Metal Contamination Of Agricultural Soils Research Articles

Synergistic mitigation of nickel toxicity in pepper (Capsicum annuum) by nitric oxide and thiourea via regulation of nitrogen metabolism and subcellular nickel distribution.

Nickel (Ni) contamination hinders plant growth and yield. Nitric oxide (NO) and thiourea (Thi) aid plant recovery from heavy metal damage, but their combined effects on pepper (Capsicum annuum ) plant tolerance to Ni stress need more study. Sodium nitroprusside (0.1mM, SNP) and 400mgL-1 Thi, alone and combined, were studied for their impact on pepper growth under Ni toxicity. Ni stress reduces chlorophyll, PSII efficiency and leaf water and sugar content. However, SNP and Thi alleviate these effects by increasing leaf water, proline and sugar content. It also increased the activities of superoxide dismutase, catalase, ascorbate peroxidase and peroxidase. Nickel stress lowered nitrogen assimilation enzymes (nitrate reductase, nitrite reductase, glutamine synthetase, glutamate synthase and glutamate dehydrogenase) and protein content, but increased nitrate, ammonium and amino acid content. SNP and Thi enhanced nitrogen assimilation, increased protein content and improved pepper plant growth and physiological functions during Ni stress. The combined treatment reduced Ni accumulation, increased Ni in leaf cell walls and potentially in root vacuoles, and decreased Ni concentration in cell organelles. It effectively mitigated Ni toxicity to vital organelles, surpassing the effects of SNP or Thi use alone. This study provides valuable insights for addressing heavy metal contamination in agricultural soils and offers potential strategies for sustainable and eco-friendly farming practices.

Enrichment, contamination, ecological and health risks of toxic metals in agricultural soils of an industrial city, northwestern China

BackgroundThe impacts of rapid urbanization and industrialization often cause toxic metal contamination in agricultural soils, which has been a global environmental issue. MethodsAgricultural soil samples were obtained from Lanzhou city, a typical industrial city in northwestern China. The levels of six toxic metals (i.e., Cd, Cr, Cu, Pb, Sb, and Zn) were determined in soil samples using Inductively Coupled Plasma Optical Emission Spectrometer. Afterwards, enrichment, contamination, ecological and health risks of them were comprehensively evaluated. ResultsThe average concentrations of toxic metals were 0.30, 79.7, 21.6, 26.7, 0.97, and 69.0 mg kg−1 for Cd, Cr, Cu, Pb, Sb, and Zn, respectively in soils. Cd was moderately enrichment while other metals were minimally enriched in soils of Lanzhou. The agricultural soils were characterized by moderate to considerable contamination of Cd and low contamination of other metals. Moreover, Cd might cause noticeable ecological risks at most sites. In addition, the average target hazard quotient (THQ) for children was 0.727, almost ten times higher than that for adults. Cr, Pb, and Sb were the most sensitive factors affecting the health risk assessment and contributed over 99% to the THQ. ConclusionLithogenic source, industrial and mining activities, and phosphorus fertilizer usage were the three main factors affecting the concentrations of Cd, Cr, Cu, Pb, Sb, and Zn in agricultural soils of Lanzhou, which should be taken into consideration in future supervision and management. Health risks of these metals, especially Cd, Cr, and Sb, for children should receive considerable attention due to their health hazard.

Pollution Characteristics and Health Risk Assessment of Heavy Metals in Agricultural Soils over the Past Five Years in Zhejiang, Southeast China.

Heavy metal contamination in agricultural soils has attracted increasing attention in recent years. In this study, 1999 agricultural soil samples were collected from 11 cities in Zhejiang Province from 2016 to 2020, and the spatial and temporal variation characteristics of 3 of the most important heavy metals, i.e., lead (Pb), cadmium (Cd), and chromium (Cr) were analyzed. The results showed that Cd had a slightly higher sample over-standard rate of 12.06%. Spatial distribution and temporal trends showed that the Pb concentrations overall increased from 2016 to 2020 and mainly accumulated in southern Zhejiang. In addition, multiple exposure routes were evaluated for human health risks. Children are more susceptible to the adverse effects of heavy metals in agricultural soils, and oral ingestion was the major exposure route. Cr poses higher human health risks to humans than Pb and Cd in agricultural soils. Therefore, more rigid environmental monitoring and related soil remediation counter-measures for some sites with high concentrations of heavy metals are necessary to limit the potential threat to human health.

The Willingness and Technology Preferences of Farmers and Their Influencing Factors for Soil Remediation

Farmers are one of the major uncertainty factors in remediation of contamination farmland. Based on the face-to-face questionnaire survey data of 553 farmers in 4 heavy metal-contaminated agricultural soil remediation projects in China, this study used methods, such as structural equation modeling and random forest to explore farmers’ willingness to remediate, technology preference, and their key influencing factors for the first time. The results showed that farmers were willing to remediate contaminated soil and preferred phytoremediation, with 82.8% choosing phytoremediation, 12.5% choosing passivation, and 4.7% believing that the soil did not need to be remediated. In terms of willingness to remediate, the perceived benefits from participation in current remediation projects directly contributed to future willingness, with participation status (total impact coefficient 0.86) and perceived benefits (impact coefficient 0.49) being the main factors positively influencing farmers’ willingness. With regard to technology preference, technical characteristics (soil quality, 17.1%; secondary contamination, 16.8%; and remediation period, 11.5%) were the main influencing factors. The sustainability of passivation effect and the possible secondary contamination restrict the promotion of passivation, whereas the cessation of agricultural production during the long remediation period restricts the promotion of phytoremediation. It is recommended to increase farmers’ willingness to remediate by improving their perceived benefits and continuously overcoming the technical barriers by: (i) developing efficient and green passivators; and (ii) improving the efficiency of phytoremediation as well as intercropping or rotating cash crops while remediating. The results have important reference value for soil remediation in agricultural countries with small arable land per capita.

Lead-Resistant Morganella morganii Rhizobacteria Reduced Lead Toxicity in Arabidopsis thaliana by Improving Growth, Physiology, and Antioxidant Activities

Biological remediation serves as a powerful technique for addressing heavy metals toxicity in metals-contaminated soils. The present study aimed to evaluate the efficacy of lead (Pb)-resistant rhizobacterial strains on growth, photosynthetic traits, and antioxidant activities of the Arabidopsis plant under lead toxicity in pot conditions. Two pre-isolated and pre-characterized Pb-resistant Morganella morganii (ABT3) and Morganella morganii (ABT9) strains were used for inoculating Arabidopsis plants grown under varying Pb concentrations (1.5 mM and 2.5 mM) using PbNO3 as the lead source. The treatments were set up in a completely randomized design with four replications. Data on growth parameters, physiological characteristics, lipid peroxidation, and antioxidant activities were recorded at harvesting. It was observed that Pb contamination caused a significant reduction in Arabidopsis growth, chlorophyll content and quantum yield at both lead concentrations. The Pb concentration of 2.5 mM, showed a substantial decrease in all parameters, including shoot fresh weight (58.72%), shoot dry weight (59.31%), root fresh weight (67.31%), root dry weight (67.28%), chlorophyll content (48.69%), quantum yield (62.36%), catalase activity (65.30%), superoxide dismutase (60.88%), and peroxidase activity (60.54%) while increasing lipid peroxidation (113.8%). However, the inoculation with Pb-resistant M. morganii strains (ABT3 and ABT9) improved plant growth, photosynthesis and antioxidant activities, while reduced the malondialdehyde content of Arabidopsis compared to control plants without inoculation. The M. morganii strain ABT9 showed a maximum increase in the shoot fresh weight (67.18%), shoot dry weight (67.96%), root fresh weight (94.04%), root dry weight (93.92%), shoot length (148.88%), root length (123.33%), chlorophyll content (52.53%), quantum yield (58.57%), catalase activity (39.46%), superoxide dismutase (21.84%), and peroxidase activity (22.34%) while decreasing lipid peroxidation (35.28%). PCA analysis further showed that all nine treatments scattered differently across the PC1 and PC2, having 81.4% and 17.0% data variance, respectively, indicating the efficiency of Pb-resistant strains. The heatmap further validated that the introduction of Pb-resistant strains positively correlated with the growth parameters, quantum yield, chlorophyll content and antioxidant activities of Arabidopsis seedlings. Both Pb-resistant strains improved Arabidopsis plant growth and photosynthetic efficiency under lead stress conditions. Thus, both Morganella morganii ABT3 and Morganella morganii ABT9 strains can be considered as bio-fertilizer for reducing lead toxicity thereby improving plant growth and physiology in metal-contaminated agricultural soils.

Environmental Risk Assessment of Metal Contamination of Agricultural Soils along Major Roads of Two Peri – Urban Areas in Nasarawa State, North Central, Nigeria

This research focused on the level, pollution, and ecological risk assessment of selected heavy metals from agricultural soils at major roadsides in Nasarawa Eggon and Doma areas. Composite soil samples were collected at 0–20 cm depth, homogenised, and assayed for metal (As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, U and Zn) levels using the X–ray fluorescence technique. Pollution and toxicity of the studied metals were determined by evaluating enrichment factor (Ef), geo–accumulation index (Igeo), contamination factor (Cf), degree of contamination (Cd), pollution load index (PLI), and ecological risk assessment (ERA). The result showed that concentrations of As, Cd, Cr, Cu, Fe and Ni were lower than the average shale values, except for As of site N2 in the Nasarawa Eggon area and Fe of site D4 in the Doma area. The Ef suggests a significant anthropogenic contribution to the presence of As, Co, Hg, Mn, Pb and Zn in some of the sampled sites. The Igeo indicated that Nasarawa Eggon sampled soils were polluted by Hg and Pb while Hg and Co polluted those of Doma. The Cf values revealed that most of the soils were contaminated with Hg in addition to As, Co, Fe, Mn, and Zn in some sites. All sites have low Cd except N2 and N4 (Nasarawa Eggon) and D2 and D4 (Doma). However, PLI showed that only sites N2 and D4 were polluted. ERA revealed that As, Co, and Hg posed potential ecological risks ranging from low to a significant level in different sites. Sites N2, D2 and D4 showed a moderate ecological risk index. Therefore, this study showed significant anthropogenic inputs from automobile emissions and human activities to the pollution of agricultural soils along major roads and the pollution could pose negative health implications to human and animal health.

Sulfhydryl grafted palygorskite amendment with varying loading rates: Characteristic differences and dose-effect relationship for immobilizing soil Cd

Heavy metal contamination in agricultural soil and immobilization remediation have generated widespread concern in all areas of society. Sulfhydryl-functionalized materials as emerging amendments exhibit application potential, but the dose-effect relationship and immobilization mechanism are poorly understood. To understand the relationship between the immobilization effect and total sulfhydryl content, sulfhydryl-grafted palygorskite (SGP) with three sulfhydryl loading rates (0.88 mmol/g, 1.83 mmol/g, and 2.77 mmol/g) was prepared and characterized in the current study. The Cd immobilization efficiency and the dose-effect relationship were investigated via sorption in solutions, soil incubation, and field-scale wheat cultivation. 29Si nuclear magnetic resonance, X-ray diffraction, differential scanning calorimetry, X-ray photoelectron spectroscopy, zeta potential, and potentiometric titration analyses confirmed that the sulfhydryl loading rates had little impact on the mineral structure but had a significant effect on the SGP surface properties. The sorption process of Cd2+ on SGP can be described by the 2nd order kinetic model and the Langmuir isotherm. The maximal sorption capacities had a linear relationship with the experimental sulfhydryl content in SGP. Meanwhile, SGP with three loading rates under different doses reduced available Cd concentrations in alkaline soil by 28.40 %–87.78 % in soil incubation and wheat grain Cd by 21.95 %–80.19 % in field-scale demonstration The relationship between immobilization efficiency and the total sulfhydryl group could be adequately described using the Michaelis-Menten equation. The sulfhydryl group was the key site for SGP amendments, which when added to the soil, reduced the bioavailability of soil Cd. Clarification of the dose-effect relationship will provide theoretical support for the accurate regulation of safe utilization of Cd-contaminated farmland.

Heavy Metal Contamination in Agricultural Soils: A Case Study in Mohammedia Benslimane Region (Morocco)

Heavy Metal Contamination in Agricultural Soils: A Case Study in Mohammedia Benslimane Region (Morocco)

Penicillium oxalicum SL2 as a sustainable option to mitigate the accumulation of Pb in rice (Oryza sativa L.)

Heavy metal contamination in agricultural soil and its associated risk of food safety are of great concern globally. It is therefore an urgent need to develop sustainable option to mitigate the accumulation of metals in crop plants. Here we investigated the potential of phosphorus-solubilizing fungus, Penicillium oxalicum SL2, on regulating the bioavailability of Pb in a lead (Pb) polluted soil-rice system. Our results showed that the content of Pb in rice grain was significantly decreased by ~80% with the application of P. oxalicum SL2. The competition between oxalate and phosphate for the complexation of Pb showed to be effective in mediating the bioavailability of Pb, and such impact varied with water fluctuation in paddy soil. The solubilization of phosphorus also played an important role in alleviating the dissolution of iron plaque caused by oxalic acid, which helped maintaining the biomass of iron plaque as a barrier to the uptake of Pb by root. The predominant indigenous microbial community was not affected by the inoculation with P. oxalicum SL2, suggesting it as an eco-friendly strain. Therefore, we suggest P. oxalicum SL2 as a promising fungus in enhancing the safe use of moderately Pb polluted paddy soil for safe rice.

Heavy Metal Contamination in Oryza sativa L. at the Eastern Region of Malaysia and Its Risk Assessment.

Paddy plants tend to accumulate heavy metals from both natural and anthropogenic sources, and this poses adverse risks to human health. The objective of this study was to investigate heavy metal contamination in paddy plants in Kelantan, Malaysia, and its health risk assessment. The bioaccumulation of heavy metals was studied by means of enrichment (EF) and translocation factors (TF). The health risk assessment was performed based on USEPA guidelines. The EF for heavy metals in the studied areas was in the descending order of Cu > As > Cr > Cd > Pb. Meanwhile, Cr and Pb exhibited higher TF values from stem to grain compared with the others. The combined hazard index (HI) resulting from five heavy metals exceeded the acceptable limit (HI >1). The lifetime cancer risk, in both adult and children, was beyond the acceptable limit (10−4) and mainly resulted from exposure. The total cancer risk (CRt) due to simultaneous exposures to multiple carcinogenic elements also exceeded 10−4. In conclusion, intake of heavy metal through rice ingestion is likely to cause both non-carcinogenic and carcinogenic health risks. Further research is required to investigate the extent of heavy metal contamination in agricultural soils and, moreover, to establish human exposure as a result of rice consumption.

Heavy metal contamination in agricultural soils of NW Himalayas: with a perspective of spatial distribution, environmental contamination and health risk assessment

Heavy metal contamination in agricultural soils of NW Himalayas: with a perspective of spatial distribution, environmental contamination and health risk assessment

Inversion of Soil Heavy Metal Content Based on Spectral Characteristics of Peach Trees

There exists serious heavy metal contamination of agricultural soils in China. It is not only time- and labor-intensive to monitor soil contamination, but it also has limited scope when using conventional chemical methods. However, the method of the heavy metal monitoring of soil based on vegetation hyperspectral technology can break through the vegetation barrier and obtain the heavy metal content quickly over large areas. This paper discusses a highly accurate method for predicting the soil heavy metal content using hyperspectral techniques. We collected leaf hyperspectral data outdoors, and also collected soil samples to obtain heavy metal content data using chemical analysis. The prediction model for heavy metal content was developed using a difference spectral index, which was not highly satisfactory. Subsequently, the five factors that have a strong influence on the content of heavy metals were analyzed to determine multiple regression models for the elements As, Pb, and Cd. The results showed that the multiple regression model could better estimate the heavy metal content with stable fitting that has high prediction accuracy compared with the linear model. The results of this research provide a scientific basis and technical support for the hyperspectral inversion of the soil heavy metal content.

Impact of a super typhoon on heavy metal distribution, migration, availability in agricultural soils

Heavy metal contamination in agricultural soils is a worldwide concerned environmental issue. However, a short-term extreme hydrodynamic event (e.g., a super typhoon) may significantly affect the distribution, migration, and availability of heavy metals in agriculture soils on a large scale. The limited understanding of such an impact prevents effective environment survey, risk assessment, and remediation strategy for heavy metal contaminated soils. Here, we show a massive migration of heavy metals during a super typhoon (Lekima) based on the field investigation, simulated experiments, and isotopic fingerprinting. The contaminations of heavy metals (Cd, Zn, Cu, Ni, Cr and As) of agricultural soils at 209 sampling sites over 3.59 × 105 km2, were significantly relieved by 10.3–42.0 % after the typhoon, because of the primary contribution of runoff erosion over interflow according to the simulated soil erosions. However, the available fractions (as % of the total amount of each metal) were metal-dependent, with Cd, Zn, Cu, and Ni increased (5.3–26.4 %), and Cr and As decreased (0.9–3.5 %). In contrary, the Pb contamination was slightly aggravated by 8.7 % after the typhoon, and the Pb isotopic signatures indicate its input and migration via wet precipitation and surface runoff. The soil properties (e.g., pH and organic matter) showed limited impact on the migration of heavy metals during this typhoon. These results suggest that a natural short-term extreme hydrodynamic event can drive the massive migration of heavy metals in agricultural soils and their trade-off with other environmental medias, providing valuable information for multi-medias environmental risk assessment and cooperative remediation that can be significantly disturbed by such an event.

Estimation of Heavy Metals in Agricultural Soils Using Vis-NIR Spectroscopy with Fractional-Order Derivative and Generalized Regression Neural Network

With the development of industrialization and urbanization, heavy metal contamination in agricultural soils tends to accumulate rapidly and harm human health. Visible and near-infrared (Vis-NIR) spectroscopy provides the feasibility of fast monitoring of the variation of heavy metals. This study explored the potential of fractional-order derivative (FOD), the optimal band combination algorithm and different mathematical models in estimating soil heavy metals with Vis-NIR spectroscopy. A total of 80 soil samples were collected from an agriculture area in Suzi river basin, Liaoning Province, China. The spectra for mercury (Hg), chromium (Cr), and copper (Cu) of the samples were obtained in the laboratory. For spectral preprocessing, FODs were allowed to vary from 0 to 2 with an increment of 0.2 at each step, and the optimal band combination algorithm was applied to the spectra after FOD. Then, four mathematical models, namely, partial least squares regression (PLSR), adaptive neural fuzzy inference system (ANFIS), random forest (RF) and generalized regression neural network (GRNN), were used to estimate the concentration of Hg, Cr and Cu. Results showed that high-order FOD had an excellent effect in highlighting hidden information and separating minor absorbing peaks, and the optimal band combination algorithm could remove the influence of spectral noise caused by high-order FOD. The incorporation of the optimal band combination algorithm and FOD is able to further mine spectral information. Furthermore, GRNN made an obvious improvement to the estimation accuracy of all studied heavy metals compared to ANFIS, PLSR, and RF. In summary, our results provided more feasibility for the rapid estimation of Hg, Cr, Cu and other heavy metal pollution areas in agricultural soils.

Effect of chromium on basic growth factors of Pennisetum glaucum L.

One of the main concerns of agricultural production is heavy metal pollutants. The industrialization has resulted in the heavy metal contamination of agricultural soil and ecosystems. Metals are a natural component of the earth, it is when their concentration increases from natural levels, ecological deterioration occurs. In the present study, transplant experiments were conducted to evaluate the effect of chromium-contaminated soil in Pennisetum glaucum L. The seeds growing in petridishes were exposed to chromium, in increasing concentrations of 1, 3, 5, 10, 50, 100, 200, 300, 500 ppm. Each treatment was replicated in a randomized design and observed over a period of 7 days. The seedlings were studied for their response based on germination rate, seed vigour index, length of the radicle, length of plumule, and fresh weight against seeds germinated using distilled water as a control. Five different chromium concentrations i.e., 5, 10, 50, 100 & 200 ppm, were applied to the plants. Each treatment was replicated in a randomized design and observed for 45 days. The plants were studied for the length of root, length of shoot, fresh weight, total chlorophyll content, protein content, and heavy metal analysis compared to a set irrigated using distilled water as a control. The root and shoot lengths decreased with an increase in Cr concentrations in the transplants. A gradual decrease was observed in the selected parameters, with an increase in Cr levels. The values related well with increased Phyto-accumulation of chromium within the tissues of both roots and shoots. It was observed that chromium's harmful effects on all the parameters were directly proportional to the concentration of solution employed, with the inhibition of growth being more pronounced from 50 ppm onwards. As Pennisetum glaucum L. an edible crop despite showing a good potential for application in phytoremediation techniques, it can’t be used to hyper accumulate chromium to remove it from the soil.

Spatial Assessment of Heavy Metal Contamination in Agricultural Soils Developed on Basaltic and Sandstone Parent Materials

Spatial Assessment of Heavy Metal Contamination in Agricultural Soils Developed on Basaltic and Sandstone Parent Materials

Features of Heavy Metal Contamination of Agricultural Soils in the Kursk Region of Russia and Economic Assessment of Restoration

Kursk region of Russia has unique fertile soils. Heavy metals are among the factors that pollute the soil. The article is devoted to the study of the spatial distribution of heavy metals in soils. The relevance of the study is that the value of the soil is determined by its value for obtaining environmentally friendly agricultural products. Data on the content of heavy metals in the soil can prevent intensive cultivation of crops. The task of the work is to identify heavy metals that predominate in the soils of various landscapes of the Kursk region. The assessment of soil contamination with chemical elements was carried out in the course of geo-ecological studies of black earth soils in the Kursk region of Russia. The selected soil samples were examined by semi-quantitative spectral analysis. The results obtained were subjected to statistical processing. It was found that cobalt is the main pollutant in the vast majority of sampling points. In other zones, molybdenum, lead, zinc, and chromium predominate in approximately equal amounts. Soils in the surveyed area belong to the permissible category of contamination with chemical elements. Soil remediation should be applied in local areas.

Metal contamination of agricultural soils amended with biosolids (sewage sludge) at a ceramic production area in NE Spain: A 10‐year resampling period

AbstractHeavy metals in ecosystems affect human health through the web chain. Castellon Province is home to the largest ceramic production hub in Spain, with 94% of the country's total production. Agricultural soils in the vicinity of the ceramic hub were reported to contain potentially toxic elements (Pb, Cr, Ni and Cd) in 2008 and have since been subject to repeated amendment with biosolids (sewage sludge). The sample sites were revisited in 2019, and the chemical distribution of these metals reassessed. The distribution of heavy chemical forms was analysed using a sequential extraction protocol that fractionates these four heavy metals into five phases. The incorporation of biosolids for the past 10 years has changed the chemistry of the soil, leading to increased levels of some hazardous elements. The carbonate‐sorbed, residual and reducible phases were dominant. From the point of view of compliance with regulations, levels of Cd remained elevated and have increased over the 10‐year period.

Dose-dependent Effect of Biochar as Soil Amendment on Reducing Copper Phytotoxicity and Mobility

Using biochar to remediate metal-contaminated agricultural soil has attracted increasing attention due to it is relatively low cost and high efficiency. In this study chemical speciation, greenhouse experiments, and column leaching study were conducted to understand the mechanisms of copper (Cu) immobilization by pine needle biochar (PNB) and sweet potato residue biochar (SPRB) to evaluate the effect of biochar amendment rate for remediation Cu contaminated soils. The results showed that both PNB and SPRB amendment effectively raised soil pH and converted Cu into more stable chemical forms. 1% (W/W) SPRB was adequate for reducing exchangeable Cu fractions from 43.3 to 9.9 mg kg−1 in the contaminated soils. 1% (W/W) SPRB and 5% (W/W) PNB treatments show the best result to promote sweet potato growth. Over liming caused by 5% (W/W) SPRB resulted in inhibition of plant growth. 5% (W/W) PNB treatment also shows the best result for reducing Cu mobility: the cumulative amount of Cu in the leachate after 9 leaching events was reduced from 7.0 to 1.0 mg kg−1. However, 5% (W/W) SPRB amendment is a little effective for reducing Cu mobility. Although the biochar amendment can provide additional sorption sites for metal pollution remediation, soil pH after an amendment is also a critical factor to estimate optimal biochar application dosage for promoting plant growth and reduce metal leachability.

Enrichment, sources and ecological risk mapping of heavy metals in agricultural soils of dhaka district employing SOM, PMF and GIS methods

Rapid urbanization and industrial growth have triggered heavy metal contamination in agricultural soil in Dhaka, which is a serious concern for ecological risk and public health issues. In this study, fifty-four soil samples from agricultural lands of Dhaka had been analyzed for assessing accumulation, spatial enrichment, ecological risk and sources apportionment of heavy metals using a combined approach of self-organizing map (SOM), positive matrix factorization (PMF), geographical information system (GIS), and enrichment factor (EF). The results of the enrichment factor, geoaccumulation index and contamination factor index showed that more than 90% of the soil samples were polluted by higher levels of Cr and Cd. The mean pollution load index (PLI) results demonstrated that about 73% of soil samples were moderately polluted by heavy metals. Based on SOM and PMF analysis, four potential sources of heavy metals were found in this study area: (i) agrochemical and sewage irrigation (Cd–As); (ii) combined effect of agriculture, industrial and natural sources (Mn, Co, Ni and Zn); (iii) atmospheric deposition and industrial emission (As–Pb); (iv) chemical and leather tanning industries (Cr). The ecological risk index demonstrated that in terms of Cd content, about 75% of soil samples were moderate to high risk, and 20% were moderate to considerable ecological risk, which was the serious environmental, ecological, and public health concern. The spatial projection of ecological risk values showed that the southern part of Dhaka (Keraniganj Upazila) is a high ecological risk in terms of heavy metal pollution. These risk maps in agricultural soils may play a vital role in reducing pollution sources; so that zonal pollution control, as well as ecological protection, may be achieved in this resource-based agricultural land.