Receptor model-based source-specific health risks of toxic metal(loid)s in coal basin-induced agricultural soil in northwest Bangladesh

Source identification of heavy metals and metalloids in soil using open-source Tellus database and their impact on ecology and human health

The presence of heavy metals and metalloids (metal(loid)s) in the food chain is a global problem, and thus, metal(loid)s are considered to be Potentially Toxic Elements (PTEs). Arsenic (As), lead (Pb), mercury (Hg), and cadmium (Cd) are identified as prominent hazards related to human health risks throughout the food chain. This study aimed to carry out a source attribution for metal(loid)s in shallow topsoil of north-midlands, northwest, and border counties of the Republic of Ireland, followed by an assessment of the potential ecological and human health risks. The positive Matrix Factorization (PMF) was used for source characterization of PTEs, followed by the Monte Carlo simulation method, used for a probabilistic model to evaluate potential human health risks. The mean concentrations of prioritized metal(loid)s in the topsoil range in the order of Pb (28.83 mg kg-1) > As (7.81 mg kg-1) > Cd (0.51 mg kg-1) > Hg (0.11 mg kg-1) based on the open-source Tellus dataset. This research identified three primary sources of metal(loid) pollution: geogenic sources (36 %), mixed sources of historical mining and natural origin (33 %), and anthropogenic activities (31 %). The ecological risk assessment showed that Ireland's soil exhibits low-moderate pollution levels however, concerns remain for Cd and As levels. All metal(loid)s except Cd showed acceptable non-carcinogenic risk, while Cd and As accounted for high to moderate potential cancer risks. Potato consumption (if grown on land with elevated metal(loid) levels), Cd concentration in soil, and bioaccumulation factor of Cd in potatoes were the three most sensitive parameters. In conclusion, metal(loid)s in Ireland present low to moderate ecological and human health risks. It underscores the need for policies and remedial strategies to monitor metal(loid) levels in agricultural soil regularly and the production of crops with low bioaccumulation in regions with elevated metal(loid) levels.

Assessment of health risks based on different populations and sources of heavy metals on agricultural lane in Tengzhou City by APCS-MLR models

To identify the sources of heavy metals in local soils and their risks to human health. This study quantified the concentrations of eight heavy metals in 504 soil samples collected in Tengzhou, China. The ecological risks of a single heavy metal (EI), a comprehensive ecological risk index (RI), and a health risk assessment model were used to evaluate the level of contamination in the city. The results of the research study indicate that there are different levels of heavy metal pollution in rural and urban agricultural areas in Tengzhou. Moreover, the spatial variability of mercury (Hg) is considerable, reaching 0.96, indicating a significant impact of anthropogenic activities. For the ecological risk, the heavy metal element with the highest EI value was mercury with a mean value of 67.22 and a peak value of 776.00. The heavy metal with the lowest mean EI value was Zn with only 1.03. Meanwhile, the average RI is only 128.59, but some areas have an RI as high as 842.2. The sources of heavy metals were identified using principal component analysis, correlation analysis, and an absolute principal component score multiple linear regression model (APCS-MLR). The non-carcinogenic risk for children, the carcinogenic risk for children, and the carcinogenic risk for adults were 1.23, 2.42×10-4 and 1.00×10-4, respectively, and these values exceeded their respective recommended values, and As and Cr had some carcinogenic hazards. Heavy metals in the soil come from natural, industrial, traffic and agricultural sources and represent 39.59%, 29.48%, 25.17% and 5.77%, respectively. The main source of heavy metals in local agricultural soils is the geological background, and the government needs to strengthen the monitoring of As and Cr in drinking water resources, as well as reduce traffic pollution and factory waste emissions to reduce Hg in soils.

Optimizing health risk assessment for soil trace metals under low-precision sampling conditions: A case study of agricultural soil

Cost limitations often lead to the adoption of lower precision grids for soil sampling in large-scale areas, potentially causing deviations in the observed trace metal (TM) concentrations from their true values. Therefore, in this study, an enhanced Health Risk Assessment (HRA) model was developed by combining Monte Carlo simulation (MCS) and Empirical Bayesian kriging (EBK), aiming to improve the accuracy of health risk assessment under low-precision sampling conditions. The results showed that the increased sampling scale led to an overestimation of the non-carcinogenic risk for children, resulting in potential risks (the maximum Hazard index value was 1.08 and 1.64 at the 500 and 1000 m sampling scales, respectively). EBK model was suitable for predicting soil TM concentrations at large sampling scale, and the predicted concentrations were closer to the actual value. Furthermore, we found that the improved HRA model by combining EBK and MCS effectively reduced the possibility of over- or under-estimation of risk levels due to the increasing sampling size, and enhanced the accuracy and robustness of risk assessment. This study provides an important methodology support for health risk assessment of soil TMs under data limitation.

Exploring the alteration of environmental radioactivity in terms of compositional elements of heavy minerals in an anthropogenically affected urban river: Radiological and ecological risks assessment

This study explored the alteration of naturally occurring radioactive materials (NORMs: 226Ra (≈238U), 232Th, 40K) in an anthropogenically disrupted urban river-basin (Turag, Bangladesh) in terms of constitutional substances (Sc, Ti, V, Fe, La, Ce, Sm, Eu, Tb, Dy, Ho, Yb, Lu, Hf, Ta, W, Th, U) of heavy-minerals. Average activity concentrations of 226Ra (≈238U), 232Th, and 40K were 41.5 ± 12.9, 72.1 ± 27.1, and 639 ± 100 Bqkg-1, respectively which were relatively higher compared to crustal origin. ∑REEs, Ta, W, Th, and U were ~2 times higher compared to crustal values with Ce and Eu-anomalies. APCS-MLR and PMF receptor models were used to determine the various anthropogenic and/or geogenic sources of NORMs and elements. Layer-wise variations of NORMs and elements were observed to trace the response of sedimentary processes towards the incoming pollution load. Presence of REEs indicates moderate degree of ecological risk to aquatic biota. However, carcinogenic risk (3.84 × 10-4 Sv-1) were significantly higher than threshold limit.

A 6-year review status on soil pollution in coal mining areas from Europe

Coal is an essential component in achieving the goal of fulfilling the energy demands of the world. Nevertheless, the extensive practice of coal mining has resulted in environmental contamination through the release of both organic and inorganic pollutants, including polycyclic aromatic compounds and potentially toxic elements, into various mediums, notably soil. The escalating coal-mining activities across Europe have amplified the concentration of specific elements in the soil. Therefore, a thorough and meticulous assessment of these environmental impacts is imperative to furnish policymakers, industries, and communities with valuable insights, facilitating the formulation and adoption of effective mitigation strategies. Considering the results of studies from 2018 to 2023, this review thoroughly evaluates the current state of soil pollution in the coal mining areas of Europe, focusing on polycyclic aromatic hydrocarbons and potentially toxic elements. By analyzing the acquired data, this study aims to evaluate the levels of contamination by these pollutants in soils. The findings reveal that low molecular weight polycyclic aromatic hydrocarbons dominate the polycyclic aromatic compounds present, while potentially toxic elements including Zn, Pb, Mn, and Cr emerge as major contributors to soil contamination in coal mining areas from Europe.

Source-specific ecological risk analysis and critical source identification of heavy metal(loid)s in the soil of typical abandoned coal mining area

Long-term coal mining activities in abandoned coal mining areas have resulted in the migration of large quantities of heavy metals into the surrounding soil environment, posing a threat to the regional ecological environment. This study focuses on the surface soil collected from a typical abandoned coal mining area. Methods such as the pollution index (PI) and potential ecological risk index (RI) were used to comprehensively evaluate the pollution levels and ecological risks of soil heavy metals. Geostatistical analysis and the APCS-MLR model were used to quantify the sources of soil heavy metals, and Nemerow integrated ecological risk (NIRI) model was coupled to apportion the ecological risks from different pollution sources. The results indicate that the average concentrations of Cd, As, and Zn are 4.58, 2.44, and 1.67 times the soil background values, respectively, while the concentrations of other heavy metals are below the soil background values. The soil of study area is strongly polluted by heavy metals, with the pollution level and ecological risk of Cd being significantly higher than those of other heavy metals. The NIRI calculation results show that the overall comprehensive ecological risk level is considerable, with sample points classified as relatively considerable, moderate, and low at 60.53 %, 36.84 %, and 2.63 %, respectively. The sources of soil heavy metals can be categorized into four types: traffic activities, natural sources, coal gangue accumulation, and a combined source of coal mining and agricultural activities, with contribution rates of 35.3 %, 36.1 %, 19.5 %, and 9.1 %, respectively. The specific source ecological risk assessment results indicate that coal gangue accumulation contributes the most to ecological risk (36.4 %) and should be prioritized for pollution control, with Cd being the priority control element for ecological risk. The findings provide theoretical support for the refined management of soil heavy metal pollution in abandoned coal mining areas.

Health risk assessment of soil heavy metals in a typical mining town in north China based on Monte Carlo simulation coupled with Positive matrix factorization model

The accumulation of heavy metals (HMs) in soil caused by mineral resource exploitation and its ancillary industrial processes poses a threat to ecology and public health. Effective risk control measures require a quantification of the impacts and contributions to health risks from individual sources of soil HMs. Based on high-density sampling, soil contamination risk indexes, positive matrix factorization (PMF) model, Monte Carlo simulation and human health risk analysis model were applied to investigate the risk of HMs in a typical mining town in North China. The results showed that As was the most dominant soil pollutant factor, Cd and Hg were the most dominant soil ecological risk factors, and Cr and Ni were the most dominant health risk factors in the study area. Overall, both pollution and ecological risks were at low levels, while there were still some higher hazard areas located in the central and south-central part of the region. According to the probabilistic health risk assessment (HRA), children suffered greater health risks than adults, with 21.63% of non-carcinogenic risks and 53.24% of carcinogenic risks exceeding the prescribed thresholds (HI > 1 and TCR>1E-4). The PMF model identified five potential sources: fuel combustion (FC), processing of building materials with limestone as raw materials (PBML), industry source (IS), iron ore mining combined with garbage (IOG), and agriculture source (AS). PBML is the primary source of soil HM contamination, as well as the major anthropogenic source of carcinogenic risk for all populations. Agricultural inputs associated with As are the major source of non-carcinogenic risk. This study offers a good example of probabilistic HRA using specific sources, which can provide a valuable reference for strategy establishment of pollution remediation and risk prevention and control.

Source specific sedimentary response towards the differential anthropogenic impacts in terms of potentially toxic elements in an urban river

To investigate the interplay between varying anthropogenic activities and sediment dynamics in an urban river (Turag, Bangladesh), this study involved 37-sediment samples from 11 different sections of the river. Neutron activation analysis and atomic absorption spectrometry were utilized to quantify the concentrations of 14 metal(oid)s (Al, Ti, Co, Fe, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Zn). This study revealed significant toxic metal trends, with Principal coordinate analysis explaining 62.91 % of the variance from upstream to downstream. The largest RSDs for Zn(287 %), Mn(120 %), and Cd(323 %) implies an irregular regional distribution throughout the river. The UNMIX-model and PMF-model were utilized to identify potential sources of metal(oid)s in sediments. ∼63.65-66.7 % of metal(oid)s in sediments originated from anthropogenic sources, while remaining attributed to natural sources in both models. Strikingly, all measured metal(oid)s' concentrations surpassed the threshold effect level, with Zn and Ni exceeding probable effect levels when compared to SQGs.

Review of soil environment quality in India near coal mining regions: current and future predictions

Production and utilization of coal are one of the primary routes of accumulation of Toxic Elements (TEs) in the soil. The exploration of trends in the accumulation of TEs is essential to establishing a soil pollution strategy, implementing cost-effective remediation, and early warnings of ecological risks. This study provides a comprehensive review of soil concentrations and future accumulation trends of various TEs (Cr, Ni, Pb, Co, Cu, Cd, Zn, Fe, Mn, and As) in Indian coal mines. The findings revealed that average concentrations of Cr, Mn, Ni, Cu, Zn, Pb, and Co surpass India's natural background soil levels by factors of 2, 4.05, 5.32, 1.77, 9.6, and 6.15, respectively. Geo-accumulation index values revealed that 27.3%, 14.3%, and 7.7% of coal mines are heavily polluted by Ni, Co, and Cu, respectively. Also, the Potential Ecological Risk Index indicates that Cd and Ni are primary contaminants in coal mines. Besides, the health risk assessment reveals oral ingestion as the main exposure route for soil TMs. Children exhibit a higher hazard index than adults, with Pb and Cr being major contributors to their non-carcinogenic risk. In addition, carcinogenic risks exist for females and children, with Cr and Cu as primary contributors. Multivariate statistical analysis revealed that TEs (except Cd) accumulated in the soil from anthropogenic sources. The assessment of future accumulation trends in soil TE concentrations reveals dynamic increases that significantly impact both the ecology and humans at elevated levels. This study signifies a substantial improvement in soil quality and risk management in mining regions.

Determining priority control toxic metal for different protection targets based on source-oriented ecological and human health risk assessment around gold smelting area

Determining the priority control source and pollutant is the key for the eco-health protection and risk management around gold smelting area. To this end, a case study was conducted to explore the pollution characteristics, source apportionment, ecological risk and human health risk of toxic metals (TMs) in agricultural soils surrounding a gold smelting enterprise. Three effective receptor models, including positive matrix factorization model (PMF), ecological risk assessment (ERA), and probabilistic risk assessment (PRA) have been combined to apportion eco-human risks for different targets. More than 95.0% of samples had a Nemerow pollution index (NPI) > 2 (NPImean=4.27), indicating moderately or highly soil TMs contamination. Four pollution sources including gold smelting activity, mining source, agricultural activity and atmosphere deposition were identified as the major sources, with the contribution rate of 17.52%, 44.16%, 13.91%, and 24.41%, respectively. For ecological risk, atmosphere deposition accounting for 30.8% was the greatest contributor, which was mainly loaded on Hg of 51.35%. The probabilistic health risk assessment revealed that Carcinogenic risks and Non-carcinogenic risks of all population were unacceptable, and children suffered from a greater health risk than adults. Gold smelting activity (69.2%) and mining source (42.0%) were the largest contributors to Carcinogenic risks and Non-carcinogenic risks, respectively, corresponding to As and Cr as the target pollutants. The priority pollution sources and target pollutants were different for the eco-health protection. This work put forward a new perspective for soil risk control and management, which is very beneficial for appropriate soil remediation under limited resources and costs.

Elevated levels of environmental radioactivity in fluvial sediment: origin and health risk assessment

To study the geogenic processes of naturally occurring radioactive materials' (NORMs') distribution, a transboundary Himalayan river (Punarbhaba) is chosen due to its trivial anthropogenic impacts. In explaining the genesis of radionuclides, transition elements (Sc, Ti, V, and Fe), rare-earth-elements (REEs: La, Eu, Ce, Yb, Sm, and Lu), Ta, Hf, Th, and U were analysed in 30 riverbed sediments collected from the Bangladeshi portion of the river. Elemental abundances and NORMs' activity were measured by neutron activation analysis and HPGe-gamma-spectrometry, respectively. Averagen=30 radioactivity concentrations of 226Ra (68.4 Bq kg-1), 232Th (85.7 Bq kg-1), and 40K (918 Bq kg-1) were 2.0-2.3-fold higher, which show elevated results compared to the corresponding world mean values. Additionally, mean-REE abundances were 1.02-1.38-times higher than those of crustal origin. Elevated (relative to earth-crust) ratios of Th/U (=3.95 ± 1.84) and 232Th/40K and statistical demonstrations invoke Th-dominant heavy minerals, indicating the role of kaolinite clay mineral abundance/granitic presence. However, Th/Yb, La/V, Hf/Sc, and Th/Sc ratios reveal the presence of felsic abundances, hydrodynamic sorting, and recycling of sedimentary minerals. Geo-environmental indices demonstrated the enrichment of chemical elements in heavy minerals, whereas radiological indices presented ionizing radiation concerns, e.g., the average absorbed-gamma-dose rate (123.1 nGy h-1) was 2.24-fold higher compared to the threshold value which might cause chronic health impacts depending on the degree of exposure. The mean excess lifetime cancer risk value for carcinogen exposure was 5.29 × 10-4 S v-1, which is ∼2-times greater than the suggested threshold. Therefore, plausible extraction of heavy minerals and using residues as building materials can alleviate the two-reconciling problems: (1) radiological risk management and (2) fluvial navigability.

Radiation exposure and health concerns associated with the environmental geochemistry of relatively higher radioactivity in a fresh water basin

This study was carried out on a negligible anthropogenically impacted Indo-Bangla transboundary river basin (Atrai, Bangladesh) to elicit radionuclides' and elemental distributions. Thirty sediment samples were collected from the Bangladesh portion of the river, and instrumental neutron activation analysis and HPGe γ-Spectrometry techniques were used to determine environmental radionuclides (e.g., 232Th, 226Ra, 40K) and associated elemental concentrations, respectively. Metal concentrations (Sc, V, Fe, Eu, Sm, La, Yb, Ce, Lu, Ta, Hf) were determined to comprehend the genesis of greater radioactivity. Recognizing the mean concentration of absorbed gamma dose rate (158.7 hGyh-1) is 2.88-times more than the recommended value (55 hGyh-1) that describes ionizing radiation concerns regarding potential health risks to the surrounding communities and the houses of native residents, which are constructed by Atrai river sediment. This work will assist relevant policymakers in exploring valuable heavy minerals and provide information regarding radiological health risks from a fluvial system.