Health and ecological risk assessment and simulation of heavy metal-contaminated soil of Tehran landfill

Metal(loid)s in urban soil from historical municipal solid waste landfill: Geochemistry, source apportionment, bioaccessibility testing and human health risks

Landfills, especially those poorly managed, can negatively affect the environment and human beings through chemical contamination of soils and waters. This study investigates the soils of a historical municipal solid waste (MSW) landfill situated in the heart of a residential zone in the capital of Slovakia, Bratislava, with an emphasis on metal (loid) contamination and its consequences. Regardless of the depth, many of the soils exhibited high metal (loid) concentrations, mainly Cd, Cu, Pb, Sb, Sn and Zn (up to 24, 2620, 2420, 134, 811 and 6220 mg/kg, respectively), classifying them as extremely contaminated based on the geo-accumulation index (Igeo >5). The stable lead isotopic ratios of the landfill topsoil varied widely (1.1679-1.2074 for 206Pb/207Pb and 2.0573-2.1111 for 208Pb/206Pb) and indicated that Pb contained a natural component and an anthropogenic component, likely municipal solid waste incineration (MSWI) ash and construction waste. Oral bioaccessibility of metal (loid)s in the topsoil was variable with Cd (73.2-106%) and Fe (0.98-2.10%) being the most and least bioaccessible, respectively. The variation of metal (loid) bioaccessibility among the soils could be explained by differences in their geochemical fractionation as shown by positive correlations of bioaccessibility values with the first two fractions of BCR (Community Bureau of Reference) sequential extraction for As, Cd, Mn, Ni, Pb, Sn and Zn. The results of geochemical fractionation coupled with the mineralogical characterisation of topsoil showed that the reservoir of bioaccessible metal (loid)s was calcite and Fe (hydr)oxides. Based on aqua regia metal (loid) concentrations, a non-carcinogenic risk was demonstrated for children (HI = 1.59) but no risk taking into account their bioaccessible concentrations (HI = 0.65). This study emphasises the need for detailed research of the geochemistry of wastes deposited in urban soils to assess the potentially hazardous sources and determine the actual bioaccessibility and human health risks of the accumulated metal (loid)s.

Modelling the Nexus of municipal solid waste sector for climate resilience and adaptation to nature-based solutions: A case study of Pakistan

Municipal solid waste management is a major concern in developing economies, requiring collective international efforts to achieve carbon neutrality by diverting waste from disposal facilities. This study aims to highlight the importance of the waste sector as it has the potential to significantly contribute to climate change and its toxicity impact on the local ecosystem. Out of the total municipal solid waste generated, only 78 % is collected, either open dumped or thrown in sanitary landfills. The waste sector's ecological impact value is calculated for the Earth's regions, and it is very high at >50 % in Africa, Asia, Latin America and the Caribbean. This sectoral impact value is mainly responsible for greenhouse gas emissions and degradation of the local ecosystem health. Current business‒as‒usual practices attribute 3.42 % of global emissions to the waste sector. Various scenarios are developed based on waste diversion and related emissions modelling, and it is found that scenarios 3 and 4 will support the policymakers of the regions in attaining zero carbon footprints in the waste sector. Our findings conclude that cost-effective nature-based solutions will help low‒income countries reduce emissions from disposal sites and significantly improve the local ecosystem's health. Developed economies have established robust waste‒handling policies and implementation frameworks, and there is a need for collaboration and knowledge sharing with developing economies at the regional level to sustain the sector globally.

Potentially toxic elements (PTEs) and ecological risk at waste disposal sites: An analysis of sanitary landfills

This study presents an analysis of soil contamination caused by Ni, Zn, Cd, Cu, and Pb at municipal solid waste (MSW) landfills, with a focus on ecological risk assessment. The approach aims to assess how different landfill practices and environmental conditions affect soil contamination with potentially toxic elements (PTEs) and associated environmental risks. Soil samples were collected from MSW landfills in Poland and the Czech Republic. The research included a comprehensive assessment of PTEs in soils in the context of global environmental regulations. The degree of soil contamination by PTEs was assessed using indices: Geoaccumulation Index (Igeo), Single Pollution Index (Pi), Nemerow Pollution Index (PN), and Load Capacity of a Pollutant (PLI). The ecological risk was determined using the Risk of PTEs (ERi) and Sum of Individual Potential Risk Factors (ERI). The maximum values of the indicators observed for the Radiowo landfill were as follows: Igeo = 4.04 for Cd, Pi = 24.80 for Cd, PN = 18.22 for Cd, PLI = 2.66, ERi = 744 for Cd, ERI = 771.80. The maximum values of the indicators observed for the Zdounky landfill were as follows: Igeo = 1.04 for Cu, Pi = 3.10 for Cu, PN = 2.52 for Cu, PLI = 0.27, ERi = 25 for Cd, ERI = 41.86. The soils of the tested landfills were considered to be non-saline, with electrical conductivity (EC) values less than 2,000 μS/cm. Varying levels of PTEs were observed, and geostatistical analysis highlighted hotspots indicating pollution sources. Elevated concentrations of Cd in the soil indicated potential ecological risks. Concentrations of Cu and lead Pb were well below the thresholds set by the environmental legislation in several countries. In addition, Ni concentrations in the soils of both landfills indicated that the average levels were within acceptable limits. Principal Component Analysis (PCA) revealed common sources of PTEs. The identification of specific risk points at the Radiowo and Zdounky sites contributes to a better understanding of potential hazards in landfill environments. By establishing buffer zones and implementing regular maintenance programs, emerging environmental problems can be addressed in a timely manner.

A comprehensive investigation of geoenvironmental pollution and health effects from municipal solid waste landfills

This study investigates human health risks associated with heavy metals (HMs) occurrence in municipal solid waste (MSW) landfills. For testing of selected MSW landfills steps were involved, including site characterization, soil sampling and chemical testing, statistical analysis, as well as health risk assessment, carcinogenic and non-carcinogenic effects. For the Polish landfill (Radiowo) the average HMs concentrations were found in the following order: Zn (52.74 mg/kg DM) > Pb (28.32 mg/kg DM) > Cu (12.14 mg/kg DM) > Ni (4.50 mg/kg DM) > Cd (3.49 mg/kg DM), while for the Czech landfill (Zdounky): Zn (32.05 mg/kg DM) > Cu (14.73 mg/kg DM) > Ni (4.73 mg/kg DM) > Pb (0.10 mg/kg DM) = Cd (0.10 mg/kg DM). Strong positive correlations between selected HMs demonstrated identical origins. Principal component analysis (PCA) performed for the Radiowo landfill transferred the soil parameters into three principal components (PCs), accounting for 87.12% of the total variance. The results of the PCA analysis for the Zdounky landfill revealed three PCs responsible for 95.16% of the total variance. The exposure pathways of HMs for landfills were in the following order: ingestion > dermal absorption > inhalation. For both landfills, the values of hazard quotient were lower than 1, indicating no potential negative health effects. In terms of the hazard index (HI), for both landfills, no adverse human health effects occur (HI < 1). The incremental lifetime cancer risk (ILCR) values indicated negligible or acceptable carcinogenic risk of HMs (average ILCR in the range from 5.01E-10 to 5.19E-06).

Bioavailability and health risk of pollutants around a controlled landfill in Morocco: Synergistic effects of landfilling and intensive agriculture

Toxic contamination of agricultural soils by trace metal(oid)s can pose detrimental effects on human health and agroecological systems. In this view, the current research explored total and available metal(oid)s in surface soils and assessed the associated hazards using pollution indices, PMF modeling, PCA, and Montecarlo probabilistic human risk assessment with 10,000 repetitions. The mean concentrations of Cd, Pb, As, Cr, Ni, Cu, Zn, and Fe were 0.89, 24.86, 1.81, 19.10, 25.44, 7.98, 49.12 and 6183.32 mg kg-1 dry weight, respectively. These findings highlighted that the concentration of pollutants exceeded the values measured in the geochemical background. Soil enrichment by heavy metal (oid)s was confirmed by analyzing available fractions using DTPA ,CaCl2 and enrichment factor (EF). Additionally, pollution indicators (Igeo, PLI, and PERI) displayed significant contamination levels, with a higher ecological risk. Matrix Factorization (PMF) receptor and multivariate statistical analysis reflected that anthropogenic activities, particularly landfilling and agricultural practices were the main causes of the contamination. Furthermore, probabilistic and deterministic human risk assessments showed that carcinogenic risks exceeded the threshold values (10-4) set by the USEPA. Consequently, it is crucial to implement continuous monitoring and supervision of landfill sites to prevent additional pollution. These measures should be integrated into the management plans for waste management.

Exploring effective network design for monitoring soil pH and potentially toxic elements based on geochemical surveys in economically developed area

Periodically visiting soil monitoring sites, i.e., sampling and analysis, is recognized as one of the most important ways to monitor soil quality. However, reconciling the monitoring costs with monitoring precision of the soil monitoring network (SMN) is a key technical problem to be solved. A statistically sound method, which depends on the spatial variation in monitoring indicators, was adopted to determine the number of monitoring sites and the monitoring interval as well as their ability to detect a particular change under an economically feasible scenario. The spatial variation in soil monitoring indicators was inquired from the "Multi-Purpose Regional Geochemical Survey in Zhejiang Province (MRGSZ)" project. Based on the data for soil pH and concentration of potentially toxic elements, the number of monitoring sites and the monitoring intervals that might be used for soil monitoring were determined with the administrative region as the monitoring unit. The results showed that there was great spatial variation in the MRGSZ region, which resulted in discrepancies in the minimum detectable changes (MDCs), monitoring site numbers, and temporal monitoring intervals for revisiting. Our research proposes a number of monitoring sites (nr) that could reconcile the monitoring costs, practicability and monitoring precision; thus, it was recommended for the design of SMNs. Under nr, the MDC values of each monitoring indicator were acceptable for all administrative regions, and the temporal monitoring intervals were practical with variations of 6.7-14.8 years.

Heavy metal contamination in soils of a decommissioned landfill southern Brazil: Ecological and health risk assessment

The incorrect disposal of waste negatively influences the population's quality of life and harms the environment. In Brazil, waste disposal in the open air is still a reality, which generates concerns about the contamination of the areas surrounding these dumpsites. The present work evaluated the possible environmental risks of a deactivated dumpsite in southern Brazil. The soil was characterized by physical and chemical tests, emphasizing the analysis of heavy metals Al, Fe, Cu, Mn, and Zn. Using geostatistical tools, it was possible to determine the distribution of these heavy metals in the influence of the landfill, since the metals Mn, Fe, and Zn showed a significant difference about the reference soil, indicating that they came from leaching from the landfill. The dispersion of the metals along the slope showed a tendency towards mobility since the highest concentrations were at elevations below the landfill. The area was considered contaminated due to the high scores of the evaluated indexes pollution, as the Improved Nemerow Pollution Index, which considers pollutant concentration, toxicity, and environmental impact to provide a measure of contamination, and was equivalent to 6.44, indicating that the area is contaminated. However, it presented low ecological risks, with a potential ecological risk of 18.55. As well as low risks to human health, with hazard index below the limit considered critical to health (HI < 1). Thus, the results of this study showed that the metals are released around the deactivated deposit, which compromises the environmental safety of the site, mainly due to its proximity to bodies of water that supply the region. Thus, the permanent control and monitoring of the areas of deactivated dumpsites are essential to avoid further pollution and should be included in the management plans for deactivating these deposits throughout the country.

Pets, Genuine Tools of Environmental Pollutant Detection

In a shared environment, our companion animals became unintended sentinels for pollutant exposure consequences, developing even earlier similar conditions to humans. This review focused on the human-pet cohabitation in an environment we all share. Alongside other species, canine and feline companions are veritable models in human medical research. The latency period for showing chronic exposure effects to pollutants is just a few years in them, compared to considerably more, decades in humans. Comparing the serum values of people and their companion animals can, for example, indicate the degree of poisonous lead load we are exposed to and of other substances as well. We can find 2.4 times higher perfluorochemicals from stain- and grease-proof coatings in canine companions, 23 times higher values of flame retardants in cats, and 5 times more mercury compared to the average levels tested in humans. All these represent early warning signals. Taking these into account, together with the animal welfare orientation of today's society, finding non-invasive methods to detect the degree of environmental pollution in our animals becomes paramount, alongside the need to raise awareness of the risks carried by certain chemicals we knowingly use.

Microplastics and mesoplastics as emerging contaminants in Tehran landfill soils: The distribution and induced-ecological risk

Environmental pollution with microplastics (MPs) and mesoplastics (MEPs) and their potential risks to human health and ecosystem quality have aroused the concern of communities. Therefore, the pioneering study was conducted on Tehran landfill soil contamination with MPs and MEPs. 56 shallow and deep soil samples were collected from different landfill areas in the wet and dry seasons. The physical and chemical characteristics of MPs and MEPs were measured using a stereomicroscope and FTIR-ATR spectroscopy, respectively. The results showed that the average MP abundance in shallow and deep soil was 863 ± 681 and 225 ± 138 particles/kg soil, and for MEPs, it was 29.8 ± 6.4 and 18.1 ± 8.3 particles/kg_soil. The low-density plastic particles were separated completely by flotation with H₂O, NaCl, and ZnCl₂ solutions, but PVC was only separated by 90%. Over 90% of MPs and MEPs were LDPE, PP, and PS polymers, explained by their widespread applications in single-use products and their consumption in Iran. Films, white and black, and 0.1-0.5 mm were the dominant shapes, colors, and sizes of MPs, respectively. The prevailing MEPs were film-shaped and in white and yellow colors, with a size of 0.5-1.0 cm. Canonical correlation analysis indicated that total organic matter and moisture were highly correlated with MP shapes. The calculated polymer hazard index values have a wide range at different sampling points, and this index yielded hazard levels III-IV and II-IV for MPs and MEPs, respectively, while according to the pollution load index category, the hazard level of MPs and MEPs was I-II and I. The potential ecological risk index from combined polymers has been estimated to be of minor to extreme danger for MPs and of minor risk for MEPs. Our findings provided baseline data on MPs contamination in Tehran landfill soil and its associated ecological risk, which aids policymakers in implementing risk-reduction measures.

Heavy metal pollution in surface sediments and human health assessment in southern Al-Khobar coast, Saudi Arabia

Surface sediment samples from twenty-nine stations in south Al-Khobar coastline, Arabian Gulf, have been examined to assess the heavy metal contamination and impact on human health through dermal contact. The content in Cu, Zn, Cd, Pb, Fe, Mn, Co, Hg and Ni, was evaluated. Pollution index, modified degree of contamination, and pollution load index agreed to exclude heavy metal pollution. Differently, soil pollution index and Nemerow integrated pollution index pointed out moderate and heavy pollution grade for Hg and Cu, respectively. The human health assessment, according to the low values of the hazard index ˂ 1.0 for both adults and children, excluded any significant impact on the human body. The chronic daily intake and the total lifetime cancer risk also were consistent in excluding any risk to human health. Similarly, the carcinogenic risks for Pb and Cd, and the total cancer risk ˂1 × 10^-6, did not imply significant health hazards.

Contamination and health risks of heavy metals in the soil of a historical landfill in northern China

Landfill-induced heavy metal (HM) contamination of soils is a widespread and complex problem. The levels and potential hazards of HM contamination in landfills must be evaluated before they can be reused for any purpose. In order to reuse a historical landfill in northern China, 376 sampling sites were selected in 2019 using the checkerboard layout method, and the levels of arsenic (As), mercury (Hg), antimony (Sb), copper (Cu), lead (Pb), cadmium (Cd), nickel (Ni), zinc (Zn), and thallium (Tl) in the soil were measured. Multiple evaluation methods established the HM pollution levels, agricultural suitability, and health risks associated with the sampling sites. In most parts of the study area, the concentrations of all nine HMs exceeded the screening levels and maximum allowable concentrations for agricultural soils. Only the soils in Zones 5 and 6 can be used for agricultural activity. Moreover, the deep soils were heavily contaminated with HMs in certain areas, possibly because of leaching and infiltration in the surface soil and the rise and diffusion of polluted groundwater. The soil HMs in the study area posed a higher carcinogenic risks to both adults and children. The average carcinogenic risk associated with As was 6.12 × 10^-4, which was the major contributor to carcinogenic risk at all HM-contaminated sites. The results of this work empirically demonstrated that soil HM pollution is severe and problematic in the study area and remedial measures are urgently required.

Investigation of health and ecological risk attributed to the soil heavy metals in Iran: Systematic review and meta-analysis

The presence of heavy metals (HMs) in the soil can pose risks to human health via ingestion and dermal absorption. This systematic review and meta-analysis study focused on both of health and ecological risks attributed to the six HMs (As, Cd, Cr, Cu, Pb, Zn) in the soil of different Provinces of Iran. Articles were selected in the Web of Science and Scopus from 2000 to August 2021. The study was carried out according to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guideline. Based on the inclusion and exclusion criteria, finally 32 studies were reviewed which the ranking of mean concentrations of the studied metals followed as: As > Zn > Cr > Pb > Cu > Cd. Mean concentration of Cd and As calculated via meta-analysis in the studied Provinces was found to be more than Iran's environment protection agency (EPA) guideline values. Other HMs met guideline values. A significant non-carcinogenic risk attributed to the As found in Kurdistan Province (hazard index, HI > 1). Furthermore, a significant carcinogenic health risk was found in Kurdistan and West Azerbaijan associated to As and in Fars, Khozestan and Khorasan-e-Razavi Provinces associated to Cd (ELCR >10^-4). Concerning the impact on the ecosystem, Cd, As and Pb caused ecological risks in some areas of Iran (ecological risk, ER > 40 and potential ecological risk, PER >150). Hence, we can conclude that Cd and As are important heavy metals from the health aspect. Moreover, Cd, As and Pb must be considered from an ecological point of view. Therefore, control of the Cd, As and Pb release in the environment and remediation of polluted sites through novel approaches is recommended.

Contamination and health risk assessment of arsenic and chromium in coastal sediments of Al-Khobar area, Arabian Gulf, Saudi Arabia

The contamination and health risks by arsenic and chromium in the Al-Khobar coastal area, Arabian Gulf, have been assessed by examining 29 samples of surface sediment. Several single and complex indices were accounted to assess contamination, while the chronic daily intake (CDI), the hazard index (HI) and the total lifetime cancer risk (LCR) were applied to assess human health. The studied sediments showed absence or low level of As and Cr contamination. Results of CDI suggested a greater intake of As and Cr in children than in adults, mainly by ingestion pathway, reaching >99.5 % from the total for both adults and children. The recorded values of HI indicated not significant non-carcinogenic effects on the human body. LCR was higher in children than in adults. However, the recorded values suggested that the present carcinogenic risk for As and Cr can be considered acceptable or tolerable.

Spatial variability and risk assessment of heavy metals in the soil surrounding solid waste from coking plants in Shanxi, China

Heavy metal pollution in the soil surrounding solid wastes from coking plants poses potential threats to human health and has attracted widespread attention. This study is the first to assess the spatial variability and risks of heavy metals in the soil surrounding solid waste from coking plants. The results showed that the concentrations of Cu, Ni, Pb, and Cd in the soil were much higher than the background value of the soil. Solid waste had a clear influence on the contents of Ni, Cd, Mn, Pb, and Cr in the soil. The ecological risk assessment of heavy metal pollution demonstrated that the pollution degree of Cu, Pb, and Cd was more serious than others, and the ecological risk of heavy metals was mainly caused by Cd in the soil. The human health risk assessment showed that adults and children near coking plants might face carcinogenic risk from exposure to Cr. This study can provide a theoretical basis for the prevention and management of soil heavy metal pollution surrounding solid waste in coking plants.

Ecological and Health Risk Assessment of Heavy Metals in Soils from Recycled Lead Smelting Sites

In this study, 258 soil samples were collected to determine the total content and each speciation fraction of chromium (Cr), manganese (Mn), copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb) in the soil by inductively coupled plasma mass spectrometry (ICP-MS), and their potential ecological and human health risks were assessed using the geo-accumulation index (Igeo), risk assessment code (RAC), and health risk assessment. The results showed that: (1) The mean concentrations of heavy metals (HMs) (mg/kg) in the surface soil of the site were in the order of Pb (1921.77) > Mn (598.21) > Zn (162.29) > Cr (84.65) > Cu (15.16) > Cd (1.8), with the mean values of Cd and Pb exceeding the local background values by 164 and 725 times. (2) In the vertical direction, Cr, Mn, and Pb have no tendency to migrate downward; Cd and Zn demonstrate a strong ability to migrate. (3) The bioavailability of Cd is the highest in the surface soil, followed by Mn and Pb; in the soil below a depth of 0.5 m, the prevalent form of HMs is its residual state (F4). (4) The degree of Igeo pollution of each HMs is: Pb > Cd > Zn > Cr = Mn = Cu, where Pb pollutes the environment to an extremely contaminated level and Cd causes heavy pollution thereof. According to the RAC results, Cd in the surface soil poses a high risk to the environment, and Pb and Mn pose a moderate risk; meanwhile, with the increase of depth, the risk posed by Cd and Mn to the ecosystem shows a tendency to increase. Health risk evaluation indicated that respiratory intake was the main pathway affecting the carcinogenic risk (CR) and hazard quotient (HQ) of HMs, where Pb and Cr were the main hazard factors for non-CR and Cr was the main carcinogenic factor. This study can provide scientific guidance and technical support for soil risk control or remediation of HM-contaminated sites.

Association between heavy metals and metabolic syndrome in drinking water and surface soil: case-control study in Iran

Although obesity is a major risk factor for metabolic syndrome (MetS), not all obese people develop MetS that is directly related to obesity. This suggests that the risk of MetS is influenced by other genetic or environmental agents such as heavy metals. The aim of this study was to investigate the relationship between heavy metals in drinking water and surface soil, and its relationship with the incidence of MetS. To determine the sampling points of drinking water and surface soil, from the location of 150 people selected for inclusion in the study, 16 points were selected randomly for heavy metal concentration analysis. Results were indicated that mean concentrations of V, Mn, Ni, As, Cd, and Sr in drinking water of MetS group were higher than control group. The concentration of heavy metals in drinking water, except for Mn and Sr, did not show a significant difference between case and control groups. The results of this study showed that concentration of heavy metals in drinking water and surface soil was positively associated with the incidence of MetS.

Statistical analysis of PN clusters in Mo/VFe protein crystals using a bond valence method toward their electronic structures

Iron valences of 129 P-clusters from FeMo/V proteins were analyzed using a bond valence method, supposing the existence of Fe3+ in a generally considered all-ferrous PN cluster in solution with excess reducing agent.

Human Health Risk Distribution and Safety Threshold of Cadmium in Soil of Coal Chemical Industry Area

Cadmium (Cd) is a highly carcinogenic metal that plays an important role in the risk management of soil pollution. In this study, 153 soil samples were collected from a coal chemical plant in northwest China, and the human health risks associated with Cd were assessed through multiple exposure pathways. Meanwhile, by the Kriging interpolation method, the spatial distribution and health risks of Cd were explored. The results showed that the average concentration of Cd in the soil was 0.540 mg/kg, which was 4.821 and 5.567 times that of the soil background value in Ningxia and China, respectively. In comparison, the concentration of Cd in the soil was below the national soil environmental quality three-level standard (1.0 mg/kg). In addition, health risk assessment results showed that the total carcinogenic risk of Cd was 1.269 × 10−6–2.189 × 10−6, both above the acceptable criteria (1 × 10−6), while the hazard quotient was within the acceptable level. Oral intake and ingestion of soil particles were the main routes of exposure, and the carcinogenic risk control value of oral intake was the lowest (0.392 mg/kg), which could be selected as the strict reference of the safety threshold for Cd in the coal chemical soil. From Kriging, a prediction map can be centrally predicted on heavy metal pollution in the area surrounding the coal entrance corridor and pedestrian entrance. This study can provide a theoretical basis for the determination of the heavy metal safety threshold of the coal chemical industry in China.

Source and Health Risk Assessment of Heavy Metals in Soil-Ginger System in the Jing River Basin of Shandong Province, North China

This study investigated the characteristics and sources of heavy metals in a soil-ginger system and assessed their health risks. To this end, 321 topsoil samples and eight soil samples from a soil profile, and 18 ginger samples with root-soil were collected from a ginger-planting area in the Jing River Basin. The average concentration of heavy metals in the topsoil followed the order: Cr > Zn > Pb > Ni > Cu > As > Cd > Hg. In the soil profile, at depths greater than 80 cm, the contents of Cr, Ni, and Zn tended to increase with depth, which may be related to the parent materials, whereas As and Cu contents showed little change. In contrast, Pb content decreased sharply from top to bottom, which may be attributable to external environmental and anthropogenic factors. Multivariate statistical analysis showed that Cr, Ni, Cu, Zn, and Cd contents in soil are affected by natural sources, Pb and As contents are significantly affected by human activities, and Hg content is affected by farmland irrigation. Combined results of the single pollution index (Pi), geo-accumulation index (Igeo), and potential ecological risk assessment (Ei and RI) suggest that soil in the study area is generally not polluted by heavy metals. In ginger, Zn content was the highest (2.36 mg/kg) and Hg content was the lowest (0.0015 mg/kg). Based on the bioconcentration factor, Cd and Zn have high potential for enrichment in ginger. With reference to the limit of heavy metals in tubers, Cr content in ginger exceeds the standard in the study area. Although Cr does not accumulate in ginger, Cr enrichment in soil significantly increases the risk of excessive Cr content in ginger.