tailings. It may be concluded from the results that the heavy metal contents of the area are impacted by anthropogenic and lithogenic factors.

Assessing the pollution effect of cement dust emission on the soil quality around Ewekoro cement factory, southwestern Nigeria

This study assessed the pollution effects of cement dust emission on the soil quality around Ewekoro, southwestern Nigeria. Composite soil samples were collected at six locations from the cement factory (0 km) to a distance of 3 km outside the factory; for two consecutive years. Soil samples were also taken from a distance of 22 km after the cement factory to serve as a control. A total of 42 soil samples were collected and subjected to laboratory assays using standard procedures. Samples were analyzed for pH, organic carbon, particle size, available phosphorus (AvP), alkalinity, exchangeable cations, and heavy metals. Data collected were subjected to simple descriptive and inferential statistics using SPSS for Windows. Pollution effect was also evaluated for pollution index (PI), ecological risk index (ERI), Nemerov integrated pollution index (NIPI), and enrichment factor (EF). Results showed significantly higher levels of exchangeable cations, alkalinity, AvP, pH, Cr, Cu, Pb, and Fe in the vicinity of the cement factory than in the control site. The distribution of metals in soils around the cement factory followed the trend of Fe > Mn > Zn > Pb > Cr > Cu. The PI of metals in soil established high pollution levels for Pb and Zn. The NIPI values for Cu, Cr, and Fe showed low levels of pollution at the vicinity of the cement industry, while no pollution level was observed at the control site. NIPI revealed that Pb varied from low to moderate pollution levels across the sampling locations. The EF values of Zn and Pb were higher than 2.0, thereby suggesting emissions from anthropogenic activities, especially from the cement industry.