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3.
Environ Sci Pollut Res Int ; 30(51): 110204-110219, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37779121

RESUMO

Groundwater is important for human survival and development, particularly in arid and semi-arid regions. This study aimed to analyze the hydrochemical characteristics, influencing factors, and the impact of human activities on groundwater in the semi-arid plains of western Jilin Province, northwest China. The study collected 88 and 151 phreatic and confined water samples, respectively, which were analyzed for 13 water quality indicators using statistical and graphical methods. In order to investigate the impact of anthropogenic activities on water quality and health risks, the improved combined weighted water quality index (ICWQI) based on the entropy weight, criteria importance though inter-criteria correlation (CRITIC), the coefficient of difference method, subjective weight based on quality grading criteria, and the water quality index (WQI) were proposed to evaluate the water quality of the study area. Meanwhile, the human health risk assessment (HHRA) model was used to assess the risks of nitrate to the health of humans in different ages and sex categories. The results indicated that the groundwater in the study area was weakly alkaline and the main hydrochemical types in the phreatic and confined water were HCO3-·Ca-Mg and HCO3--Na. Rock weathering was the dominant process responsible for the generation of groundwater ions, the ions in groundwater primarily originate from the dissolution of halite, gypsum, and feldspar, while dolomitization promotes an increase in Mg2+. Human activities lead to an increase in NO3- in groundwater and have an impact on water quality and human health risks. The ICWQI method was found to yield more precise and rational assessments of water quality. Groundwater quality is primarily affected by nitrate ions. The areas in which groundwater nitrate posed a higher risk to human health were found to be mainly in the saline-alkali lands of Qian'an, Tongyu, and Zhenlai. Fertilizers, pesticides, and livestock farming activities contribute to the pollution of surface water. This surface contamination then infiltrates abandoned confined wells, leading to contamination of the confined aquifers. This study can improve the understanding of groundwater hydrochemical characteristics and the impact of human activities on groundwater in the study area. This study can also contribute to the study of groundwater in semi-arid regions.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , Humanos , Monitoramento Ambiental/métodos , Nitratos/análise , Poluentes Químicos da Água/análise , Qualidade da Água , China , Atividades Humanas
4.
Front Immunol ; 14: 1196793, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37404816

RESUMO

Introduction: Immune checkpoint inhibitor (ICI) combination therapy has changed the treatment landscape for metastatic renal cell carcinoma (mRCC). However, little evidence exists on the treatment-related severe adverse events (SAEs) and fatal adverse events (FAEs) of ICI combination therapy in mRCC. Method: We searched PubMed, Embase, and Cochrane Library databases to evaluate randomized controlled trials (RCTs) of ICI combination therapy versus conventional tyrosine kinase inhibitor (TKI)-targeted therapy in mRCC. Data on SAEs and FAEs were analyzed using revman5.4 software. Results: Eight RCTs (n=5380) were identified. The analysis showed no differences in SAEs (60.5% vs. 64.5%) and FAEs (1.2% vs. 0.8%) between the ICI and TKI groups (odds ratio [OR], 0.83; 95%CI 0.58-1.19, p=0.300 and OR, 1.54; 95%CI 0.89-2.69, p=0.120, respectively). ICI-combination therapy was associated with less risk of hematotoxicities, including anemia (OR, 0.24, 95%CI 0.15-0.38, p<0.001), neutropenia (OR, 0.07, 95%CI 0.03-0.14, p<0.001), and thrombocytopenia (OR, 0.05, 95%CI 0.02-0.12, p<0.001), but with increased risks of hepatotoxicities (ALT increase [OR, 3.39, 95%CI 2.39-4.81, p<0.001] and AST increase [OR, 2.71, 95%CI 1.81-4.07, p<0.001]), gastrointestinal toxicities (amylase level increase [OR, 2.32, 95%CI 1.33-4.05, p=0.003] and decreased appetite [OR, 1.77, 95%CI 1.08-2.92, p=0.020]), endocrine toxicity (adrenal insufficiency [OR, 11.27, 95%CI 1.55-81.87, p=0.020]) and nephrotoxicity of proteinuria (OR, 2.21, 95%CI 1.06-4.61, p=0.030). Conclusions: Compared with TKI, ICI combination therapy has less hematotoxicity in mRCC but more specific hepatotoxicity, gastrointestinal toxicity, endocrine toxicity, and nephrotoxicity, with a similar severe toxicity profile. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42023412669.


Assuntos
Antineoplásicos , Carcinoma de Células Renais , Neoplasias Renais , Humanos , Carcinoma de Células Renais/tratamento farmacológico , Antineoplásicos/efeitos adversos , Inibidores de Checkpoint Imunológico/efeitos adversos , Neoplasias Renais/tratamento farmacológico , Neoplasias Renais/patologia
6.
Environ Geochem Health ; 45(8): 6069-6094, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37246206

RESUMO

Jilin Qian'an, located in Northeastern China's Songnen Plain, relies almost exclusively on groundwater for drinking. The quaternary phreatic aquifer (Q3) is distinguished by high geogenic fluoride and arsenic concentrations, which necessitates reliance on quaternary confined (Q1) and neogene confined (N) aquifers (deeper aquifers) as source point management (SPM) alternatives. However, deeper aquifers are contaminated, necessitating temporal monitoring and unique management strategies. Using 165 samples, this study investigated the appropriateness of deeper restricted aquifers as a continuous SPM alternative by assessing the spatiotemporal groundwater quality and human health risk of the multi-aquifers in Jilin Qian'an from the 1980s to the 2010s. In addition, a source point management zonation (SPMZ) was implemented to define the specific intervention necessary in various portions of the study area. Results indicate water quality parameters were within recommended limits for most samples except fluoride, while arsenic was the most significant heavy metal pollutant. Mean groundwater mineralization in all the aquifers increased with time. Deeper aquifers are still a better alternative to the shallow phreatic aquifer as groundwater quality in the study is of the order N > Q1 > Q3 in the respective aquifers. Cancer risk assessment (CR) shows increases from 2001 to the 2010s in all aquifers except in Q3. SPMZ delineated: High As and high F zones; high As and low F zones; high As zones; high F zones; low F zones; and safe zones. Localized intervention based on SPMZ is recommended, along with the use of alternative water sources.


Assuntos
Arsênio , Água Subterrânea , Poluentes Químicos da Água , Humanos , Fluoretos/análise , Arsênio/análise , Poluentes Químicos da Água/análise , Monitoramento Ambiental , China
7.
Artigo em Inglês | MEDLINE | ID: mdl-35954956

RESUMO

As a numerical indicator, the pollution index of groundwater (PIG) has gained a great deal of popularity in quantifying groundwater quality for drinking purposes. However, its weight-determination procedure is rather subjective due to the absolute dependence on experts' experience. To make the evaluation results more accurate and convincing, two improved PIG models (CRITIC-PIG and Entropy-PIG) that integrate subjective weights and objective weights were designed, and they were employed to appraise groundwater suitability for drinking purposes in the northern part of Changchun City. A total of 48 water samples (34 unconfined water samples and 14 confined water samples) with abundances of Ca2+ and HCO3- were collected and tested to obtain the data for the analyses. The results showed that 60.4%, 47.9% and 60.4% of the water samples manifested insignificant pollution and were marginally potable based on the values of the PIG, CRITIC-PIG and Entropy-PIG, respectively. Though 48% of the water samples had different evaluation results, their level difference was mostly 1, which is relatively acceptable. The distribution maps of the three sets of PIG values demonstrated that the quality of groundwater was the best in Dehui City and the worst in Nongan County. Groundwater contamination in the study area was mainly caused by the high concentrations of TDS, TH, Fe3+, F- and NO3-, which not only came from geogenic sources but also anthropogenic sources.


Assuntos
Água Potável , Água Subterrânea , Poluentes Químicos da Água , China , Água Potável/análise , Monitoramento Ambiental/métodos , Água Subterrânea/análise , Poluentes Químicos da Água/análise , Qualidade da Água
8.
Ecotoxicol Environ Saf ; 236: 113473, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-35364507

RESUMO

Groundwater is an important source of water, especially in semi-arid areas. The assessment of the chemical characteristics of groundwater under different land use types the associated risk to human health is of important significance for water resources utilization and protecting the ecological environment. The present study analyzed the hydrochemical characteristics and ion sources of groundwater, taking Shuangliao City as an example. The analysis was based on the field investigation (82 water samples), descriptive statistics, correlation analysis, ion proportionality coefficient method, and principal component analysis (PCA). The results indicated that the concentrations of most ions in the aquifer had wide spatiotemporal variation and were susceptible to environmental influences. NO3- showed the highest spatial variability, with concentrations ranging from 0.0 to 529.48 mg·L-1. The processes contributing the most to the chemical composition of groundwater were leaching/dissolution and cation exchange. The spatial distribution of groundwater chemistry types was visually obtained through the combined use of Piper trilinear charts and a Digital Terrain Model (DTM). The HCO3-Ca type dominated. Groundwater Cl-, SO42-, and Ca2+ were negatively correlated with the Normalized Difference Vegetation Index (NDVI) due to the absorption of inorganic salt by vegetation roots, indicating that land use types affect groundwater hydrochemistry in the area. The hazard quotient (HQ) used in the human health risk assessment (HHRA) model indicated children (0.0010-6.4162) to be at the highest risk, followed by adult females (0.0007-4.0396), with adult males (0.0005-3.0863) under the lowest risk. The spatial distribution of groundwater nitrate was shown to pose risks to children, adult females, and adult males across 62.97%, 50.01%, and 39.34% of the study area, respectively. This study can improve the understanding of groundwater evolution and the relationship between water chemistry and land use types. This study can also guide the development and utilization of groundwater resources and conservation of water quality in semi-arid areas.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , Adulto , Criança , China , Monitoramento Ambiental , Feminino , Água Subterrânea/química , Humanos , Masculino , Nitratos/análise , Óxidos de Nitrogênio/análise , Medição de Risco , Poluentes Químicos da Água/análise , Qualidade da Água
9.
Environ Geochem Health ; 44(7): 1995-2007, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33661451

RESUMO

Mineral water from the Changbai Mountain basalt area is China's most important source of drinking water. Mineral water with abundant output and enriched trace elements has driven the rapid development of the local economy. However, the extensive exploitation of mineral water and the neglect of ecological base flows threaten interdependent river ecosystems. In order to ensure the sustainable use of mineral water, it's necessary to calculate the exploitation and utilization of mineral water according to the ecological base flow. In this study, four hydrological methods were used to analyze the intra-annual and inter-annual ecological base flows, namely the Tennant method, the base flow ratio method, the driest monthly average flow method and the Texas method. The results show that the ecological base flow during the flood season is about 3-4 times that during the non-flood season. Affected by rainfall and runoff, the inter-annual ecological base flow also fluctuated within a small range. This study divides the mineral water exploitation coefficient into five categories and proposes an assessment of the mineral water exploitation potential based on the ecological base flow. It shows that the flow of Baijiang River spring group is the largest, but it's exploitation potential is normal. Huangni River spring group at weak level for exploitation because of its small flow rate. It's obvious that river runoff is not the only factor that determines the exploitation coefficient of the spring group. The proportion of ecological base flow and the proportion of river base flow are also important factors.


Assuntos
Ecossistema , Águas Minerais , China , Rios , Silicatos
10.
Environ Geochem Health ; 44(7): 2215-2233, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34436721

RESUMO

Mathematical statistics, correlation analysis, Piper and Gibbs diagrams, and geographic information system- based multi-criteria decision analysis were used to study the hydrochemical characteristics and identification of hydrochemical ions affected by human activities of the springs in the south of Yanbian City, China. Four criteria were selected: land use/land cover, village density, distance to towns, and distance to main roads. The improved entropy method was used to assign weight to each criterion, followed by evaluating the human activities impact index map, which was used to extract the human activities impact index of springs. The correlation coefficient was calculated to identify the hydrochemical parameters affected by human activities. The results show that the main hydrochemical parameters are Ca2+ among cations and HCO3- among anions. Ca2+, Mg2+, HCO3-, Cl-, and total dissolved solids (TDS) have a strong correlation and similar spatial distribution, showing a decreasing trend from northwest to southeast. Most hydrochemical parameters show a similar spatial distribution trend. The hydrochemical types of springs are HCO3-Ca, HCO3-Ca•Mg, HCO3-Na•Ca, and HCO3-Ca. In the study area, Na+, K+, TFe, Mn2+, F-, PO43-, and oxygen consumption are negligibly affected by human activities, Mg2+, HCO3-, and Cl- were slightly affected, and TDS and total hardness (TH) were strongly affected. With a correlation coefficient of 0.913, nitrate exhibited the highest correlation with the human activities impact index; it was significantly affected by human activities. We conclude that nitrate was the most affected by human activities, followed by TH, TDS, and other hydrochemical parameters.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , China , Cidades , Monitoramento Ambiental/métodos , Água Subterrânea/análise , Humanos , Nitratos/análise , Poluentes Químicos da Água/análise , Qualidade da Água
11.
Chemosphere ; 287(Pt 1): 131987, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34474385

RESUMO

As traditional methods of oil shale production emitting high levels of pollutants, in-situ exploitation has aroused great concerns. In order to study the effect of in-situ pyrolysis products on the underground environment, an in-situ oil shale exploitation of underground environment impact laboratory simulation system was designed. Based on the hydrogeological condition of oil shale area in Nong'an City, a physical simulation test was conducted. It was found the temperature of surrounding layers continued to be perturbed after heating of the formation had stopped. The time during which the temperature was perturbed was about 4-5 times the heating period. During the simulation test, stray gas migration through fractures and faults was considered a mechanism for groundwater contamination. In the test, the maximum TOC content in aquifer was the value of 97.0 mg/L. The maximum total petroleum hydrocarbon (TPH) content of the simulated formation was 129 mg/kg after oil pyrolysis.


Assuntos
Água Subterrânea , Petróleo , Minerais , Mineração , Modelos Teóricos
12.
Sci Rep ; 11(1): 16166, 2021 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-34373512

RESUMO

Oil shale has received attention as an alternative energy source to petroleum because of its abundant reserves. Exploitation of oil shale can be divided into two types: ex situ and in situ exploitation. In situ transformation has been favoured because of its various advantages. Heating of oil shale leads to the production of oil and gas. To explore the influence of solid residue after pyrolysis of oil shale on the groundwater environment, we performed ultrapure water-rock interaction experiments. The results showed that Pb tended to accumulate in solid residues during pyrolysis. Additionally, the Pb concentration goes up in the immersion solution over time and as the pyrolysis temperature increased. In contrast, when we measured the soaking data of benzene series, the concentrations of benzene and toluene produced at temperatures over 350 â„ƒ were highest in the four oil shale pyrolysis samples after pyrolysis. The water-rock interaction experiment for 30 days led to benzene and toluene concentrations that were 104 and 1070-fold over the limit of China's standards for groundwater quality. Over time, the content of benzene series was attenuated via biological actions. The results show that in situ oil shale mining can lead to continuous pollution in the groundwater environment.

13.
Huan Jing Ke Xue ; 42(6): 2699-2712, 2021 Jun 08.
Artigo em Chinês | MEDLINE | ID: mdl-34032069

RESUMO

Aerosol optical depth (AOD) is one of the most fundamental optical properties of aerosols that characterizes the attenuation of light by aerosols and is an indicator of regional air pollution. Based on the blue band surface reflectance database from the MOD09A1 products for the period 2000-2019 and the ASTER spectral database, AOD was estimated from Landsat TM/OLI data using the deep blue algorithm (DB). Multi-year average/annual average and seasonal AOD values for the period 2000-2019 were then calculated to analyze the spatial characteristics and temporal variations of AOD using the empirical orthogonal function method (EOF). Furthermore, the impacts of urbanization on the spatio-temporal distribution of AOD were analyzed. The obtained results are summarized as follows:① The multi-year average AOD spatial distribution in the hinterland of the Guanzhong Basin was significantly affected by topography and human activities, with higher AOD values and variationsin areas of low altitude and high-intensity human activities compared to the surrounding mountains. Thus, changes in AOD in the study area are mainly affected by anthropogenic factors. AOD also showed significant seasonal variations, whereby spring (0.34) > summer (0.33) > autumn (0.23) > winter (0.12), and the largest regional differences occurred in summer; ② The annual average AOD (from 2000-2019) showed the trend of "increase-decrease-increase", and reached a maximum in 2005, with the high AOD area gradually moving to the south. The distribution of AOD values in spring and summer was relatively discrete, while it is in a low-value agglomeration state in winter; ③ Three main AOD spatial distribution modes were identified based on the EOF, which had cumulative contribution rate of 83.0%. The spatial distribution trend of AOD showed regional consistency, with feature vectors consistent with the altitude, thus reflecting the difference of AOD at different altitudes. Taking the Qinling Mountains as the dividing line, the AOD presented the "north-south" pattern, AOD showed a "north-south" pattern, reflecting the uniqueness of the regional development in the Guanzhong Basin compared to the southern Qinling Mountains. The "southeast-northwest" distribution pattern indicated that the AOD presented a reverse change trend between urban and non-urban; and ④ The results of correlation analysis between the AOD and urbanization revealed a positive correlation with permanent population density (R2=0.707, P<0.05), impervious surface density (R2=0.377, P<0.05), and industrial POI density (R2=0.727, P<0.5). These results are significant for improving the monitoring of air quality in the Guanzhong Basin and for the construction of an urban ecological environment.

14.
Environ Sci Pollut Res Int ; 28(30): 41109-41119, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33774796

RESUMO

Excessive Fe and Mn in groundwater of the Songnen Plain, northeast China, pose a threat to water security. Human activities over recent decades have had significant effects on the water quantity and quality of the Songnen Plain. By adopting the large city of Changchun in the Songnen Plain as a research area, this study analyzed the effects of the natural environment (including characteristics of soil and aquifer, climate, and groundwater level) and human activities (including groundwater salinization, groundwater exploitation, and nitrate effects) on groundwater Fe and Mn using statistical and spatial analysis methods. The results showed that the characteristics of soil and aquifer determine the source of groundwater Fe and Mn. The correlations between Fe and Mn with TDS (total dissolved solids) increased with increasing TDS from southeast to northwest in different microclimate regions. The salinization of groundwater caused by human activities will also lead to the increase of Fe content. The decrease in groundwater Fe and Mn was attributed to an increase in groundwater [Formula: see text], through the use of chemical fertilizers. The variation of Fe concentration in groundwater corresponded well with that of groundwater depth, but the excessive exploitation will lead to the continuous decrease in groundwater level and a corresponding decrease in the concentration of groundwater Fe. This study provides a reference for understanding the influence of human activities and the natural environment on groundwater hydrochemistry in the Songnen Plain.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , China , Monitoramento Ambiental , Atividades Humanas , Humanos , Ferro/análise , Manganês/análise , Nitratos/análise , Poluentes Químicos da Água/análise
15.
Ecotoxicol Environ Saf ; 211: 111926, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33472111

RESUMO

Groundwater from deep confined aquifers is often recommended for use because of it's low fluoride health risk. Thus, this study appraised groundwater fluoride hydrochemistry in a multi-aquifer system in Jilin Qianan to determine the non-carcinogenic health risk liable from exploiting the respective aquifers. 124 samples collected from the tertiary confined aquifer (N), quaternary confined aquifer (Q1), and quaternary phreatic aquifer (Q3) during surveys in 2001 and 2017 was analyzed using hydrochemical, statistical, spatial, and health risk assessment methods. Results show that the dominant water facies in the respective aquifer layers was Na+K-HCO3+CO3 except in Q1, where Ca+Mg - HCO3 + CO3 was marginally dominant. Fluoride concentrations outside the recommended guideline occurred in all the aquifers except N, where concentrations were optimum. The mean fluoride concentration of groundwater in the aquifers was of the order Q3 (2017) > Q3 (2001) > Q1 > N ( mean 2.09, 2.03, 1.41 and 0.75 mg/L with 51.85%, 57.44%, 36.36% and 0% occurring beyond recommended guideline values respectively). Silicate weathering, cation exchange, and fluorite dissolution in an alkaline environment were the significant fluoride contributing processes. Evaporation and MgF+ complex additionally influenced Q1 and Q3 (2017). The total hazard quotient (THQ) from oral and dermal pathways shows fluoride health risks in the order: infant > children > adult. The associated risks likely from using water in the respective aquifer layers is of the order Q3 (2017) > Q3 (2001) > Q1 > N. The mean groundwater fluoride in 2017 was marginally higher than that of 2001 ( 2.09>2.03 mg/L respectively) although the percentage of age group members disposed to fluoride risk from using water from Q3 decreased from 2001 to 2017. Knowledge of local hydrogeology in exploiting deep groundwater free of fluoride pollution and on-site defluoridation treatment of groundwater was recommended in the study area and other areas with similar characteristics.


Assuntos
Exposição Ambiental/estatística & dados numéricos , Monitoramento Ambiental , Fluoretos/análise , Poluentes Químicos da Água/análise , Criança , China , Água Subterrânea/química , Humanos , Medição de Risco , Sódio
16.
Environ Sci Pollut Res Int ; 28(16): 20045-20057, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33405130

RESUMO

Stable isotopes (δDVSMOW and δ18OVSMOW) and hydrochemical characteristics were analyzed to determine the groundwater and surface water characteristics of the Taizi River Basin in Northeast China. Total dissolved solids and major ion concentrations gradually increase along the Taizi River, and only parts of the middle and lower reaches were slightly reduced by replenishment from the Hun River and the tributaries of the eastern mountainous areas. The hydrochemical evolution of the surface water and groundwater may be due to a combination of mineral dissolution, mixing processes, cation exchange, and evaporation along the groundwater flow path. The geochemical and isotopic characteristics of the waters suggest that the surface water from the piedmont recharges the groundwater through faults and that precipitation near the mountain reservoirs contributes immensely to both water types. Lateral groundwater movement from the piedmont may be an effective source for replenishing river water in the middle and lower reaches. The geochemical and isotopic characteristics of the groundwater and surface water interaction in the Taizi River Basin contribute toward their comprehensive management.


Assuntos
Água Subterrânea , Rios , China , Monitoramento Ambiental , Água
17.
Biochem Cell Biol ; 99(2): 203-213, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-32830518

RESUMO

The early metastasis of cervical cancer is a multistep process requiring the cancer cells to adapt to the signal input from different tissue environments, including hypoxia. Hypoxia-induced epithelial-to-mesenchymal transition (EMT) plays a critical role in the ability to invade surrounding tissues. However, the molecular mechanisms underlying EMT in cervical cancer remain to be elucidated. Herein, we show that hypoxia-inducible factor-1alpha (HIF-1α) and aryl hydrocarbon receptor nuclear translocator (ARNT) are recruited to the human coilin-interacting nuclear ATPase protein (hCINAP) promoter and initiate hCINAP expression in hypoxia. Ablation of hCINAP decreased the migratory capacity and EMT of cervical cancer cells under hypoxic conditions. Furthermore, hCINAP regulated EMT through the Akt-mTOR signaling pathway, and inhibits hypoxia-induced p53-dependent apoptosis. Our data collectively show that hCINAP may have essential roles in the metastasis of cervical cancer and could be a potential target for curing cervical cancer.


Assuntos
Adenilato Quinase/genética , Apoptose/genética , Transição Epitelial-Mesenquimal/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Hipóxia/genética , Neoplasias do Colo do Útero/genética , Adenilato Quinase/metabolismo , Feminino , Humanos , Hipóxia/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Células Tumorais Cultivadas , Neoplasias do Colo do Útero/metabolismo
18.
Environ Monit Assess ; 192(10): 619, 2020 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-32885322

RESUMO

The present state of iron (Fe) and manganese (Mn) concentration in groundwater of Changchun city located within the Songnen Plain of northeastern China was evaluated in this study. Heavy metal sources, as well as triggering mechanism, were analyzed using a physicochemical, statistical and spatial approach. Results revealed that out of the 2600 samples analyzed, 214 (representing 8.24%) for Fe and 606 wells (representing 23.34%) for Mn exceeded the water standard. Organic matter-rich sediments and Fe-Mn nodules in aquifer and soil serve as sources of Fe and Mn. Organic and inorganic complex formations, as well as long residence time, were found to foster the release of Fe and Mn into groundwater. Additionally, pH and well depth was important in triggering Mn dissolution while groundwater mineralization, depth to the water table and well proximity to the river were found to have minimal/negligible effect on heavy metal mobilization. The removal of Fe and Mn from the water before use was proposed along with the sinking of deeper wells for groundwater exploitation to limit the use of polluted water.


Assuntos
Água Subterrânea , Poluentes Químicos da Água/análise , China , Monitoramento Ambiental , Ferro/análise , Manganês/análise
19.
Environ Sci Pollut Res Int ; 26(34): 34964-34976, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31664670

RESUMO

In this study, the quality of groundwater was tested in 95 sampling wells in Shuangliao City. Based on the results, the coefficient of variation method was used to calculate the comprehensively evaluated value F, and the grade of groundwater quality, in accordance with the actual scenario in the study area, was classified according to the results of the evaluation. The spatial distribution of groundwater quality types in the study area was classified. In addition, the influence of human activity on each groundwater subsystem was assessed. Combined with the land use types in the study area, the Circle model was used to extract the land use types in the circular buffer zone with a radius of 500 m, and the Kendall rank correlation test was used to analyze the influence of the land use types on the spatial distribution of groundwater pollution. Based on the coefficient of variation, the groundwater quality standard was divided into four sections considering the actual scenario: ≤ 0.92 (I), 0.92~≤ 1.75 (II), 1.75~≤ 2.40 (III), and > 2.40 (IV). Water from class II was considered the main type for groundwater quality. NO3-, TFe, and Mn were deemed the main indexes of groundwater pollution. Further, land use type was found to have a great influence on the spatial distribution of groundwater pollution; specifically, dry land, paddy field, areas with dense traffic, and residential areas are the main land types that affect the groundwater environment.


Assuntos
Monitoramento Ambiental/métodos , Água Subterrânea/química , Poluentes Químicos da Água/análise , Agricultura , Cidades , Humanos , Poluição da Água/estatística & dados numéricos , Poços de Água
20.
Chemosphere ; 228: 384-389, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31042612

RESUMO

Oil shale samples were obtained from Nong'an oil shale ore-bearing area which was located in the southeastern uplift of Songliao basin, China. The XRD test for oil shale identified the minerals in it and a series of water-rock interaction experiment between oil shale-water and oil shale ash-water were carried out to the study the release of organic matter from groundwater during oil shale in-situ exploitation. The content of phenol, BTEX, TOC and TPH in oil shale and oil shale ash aqueous solution were determined. The phenol and TOC in oil shale aqueous solution were higher than that of oil shale ash aqueous solution, conversely, more BTEX and TPH were existed in oil shale ash aqueous solution. The reaction temperature had significant influence on phenol, TOC and TPH in oil shale aqueous solution, which was not obvious in oil shale ash aqueous solution. Besides, the TOC average content in oil shale aqueous solution gradually increased along with the reaction time. The results show that not only oil shale in situ mining process make groundwater organic pollution aggravate but also continuous pollution of groundwater caused by the residual oil shale ash still exist.


Assuntos
Água Subterrânea/química , Minerais/química , Mineração/métodos , Campos de Petróleo e Gás/química
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