Environmental Geochemistry and Health最新文献

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.

Biochar has been widely used to solve the wastewater pollution of polycyclic aromatic hydrocarbons (PAHs). However, the competition of PAHs with different benzene ring numbers (e.g., phenanthrene [Phe], pyrene [Pyr], and benzo[a]pyrene [BaP]) for adsorption sites on biochar has received little attention. In this study, biochar was produced by co-pyrolysis of sludge and phosphorus tailing at different temperatures (300, 500, or 800 °C) to adsorb PAHs. The results show that phosphorus tailing increased the adsorption of PAH by increasing the biochar's BET surface area (S_BET), micropore volume, hydrophobicity (at low temperatures) and aromaticity (at high temperatures). The maximum adsorption capacities were 29.90 µmol/g for Phe, 25.58 µmol/g for Pyr and 20.45 µmol/g for BaP, respectively. Importantly, the types and functions of groups involved in the adsorption of various PAHs were discussed. Adsorption of Phe and Pyr on the biochar mainly involved C=O and C-O-C functional groups, and there was a certain degree of competition between these PAHs for those sites. In contrast, BaP mainly adsorbed at C-OH and C=C moieties, without competing with Phe or Pyr at C-OH sites. The competitive edge of BaP was also stronger than that of Phe and Pyr on C=C functional groups. The adsorption mechanisms involving pore filling, hydrophobic interactions, and π-π interactions governed the adsorption of the evaluated PAHs. Overall, the adsorption of PAHs on biochar followed a heterogeneous chemical adsorption process.

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.

Freshwater and groundwater are important resources for the drinking water supporting agricultural and livestock activities in the Córdoba province, Argentina. The aim of this study was to assess the physicochemical and microbiological quality of surface water (n = 14) and groundwater (n = 17) sites in the middle-lower basin of the Ctalamochita River (Córdoba, Argentina) for human and animal consumption. A total of 18 physicochemical and five microbiological parameters were evaluated to determine the hydrogeological characteristics of both water resources and their suitability for human and animal consumption using the Water Quality Index (WQI). The results indicated that Na⁺ and HCO₃^- were the dominant cation and anion, respectively, in both water resources. Physicochemical and microbiological parameters values were compared with national and international guidelines. The WQI showed that groundwater samples exhibited poorer quality when compared to surface waters for human consumption, primarily due to elevated concentrations of major ions and the presence of total coliforms and Pseudomonas aeruginosa. Meanwhile, the WQI for animal consumption indicated that both surface and groundwater samples were suitable for this purpose. The Piper diagram showed that most of the surface water samples were classified as Na⁺-Cl^--HCO₃^-, while groundwater samples were classified as Na⁺-HCO₃^-. This classification highlights the hydrogeochemical differences between the two water resources. The Gibbs diagram indicates that the chemical composition of both surface and groundwater sources is primarily controlled by processes of rock-water interaction and evaporation. The findings of this study will facilitate the development of a proactive plan to safeguard and sustain water resources in the middle-lower basin of the Ctalamochita River. This can be achieved through the implementation of preventive strategies and the introduction of innovative policies.

Staple food is a crucial exposure route for the human intake of potentially toxic elements (PTEs), but it has been neglected in previous human health risk (HHR) studies. Lack of attention to this issue will lead to an underestimation of HHR caused by PTEs. This study establishes a comprehensive regional identification method for health risk assessment (HRA), namely, soil-maize health risk assessment (SMHRA) and applies it to Ziyang, Shaanxi, which is a typical agricultural county. SMHRA considered the exposure pathway of staple food and utilized Monte Carlo simulation to enhance the accuracy of HRA for PTEs. Results indicated the PTE spatial heterogeneity in a soil-maize system. Introducing staple food exposure pathway would increase HHR values and probabilities 1.57-2.80 and 1.53-5.63 times than that when food route was not considered. Overall, the HHR caused by a single PTE was low, which relatively safe. The introduction of food pathway contributed to accurate estimate the HHR of As and Ni, and the risk probabilities ranged from 0.04% to 12.46%. Few areas had high levels of Ni, which pose health risks: approximately 1.8% for children and higher than 0.5% for adults. Both As and Ni had the highest contribution to HHR among all PTEs, with 33.84%-41.56% TNCR caused by As, and 54.73%-56.90% TCR created by Ni, respectively. For human health risk routes, the staple food exhibited the highest contribution to HHR among all exposure routes, with TNCR of 36.15%-56.73% and the TCR of 44.96%-64.28%. Our research imply that dietary intake of PETs must be considered in the human health risk assessment in agricultural environment, which offers the foundation for subsequent environmental risk prevention and control.

A tremendous amount of recent work has been done on different metal oxide nanomaterials for biological activities and photocatalytic dye degradation. This work used the Cissus quadrangularis leaf extract to prepare TiO₂, CdO, Mn₂O₃, and ZnO nanoparticles using a green synthesis approach. To ascertain the physicochemical characteristics of the generated metal oxide nanoparticles, various characterisation techniques were used. The X-ray diffraction technique was used to determine the composition of the crystal and phase. Metal oxide nanoparticles have been proven to be present through surface morphological investigations using a scanning electron microscope and energy dispersive spectroscopy analysis. UV-Vis and Fourier transform infrared spectra were used for spectroscopic analysis. X-ray photoelectron spectroscopy can determine a material's elemental composition in addition to the electronic and chemical states of its atoms. The nanomaterial's distinct morphology, which resembles rods, rose petals, platelets, and spheres, was discovered by scanning electron microscope. Synthesized metal oxide nanoparticles have demonstrated a remarkable efficiency of 87.5-90.6% when utilized as a catalyst towards the removal of the malachite green dye under UV light irradiation. Additionally, we use the disc diffusion method to assess antibiotic efficacy against Bacillus subtilis, Candida tropicalis, and Escherichia coli. ZnO nanoparticles had the greatest zones of inhibition for 80 μL doses, measuring 26.99 mm for Bacillus subtilis, 27.57 mm for Escherichia coli, and 25.28 mm for Candida tropicalis. The antimicrobial activity was strongly impacted by the size of the nanoparticles and increased with decreasing particle size. Overall, our research demonstrates that metal oxide nanoparticles are a promising photocatalytic agent for wastewater treatment and biological applications.

Aquaculture operations produce large amounts of wastewater contaminated with organic matter, nitrogenous compounds, and other emerging contaminants; when discharged into natural water bodies, it could result in ecological problems and severely threaten aquatic habitats and human health. However, using aquaculture wastewater in biorefinery systems is becoming increasingly crucial as advancements in valuable bioproduct production continue to improve economic feasibility. Research on utilising microalgae as an alternative to producing biomass and removing nutrients from aquaculture wastewater has been extensively studied over the past decades. Microalgae have the potential to use carbon dioxide (CO₂) effectively and significantly reduce carbon footprint, and the harvested biomass can also be used as aquafeed. Furthermore, aquaculture wastewater enriched with phosphorus (P) is a potential resource for P recovery for the production of biofertiliser. This will reduce the P supply shortage and eliminate the environmental consequences of eutrophication. In this context, the present review aims to provide a comprehensive overview of the current state of the art in a generation, as well as the characteristics and environmental impact of aquaculture wastewater reported by the most recent research. Furthermore, the review synthesized recent developments in algal biomass cultivation using aquaculture wastewater and its utilisation as biorefinery feedstocks for producing value-added products, such as aquafeeds, bioethanol, biodiesel, biomethane, and bioenergy. This integrated process provides a sustainable method for recovering biomass and water, fully supporting the framework of a circular economy in aquaculture wastewater treatment via resource recovery.

The rise in antibiotic-resistant genes (ARGs) has recently become a pressing issue, with livestock manure identified as a significant source of these genes. Yet, the distribution of fertilizers derived from livestock manure sold online, potentially containing high levels of ARGs and antibiotic-resistant bacteria (ARB), is often not considered. Our study involved a random survey of commercial organic fertilizers available on online marketplaces, focusing on 13 common ARGs and 2 integrons (intI1, intI2). We found significant ARGs linked to sulfonamides, macrolides, and tetracycline in the 20 fertilizer samples we tested. The gene copy numbers for ermC, sul2, and tetL were exceptionally high, reaching up to 10¹¹ copies per gram of fertilizer in specific samples. Additionally, 18 out of 20 samples contained the critical β-lactam resistance genes blaTEM and blaKPC, with gene copy numbers up to 10¹⁰ copies/g. Integrons, intI1, and intI2 were present in all samples, with abundances ranging from 10³ to 10¹⁰ copies/g. We categorized the 20 samples into three types for further analysis: poultry manure, livestock manure, and earthworm manure. Our findings indicated a high presence of ARGs in poultry manure compared to a lower occurrence in earthworm manure. The study also showed a strong correlation between integrons and specific ARGs. This research underscores the potential risk of commercial organic fertilizers as a pathway for spreading ARGs from the animal breeding environment to human settings through express transportation.

Identifying the source-specific health risks of potentially toxic elements (PTE) in urban park soils is essential for human health protection. However, previous studies have mostly focused on the deterministic source-specific health risks, ignoring the health risk assessment from a probabilistic perspective. To fill this gap, we developed a hybrid model that incorporated machine learning (ML) interpretability into positive matrix factorization (PMF) and probability health risk assessment (PHRA) based on the Monte Carlo simulation. The results indicated that concentrations of soil PTEs except for Mn and Sb were significantly higher than their corresponding background values. Random forest (RF) was regarded as the best ML model to identify key drivers for As, Cd, Cr, Cu, Ni, Pb, and Zn, with R² > 0.60, but was less effective for other soil PTEs (R² < 0.49). Specifically, the contributions of the four potential pollution sources were mixed sources, traffic emission, fuel combustion, and building materials, with contribution rate of 24.88%, 30.56%, 28.99%, and 15.56%, respectively. Fuel combustion contributed the most to non-carcinogenic for children (39.45%), male (43.84%), and female (43.76%), and the non-carcinogenic risk could be considered negligible for human. However, building materials was the major contributor to carcinogenic risk for children (36.1%), male (44.9%), and female (43.2%). The integration of the RF model with PMF and PHRA improved the accuracy of the results by identifying and quantifying the specific sources of each soil PTE using the relative importance analysis from the RF model. The results of this study assisted in providing efficient strategies for risk management and control of soil PTEs in Beijing parks.