Environmental Geochemistry and Health最新文献

This study analyzed skin wipe samples from the forehead, palm, forearm, and lower leg of 120 volunteers across different age groups-preschoolers, thresholders, middle-aged, and elderly-with each group comprising 30 individuals with a balanced sex ratio from a city in South China. The research aimed to assess the occurrence, concentration, and associated health risks of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) adsorbed onto human skin from environmental sources. We identified 13 PBDE congeners and 10 PCB congeners across all samples, with average detection frequencies of 48% for PBDEs and 16% for PCBs, with concentrations ranging from non-detectable (ND) to 4200 and ND to 2300 ng/m², respectively. Skin concentrations of both PBDEs and PCBs decreased in the order of face > hand > arm > shank (ANOVA, P < 0.001), suggesting higher exposure to uncovered skin areas than to those covered by clothing, regardless of age or sex. The daily average dose of dermal (DAD_derm) and oral (DAD_oral) for PBDEs spanned from 7.0 × 10^-4-0.19 ng/kg/d and ND-15 ng/kg/d, respectively, whereas the PCB exposure doses ranged from ND-7.8 ng/kg/d (DAD_derm) and ND-2.0 ng/kg/d (DAD_oral), respectively. Preschool children displayed notably higher DAD_oral levels than the other groups (P < 0.0001), which was attributed to their more frequent hand-to-mouth activity. Preschool boys exhibiting a higher DAD_derm (P < 0.05) and both preschool boys and university women showing elevated DAD_oral levels (P < 0.01 and P < 0.05, respectively). Health risk assessments concluded that the carcinogenic risks from BDE209 and PCBs were within acceptable limits (10^-4) for all sampled populations.

In recent years, industrial waste and agrochemicals have reduced soil fertility and productivity, significantly impacting food security and ecosystems. In China, areas near red mud deposits from the aluminum industry show severe heavy metal contamination. This study examines agricultural soil near a red mud site in Shanxi Province, analyzing Cd, Cr, Hg, Ni, Pb, As, Cu, and Zn levels and distribution. Geostatistical methods and GIS are utilized to assess heavy metal pollution using the single factor index, the Nemerow integrated index, and the Hakanson potential ecological risk index. Absolute Principal Component Scores-Multiple Linear Regression (APCS-MLR) and Positive Matrix Factorization (PMF) models are used for quantitative analysis of pollution sources. Research indicates that the average concentrations of eight heavy metals exceed the natural background values of Shanxi, placing them at a severe pollution level with moderate ecological risk. Specifically, indices for As, Pb, and Cr are 3.79, 3.38, and 3.26, indicating severe pollution; Cd, Cu, and Hg at 2.36, 2.62, and 3.00 suggest moderate pollution; Ni at 1.87 shows mild pollution, while Zn at 0.97 is not polluted. Hg presents the highest ecological risk with a coefficient of 120.00, followed by Cd (70.69) and As (37.92). Spatial analysis shows significant correlations among Pb, Zn, Cu, and Ni, while Cr, Cd, Hg, and As show greater variability and weaker correlations. Both models identify five main sources: industrial activities, agricultural fertilizers, red mud leachate, energy combustion, and natural geological backgrounds, with respective contribution rates in the APCS-MLR model at 27.7%, 24.6%, 18.1%, 15.2%, and 14.4%, and in the PMF model at 29.2%, 21.5%, 16.9%, 16.7%, and 15.7%. This study offers a scientific basis for controlling soil pollution in the region, filling a literature gap.

Excessive levels of Nickel in the soil can compromise the security of agricultural products, posing a threat to health of human beings; therefore, the repair and treatment of Nickel exceeding the standard levels in soil are particularly critical. Although it is crucial that the potential restoration of Nickel in ensuring the security of both soil and farm produce within karst regions., few studies have been conducted on the potential restoration of large-scale Nickel-contaminated soils. In this study, the soil in Wuming, Guangxi, a typical karst area, was comprehensively studied. 12,547 surface soil samples, 134 deep soil samples and 60 soil profiles were collected systematically. The results showed that the Nickel background value of the surface soil was 34.9 mg/kg, indicating strong background characteristics and high variability. Principal component analysis showed that soil Nickel was primarily derived from natural sources in the geological background and partly derived from agricultural sources. Analysis of variance showed that the Nickel content of the soil was affected by the parent rock, soil type, soil use type, and topography. In addition, the distribution of Nickel in the soil profile increased exponentially with depth. Therefore, the exponential model and multiple integrals were used to derive the formula for the Nickel potential restoration amount at different depth ranges, and the potential restoration amount of soil Nickel was calculated based on different parent material, soil, and land use types. The formula is reasonable and representative and can provide a theoretical basis for the remediation and treatment of Nickel-polluted soil in karst areas.

Polybrominated diphenyl ethers (PBDEs), a category of persistent organic pollutants (POPs), are ubiquitous in the environment and have been reported to have endocrine-disrupting and tumor-promoting activities. However, the evidence for the correlation between plasma PBDEs levels, thyroid homeostasis and thyroid carcinoma in humans remains limited. Herein, we analyzed eight PBDE congeners in 53 patients undergoing thyroid surgery. BDE-209 was identified as the most abundant PBDE congener in plasma (median, 11.36 ng/g lipid). BDE-100 concentration was positively associated with free triiodothyronine (FT3), indicating a potential interference with thyroid function. Point-biserial correlation analysis revealed positive associations between certain plasma PBDE congeners (BDE-28, BDE-47, BDE-99, BDE-100, and BDE-154) and aggressive pathological parameters. There was no significant correlation between PBDEs and BRAF or RAS mutations in PTC patients, indicating that PBDEs may not directly promote the initiation and progression of thyroid cancer through these genetic mutations. It implies the complexity of the relationship between PBDEs exposure and thyroid cancer development. Although not statistically significant, Bayesian kernel-machine regression (BKMR) analysis of single-exposure effects model found that BDE-47 and BDE-99 were positively associated with the risk of malignant neoplasms. The present study not only contributes to the growing evidence regarding the impact of PBDEs on thyroid function but also provides new insights into the association between exposure to certain PBDE congeners and the aggressive pathological parameters of thyroid cancer. Large-scale prospective studies are still needed to support our findings.

Uncontrolled use or improper disposal of bulk forms and nanoparticles of heavy metals may lead to their release into the environment. Coastal and floodplain ecosystems are particularly vulnerable, and the effects of metal nanoparticles on Fluvisol and Stagnic Fluvisol are poorly studied. This study aims to examine the effect of heavy metals on the enzymatic activity of the soil, the abundance of culturable microorganisms, growth, and antioxidant status of H. vulgare L. A model experiment was carried out with contamination of Stagnic Fluvisol Humic and Fluvisol with 2200 and 1320 mg kg^-1 Zn and Cu, to assess the ecotoxicity of bulk forms and nanoparticles of ZnO and CuO in floodplain soils. The abundance of culturable microorganisms, namely copiotrophs, prototrophs, oligotrophs and nitrogen fixers increased. However, a sharp decrease in dehydrogenase activity and denitrification occurred. This effect was more pronounced in Fluvisol (7 times) than in Stagnic Fluvisol Humic (3 times). The accumulation of HMs was also higher in plants grown in Fluvisol (16-32 times) than in Stagnic Fluvisol Humic (13-24 times), which led to a decrease in plant growth and activation of antioxidant defense systems. An increase in the level of malondialdehyde, and the activity of superoxide dismutase and catalase indicates the induction of oxidative stress. Heavy metals have a greater impact on the biological properties of Fluvisol compared to Stagnic Fluvisol Humic. The presence of heavy metals boosts the abundance of culturable microorganisms, while nanoparticles hinder plant growth more than bulk heavy metals.

The prevalence of microplastics (MPs) in agricultural ecosystems poses a notable threat to dynamics of soil ecosystems, crop productivity, and global food security. MPs enter agricultural ecosystems from various sources and have considerable impacts on the physiochemical properties soil, soil organisms and microbial communities, and plants. However, the intensity of these impacts can vary with the size, shape, types, and the concentrations of MPs in the soil. Besides, MPs can enter food chain through consummation of crops grown on MPs polluted soils. In this study, we conducted a bibliometric analysis of 1636 publications on the effects of MPs on agricultural ecosystems from 2012 to May 2024. The results revealed a substantial increase in publications over the years, and China, the USA, Germany, and India have emerged as leading countries in this field of research. Social network analysis identified emerging trends and research hotspots. The latest burst keywords were contaminants, biochar, polyethylene microplastics, biodegradable microplastics, antibiotic resistance genes, and quantification. Furthermore, we have summarized the effects of MPs on various components of agricultural ecosystems. By integrating findings from diverse disciplinary perspectives, this study provides a valuable insight into the current knowledge landscape, identifies research gaps, and proposes future research directions to effectively tackle the intricate challenges associated with MPs pollution in agricultural environments.

Soil plays a critical role in nutrient availability, microbial activity, and fertility in agriculture. However, the effects of agroclimatic conditions on soil pH are not well understood, particularly in the Horro Guduru Zone of Ethiopia. This study aimed to investigate the soil pH under extremely wet and dry conditions across 3 shared socioeconomic pathway (SSP) scenarios: SSP1-2.6, SSP2-4.5, and SSP5-8.5. Baseline agroclimatic data (1981-2010) and future projections (2041-2070) were obtained from the European Commission Climate Change Services. Soil pH data at a 250 m resolution were extracted from the FAO-UNESCO global soil map. Missing values, multicollinearity, and outliers were addressed before modeling. Predictive models, including neural networks, generalized regression, and bootstrap forests, were validated, with the generalized regression model showing the best performance. The results indicate that soil pH decreases under consecutive dry‒wet conditions and increases with increasing maximum day temperatures across all scenarios. Soil pH is significantly influenced by the number of consecutive dry days, consecutive wet days, and maximum day temperature. The SSP1-2.6 and SSP2-4.5 scenarios resulted in improved pH levels, whereas SSP5-8.5 led to a decrease in soil pH, averaging 5.79 and decreasing to 5.54. These findings suggest that under SSP5-8.5, soil health and farming productivity may be compromised. This study emphasizes the need to adjust soil management practices based on prevailing climatic conditions to ensure soil health and agricultural sustainability.

The use of organochlorine pesticides (OCPs) in specific regions is still prevalent. Moreover, the impact of past utilization can be observed in the present environmental matrices. The present study monitored the extent of contamination of OCPs in the soil and vegetable samples of Gaya, Bihar, India. For this, 63 soil and vegetable samples were collected from the vegetable cultivated area of Gaya. The collected samples were extracted using a Soxhlet extraction unit and OCPs were analysed with a gas chromatography-mass spectrometry detector. The concentration data generated from the analysis were interpreted using statistical tools and software. Mean concentration (μg/g) of Σ₁₉OCPs in soil from residential, agricultural, commercial, and polyhouse sites were 0.69, 2.21, 0.17, and 0.72, respectively. Similarly, in vegetable samples, mean concentration (μg/g) of Σ₁₉OCPs were 0.91, 0.96, 1.00, and 0.67, respectively. Among the monitored vegetable types, the concentration of OCPs increased in the order: pods > tubers > leaves > fruits > roots > stem. The bioconcentration factor of 19 OCPs showed that 61.90% of vegetable samples were hyperaccumulators. The results of molecular diagnostic ratio and positive matrix factorization reported the recent inputs of heptachlor, aldrin, endrin and methoxychlor; the past application of dichlorodimethyltrichloroethane (DDT), endosulfan, and chlordane; and the degradation of DDT to its metabolites and aldrin to dieldrin, which make up an overall source profile of OCPs in study area. The study found that incremental lifetime cancer risks and hazard quotients ranged from 6.98 × 10^-8 to 1.31 × 10^-5 and 4.25 × 10^-2 to 4.63 × 10^-1, respectively in vegetable samples which indicate low to high ILCR and low non-carcinogenic risk to populations exposed to OCPs. The study indicates the long lasting impact of past pesticide use by studying the contamination in soil and vegetables, and raises serious concerns about food safety. The contamination poses direct health risk to consumers related to potential carcinogenic and endocrine disrupting effects. Thus monitoring on the ground level could be a force to modify region specific policies, health, and remediation measures related to exposure to OCPs.

Identifying nitrate sources and migratory pathways is crucial for controlling groundwater nitrate pollution in agricultural watersheds. This study collected 35 shallow groundwater samples in the Nansi Lake Basin (NLB) to identify groundwater nitrate sources and potential health risks. Results showed that NO₃^- concentration in 62.9% of groundwater samples exceeded the drinking water standard (50 mg/L). Hierarchical cluster analysis (HCA) was used to classify the sampling points into three groups based on hydrochemical and isotopic data. Groups A and C were situated in the eastern recharge and discharge regions of Nansi Lake, while Group B was located in the Yellow River floodplain west of the lake. Hydrochemical data and nitrate stable isotopes (δ¹⁵N-NO₃^- and δ¹⁸O-NO₃^-) indicated that elevated NO₃^- primarily originated from soil organic nitrogen (SON) in Group A, while manure and sewage (M&S) were the primary sources in Groups B and C samples. Microbial nitrification was identified as the primary nitrogen transformation process across all groups. The source apportionment results indicated that SON contributed approximately 40.1% in Group A, while M&S contributed about 53.9% and 81.2% in Groups B and C, respectively. The Human Health Risk Assessment (HHRA) model indicated significant non-carcinogenic risks for residents east of Nansi Lake, primarily through the oral pathway, with NO₃^- concentration identified as the most influential factor by sensitivity analysis. These findings provide new perspectives on identifying and handling groundwater nitrogen pollution in agriculture-dominated NLB and similar basins that require enhanced nitrogen contamination management.

Although phytoremediation is more economical when compared with traditional physical and chemical soil remediation methods, it remains very expensive when considering the substantial area of the contaminated field. If the quantity of harvested residues can be reduced after each phytoremediation cycle, the practicability and commercial implementation of this environment friendly method can be improved. In this study, cadmium excretion on the leaf surface of Festuca arundinacea was evaluated under various blue and red light conditions. The results indicated that the percentage of decaying and deceased leaves increased by 8.5%, 31.1%, 59.7%, and 35.9% at a blue light ratio of 10%, 50%, 75%, and 100%, respectively, when compared with the control. The highest cadmium concentration was found in decaying and deceased leaves under 75% blue light treatment. Light treatments also altered the excreted cadmium amount on different leaf types. Under all treatments including the control, significantly more cadmium can be washed off from emerging and mature leaves than from decaying and deceased leaves, owing to the detoxification mechanism of the plant (p < 0.05). The differences in cadmium excretion on senescent and dead leaves under all treatments were not statistically significant, but the mass of cadmium excretion on young leaves under 75% and 100% blue light irradiation were significantly higher than that under other treatments (p < 0.05). Herein, a novel phytoremediation method involving the harvesting decaying and deceased leaves and washing emerging and mature leaves was proposed to decrease the costs of plant residue disposal.