Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 434
Filtrar
1.
Hum Brain Mapp ; 45(11): e26793, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39037186

RESUMO

The auditory system can selectively attend to the target source in complex environments, the phenomenon known as the "cocktail party" effect. However, the spatiotemporal dynamics of electrophysiological activity associated with auditory selective spatial attention (ASSA) remain largely unexplored. In this study, single-source and multiple-source paradigms were designed to simulate different auditory environments, and microstate analysis was introduced to reveal the electrophysiological correlates of ASSA. Furthermore, cortical source analysis was employed to reveal the neural activity regions of these microstates. The results showed that five microstates could explain the spatiotemporal dynamics of ASSA, ranging from MS1 to MS5. Notably, MS2 and MS3 showed significantly lower partial properties in multiple-source situations than in single-source situations, whereas MS4 had shorter durations and MS5 longer durations in multiple-source situations than in single-source situations. MS1 had insignificant differences between the two situations. Cortical source analysis showed that the activation regions of these microstates initially transferred from the right temporal cortex to the temporal-parietal cortex, and subsequently to the dorsofrontal cortex. Moreover, the neural activity of the single-source situations was greater than that of the multiple-source situations in MS2 and MS3, correlating with the N1 and P2 components, with the greatest differences observed in the superior temporal gyrus and inferior parietal lobule. These findings suggest that these specific microstates and their associated activation regions may serve as promising substrates for decoding ASSA in complex environments.


Assuntos
Atenção , Percepção Auditiva , Eletroencefalografia , Potenciais Evocados Auditivos , Percepção Espacial , Humanos , Masculino , Atenção/fisiologia , Feminino , Adulto Jovem , Percepção Espacial/fisiologia , Potenciais Evocados Auditivos/fisiologia , Adulto , Percepção Auditiva/fisiologia , Estimulação Acústica , Mapeamento Encefálico
2.
J Hazard Mater ; 477: 135072, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-39042988

RESUMO

During the process of black shale weathering, multiple heavy metal elements are concentrated in the soil, causing pollution. This study selected soil and black shale bedrock samples from high geological background areas to investigate the control of heavy metal element pollution by bedrock using spatial analysis. The research results indicate that the heavy metal content in black shale bedrock is extremely high, ranging from 2.3 to 13.1 times the background values of rock heavy metal elements. The heavy metal content in the soil formed through weathering is positively correlated with the bedrock, ranging from 1.1 to 21.3 times the background values. The coefficient of variation of rock samples ranges from 1.09 to 7.18, indicating significant variability.The analysis reveals that the control ability of pure rock over heavy metal elements is mainly moderate and high, accounting for over 70 %, with d being the most affected metal element. Except for As, the other seven elements exhibit strong spatial autocorrelation, showing distinct regional distribution characteristics. The soil elements demonstrate high homogeneity, with heavy metal elements from black shale bedrock primarily released through weathering serving as the main source of these elements.

3.
Huan Jing Ke Xue ; 45(7): 3789-3798, 2024 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-39022927

RESUMO

Guanzhong urban agglomeration has a good development foundation and great development potential, and it has a unique strategic position in the national all-round opening up pattern. In recent years, the problem of near-surface ozone (O3) in the Guanzhong Region has become increasingly prominent, which has become a bottleneck affecting the continuous improvement of air quality. In order to effectively prevent and control O3 pollution, this study analyzed the characteristics of annual, monthly, and daily changes in O3 concentration in the Guanzhong Region based on the environmental monitoring data from 2018 to 2021. A geo-detector was used to study the driving factors of the spatial differentiation of O3 concentration, and the sources of O3 were analyzed using a backward trajectory model and emission inventory construction. The results showed that the daily and monthly variation in O3 concentration in the Guanzhong Region were unimodal. The daily maximum value appeared at 15:00, the minimum value appeared at 07:00, the peak value of the monthly average appeared in June, and the valley value appeared in December. The O3 concentration was highest in summer, followed by that in spring, and the lowest in winter. The days of O3 exceeding the standard showed mainly mild pollution, and moderate and above pollution showed a trend of decreasing first and then increasing. The O3 concentration in the Guanzhong Region was mainly closely related to precursors and meteorological factors, and the explanatory power of the interaction of each factor was significantly greater than that of any single factor. The regional transport of O3 concentration in the Guanzhong Region was mainly affected by easterly airflow, followed by the northwest direction, with the potential source areas located mainly in Henan Province and Hubei Province. The main local sources of volatile organic compounds (VOCs) were solvent use sources, process sources, and mobile sources, and the main emission sources of nitrogen oxides (NOx) were mobile sources and industrial production combustion sources. The research results have a guiding significance for O3 joint prevention and control in the Guanzhong Region.

4.
Huan Jing Ke Xue ; 45(7): 3828-3838, 2024 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-39022931

RESUMO

Based on a typical ozone (O3) pollution process in Jinan City from June 16 to 26, 2021, the variation characteristics of O3 and its precursor volatile organic compounds (VOCs) during different pollution periods (clean period (CP), pollution rise period (PRP), heavy pollution period (HPP), and pollution decline period (PDP)) in the urban area were analyzed. Both positive matrix factorization (PMF) and an observation-based model (OBM) were used to identify the main sources of VOCs, O3 production mechanisms, and sensitive species. The results showed that the average value of ρ(O3-8h) during the HPP period in the urban area was (246.67±11.24) µg·m-3, and ρ(O3-1h) had a peak value of 300 µg·m-3. The volume fractions of VOCs and NO2 concentration were affected by the decrease in planetary boundary layer and wind speed, which were 76.99%-145.36% and 127.78%-141.18% higher than those in the other three periods, respectively, and were the main reasons for the aggravation of O3 pollution. Alkanes, oxygenated volatile organic compounds (OVOCs), and halogenated hydrocarbons accounted for 43.81%, 20.98%, and 17.43% of VOCs in urban areas, respectively. All of them showed significant growth during the HPP period, with acetone, propane, and ethane being the top three species by volume in each stage and isopentane showing the highest growth during the HPP period. Alkene, alkanes, and aromatic hydrocarbons accounted for 40.19%, 28.06%, and 21.92% of the ozone generation potential (OFP). 1-butene, toluene, isopentane, and isoprene were the species with higher OFP. Isoprene had the highest OFP during the PRP phase, and 1-butene had the highest OFP during the HPP phase. The volume fraction of isopentane significantly increased OFP. The correlation coefficient between VOCs and CO preliminarily indicated that motor vehicle exhaust and oil and gas volatilization were the main sources of VOCs during the HPP period. Further use of PMF revealed that solvent use sources, combustion sources, motor vehicle exhaust+oil and gas volatilization sources, industrial emission sources, and plant sources were important sources of VOCs in urban areas. The contribution of motor vehicle exhaust+oil and gas volatilization sources in the HPP period to VOCs was 3.09-14.72 times higher than that in other periods. The contribution of solvent use sources to VOCs was approximately 2.50 times higher than that in the CP and PRP periods. The main sources of VOCs volume fraction increase were motor vehicle exhaust, oil and gas volatilization sources, and solvent use sources. Potential sources and concentration weight analysis found that VOCs were also affected by the transmission of VOCs to Binzhou and Dongying in the northeast direction. The OBM results indicated that the main pathway of O3 formation in urban areas was the reaction of peroxide hydroxyl radicals (HO2·ï¼‰ and methyl peroxide radicals (CH3O2·ï¼‰ with NO, and the net ozone generation rate during the HPP phase [P(O3)net] was 24×10-9 h-1. Based on the sensitivity experiment results, the alkene components of 1-butene, propylene, cis-2-butene, and ethylene were the dominant species for O3 production.

5.
Comput Methods Programs Biomed ; 255: 108328, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39038390

RESUMO

BACKGROUND AND OBJECTIVES: Patch-Clamp recordings allow for in depth electrophysiological characterization of single cells, their general biophysical properties as well as characteristics of voltage- and ligand-gated ionic currents. Different acquisition modes, such as whole-cell patch-clamp recordings in the current or voltage clamp configuration, capacitance measurements or single channel recordings from cultured cells as well as acute brain slices are routinely performed for these purposes. Nevertheless, multipurpose transparent and adaptable software tools to perform reproducible state-of-the-art analysis of multiple experiment types and to manage larger sets of experimental data are currently unavailable. METHODS: Biophysical Essentials (BPE) was developed as an open-source full stack python software for transparent and reproducible analysis of electrophysiological recordings. For validation, BPE results were compared with manually analyzed single-cell patch-clamp data acquired from a human in vitro nociceptor-model and mouse dorsal root ganglia neurons. RESULTS: While initially designed to improve time consuming and repetitive analysis steps, BPE was further optimized as a technical software solution for entire workflow processing including data acquisition, data preprocessing, normalization and visualization and of single recordings up to stacked calculations and statistics of multiple experiments. BPE can operate with different file formats from different amplifier systems and producers. An in-process database logs all analysis steps reproducible review and serves as a central storage point for recordings. Statistical testing as well as advanced analysis functions like Boltzmann-fitting and dimensional reduction methods further support the researchers' needs in projects involving electrophysiology techniques. CONCLUSIONS: BPE extends beyond available patch-clamp specific, open source - and commercial analysis tools in particular because of reproducible and sharable analysis workflows. BPE enables full analysis from raw data acquisition to publication ready result visualizations - all within one single program. Thereby, BPE significantly enhances transparency in the analytical process of patch-clamp data analysis. BPEs function scope is completely accessible through an easy-to-use graphical user interface eliminating the need for programing language proficiency as required by many community patch-clamp analysis frameworks and algorithms.

6.
Mar Pollut Bull ; 206: 116735, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39029149

RESUMO

Surface sediment samples were collected from the surrounding sea areas of the two largest tourist islands in Sanya City, China, to compare and assess the sources, distribution, and ecological risks of 16 polycyclic aromatic hydrocarbons (PAHs). The total PAHs concentrations ranged from 31.16 to 163.3 ng/g, with an average concentration of 102.46 ng/g, which is still lower than the levels detected in most other sediment studies worldwide. PAHs from coal combustion (Flu, Pyr, Fl, Phe) showed positive correlations with TOC, Silt, and Clay, indicating that these PAHs are easily adsorbed in muddy and silty sediments. Sanya Bay is primarily composed of mud and silt, whereas Haitang Bay is mainly sandy. This corresponds to the significantly higher concentrations of Fl, Phe, and Pyr in Sanya Bay compared to Haitang Bay. The main industrial activities in the study area are related to power and heat production and supply. The results indicate that the primary sources of sediment PAHs are high-temperature combustion during heavy industrial production, followed by maritime transportation and petroleum sources. Overall, the PAHs pollution levels in the study area range from slight to moderate. Sediment quality assessments show that only Ace and Phe have higher individual risk values. Six stations in Sanya Bay have higher adverse impact risks, while in Haitang Bay, only HT07 poses a high risk to biological impact. These two areas require enhanced monitoring and pollution source control.

7.
Brain Sci ; 14(7)2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-39061436

RESUMO

Mirror Visual Feedback (MVF)-induced illusion of hand movements produces beneficial effects in patients with chronic pain. However, neurophysiological mechanisms underlying these effects are poorly known. In this preliminary study, we test the novel hypothesis that such an MVF-induced movement illusion may exert its effects by changing the activity in midline cortical areas associated with pain processing. Electrical stimuli with individually fixed intensity were applied to the left hand of healthy adults to produce painful and non-painful sensations during unilateral right-hand movements with such an MVF illusion and right and bilateral hand movements without MVF. During these events, electroencephalographic (EEG) activity was recorded from 64 scalp electrodes. Event-related desynchronization (ERD) of EEG alpha rhythms (8-12 Hz) indexed the neurophysiological oscillatory mechanisms inducing cortical activation. Compared to the painful sensations, the non-painful sensations were specifically characterized by (1) lower alpha ERD estimated in the cortical midline, angular gyrus, and lateral parietal regions during the experimental condition with MVF and (2) higher alpha ERD estimated in the lateral prefrontal and parietal regions during the control conditions without MVF. These preliminary results suggest that the MVF-induced movement illusion may affect nociception and neurophysiological oscillatory mechanisms, reducing the activation in cortical limbic and default mode regions.

8.
Toxics ; 12(7)2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-39058113

RESUMO

The goals of the "dual carbon" program in China are to implement a series of air pollution policies to reduce the emission of carbon-bearing particulate matter (PM). Following improvements in the reduction in carbon emissions in Handan City, China, fine particulate matter (PM2.5) was collected in the winters from 2016 to 2020 to characterize the concentrations and sources of carbonaceous components in PM2.5. Trend analysis revealed that both organic carbon (OC) and elemental carbon (EC) concentrations significantly decreased. The proportion of total carbon aerosol (TCA) in PM2.5 decreased by 47.0%, highlighting the effective reduction in carbon emissions. Secondary organic carbon (SOC) concentrations increased from 2016 (12.86 ± 14.10 µg·m-3) to 2018 (36.76 ± 21.59 µg·m-3) and then declined gradually. SOC/OC was larger than 67.0% from 2018 to 2020, implying that more effective synergistic emission reduction measures for carbonaceous aerosol and volatile organic compounds (VOCs) were needed. In the winters from 2016 to 2020, primary organic carbon (POC) concentrations reduced by 76.1% and 87.6% under a light/moderate pollution period (LP) and heavy/severe pollution periods (HPs), respectively. The TCA/PM2.5 showed a decreasing trend under LP and HP conditions, decreasing by 42.1% and 54.7%, respectively. Source analysis revealed that carbonaceous components were mainly from biomass burning, coal combustion and automotive exhaust emissions in the winters of 2016 and 2020. OC/EC and K+/EC analysis pointed out that air pollutant reduction measurements should focus on rectification biomass fuels in the next stage. Compared with 2016, the contributions of automotive exhaust emissions decreased in 2020. OC and EC concentrations decreased due to control measures on automotive exhaust emissions.

9.
Sci Rep ; 14(1): 15127, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38956253

RESUMO

The soil environment plays an important role in urban ecosystems. To study the heavy metal contamination of soil in Beilun District, Ningbo, we collected soil samples from 60 points in urban and peri-urban areas of Beilun District and analyzed the spatiotemporal variation and sources of heavy metal pollution in various land-use types. The results shown that the heavy metal contents in 2015 and 2022 were higher than the background soil values of Ningbo city, and there was an accumulation of heavy metals over these 7 years. The contents of heavy metals in green belts and woodland in 2022 were higher than those in 2015, while there was no significant change in agricultural land. The heavy metal contents in both years were mainly in the order green belts > agricultural land > woodland. The spatiotemporal distribution of heavy metal content showed that heavy metal pollution in Beilun District was concentrated in five industrial areas, and there was a trend toward the disappearance of highly polluted points. But the single-factor pollution index, pollution load index (PLI), and geoaccumulation index (Igeo) indicated that there was no significant heavy metal pollution in Beilun District, and individual elements at specific points showed slight pollution. The source analysis results showed that the main source of Hg is chemical, As is mainly derived from agricultural, Cr, Ni and Cu are mainly derived from natural, the main sources of Zn and Cd are electroplating and machinery activities, and the main source of Pb is traffic. These results specify a reference for future investigation on urban soil heavy metals, and the source apportionment results provide a scientific foundation for subsequent soil heavy metal pollution treatment.

10.
Environ Geochem Health ; 46(8): 270, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38954122

RESUMO

Radioactive nuclides cesium (Cs) and strontium (Sr) possess long half-lives, with 135Cs at approximately 2.3 million years and 87Sr at about 49 billion years. Their persistent accumulation can result in long-lasting radioactive contamination of soil ecosystems. This study employed geo-accumulation index (Igeo), pollution load index (PLI), potential ecological risk index (PEPI), health risk assessment model (HRA), and Monte Carlo simulation to evaluate the pollution and health risks of Cs and Sr in the surface soil of different functional areas in a typical mining city in China. Positive matrix factorization (PMF) model was used to elucidate the potential sources of Cs and Sr and the respective contribution rates of natural and anthropogenic sources. The findings indicate that soils in the mining area exhibited significantly higher levels of Cs and Sr pollution compared to smelting factory area, agricultural area, and urban residential area. Strontium did not pose a potential ecological risk in any studied functional area. The non-carcinogenic health risk of Sr to the human body in the study area was relatively low. Because of the lack of parameters for Cs, the potential ecological and human health risks of Cs was not calculated. The primary source of Cs in the soil was identified as the parent material from which the soil developed, while Sr mainly originated from associated contamination caused by mining activities. This research provides data for the control of Cs and Sr pollution in the surface soil of mining city.


Assuntos
Radioisótopos de Césio , Mineração , Poluentes Radioativos do Solo , Medição de Risco , China , Poluentes Radioativos do Solo/análise , Radioisótopos de Césio/análise , Humanos , Radioisótopos de Estrôncio/análise , Césio/análise , Cidades , Solo/química , Método de Monte Carlo , Monitoramento de Radiação
11.
Sci Total Environ ; 947: 174506, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38971251

RESUMO

Long-term coal mining activities in abandoned coal mining areas have resulted in the migration of large quantities of heavy metals into the surrounding soil environment, posing a threat to the regional ecological environment. This study focuses on the surface soil collected from a typical abandoned coal mining area. Methods such as the pollution index (PI) and potential ecological risk index (RI) were used to comprehensively evaluate the pollution levels and ecological risks of soil heavy metals. Geostatistical analysis and the APCS-MLR model were used to quantify the sources of soil heavy metals, and Nemerow integrated ecological risk (NIRI) model was coupled to apportion the ecological risks from different pollution sources. The results indicate that the average concentrations of Cd, As, and Zn are 4.58, 2.44, and 1.67 times the soil background values, respectively, while the concentrations of other heavy metals are below the soil background values. The soil of study area is strongly polluted by heavy metals, with the pollution level and ecological risk of Cd being significantly higher than those of other heavy metals. The NIRI calculation results show that the overall comprehensive ecological risk level is considerable, with sample points classified as relatively considerable, moderate, and low at 60.53 %, 36.84 %, and 2.63 %, respectively. The sources of soil heavy metals can be categorized into four types: traffic activities, natural sources, coal gangue accumulation, and a combined source of coal mining and agricultural activities, with contribution rates of 35.3 %, 36.1 %, 19.5 %, and 9.1 %, respectively. The specific source ecological risk assessment results indicate that coal gangue accumulation contributes the most to ecological risk (36.4 %) and should be prioritized for pollution control, with Cd being the priority control element for ecological risk. The findings provide theoretical support for the refined management of soil heavy metal pollution in abandoned coal mining areas.

12.
Huan Jing Ke Xue ; 45(6): 3129-3141, 2024 Jun 08.
Artigo em Chinês | MEDLINE | ID: mdl-38897737

RESUMO

Groundwater nitrate (NO3-) contamination in China has become a serious environmental problem, especially in agricultural production areas, which greatly affects the safety of drinking groundwater and requires urgent attention. In this study, the main sources of groundwater nitrate in China were reviewed, including atmospheric deposition, soil nitrogen, agricultural fertilization, and fecal sewage, among which fecal sewage and agricultural fertilization were the main reasons for the excessive groundwater nitrate. The application of hydrochemical analysis, multivariate statistical analysis, stable isotope tracer method, and microbial source tracking in the source apportionment of groundwater nitrate was summarized. All types of source apportionment methods had certain limitations. It is suggested that a variety of methods should be used to identify the source of groundwater nitrate, and the contribution rate of different pollution sources should be calculated using multivariate statistical analysis and isotope quantitative analysis models. The source apportionment of nitrate pollution has undergone a process from qualitative to quantitative research. At present, the SIAR and MixSIAR models based on δ15N-NO3-and δ18O-NO3- have been used widely to analyze the source of nitrate. However, due to the overlap of isotope characteristic values of different input end-members, the difference in δ15N-NO3-and δ18O-NO3- values under different spatial and temporal changes, and the influence of isotope fractionation in the process of nitrogen migration and transformation, the results calculated by the model remain uncertain. It is necessary to further optimize the analytical method of the model to obtain the source of nitrate pollution and its contribution rate more accurately to further aid in the scientific management of groundwater resources.

13.
Huan Jing Ke Xue ; 45(6): 3512-3522, 2024 Jun 08.
Artigo em Chinês | MEDLINE | ID: mdl-38897771

RESUMO

Heavy metal pollution in farmland soil can affect the growth, development, and yield of vegetable crops, as well as the quality and taste of vegetables, and can be continuously transmitted and enriched through the food chain, which ultimately poses a certain hazard to human health in the long term. Therefore, in order to investigate the distribution characteristics of soil heavy metals after years of multi-crop planting of vegetables supplied to Hong Kong, predict their ecological risks, and analyze the causes of pollution formation, 477 surface soil samples of vegetable fields supplied to Hong Kong in Ningxia were collected for three consecutive years from 2019 to 2021, and the contents and distribution characteristics of eight heavy metals, namely, As, Cd, Cr, Hg, Pb, Cu, Zn, and Ni were analyzed. The soil heavy metal pollution status of vegetable fields supplied to Hong Kong in Ningxia was evaluated using the single-factor pollution index method, Nemero's comprehensive pollution index method, land accumulation index method, and potential ecological risk index method, and the sources of heavy metals in vegetable fields supplied to Hong Kong in Ningxia were analyzed using the Pearson's correlation analysis and the principal component analysis method. The results showed that the mean values of As, Cd, Cr, Hg, Cu, and Zn in the soils of Ningxia's vegetable fields were higher than the background values of Ningxia soils, but the contents of all eight heavy metals were lower than the risk screening values of domestic agricultural soils; in terms of spatial distribution, As, Cr, and Ni showed contiguous high values in the northwestern, central, and southern parts of the study area, whereas Pb, Zn, Cd, Hg, and Cu showed high values in the northwestern and southern parts of the study area. The single-factor index method and the Nemero's comprehensive pollution index method showed that the soil of Ningxia's vegetable farmland for Hong Kong was at the clean level as a whole. The results of the ground accumulation index method showed that the pollution in the study area was mainly Hg and Cd pollution, and the pollution areas were mainly concentrated in the northwest and south of the study area. The potential ecological risk index showed that Hg and Cd were the main risk elements, among which Hg was dominated by moderate, strong, and very strong ecological risks, accounting for 44.65 %, 44.65 %, and 1.26 %, respectively, and Cd was dominated by moderate and strong risks, accounting for 65.83 % and 3.56 %. The comprehensive Pearson correlation analysis and principal component analysis showed that the pollution sources of eight heavy metals could be divided into three categories, namely, natural sources:Cu, Zn, Pb, As, Ni, and Cr; agricultural sources:Cd; and industrial and agricultural sources:Hg. From a comprehensive point of view, the heavy metals of the soil in the fields of vegetables supplied to Hong Kong had not exceeded the standard, and the environmental conditions of the soil were good, such that the production of vegetables supplied to Hong Kong by Ningxia was at a safe level overall. The results of the study can provide a theoretical basis for the safe utilization of soil in vegetable fields and the green production of vegetables supplied to Hong Kong in Ningxia, which were aimed to provide help for the safe production of vegetable fields supplied to Hong Kong, the rational application of fertilizers, agronomic planning, and the adjustment of planting structure.


Assuntos
Monitoramento Ambiental , Metais Pesados , Poluentes do Solo , Verduras , Metais Pesados/análise , Poluentes do Solo/análise , Verduras/crescimento & desenvolvimento , Verduras/química , Hong Kong , Medição de Risco , China , Solo/química
14.
Huan Jing Ke Xue ; 45(6): 3756-3764, 2024 Jun 08.
Artigo em Chinês | MEDLINE | ID: mdl-38897795

RESUMO

To investigate the concentration characteristics and sources of metal elements in PM2.5 during winter heavy pollution in the southern Sichuan urban agglomeration (Zigong, Luzhou, Neijiang, and Yibin), the metal elements in PM2.5 were measured using membrane sampling methods from December 30, 2018 to January 14, 2019, and the enrichment factor method (EF) and positive matrix factorization(PMF) were applied to investigate the sources of metal elements. The metal element observation data of Zigong in the same period of 2015 were also used to investigate the changes in metal element pollution and enrichment in Zigong in the middle and end of the implementation of China's Air Pollution Prevention and Control Action Plan. The main findings were as follows:① The concentrations and percentages of metal elements in particulate matter in different cities did not differ significantly. The elements with higher concentrations in the four cities showed similarities, with Al, Sb, and Fe at the top. From the comparison of different observation periods in Zigong, the concentrations of all elements except Tl changed. ② The results of the enrichment factor calculation showed that the enrichment of the elements Cr (Zigong and Yibin), Ni, Cu, As, Se, Ag, Cd, Sb, Tl, and Pb in the urban agglomeration was high. The comparison of the enrichment levels of elements in Zigong for different observation periods showed that the enrichment levels of all elements, except Cu, tended to decrease in the winter observation period of 2018. ③ The results of PMF source analysis showed that the metal elements in each city mainly originated from dust sources, coal-fired sources, industrial sources, and traffic sources, whereas there was a mixed contribution among the sources. The contribution of the main sources differed among cities, in which Zigong was dominated by traffic dust sources and mixed sources, Luzhou was dominated by industrial sources, Neijiang had a similar contribution from different sources, and Yibin was dominated by traffic sources.

15.
Environ Sci Pollut Res Int ; 31(28): 41013-41024, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38842776

RESUMO

Severe pollution threatens the ecosystem and human health in the Yangtze River Delta (YRD) in China because of the rapid development of industry in this area. This study examines the types, distribution, concentration, and origin of fourteen typical organophosphate flame retardants (OPFRs) in agricultural soils within the YRD region to offer insights for pollutant control and policy-making. The total concentration of OPFRs (ΣOPFRs) varied between 79.19 and 699.58 µg/kg dry weight (dw), averaging at 209.61 µg/kg dw. Among the OPFRs detected, tributoxyethyl phosphate (TBEP) was identified as the main congener, followed by tri-n-butyl phosphate (TnBP), tris(2-chloroisopropyl) phosphate (TCPP), and trimethyl phosphate (TMP). Source analysis, conducted through correlation coefficients and PCA, indicated that OPFRs in agricultural soils within the YRD region mainly originate from emissions related to plastic products and transportation. The health risk exposure to ΣOPFRs in agricultural soil was considered negligible for farmers, with values below 1.24 × 10-2 and 1.76 × 10-9 for noncarcinogenic and carcinogenic risks, respectively. However, the ecological risk of ΣOPFRs in all the samples ranged from 0.08-1.08, indicating a medium to high risk level. The results offer a comprehensive understanding of OPFR pollution in agricultural soils in the YRD region and can be useful for pollution control that mitigates ecological and health risks in this region.


Assuntos
Agricultura , Monitoramento Ambiental , Retardadores de Chama , Organofosfatos , Poluentes do Solo , Solo , Retardadores de Chama/análise , China , Medição de Risco , Poluentes do Solo/análise , Organofosfatos/análise , Solo/química , Rios/química , Humanos
16.
bioRxiv ; 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38826206

RESUMO

Objective: To compare cortical dipole fitting spatial accuracy between the widely used yet highly simplified 3-layer and modern more realistic 5-layer BEM-FMM models with and without adaptive mesh refinement (AMR) methods. Methods: We generate simulated noiseless 256-channel EEG data from 5-layer (7-compartment) meshes of 15 subjects from the Connectome Young Adult dataset. For each subject, we test four dipole positions, three sets of conductivity values, and two types of head segmentation. We use the boundary element method (BEM) with fast multipole method (FMM) acceleration, with or without (AMR), for forward modeling. Dipole fitting is carried out with the FieldTrip MATLAB toolbox. Results: The average position error (across all tested dipoles, subjects, and models) is ~4 mm, with a standard deviation of ~2 mm. The orientation error is ~20° on average, with a standard deviation of ~15°. Without AMR, the numerical inaccuracies produce a larger disagreement between the 3- and 5-layer models, with an average position error of ~8 mm (6 mm standard deviation), and an orientation error of 28° (28° standard deviation). Conclusions: The low-resolution 3-layer models provide excellent accuracy in dipole localization. On the other hand, dipole orientation is retrieved less accurately. Therefore, certain applications may require more realistic models for practical source reconstruction. AMR is a critical component for improving the accuracy of forward EEG computations using a high-resolution 5-layer volume conduction model. Significance: Improving EEG source reconstruction accuracy is important for several clinical applications, including epilepsy and other seizure-inducing conditions.

17.
Environ Pollut ; 355: 124164, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38754692

RESUMO

Air quality considerably affects bioaerosol dynamics within the atmosphere. Frequent haze events, with their associated alterations in bioaerosol composition, may pose potential health risks. This study investigated the microbial diversity, community structure, and factors of PM2.5 within an urban environment. We further examined the impact of haze on potentially pathogenic bacteria in bioaerosols, and analyzed the sources of haze pollution. Key findings revealed that the highest levels of microbial richness and diversity were associated with lightly polluted air conditions. While the overall bacterial community structure remained relatively consistent across different air quality levels, the relative abundance of specific bacterial taxa exhibited variations. Meteorological and environmental conditions, particularly sulfur dioxide, nitrogen dioxide, and carbon monoxide, exerted a greater influence on bacterial diversity and community structure compared to the physicochemical properties of the PM2.5 particles themselves. Notably, haze events were observed to strengthen interactions among airborne pathogens. Stable carbon isotope analysis suggested that coal combustion and automobile exhaust were likely to represent the primary source of haze during winter months. These findings indicate that adoption of clean energy alternatives such as natural gas and electricity, and the use of public transportation, is crucial to mitigate particle and harmful pollutant emissions, thereby protecting public health.


Assuntos
Aerossóis , Microbiologia do Ar , Poluentes Atmosféricos , Poluição do Ar , Monitoramento Ambiental , Material Particulado , Aerossóis/análise , Poluentes Atmosféricos/análise , Material Particulado/análise , Poluição do Ar/estatística & dados numéricos , Bactérias/isolamento & purificação , Cidades , Dióxido de Enxofre/análise
18.
J Hazard Mater ; 473: 134511, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38772103

RESUMO

Phthalate esters (PAEs) are widely utilized and can accumulate in lacustrine ecosystems, posing significant ecological and human health hazards. Most studies on PAEs focus on individual lakes, lacking a comprehensive and systematic perspective. In response, we have focused our investigation on characteristic lakes situated along the Eastern Route of the South-to-north Water Diversion Project (SNWDP-ER) in China. We have detected 16 PAE compounds in the impounded lakes of the SNWDP-ER by collecting surface water samples using solid-phase extraction followed by gas chromatography analysis. The concentration of PAEs were found to between 0.80 to 12.92 µg L-1. Among them, Bis (2-ethylhexyl) phthalate (DEHP) was the most prevalent, with mean concentration of 1.56 ±â€¯0.62 µg L-1 (48.44%), followed by Diisobutyl phthalate (DIBP), 0.64 ±â€¯1.40 µg L-1 (19.87%). Spatial distribution showed an increasing trend in the direction of water flow. Retention of DEHP and DIBP has led to increased environmental risks. DEHP, Dimethyl phthalate (DMP) etc. determined by agriculture and human activities. Additionally, Dibutyl phthalate (DBP) and DIBP mainly related to the use of agricultural products. To mitigate the PAEs risk, focusing on integrated management of the lakes, along with the implementation of stringent regulations to control the use of plasticizes in products.

19.
J Hazard Mater ; 473: 134621, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38795494

RESUMO

Neonicotinoids (NEOs) are widely used insecticides and have been detected in aquatic environments globally. However, little is known about NEOs contamination in the coastal environments under the terrestrial pressure of multiple planting types simultaneously. This study investigated the occurrence, spatial-seasonal variability, and ecological risks of NEOs along the coast of the Shandong Peninsula during the dry and wet seasons, where located many largest fruit, vegetable, and grain production bases in China. The concentrations of ∑NEOs in seawater were higher in wet seasons (surface: 195.46 ng/L; bottom: 14.56 ng/L) than in dry seasons (surface: 10.07 ng/L; bottom: 8.45 ng/L). During the wet seasons, NEOs peaked in the northern and eastern areas of the Shandong Peninsula, where the inland fruit planting area is located. While dry seasons had higher concentrations in Laizhou Bay, influenced by rivers from vegetable-growing areas. Grain crops, fruit, and cotton planting were major NEOs sources during wet seasons, while wheat and vegetables dominated in dry seasons. Moderate or above ecological risks appeared at 53.8% of the monitoring sites. Generally, NEOs caused high risks in the wet seasons mainly caused by Imidacloprid, and medium risk in the dry seasons caused by Clothianidin, which should be prevented and controlled in advance.


Assuntos
Agricultura , Monitoramento Ambiental , Inseticidas , Neonicotinoides , Estações do Ano , Água do Mar , Poluentes Químicos da Água , Inseticidas/análise , Inseticidas/toxicidade , Água do Mar/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Neonicotinoides/análise , Neonicotinoides/toxicidade , China , Medição de Risco
20.
Mar Pollut Bull ; 203: 116485, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38754319

RESUMO

In this study, the accumulation rate of plastic litter was investigated by sampling quadrats placed on the North Island of Qilianyu, and the composition was analyzed and identified to determine its source. The results showed that the annual average accumulation rate of plastic litter on North Island was 0.64 ± 0.32 pieces·m-2·month-1, with a mass accumulation rate of 11.30 ± 7.73 g·m-2·month-1. The accumulation rate of plastic litter was mainly influenced by wind speed and direction, with higher accumulation rates occurring during the southwest monsoon season and tropical cyclones. ATR-FTIR analysis indicated that polyethylene (44 %) and polypropylene (41 %) were the most abundant types of polymers. This study reveals the current status of plastic litter pollution in green turtle nesting grounds on North Island in Qilianyu, which can be used as a reference for management strategies that mitigate plastic litter pollution.


Assuntos
Monitoramento Ambiental , Plásticos , Tartarugas , Animais , Plásticos/análise , China , Poluentes Químicos da Água/análise , Ilhas , Comportamento de Nidação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...