Hydrogeochemical characteristics and risk evaluation of potential toxic elements in groundwater from Shanmughanadhi, Tamilnadu, India

Integrated Approach to Hydrogeochemical Assessment of Groundwater Quality in Major Industrial Zone of Punjab, Pakistan

Groundwater contamination with arsenic (As) is a significant concern in Pakistan's Punjab Province. This study analyzed 69 groundwater samples from Faisalabad, Gujranwala, Lahore, and Multan to understand hydrogeochemistry, health impacts, contamination sources, and drinking suitability. Results revealed varying as concentrations across districts, with distinctive cation and anion orders. Faisalabad exhibited Na+ > Mg2+ > Ca2+ > K+ > Fe2+ for cations and SO42- > Cl- > HCO3- > NO3- > F- for anions. Gujranwala showed Na+ > Ca2+ > Mg2+ > K+ for cations and HCO3-  > SO42- > Cl- > NO3-  > F- for anions. In Lahore, demonstrated: Na+ > Ca2+ > Mg2+ > Fe > K+ for cations and HCO3-  > SO42- > Cl- > NO3-  > F- for anions. Multan indicated K+ > Ca2+ > Mg2+ > Na+ > Fe for cations and HCO3-  > SO42- > Cl- > F- > NO3- ) for anions. Hydrochemical facies were identified as CaHCO3 and CaMgCl types. Principal Component Analysis (PCA), highlighted the influence of natural processes and human activities on groundwater pollution. Water Quality Index (WQI) result reveal that most samples met water quality standards. The carcinogenic risk values for children exceeded permissible limits in all districts, emphasizing a significant cancer risk. The study highlights the need for rigorous monitoring to mitigate (As) contamination and protect public health from associated hazards.

Chemical characteristics and health risk evaluation of natural waters in the Du River Source National Nature Reserve: A case study in Zhushan County, Hubei Province, China

To study the distribution of trace elements in natural water of the Du River Source National Nature Reserve and to assess the water quality and health risks, Zhushan County in Hubei Province was selected as the study area. Element content in 361 natural water samples collected from Zhushan County were measured by ICP-MS, ICP-OES, and HG-AFS. The main anions and cations present in water samples from Zhushan County are Ca2+ and HCO3-. The water chemistry is predominantly influenced by the weathering of carbonate rocks. The water samples with high content of selenium (Se) (0∼82.9 μg/L, mean 4.6 μg/L) in natural water in Zhushan County are mainly distributed in the northern part of Zhushan. The strontium (Sr) content of 49.6% of the water samples (0.001-2.177 mg/L, mean 0.234 mg/L) reached the criteria of natural mineral water for drinking in China (Sr ≥ 0.2 mg/L), which is distributed throughout the county. The high content of metasilicic acid (H2SiO3) (0.026-35.910 mg/L, mean 12.598 mg/L) and zinc (Zn) (0∼407.218 μg/L, mean 12.406 μg/L) are concentrated in northern Zhushan County. 99.7% water samples were freshwater and 98.9% meet the criteria of "good" water quality. All of the natural water samples have low health risk and low heavy metal pollution. 6.1% water samples meet the criteria of Se-type mineral water, while 45.4% meet the criteria of Sr-type mineral water, and 4.4% water samples meet the criteria of "low sodium, high Se, and high Sr" mineral water. Zhushan County has the potential for Se-type mineral water and Sr-type mineral water development. The findings of this study hold immense significance for the public health implications of drinking water in Du River Source, thereby offering valuable insights for effective water resources management.

Designing dynamic groundwater management strategies through a composite groundwater vulnerability model: Integrating human-related parameters into the DRASTIC model using LightGBM regression and SHAP analysis

Groundwater nitrate contamination has emerged as a pressing global concern. Given its potential for long-term impacts on aquifers, protective measures should primarily focus on prevention. Drawing on the theory of groundwater vulnerability (GV), the original DRASTIC model and parameters related to human activities are employed as inputs and integrated with the LightGBM regression algorithm to facilitate nitrate index (NI) prediction tasks. The SHAP analysis is conducted to effectively examine the contribution of parameters to the NI prediction and interpret the issue of parameter interactions. In addition, to mitigate the limitations of the intrinsic GV model, a composite nitrate index (CNI) is developed by linearly combining the DRASTIC index with the NI. The framework presented in this study provides adaptive strategies for managing groundwater resources over different time periods. A representative region for arid and semiarid climates, the Yinchuan region, is studied using the framework. As compared to 2012, the intrinsic GV index has changed spatially in 2022. Human activities have increased the influence of the nitrate concentration as shown by the Pearson correlation coefficient of -0.082 between the DRASTIC index and nitrate concentration. A significant increase in pollution levels was predicted by NI, ranging from -0.116 to 0.968. According to SHAP analysis, the significant increase in NI levels in 2022 was mainly due to high-value industrial and agricultural production. In 2022, 12.02% of the areas had an increase of at least 0.549 in the CNI. 42.1% of the areas were classified as moderate or high CNI levels. The farm was identified as a high-contributing source to nitrate pollution. The small-scale agricultural and livestock activities in non-urban areas also contribute to groundwater pollution. Dynamic groundwater management strategies need to be implemented in high-growth and high-level CNI areas.

Estimation of Polycyclic Aromatic Hydrocarbons in Groundwater from Campania Plain: Spatial Distribution, Source Attribution and Health Cancer Risk Evaluation

The aim of this study was to evaluate the concentrations of polycyclic aromatic hydrocarbons (PAHs) in 1168 groundwater samples of the Campania Plain (Southern Italy), taken using a municipal environmental pressure index (MIEP), and to analyze the distribution of these compounds to determine source PAHs using ratios of isomers diagnostic. Lastly, this study also aimed to estimate the potential health cancer risk in groundwaters. The data indicated that the highest concentration of PAHs was found in groundwater from Caserta Province and the contents of BghiP, Phe, and Nap were detected in the samples. The spatial distribution of these pollutants was evaluated using the Jenks method; moreover, the data indicated that incremental lifetime cancer risk ILCR_ingestion ranged from 7.31 × 10^-20 to 4.96 × 10^-19, while ILCR_dermal ranged from 4.32 × 10^-11 to 2.93 × 10^-10. These research findings may provide information about the Campania Plain's groundwater quality and aid in the development of preventative measures to lessen PAH contamination in groundwater.

Coupled controls of the infiltration of rivers, urban activities and carbonate on trace elements in a karst groundwater system from Guiyang, Southwest China

Hydrogeochemical processes of trace elements (TEs) are of considerable significance to river water and groundwater resource assessment and utilization in the karst region. Therefore, seven TEs were analyzed to investigate their contents, spatial variations, sources, and controlling factors in Guiyang, a typical karst urban area in southwest China. The results showed that the average content of TEs in river water (e.g., As = 1.44 ± 0.47 μg/L andCo = 0.15 ± 0.06 μg/L) was higher than that of groundwater (e.g., As = 0.51 ± 0.42 μg/L andCo = 0.09 ± 0.05 μg/L). The types of groundwater samples were dominated by Ca/Mg-HCO₃ and Ca/Mg-Cl types, while those of the river water samples were Ca-Cl and Ca/Mg-Cl types. Principal component analysis (PCA) and correlation analysis (CA) analyses indicated that As and Mn in the groundwater of the study area were related to river infiltration. The end-member analysis further revealed that river infiltration (As = 0.86-1.81 μg/L, Cl/SO₄^2- = 0.62-0.89) and urban activities (As = 0.21-0.32 μg/L, Cl/SO₄^2- = 0.51-0.89) were two main controlling factors of TEs (e.g., As, Co, and Mn) in the study area. In addition, the ion ratios in river and groundwater samples indicated that the weathering of carbonates was also an important control on the hydrogeochemistry of TEs (e.g., Fe and Mn) in Guiyang waters. This study showed that the trace element (TE) contents of groundwater in the Guiyang area were greatly associated with urban input and river recharge, and provided a new perspective for understanding the geochemical behavior of TEs in urban surface and groundwater bodies, which will help the protection of groundwater in the karst areas of southwest China.

Assessment of Heavy Metal Accumulation in Soil and Garlic Influenced by Waste-Derived Organic Amendments

Simple Summary

The utilization of organic wastes, for example, poultry waste, sugarcane press mud, and farmyard manure is extremely common among farmers from South Asia including Pakistan. We assess the biochemical nature and dietary benefit for plants and record the presence of heavy metals in garlic following cultivation in a soil amended with these organic wastes. Present investigation showed the grouping of toxicity and bioaccumulation of heavy metals with a particular link to their source of origin and highlight the hazard of some of them for public health through their excessive utilization. Selecting appropriate manure can significantly reduce health risks for humans.

Abstract

In South Asia, the high costs of synthetic fertilizers have imposed research on alternative nutrient inputs. We aimed to identify potential trace elements (PTE) present in some organic manure that might be a source of environmental pollutions and risk to public health following consumption. The study aims to evaluate how different organic waste (poultry waste, PW; press mud, PM; and farmyard manure, FYM) influences the heavy metal migration in soil, the accumulation in garlic, and their potential health risks. Organic waste caused a higher accumulation of certain metals (Zn, Cu, Fe, and Co), whereas Mn, Cd, Cr, and Pb were in lower concentrations in soil. Amendments of soil with PM revealed a higher accumulation of Cd, Cr, Fe, and Pb, whereas PW resulted in Cu and Zn accumulation in garlic. Treatment of soil with FYM exhibited higher metal concentration of Co and Mn. An environmental hazard indices study revealed that pollution load index (PLI) was highest for Cu following treatment with PM. The health risk index (HRI) was greater for Cd following amendment with PM. Maximum daily intake of metals (DIM) was observed for Zn after treatment with PW. The Pb exhibited maximum bioconcentration factor (BCF) in PM-amended plants. Based on these findings, we concluded that garlic grown on contaminated soil with organic waste may pose serious health hazards following consumption.

Hydrochemical Characteristics and Hydrogeochemical Simulation Research of Groundwater in the Guohe River Basin (Henan Section)

With the implementation of the policy of ecological protection and high-quality development of the Yellow River Basin, the Guohe River Basin, which is close to the middle reaches of the Yellow River Basin, is also an important part of future development. Mathematical statistics, the Piper diagram, ion proportion coefficient method, Gibbs diagram and reverse hydrogeochemical simulation are used to analyze the chemical characteristics and evolution of groundwater in the Guohe River Basin (Henan Section). The dominant ions in the study area are HCO3− and Na+, and the three-layer aquifer has obvious zoning characteristics. The results show that the chemical types of shallow groundwater in this area are HCO3−Na • Mg • Ca, intermediate HCO3-Na and deep HCO3−Na. Using the ion proportion coefficient method, it is found that Na+, Ca2+, and Mg2+ in the groundwater aquifer undergo cation exchange in the aquifer. According to the reverse hydrogeochemical simulation, gypsum in the three aquifers is in a dissolved state, carbonate and sulfide ores in the shallow layer are dissolved, dolomite and halite in the intermediate layer are dissolved, calcite and sulfide ores are precipitated and carbonate, halite and sulfide ores in the deep layer are precipitated; the hydrogeochemical evolution model is established to find that Ca2+ in groundwater displaces Na+ in the aqueous medium. This research can provide a scientific basis for the rational development and utilization of groundwater and ecological protection in the Yellow River Basin.