Environmental Geochemistry and Health最新文献

The effect of open-pit bauxite mining on beach sediment contamination in the urban coastal environment of Kuantan City, Malaysia, was investigated. The contents of 11 heavy metals (Pb, Cd, Al, Mn, Cu, Zn, Fe, As, Ni, Cr, and Ag) in 30 samples from Kuantan beach sediment zones (supratidal, intertidal, and subtidal) were determined using inductively coupled plasma optical emission spectrometry followed by contamination indexes, Pearson's correlation analysis, and principal component analysis (PCA). The results indicated that Cd, As, Ni, and Ag values in beach sediment zones were significantly higher compared to background values. Contamination indexes suggest that Cd, As, Ni, and Ag were highly contaminated, and moderate to extremely enriched near the Kuantan Port. However, these heavy metal concentrations are lower compared to previous studies in the region. Sediment quality guidelines highlighted the occasional presence of Cd and Ag. Based on Pearson's correlation analysis, PCA, and cluster analysis, sources of these heavy metals in beach sediments were likely from agricultural runoff, uncontrolled industrial and residential discharge, and unprotected mine waste near the Kuantan Port. Furthermore, effective management of mining practices and ongoing monitoring are essential to reduce contamination risks.

The "La Esperanza" native mercury mine in Aranzazu, (Caldas, Colombia) was active from 1948 until 1975. Before the final closure of the mine, the company began using dimercaprol (BAL, British Anti-Lewisite) and penicillamine for the treatment of hydrargyrism among workers. Mercury poisoning among miners was frequent due to precarious working conditions, inadequate technology, difficult terrain, and the high toxicity of native mercury within the mine. The costs associated with the treatment was one of the causes of the closure of the mine. The early use of these chelators corresponds to the first systematic use of an antidote in occupational health in Colombia. This paper describes the context in which dimercaprol and penicillamine were used, a milestone in the history of toxicology, medical geology and occupational health in Colombia and Latin America.

Selenium (Se) is an essential element for humans, playing a critical role in the functioning of the immune system. The global prevalence of dietary Se deficiency is a significant public health concern, largely attributed to the low levels of Se present in crops. The sufficient Se in plants and humans is determined by the presence of stable Se sources in the soil. The Leizhou Peninsula is an important agricultural region in China, but the concentration and spatial distribution of Se in its soils remain unclear. To address this issue, we analyzed Se concentration data from 3333 soil samples collected at the depth of 0-20 cm from the Leizhou Peninsula, covering an area of 13,225 km². The results indicate that the mean soil Se concentration was 0.50 mg kg^-1, with Se-enriched soils being widely distributed. This provides prospects for the development of Se-enriched crops. Using random forest (RF) modeling and correlation analysis, the clay minerals (Fe-Al oxides), chemical index of alteration (CIA), and soil organic carbon (SOC) have been identified as the principal determinants of Se distribution in soil. During the weathering processes of the basalts, Fe-Al oxides serve as a crucial factor in Se accumulation in the red soils. Furthermore, the tropical climate further contributes to increasing the degree of weathering and the proportion of clay minerals and SOC in the soil. Atmospheric deposition derived from marine and precipitation is another important factor that promotes Se flux into soils. In conclusion, the distribution pattern of Se is jointly determined by the weathering process of basalt and climatic conditions. The results of the geographically weighted regression (GWR) analysis revealed that SOC, Al₂O₃, TFe₂O₃ and CIA change spatially and exhibit a spatial non-stationarity relationship with Se. This study offers a theoretical foundation and practical guidance for the sustainable development of Se-enriched agriculture and similar climate settings worldwide.

Cadmium (Cd) contamination in aquatic systems is a widespread environmental issue. In this study, a solid waste iron tailings and biochar hybrid (Fe-TWBC) was successfully synthesized derived from co-pyrolysis of peanut shell and tailing waste (Fe-TW). Characterization analyses showed that the metal oxides from solid waste iron tailings successfully loaded onto the biochar surface, with more functional groups in Fe-TWBC. The Fe-TWBC had a maximum capacity of 95.06 mg·g^-1 on Cd²⁺ adsorption, which was 1.40 times to pristine BC (70.46 mg·g^-1) and 2.53 times to Fe-TW (37.51 mg·g^-1). The adsorption behavior followed the pseudo-second-order kinetics and Freundlich models. DFT calculations revealed that the O-top of Fe-O group was the most chemically reactive site for Cd²⁺ adsorption with the high adsorption energy values of - 4.05 eV, short O-Cd bond lengths (2.133 Å), low electrostatic potentials in small blue regions near the O atom of Fe-O group, low energy gap (0.22 eV) and large electrophilic Fukui index (f^- = 0.18). Overall, these findings suggest that Fe-TWBC is effective in removing Cd²⁺ from aqueous solution and promotes the utilization of biowaste and solid waste iron tailing waste for cleaner production.

The present study aimed to investigate the hydrogeochemical patterns and contamination of the radiogeology, especially radon activity, related to geothermal aquifer properties and to perform a risk assessment of annual effective doses covering all hydrothermal spring attractions in Southern Thailand. Radon is an established lung carcinogen; especially longer term exposure to radioactive radon through inhalation could be a cause of lung cancer risk. Altogether 22 hydrothermal spring samples were collected from the six hydrothermal provinces in Southern Thailand in early November of 2023. Geochemical data represented by calcium chloride and sodium chloride type, most of which were influenced by seawater intrusion. In addition, the hydrothermal springs that located along local fault zones were mainly controlled by water‒rock interactions, indicating that hydrothermal spring quality was influenced by weathering. Hydrothermal springs located along the coastlines of the Gulf of Thailand and Andaman Sea were dominated by evaporation. Radon activity concentrations show value levels from 9 Bq/L (PG1) to 7,070 Bq/L (SR3), with an average of 580 Bq/L. Radon levels of hydrothermal spring attractions can be divided into three categories: (a) low radon levels below 100 Bq/L, (b) moderate to high radon levels between 100 and 580 Bq/L, and (c) very high radon levels greater than 580 Bq/L. The total annual effective doses for adults due to ingestion and dominantly inhalation of radon at hydrothermal spring attractions varied from 0.01 to 19.30 mSv/year. These results highlight the usefulness of this method as an essential tool for delineating radon concentrations, which could be used to introduce guidelines for health risk assessment.

Per- and polyfluoroalkyl substances (PFAS) have been detected in lake ecosystems globally, even in remote areas at high altitudes. Compared to plain lakes with short water change cycles and significant human influence, plateau lakes are primarily tectonic closed or semi-closed lakes with steep terrain. Their long water change cycles lead to an obvious cumulative effect on pollutants. In this study, a targeted screening method for 74 PFAS in aquatic environment was established. The contamination characteristics of PFAS in surface water samples (0.5 m below the water surface) and bottom samples (0.5 m above the lake bottom) of plateau Lake Yangzonghai were studied and compared to a reference site in Dianchi Lake which has been severely affected by anthropogenic sources. Results showed that 32 PFAS were detected in Lake Yangzonghai with the total concentration (∑₃₂PFAS) ranging from 14.95 to 26.42 ng L^-1. Among the 27 PFAS with available standards for accurate quantification, 22 PFAS were detected, with the concentration of ∑₂₂PFAS ranging from 13.27 to 20.17 ng L^-1. Significant differences (p < 0.05) in PFAS concentrations were observed between surface water (22.12 ng L^-1) and bottom water (18.18 ng L^-1), demonstrating a stratification phenomenon. The spatial differences in PFAS concentrations in surface water were minimal, indicating that the surface water was uniformly mixed with limited local disturbance from human pollution. The main PFAS monomers were perfluorooctanoic acid (PFOA), 8-3 fluorotelomer carboxylic acid (8-3 FTCA), perfluoroheptanoic acid (PFHpA) and 2H-perfluoro-2-decenoic acid (8-2 FTUCA), while PFBA was not detected. This distribution remarkably differed from many other plain lakes and the reference lake. Source apportionment analysis showed that PFAS primarily originated from atmospheric transport and precursor degradation. The results provide a background pollution level of PFAS in the plateau lake near the city and will benefit for formulating control policies.

Imidacloprid, a key neonicotinoid insecticide for pest control, is widely used in various crops, including peanuts. This study aimed to fill research gaps by analysing the residue behaviour of imidacloprid in peanut fields treated with flowable concentrate for seed treatment (FS) formulations while assessing potential risks to human health and ecosystems. A validated analytical method, using QuEChERS separation and UPLC-MS/MS detection, reliably quantified imidacloprid residues in peanuts and soil. Imidacloprid degradation followed a first-order kinetic model, with half-lives ranging from 21.0 to 46.2 days in plants and 10.3-30.1 days in soil. Residues in peanut kernels were below 0.05 mg/kg, and the maximum soil residue was 0.370 mg/kg. Dietary risk assessment indicated no health risks to adult consumers. However, ecological risk assessment predicted low to moderate earthworm toxicity and a medium risk from ecotoxicity exposure. These findings highlight the importance of adhering to recommended imidacloprid FS seed treatment dosages to minimise adverse effects on non-target soil organisms.

The study delved into an extensive assessment of outdoor air pollutant levels, focusing specifically on PM_2.5, SO₂, NO₂, and CO, across the Mashhad metropolis from 2017 to 2021. In tandem, it explored their intricate correlations with meteorological conditions and the consequent health risks posed. Employing EPA health risk assessment methods, the research delved into the implications of pollutant exposure on human health. Results unveiled average annual concentrations of PM_2.5, SO₂, NO₂, and CO, standing at 27.22 µg/m³, 72.48 µg/m³, 26.8 µg/m³, and 2.06 mg/m³, respectively. Intriguingly, PM_2.5 displayed positive correlations with temperature and wind speed, while exhibiting negative associations with relative humidity and precipitation. Conversely, both SO₂ and NO₂ concentrations showcased negative correlations with temperature, relative humidity, wind speed, and precipitation. Furthermore, CO demonstrated negative relationships with both wind speed and precipitation. The analysis of mean hazard quotients (HQ) for PM_2.5 and NO₂ indicated values exceeding 1 under 8- and 12-h exposure scenarios, pointing towards concerning health risks. Spatial distribution revealed elevated CO levels in the northwest, north, and east areas, while NO₂ concentrations were predominant in the north and south regions. Through Sobol sensitivity analysis, PM_2.5, EF, and NO₂ emerged as pivotal influencers, offering valuable insights for refining environmental models and formulating effective pollution mitigation strategies. Air pollution index (AQI) forecasting was modeled using advanced machine learning comprising Random Forest (RF), Decision Tree (DT), K-Nearest Neighbors (KKN), and Naive Bayesian (NB). Results showed that the RF model with the highest accuracy (R² = 0.99) was the best prediction model.

This study investigates the quantities of Rare Earth Elements (REEs) and Potentially Toxic Elements (PTEs) in Dong Nai Province's surface soils. Atomic Absorption Spectrometry (AAS) and Instrumental Neutron Activation Analysis (INAA) were used to determine element concentrations. To validate the concentration results, established reference materials (NIST 2711 and IAEA Soil-7) were used. Element concentrations followed a certain order, with Mn, Cr, V, and Zn dominating, except for Al, which were used to determine the enrichment factor. Arsenic (As) concentrations ranged from 0.8 to 37.5 mg/kg, exceeding global averages but below Vietnam quality standards. Cadmium (Cd) concentrations ranged from 0.03 to 0.16 mg/kg, below global averages and quality standards. Cobalt (Co) and chromium (Cr) concentrations ranged from 0.5 to 135.1 mg/kg and 18 to 844 mg/kg, respectively, with notable percentages of samples exceeding global averages. Copper (Cu) and lead (Pb) exhibited elevated concentrations, with varying proportions exceeding quality standards. Manganese (Mn) and antimony (Sb) exceeded global averages in a significant percentage of samples. Vanadium (V) concentrations surpassed the crustal average by over half of the sites. Zinc (Zn) concentrations were below reference values. REEs showed significantly higher concentrations than global soil averages, with a substantial proportion of samples exceeding reference values. Geo Accumulation Index (Igeo), Enrichment Factor (EF), and Pollution Load Index (PLI) analyses provided a detailed numerical assessment of contamination and soil quality. Statistical analysis showed correlations and clusters of toxic elements and highlighted the spatial distribution of samples based on elemental compositions.

This study investigated the occurrence, concentration and human health risks of five pharmaceutical residues-metronidazole, sulfamethoxazole, ciprofloxacin, carbamazepine, and caffeine-in groundwater and surface water samples from Kampala and Mbarara districts of Uganda. The present study also employed techniques of remote sensing and geographic information system (GIS); thereby, emphasizing the importance of thematic mapping, land use classification, and spatial buffering to evaluate pharmaceutical contaminants in an environmental setting. The risk quotient (RQ) approach was also employed to assess the risk of exposure to the pharmaceutical contaminants. Caffeine was found with the highest average concentration in groundwater (53.515 µg/L), whereas carbamazepine had the highest average concentration in surface water (48.635 µg/L) during the dry season. Ciprofloxacin consistently recorded the lowest average concentrations in both groundwater and surface water across all seasons. Overall, the data revealed high concentrations of pharmaceutical residues in surface water compared to groundwater during both seasons, except for caffeine which was not detected in surface water across the seasons. Notable seasonal changes were also observed in caffeine and metronidazole concentrations, indicating the role of human activities and environmental factors in influencing contamination patterns during specific seasons. The factor analysis revealed that consumption rate of pharmaceuticals and anthropogenic activities are the main factors responsible for the contamination of groundwater and surface water. Moreover, results revealed that the risk of adverse human health effects for carbamazepine and metronidazole during both seasons were high (RQ > 1), thereby highlighting the prioritization of frequent monitoring by the environmental protection agencies. Given that the combined risk of exposure for all the pharmaceuticals exceeded one, adopting stringent pharmaceutical disposal and control measures are essential for mitigating potential human health risks associated with their exposure. Further investigation into optimal and effective pharmaceutical remediation strategies for both groundwater and surface water are highly recommended.