Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 239
Filtrar
1.
Acta Trop ; : 107308, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38945422

RESUMO

Dengue fever is a viral illness, mainly transmitted by Aedes aegypti and Aedes albopictus. With climate change and urbanisation, more urbanised areas are becoming suitable for the survival and reproduction of dengue vector, consequently are becoming suitable for dengue transmission in China. Chongqing, a metropolis in southwestern China, has recently been hit by imported and local dengue fever, experiencing its first local outbreak in 2019. However, the genetic evolution dynamics of dengue viruses and the spatiotemporal patterns of imported and local dengue cases have not yet been elucidated. Hence, this study implemented phylogenetic analyses using genomic data of dengue viruses in 2019 and 2023 and a spatiotemporal analysis of dengue cases collected from 2013 to 2022. We sequenced a total of 15 nucleotide sequences of E genes. The dengue viruses formed separate clusters and were genetically related to those from Guangdong Province, China, and countries in Southeast Asia, including Laos, Thailand, Myanmar and Cambodia. Chongqing experienced a dengue outbreak in 2019 when 168 imported and 1,243 local cases were reported, mainly in September and October. Few cases were reported in 2013-2018, and only six were imported from 2020 to 2022 due to the COVID-19 lockdowns. Our findings suggest that dengue prevention in Chongqing should focus on domestic and overseas population mobility, especially in the Yubei and Wanzhou districts, where airports and railway stations are located, and the period between August and October when dengue outbreaks occur in endemic regions. Moreover, continuous vector monitoring should be implemented, especially during August-October, which would be useful for controlling the Aedes mosquitoes. This study is significant for defining Chongqing's appropriate dengue prevention and control strategies.

2.
Sci Total Environ ; 946: 174127, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38908574

RESUMO

Black carbon (BC), as a critical light-absorbing constituent within aerosols, exerts profound effects on atmospheric radiation balance, climate, air quality and human health, etc. And it is also a long-standing focus in rapidly developing megacities. So, this study primarily focuses on investigating the variation characteristics and underlying causes of BC in Chongqing (31,914,300 population), which is one of the municipalities directly under the central government of China, serving as a pivotal economic hub in southwest China. Utilizing MERRA-2 reanalysis data, we examined the long-term changes of atmospheric BC over Chongqing 20 years (from 2002 to 2021). Moreover, BC mass concentration observations were conducted using an Aethalometer (AE-33) from March 15 to June 14, 2021 in Liangping District, Chongqing. The statistical analysis over the last 20 years reveals an annual mean BC concentration in Chongqing of 3.42 ± 0.20 µg/m3, exhibiting growth from 2002 to 2008, followed by a decline from 2008 to 2021. Monthly concentration displays a "U-shaped" trend, with the lowest values occurring in summer and the highest in winter. Due to topographical and meteorological influences, local emissions primarily contribute to BC pollution, characterized by a spatial distribution pattern of high in the west and low in the east. Ground observation indicates a distinct dual-peaked pattern in the diurnal variation of BC, with peak concentrations aligning with periods of high traffic emissions. The variation in BC is significantly influenced by meteorological conditions (wind, temperature, atmospheric boundary layer) and local pollution sources (predominantly traffic). Furthermore, extreme events analysis suggests that local emissions and regional transport (with higher contributions from Chongqing and the Sichuan Basin) predominantly contributed to BC pollution. This study effectively makes up for the deficiency in analyzing the distribution and sources of BC pollution in Chongqing, providing valuable scientific insights for the atmospheric environment of megacities.

3.
Heliyon ; 10(11): e31578, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38841457

RESUMO

Optimizing the pattern of territorial space utilization is one of the key tasks to achieve the sustainable development goals. With the accelerating rate of global urbanization, the understanding of territorial space utilization efficiency, role and potential is a prerequisite for alleviating contradictions in urban and rural space distribution. The city cluster is the main form of organization for urban development in future, so the study attempted to explore the urban and rural space utilization efficiency (URSUE) in Chengdu-Chongqing urban agglomeration (CCEC) from coupling coordination degree (CCD) perspective. Considering the gradual increase in the trend of remote interactions between URSUE, we further introduced the Local and Tele-coupling coordination (LTCCD) model that takes into account interactive development relationship between different systems. The results of the study show that: In CCEC, the more economically developed cities indicated that urban spatial utilization efficiency lags behind rural spatial utilization efficiency; The LTCCD in the geographic center region will indicate a higher level but the LTCCD in the economic core cities is higher compared with their CCD level, especially in Chengdu City. This suggests that the LTCCD model is better able to take into account regional development correlations and spatial spillovers effect. This study attempts to explore several key issues of urban-rural spatial allocation in the process of urbanization development and to provide guidance for the territorial space utilization planning in urban agglomerations.

4.
Heliyon ; 10(11): e31577, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38828355

RESUMO

The fast urbanization in China makes it all the more important to find sustainable solutions that are both comprehensive and energy-efficient. Because of its important role in lowering logistical expenses and pollutant emissions, intermodal transport is generally seen as an effective method of coordinating transportation operations, helping to address the growing economic and environmental issues. Considering the characteristics of a growing city, this article lays out a multi-criteria method for selecting which new initiatives for China's public transportation system should be prioritized. "Electric municipality bus," "light rail system," and "modernization to the current fleet and optimization" are the three enhancement initiatives that are outlined. Using transportation-related economic, social, and environmental sub-criteria, this research applies TOPSIS, an analytic hierarchy method and fuzzy approach for order preference by resemblance to ideal circumstance application, to prioritize transportation projects. The study aims to improve city life in Chongqing, China, by identifying the most environmentally friendly development projects. Applying the analytical hierarchy method (AHP), the relative importance of several sustainability criteria was established for use in making strategic decisions. The alternative projects for the given city have been ranked using the fuzzy TOPSIS approach. However, the investigated results show the supportive response of hybrid to environmental sustainability and vice versa for non-hybrid vehicles. However, the energy consumption in public transport remains a leading hurdle in sustainability across the three modes of transport: taxis, rail transit and buses. Finally, computer trains in public transport also surprisingly deal with environmental sustainability to keep the current & forthcoming generation from ecological harm. However, theoretical and empirical policy suggestions have been proposed to become clean & green shortly.

5.
Hum Vaccin Immunother ; 20(1): 2363076, 2024 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38847280

RESUMO

To optimize seasonal influenza control and prevention programs in regions with potentially complicated seasonal patterns. Descriptive epidemiology was used to analyze the etiology of influenza, and chi-square tests were used to compare the epidemic patterns among different influenza virus types and subtypes/lineages. From January 2010 to December 2019, a total of 63,626 ILI cases were reported in Chongqing and 14,136 (22.22%) were laboratory-confirmed influenza cases. The proportions of specimens positive for influenza A and influenza B were 13.32% (8,478/63,626) and 8.86% (5,639/63,626), respectively. The proportion of positive specimens for influenza A reached the highest in winter (23.33%), while the proportion of positive specimens for influenza B reached the highest in spring (11.88%). Children aged 5-14 years old had the highest proportion of positive specimens for influenza. The influenza virus types/subtypes positive was significantly different by seasons and age groups (P<.001), but not by gender (p = .436). The vaccine strains were matched to the circulating influenza virus strains in all other years except for 2018 (vaccine strain was B/Colorado/06/2017; circulating strain was B/Yamagata). The study showed significant variations in epidemic patterns, including seasonal epidemic period and age distributions, among different influenza types, subtypes/lineages in Chongqing. Influenza vaccines matched to the circulating influenza virus strain in nine of the ten years. To prevent and mitigate the influenza outbreaks in this area, high risk population, especially children aged 5-14 years, are encouraged to get vaccinated against influenza before the epidemic seasons.


Assuntos
Vírus da Influenza B , Influenza Humana , Estações do Ano , Humanos , Criança , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Influenza Humana/virologia , China/epidemiologia , Adolescente , Pré-Escolar , Masculino , Feminino , Vírus da Influenza B/classificação , Vírus da Influenza B/isolamento & purificação , Lactente , Adulto Jovem , Pessoa de Meia-Idade , Adulto , Idoso , Vírus da Influenza A/classificação , Vírus da Influenza A/isolamento & purificação , Vacinas contra Influenza/administração & dosagem , Epidemias , Recém-Nascido
6.
Huan Jing Ke Xue ; 45(6): 3402-3411, 2024 Jun 08.
Artigo em Chinês | MEDLINE | ID: mdl-38897761

RESUMO

Studies on the spatio-temporal variation and coordinated development level of compactness with carbon emission intensity in the Chengdu-Chongqing urban agglomeration is of great significance to achieve green, low-carbon, and high-quality development of society. The spatial-temporal differentiation, coupling coordination, and driving factors of the compactness and carbon emission intensity of the Chengdu-Chongqing urban agglomeration from 2010 to 2020 were analyzed by using the methods of comprehensive evaluation, carbon emission identical equality, coupling coordination, and the Geo-detector model. The results showed that:① The compactness of the Chengdu-Chongqing urban agglomeration continued to rise from 0.18 in 2010 to 0.22 in 2020, with an overall increase of 22.22 %, in which the contribution rate of economic compactness to urban compactness increased yearly. There were significant regional differences in the compactness of cities. The high-value areas were concentrated in Chengdu, Deyang, and Mianyang in the northwest and Zigong, Neijiang, and Luzhou in the southwest, whereas the low-value areas were distributed in the middle. Ya'an was always the area with the lowest compactness of urban agglomeration. ② The carbon emission intensity of the Chengdu-Chongqing urban agglomeration was decreasing yearly, with a decrease rate of 39.57 % during the study period. The carbon emission intensity in the southern part of the urban agglomeration was higher than that in other regions as a whole, whereas Chengdu and Chongqing were low-value areas all the year round, and the regional differences of carbon emission intensity were gradually narrowing. ③ The coupling degree between urban compactness and carbon emission intensity changed from the antagonistic stage to the running-in stage; the coupling coordination degree increased notably, from 0.21 in 2010 to 0.69 in 2020; and the two systems gradually moved towards benign and coordinated development. The coupling coordination between the northwest of the urban agglomeration (Chengdu, Deyang, and Mianyang) and the south of Sichuan (Zigong and Luzhou) was generally high. Industrial structure, scientific and technological innovation, urbanization level, government intervention, and environmental livability all had significant effects on the coupling and coordination of the two systems. ④ Optimizing industrial structure, strengthening scientific and technological support, improving the quality of urbanization development, implementing active policy guidance, and building green barriers were effective ways to promote the coordinated development of compactness and low carbon in the Chengdu-Chongqing urban agglomeration.

7.
Heliyon ; 10(9): e30375, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38756590

RESUMO

With the strengthening of the cross-regional flows of the economy, information, innovation, and population, this paper constructs a network model of multi-flow integration and analyzes the spatial pattern and influencing factors of urban networks in Chengdu-Chongqing Urban Agglomeration using social network analysis and spatial analysis technology. The main conclusions are as follows. (1) The density and efficiency are in the transition stage from the primary level to the medium level in the comprehensive network. (2) The overall pattern keeps a polyhedral pyramid structure with Chengdu ↔ Chongqing as the core axis, and the grade of each axis has been significantly raised. (3) Four groups are formed using the social network method and show a geographic proximity effect. In addition, the connections within each group are relatively close, but the connections between the groups are significantly different. (4) Location conditions, economic development level, enterprise development level, scientific research investment, scientific and technological development level, and government support have a greater impact on the formation of the comprehensive network of Chengdu-Chongqing urban agglomeration. Information application level and transportation accessibility show a small impact and human capital level has not yet produced a significant impact.

8.
Disaster Med Public Health Prep ; 18: e85, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38699831

RESUMO

OBJECTIVE: To investigate the rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody among unvaccinated voluntary blood donors in Chongqing, and to provide evidence for epidemic surveillance. METHODS: A total of 10,208 voluntary blood donors from January 5 to January 20, 2021, in the Chongqing area were collected, and the SARS-CoV-2 immunoglobulin (Ig) G and IgM antibodies were detected by chemiluminescence, and the differences of antibody-positive rate in different gender, age, ABO blood group, and different risk areas were analyzed. RESULTS: Among 10208 blood donors, 10 were found to be positive for SARS-COV-2 IgG antibody, giving a positivity rate of SARS-COV-2 IgG at 0.10%, and 29 were positive for SARS-CoV-2 IgM antibody, with a positivity rate of SARS-CoV-2 IgM at 0.28%. There was no statistical difference in the positive rate of antibody among different genders, ages, and ABO blood types, but it was related to the number of confirmed coronavirus disease 2019 (COVID-19) cases in each city. CONCLUSIONS: The SARS-CoV-2 seroprevalence rate in Chongqing was low and correlated with the number of confirmed COVID-19 cases.


Assuntos
Anticorpos Antivirais , Doadores de Sangue , COVID-19 , Imunoglobulina G , Imunoglobulina M , SARS-CoV-2 , Humanos , China/epidemiologia , Doadores de Sangue/estatística & dados numéricos , Masculino , Feminino , COVID-19/epidemiologia , COVID-19/sangue , COVID-19/diagnóstico , COVID-19/imunologia , Adulto , SARS-CoV-2/imunologia , Pessoa de Meia-Idade , Anticorpos Antivirais/sangue , Imunoglobulina M/sangue , Imunoglobulina G/sangue , Adolescente , Programas de Rastreamento/métodos , Programas de Rastreamento/estatística & dados numéricos , Estudos Soroepidemiológicos
9.
Nutrients ; 16(9)2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38732561

RESUMO

Background: Unhealthy lifestyles among adolescents are reaching alarming levels and have become a major public health problem. This study aimed to assess the relationship between sleep time, physical activity (PA) time, screen time (ST), and nutritional literacy (NL). Methods: This cross-sectional online study involving adolescents aged 10-18 years was conducted in September 2020 in 239 schools in Chongqing, China. NL was measured using the "Nutrition Literacy Scale for middle school students in Chongqing (CM-NLS)". According to the recommended by the Chinese dietary guidelines (2022), we divided the sleep time of junior high school students into <9 h and ≥9 h, high school students into <8 h and ≥8 h, divided the workdays into weekend PA time < 1 h and ≥1 h, and divided the workdays into weekend ST < 2 h and ≥2 h. The multinomial logistic regression model was used to examine the association. Results: A total of 18,660 adolescents (50.2% males) were included. The proportion of participants that were junior high school students and attended boarding schools was 57.2% and 65.3%, respectively. Compared with senior high school students, junior high school students had a higher level of NL. Whether on workdays or weekends, participants with sleep time ≥ 8/9 h, PA time ≥ 1 h, and ST < 2 h per day had higher levels of NL. On weekdays, participants who met the sleep time ≥ 8 h/9 h (OR = 1.48, 95% CI: 1.36, 1.62) and PA time ≥ 1 h (OR = 1.69, 95% CI: 1.59, 1.81) had higher reporting of NL levels. Conclusions: Sleep time, PA time, and ST were positively correlated with NL among adolescents, especially junior high school students.


Assuntos
Exercício Físico , Letramento em Saúde , Tempo de Tela , Sono , Humanos , Adolescente , Estudos Transversais , Masculino , Feminino , China , Sono/fisiologia , Criança , Letramento em Saúde/estatística & dados numéricos , Fatores de Tempo , Estudantes/estatística & dados numéricos
10.
Environ Sci Pollut Res Int ; 31(21): 30914-30942, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38622421

RESUMO

The quantification of green space green plot ratio (GPR) is mostly based on estimation formulas, and the leaf area index (LAI) estimation values in these estimation formulas have not been well verified by measured LAI values, resulting in errors and uncertainties in GPR quantification results. This study aims to address this gap by measuring the LAI of 113 regional plants in Chongqing, China, following a standardized measurement path for digital hemispherical photography (DHP). The results indicate that the optimal relative exposure value (REV) was - 1 under overcast conditions and - 2 under sunny and cloudy conditions. Among the threshold algorithms for hemispherical images, the Intermodes algorithm in ImageJ was the best. The LAI of regional plants is highest in summer, followed by spring and autumn, and lowest in winter. Tree height (h) and crown width (w) are key factors affecting LAI, but the LAI also varies with plant species. Overall, the LAI of evergreen trees is higher than that of deciduous trees. The LAI of evergreen trees and shrubs with a height shorter than 5 m is the largest, and that of deciduous trees and shrubs with a crown width larger than 8 m is the largest. The study further verified that the existing GPR estimation formula exhibited large errors in Chongqing, while there was a strong correlation (R2 = 0.973) between the GPR estimation value and the measured value. A conversion formula was developed to reduce estimation biases, and the corrected formula is capable of estimating GPR values more accurately when actual LAI measurements are insufficient. Overall, this study verifies the significance of measuring localized LAI values, promotes the understanding of LAI suitability for GPR calculations, and provides an empirical formula for GPR estimation in Chongqing, China.


Assuntos
Folhas de Planta , China , Algoritmos , Árvores , Monitoramento Ambiental/métodos
11.
Environ Sci Pollut Res Int ; 31(16): 24425-24445, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38443529

RESUMO

The Chengdu-Chongqing twin-city economic circle is a vital growth pole and a new power source for Chinese high-quality development. Studying the spatial-temporal characteristics of carbon emissions and the role of factors affecting them under the transportation perspective is of great significance for this region to realize the carbon peak and carbon neutrality and to formulate carbon emission reduction policies. We use the exploring spatial data analysis (ESDA) and spatial regression model combined with the STIRPAT model, and research finding: (1) The total carbon emissions in the research area gradually increased from 2014 to 2020, but the growth rate showed a significant decline in 2019. (2) There is significant spatial heterogeneity of carbon emissions in the study area; the hotspot areas of total carbon emissions are in Chongqing and Chengdu, forming a high-low aggregation of carbon emissions. Per capita carbon emissions show a high trend in the southwest and a low in the northeast. (3) From the factors of transportation perspective, highway density and private vehicles have a positive impact on carbon emissions, and urban road areas and public transportation have a very significant inhibition of carbon emissions and a spatial spillover effect. (4) Other factors, such as population size, national economic development, urbanization level, and industrial structure, all have a positive effect on carbon emissions, and disposable income has a negative effect on carbon emissions.


Assuntos
Carbono , Dióxido de Carbono , China , Desenvolvimento Econômico , Fontes de Energia Elétrica
12.
Foods ; 13(6)2024 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-38540826

RESUMO

Green huajiao has a unique flavor and is widely used in cooking as an edible spice. In this study, the intensity of overall aroma and aroma attributes of seven green huajiao samples from the Sichuan and Chongqing regions were evaluated using a dynamic dilution olfactometer and ranking descriptive analysis (RDA) technology. The volatile compounds and major aroma components were determined by GC-MS in combination with odor activity value (OAV) analysis. The partial least squares regression (PLSR) model was further used to identify the key aromas contributing to the aroma sensory attributes. Seven green huajiao samples were categorized into three groups: (1) huajiao samples from Liangshan have a strong intensity of pungent, floral and herbal aromas and a medium-high intensity of sweet aroma, and the key contributing aroma compounds were α-pinene, sabinene, ß-pinene, myrcene, ocimene and linalool; (2) huajiao samples from Panzhihua and Hongya have a strong intensity of citrusy, lemony and minty aromas, and the key contributing aroma compound was linalool; and (3) the huajiao sample from the Chongqing region was categorized into a separate group and was characterized by a medium-high intensity of green, minty and sweet aromas, and the main aroma compounds are ocimene, citronellal and α-terpineol. These results provide useful basic data for evaluating the aroma quality and analyzing the key aroma characteristics of green huajiao in the Sichuan and Chongqing regions.

13.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 32(1): 214-218, 2024 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-38387924

RESUMO

OBJECTIVE: To analyze the genotype distribution and hematological characteristics of children with thalassemia in Chongqing. METHODS: A total of 207 children with thalassemia admitted to Chongqing University Three Gorges Hospital from January 2021 to October 2022 were selected as the research objects. The genotype distribution and hematological characteristics were retrospectively analyzed. RESULTS: 207 cases of thalassemia were confirmed from 482 samples by gene detection, the detection rate was 42.95%, α-thalassemia accounted for 17.63%(85/482), ß-thalassemia accounted for 24.27%(117/482), and compound αß thalassemia accounted for 1.04%(5/482). A total of 5 gene mutation types of α-thalassaemia were detected in this study, which constituted 6 genotypes, αα/-SEA was the most common one, followed by αα/-α3.7. A total of 8 gene mutation types of ß-thalassemia were detected, which constituted 9 genotypes, the top three were CD17/N, CD654/N and CD41-42/N. The highest detection rate was found in the patients aged 0-3 years (57%), and the degree of anemia was mainly mild (88.41%). 97.58% of the patients were MCV< 80 fl, 98.55% were MCH< 28 pg, 60.87% were MCHC< 320 g/L, and 71.50% were RDW-SD < 37%. The MCV and MCH of ß-thalassemia group were lower than that of α-thalassemia group, and the MCHC was higher than that of α-thalassemia group (P <0.05), but RDW-SD was not significantly different between the two groups (P >0.05). There were no significant differences in MCV, MCH, MCHC and RDW-SD between ß+/ßN and ß0/ßN groups ( P >0.05). The MCV and RDW-SD of --/αα thalassemia group were lower than that in -α/αα thalassemia group, the differences were statistically significant (P < 0.05), but MCH and MCHC were not significantly different between the two groups (P >0.05). CONCLUSION: The genotypes of children with thalassemia in Chongqing are diverse and heterogeneous, and the majority of them are mild anemia. There are differences in haematological indexes among different genotypes of thalassemia.


Assuntos
Talassemia alfa , Talassemia beta , Criança , Humanos , Talassemia beta/genética , Talassemia alfa/genética , Talassemia alfa/diagnóstico , Estudos Retrospectivos , Genótipo , Mutação , China/epidemiologia
14.
Environ Sci Pollut Res Int ; 31(15): 22976-22993, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38418788

RESUMO

The research on the spatiotemporal changes and driving factors of ecosystems in rapidly urbanizing regions has always been a topic of widespread concern. As the fourth pole of China's economic development, the research on the Chengdu-Chongqing region has reference significance for the urbanization process of developing countries such as India, Brazil, and South Africa.The normalized difference vegetation index (NDVI) has been widely applied in studies of plant and ecosystem changes. Based on MODIS NDVI data from 2001 to 2020 and meteorological data of the same period, this study reveals the evolution of NDVI in the Chengdu-Chongqing region from three aspects: the spatiotemporal variation characteristics of NDVI, the prediction of future trends in vegetation coverage, and the response of vegetation to climate change and human activities. During the period of plant growth, the mean NDVI achieved a value of 0.78, and the vegetation coverage rate is increasing year by year. According to the Hurst index, the future NDVI in Chengdu-Chongqing region will tend to decrease, and its trend is opposite to that of the past period of time. The Chengdu-Chongqing region vegetation positively affected by human activities is greater than those negatively affected, and in terms of vegetation degradation, the impact of human activities is greater than climate change.


Assuntos
Ecossistema , Urbanização , Humanos , Desenvolvimento Vegetal , China , Mudança Climática , Temperatura
15.
Huan Jing Ke Xue ; 45(1): 48-60, 2024 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-38216457

RESUMO

To investigate the characteristics, source apportionment, and potential source areas of carbonaceous aerosols in Chongqing during winter, PM2.5 samples were collected from January 2021 to February 2021 in the urban areas of Wanzhou (WZ), Yubei (YB), and Shuangqiao (SQ). The results showed that the average mass concentrations of PM2.5, OC, and EC in SQ were (72.6 ±33.3), (18.2 ±8.2), and (4.4 ±1.7) µg·m-3, respectively, higher than those in WZ[(67.2 ±30.3), (17.2 ±7.4), and (5.1 ±2.4) µg·m-3] and YB[(63.4 ±25.7), (15.4 ±6.3), and (4.2 ±1.9) µg·m-3]. Compared with that during the clear period, the concentration and fraction of EC in total carbon increased by 103.0% and 8.1%, respectively, in WZ compared to that in other areas during pollution period, whereas the OC/EC ratio was decreased significantly (-10.5%), indicating that the primary emission of carbonaceous aerosols increased significantly during the pollution period. The average mass concentrations of secondary organic carbon (SOC) in SQ and YB were (7.7 ±4.8) µg·m-3 and (6.9 ±2.8) µg·m-3 significantly higher, respectively, than that in WZ[(4.5 ±1.9) µg·m-3] during the campaign. This indicated that the secondary transformation had a greater influence on the carbonaceous aerosols in SQ and YB than that in WZ. Furthermore, in contrast to that in WZ, the ratios of SOC/OC were increased with the increase in PM2.5 concentrations, and significant correlations between SOC concentration and aerosol water content, NO2 concentration, and the value of NOR were observed in SQ and YB (P < 0.01), indicating that the increasing of carbonaceous aerosol concentrations might be mainly driven by the SOC with -NO2 groups produced by aqueous chemical reactions during winter in SQ and YB. The positive definite matrix factor (PMF) results in these urban areas showed that the contribution of biomass/coal combustion source in WZ (47.4%) was significantly higher than that in YB (34.2%) and SQ (38.1%), whereas the gasoline motor vehicle emission and secondary transformation impacts were more significant in YB. The results of the concentration weighted trajectory (CWT) showed that the potential sources of carbonaceous aerosols were mainly the local and northeastern parts of these urban areas (such as Changshou).

16.
Huan Jing Ke Xue ; 45(1): 396-406, 2024 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-38216489

RESUMO

To analyze the source apportionment and health risk of heavy metals in agricultural soils of major producing areas of agricultural products in Chongqing, a positive matrix factorization (PMF) model and health risk assessment (HRA) model based on Monte Carlo simulation were used. Meanwhile, both the PMF and HRA model were combined to explore health risks of heavy metals in agricultural soils by different pollution sources in order to determine the priority control factors. The results showed that the average values of Cd concentration were higher than its corresponding background value; the average values of Cr concentration were lower than its corresponding background value; and the average values of As, Pb, Cu, Ni, and Zn concentration were basically consistent with their corresponding background values. Using PMF model analysis, natural sources, industrial sources, and agricultural sources were identified as the determinants for the accumulation of heavy metals in agricultural soils, with the contribution rates of 35%, 24%, and 41%, respectively. Using the HRA model based on Monte Carlo simulation analysis, carcinogenic risks of adult and children were tolerable (1.00E-6 < TCR ≤ 1.00E-4), whereas non-carcinogenic risks were acceptable (HI ≤ 1). Oral ingestion was the main exposure pathway. The analysis results of the relationship among heavy metals, pollution sources, and health risks showed that industrial pollution and As were identified as priority control factors, and agricultural pollution and Cd were identified as secondary control factors. Our findings provide scientific support for decision makers to control soil pollution and reduce the management costs of soil pollution.


Assuntos
Metais Pesados , Poluentes do Solo , Adulto , Criança , Humanos , Solo , Monitoramento Ambiental , Cádmio/análise , Poluentes do Solo/análise , Metais Pesados/análise , Medição de Risco , China
17.
Environ Sci Pollut Res Int ; 31(2): 3134-3151, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38085472

RESUMO

Under the western development strategy of China, the urbanization process of Chengdu-Chongqing economic circle (CCEC) develops rapidly, but also brings a series of ecological and environmental problems. Understanding the coordination mechanism that links urbanization and the ecological environment (UE) is crucial for promoting environmental conservation and sustainable development. Using the comprehensive nighttime light index (CNLI) and the remote sensing ecological index (RSEI), this study objectively evaluated the urbanization level and ecological environment quality and used the modified coupling coordination degree model to quantify the coupling coordination of UE for the two indexes. The results show that (1) the urbanization level of each city in the CCEC presents an increasing trend year by year, showing a circle distribution pattern with the twin cities as the core. (2) The overall eco-environmental quality presents a fluctuating upward trend, and in recent years, it has been significantly improved, showing a spatial pattern of higher in the surrounding areas and lower in the middle. (3) The overall coupling coordination of the study area is developing, and the upward trend is larger in recent years. The spatial distribution is centered on the "double nucleus," and the distribution of circles is characterized by a gradual decrease from the inside to the outside; the coupling coordination of cities in the northwest and east of the CCEC is decreasing, and that of cities in the northeast and southwest is increasing. During the study period, a total of 5 cities have reached the level of coordinated development, while most other cities are in the stage of uncoordinated development, mainly due to the lagging development of urbanization. CCEC still needs to strengthen the construction of urbanization, in order to improve the degree of coordination between economic development and ecological environment.


Assuntos
Meio Ambiente , Urbanização , Cidades , China , Desenvolvimento Sustentável , Desenvolvimento Econômico
18.
Chemosphere ; 349: 140796, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38029936

RESUMO

Atmospheric humic-like substances (HULIS) could affect regional climate due to their strong light-absorbing capacity. Daily fine particulate matter (PM2.5) samples were collected from December 18, 2016 to January 8, 2017 at an urban site in Chongqing, Southwest China. The mean concentration of HULIS in terms of carbon (HULIS-C) was 6.4 ± 3.4 µg m-3, accounting for 72% of water-soluble organic carbon. The mass absorption efficiency at 365 nm (MAE365) and absorption Ångström index (AAE) of atmospheric HULIS were 2.8 ± 0.30 m2 g-1 C and 4.6 ± 0.37, respectively. Good correlations between the light absorption coefficients of HULIS at 365 nm (Abs365) and the concentrations of K+, elemental carbon, NO3-, and NH4+ were observed, with correlation coefficients higher than 0.83, indicating that biomass burning and secondary formation were potential sources of light-absorbing HULIS, as evidenced by abundant fluorescent components related to less-oxygenated HULIS. Comparing the changes in Abs365 values, concentrations of major water-soluble inorganic ions and carbonaceous compounds in PM2.5, and environmental factors during the clean and pollution periods, we found that extensive biomass burning during the pollution period contributed significantly to the increase of Abs365 values. Moreover, the aerosol pH during the pollution period was close to 4, and NO2 concentration and aerosol water content were about 1.6 and 2.7 times higher than those during the clean period, respectively, which were favorable to form secondary HULIS through aqueous phase reactions in the presence of high NOx, resulting in an evident increase in its light absorption. Knowledge generated from this study is critical for evaluating the regional radiative forcing of brown carbon in southwest China.


Assuntos
Poluentes Atmosféricos , Poluentes Atmosféricos/análise , Substâncias Húmicas/análise , Água/química , Monitoramento Ambiental/métodos , Material Particulado/análise , Carbono/análise , Aerossóis/análise
19.
Heliyon ; 9(12): e22481, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38107299

RESUMO

Chongqing, as the last ecological barrier of the Upper Yangtze River, is constrained to achieve "dual carbon" goals due to imbalanced energy structure. Based on selecting the energy structure influencing factors through Copula function and Granger causality, a multi-dimensional dynamic support vector machine model (SSA-MFD-SVR-ARIMA) by adopting sparrow algorithm was constructed to predict the proportion of Chongqing's energy structure from 2021 to 2030 under the drive of green finance development, and an optimization path was obtained. The novel findings confirm that (1) the correlated contribution rate of Green Finance to optimizing Chongqing's Energy Structure is 10.8 %; (2) under the sustained growth rate of Green Finance at 4.5 %, the proportion of coal consumption will reach 40.03 % by 2030, and non-fossil energy consumption will account for 27 %. It confirms that Chongqing can achieve the Energy Development Plan assigned by the Central Government in 2025. The research proposes a four-dimensional optimized pathway from a financial perspective that includes green equity investments, digital finance for energy, financing environmental rights and interests, and developing an industry fund. Furthermore, our put forward the safeguard strategies for financing, innovation, linkage, and protection mechanisms of this pathway optimization.

20.
Zookeys ; 1186: 15-24, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38107660

RESUMO

Graphidessajinfoensissp. nov. is described from Chongqing and Guizhou in Southwest China. The diagnostic morphological characters of the new species are described and illustrated in color plates. The distribution of all species of the genus Graphidessa Bates, 1884 is mapped and the key to all species of this genus is updated. The COI gene sequence of the new species is also provided.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...