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1.
BMC Infect Dis ; 22(1): 59, 2022 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-35039000

RESUMO

BACKGROUND: In March 2020, the WHO declared the novel coronavirus outbreak a global pandemic. While great success in coronavirus disease 2019 (COVID-19) control has been achieved in China, imported cases have become a major challenge. This study aimed to describe the epidemiological and clinical characteristics of imported COVID-19 cases and to assess the effectiveness of screening strategies in Beijing, China. METHODS: This retrospective study included all imported cases transferred to Beijing Ditan Hospital from 29 February to 20 March 2020 who were screened by both chest computed tomography (CT) and reverse-transcriptase-polymerase chain reaction (RT-PCR) at the initial presentation. Demographic, clinical and laboratory data, in addition to chest CT imaging, were collected and analysed. RESULTS: In total, 2545 cases were included, among which 71 (2.8%) were finally diagnosed with laboratory-confirmed COVID-19. The majority 63 (88.7%) were from Europe. The most common initial symptoms were cough and fever, which accounted for 49.3% and 42.3%, respectively. Only four cases (5.6%) had lymphocytopenia, and thirteen cases (18.3%) demonstrated elevated levels of C-reactive protein (CRP). All cases had normal serum levels of procalcitonin (PCT). At initial presentation, among the 71 confirmed cases, 59 (83.1%) had a positive RT-PCR assay, and 35 (49.3%) had a positive chest CT. Twelve (16.9%) had a negative RT-PCR assay but a positive chest CT. CONCLUSIONS: A combination of RT-PCR and chest CT is an effective strategy for the screening of imported COVID-19 cases. Our findings provide important information and clinical evidence about the infection control of imported COVID-19 cases.


Assuntos
COVID-19 , Pequim/epidemiologia , China/epidemiologia , Humanos , Pandemias , Estudos Retrospectivos , SARS-CoV-2
2.
Environ Monit Assess ; 194(2): 91, 2022 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-35024963

RESUMO

Taking detailed rules for implementing of the plan on atmospheric pollution prevention and control in Beijing-Tianjin-Hebei region and surrounding areas promulgated and implemented in 2013 as the starting point, taking air pollution as the research object, using the propensity score matching method and difference-in-differences method to answer whether coordinated development of Beijing-Tianjin-Hebei is conducive to resolving the problem of air pollution. Using panel data from 251 cities in China 2003-2016, this paper discusses the environmental effects and mechanisms of coordinated urban cluster development. The results showed that the coordinated development of Beijing-Tianjin-Hebei had a significant and continuous effect on the convergence of PM2.5 to low levels. The results of further mechanism identification show that the policy of atmospheric joint defense rules in the process of Beijing-Tianjin-Hebei coordinated development mainly promotes the convergence of PM2.5 through population and economic scale effect, structural effect and technical effect, and promotes the convergence of PM2.5 in the low direction by reducing the economic growth scale of the city itself. It is suggested to further promote the formation and development of Beijing-Tianjin-Hebei integration, strengthen cooperation among local governments in environmental governance e across regions, and promote the green growth and coordinated development of urban clusters.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Pequim , China , Cidades , Conservação dos Recursos Naturais , Monitoramento Ambiental , Política Ambiental , Poluição Ambiental , Material Particulado/análise
3.
BMC Infect Dis ; 22(1): 22, 2022 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-34983383

RESUMO

BACKGROUND: The incidence of hepatitis A virus (HAV) infection is low in Beijing, China, but the risk of outbreaks still exists. It is difficult to identify possible sources of infection among sporadic cases based on a routine surveillance system. Therefore, a more effective surveillance system needs to be established. METHODS: The epidemiological data of hepatitis A were obtained from a routine surveillance system. Patients with HAV confirmed at the local hospitals were asked to complete a questionnaire that included additional case information and possible sources of infection. Serum and fecal specimens were also collected for testing HAV RNA by polymerase chain reaction. In addition, the 321-nucleotide segment of the VP1/2A junction region was sequenced to determine the HAV genotype. RESULTS: In 2019, 110 HAV cases were reported in Beijing, with an incidence rate of 0.51/100,000. 61(55.5%) of these patients were male. The greatest proportion of these patients were aged from 30 to 60 years. The rate was lower in suburban and rural areas compared to urban areas. Contaminated food consumption, particularly seafood consumption, was the primary potential source of infection. Among the 16 specimens of confirmed HAV cases that could be sequenced, 93.8% were HAV IA, and 6.3% were HAV IB. In addition, the samples collected from all HAV sequences in this investigation showed 89.4-100% nucleotide homology. Two groups (each with three sporadic cases) showed 100% nucleotide homology. The three sporadic cases in one group had the same possible source of infection: contaminated salad with raw vegetables and seafood. In the other group, the three sporadic cases did not have an epidemiological connection. CONCLUSIONS: In a low HAV prevalent area, such as in Beijing, incorporating molecular epidemiology into the routine surveillance system could help inform possible clusters of outbreaks and provide support for earlier control of HAV transmission. Nevertheless, increased sampling from detected cases and improved specimen quality are needed to implement such a system.


Assuntos
Vírus da Hepatite A , Hepatite A , Pequim/epidemiologia , Genótipo , Hepatite A/epidemiologia , Vírus da Hepatite A/genética , Humanos , Masculino , Epidemiologia Molecular , Filogenia , RNA Viral/genética
4.
Zhonghua Er Ke Za Zhi ; 60(1): 30-35, 2022 Jan 02.
Artigo em Chinês | MEDLINE | ID: mdl-34986620

RESUMO

Objective: To compare the clinical characteristics of different types of human adenovirus (HAdV) infection in hospitalized children with acute respiratory infection in Beijing, and to clarify the clinical necessity of adenovirus typing. Methods: In a cross-sectional study, 9 022 respiratory tract specimens collected from hospitalized children with acute respiratory infection from November 2017 to October 2019 in Affiliated Children's Hospital, Capital Institute of Pediatrics were screened for HAdV by direct immunofluorescence (DFA) and (or) nucleic acid detection. Then the Penton base, Hexon and Fiber gene of HAdV were amplified from HAdV positive specimens to confirm their HAdV types by phylogenetic tree construction. Clinical data such as laboratory results and imaging data were analyzed for children with predominate type HAdV infection using t, U, or χ2 test. Results: There were 392 cases (4.34%) positive for HAdV among 9 022 specimens from hospitalized children with acute respiratory infection. Among those 205 cases who were successfully typed, 131 were male and 74 were female, age of 22.6 (6.7, 52.5) months,102 cases (49.76%) were positive for HAdV-3 and 86 cases (41.95%), HAdV-7, respectively, while 17 cases were confirmed as HAdV-1, 2, 4, 6, 14 or 21. In comparison of clinical characteristics between the predominate HAdV type 7 and 3 infection, significant differences were shown in proportions of children with wheezing (10 cases (11.63%) vs. 25 cases (24.51%)), white blood cell count >15 ×109/L (4 cases (4.65%) vs.14 cases (13.73%)), white blood cell count <5×109/L (26 cases (30.23%) vs.11 cases (10.78%)), procalcitonin level>0.5 mg/L (43 cases (50.00%) vs. 29 cases (28.43%)), multilobar infiltration (45 cases (52.33%) vs.38 cases (37.25%)), pleural effusion (23 cases (26.74%) vs. 10 cases (9.80%)), and severe adenovirus pneumonia (7 cases (8.14%) vs. 2 cases (1.96%)) with χ²=5.11, 4.44, 11.16, 9.19, 4.30, 9.25, 3.91 and P=0.024, 0.035, 0.001, 0.002, 0.038, 0.002, 0.048, respectively, and also in length of hospital stay (11 (8, 15) vs. 7 (5, 13) d, Z=3.73, P<0.001). Conclusions: HAdV-3 and 7 were the predominate types of HAdV infection in hospitalized children with acute respiratory tract infection in Beijing. Compared with HAdV-3 infection, HAdV-7 infection caused more obvious inflammatory reaction, more severe pulmonary symptoms, longer length of hospital stay, suggesting the clinical necessity of further typing of HAdVs.


Assuntos
Infecções por Adenovirus Humanos , Adenovírus Humanos , Infecções Respiratórias , Infecções por Adenovirus Humanos/epidemiologia , Adenovírus Humanos/genética , Pequim/epidemiologia , Criança , Criança Hospitalizada , Estudos Transversais , Feminino , Humanos , Lactente , Masculino , Filogenia , Infecções Respiratórias/epidemiologia
5.
Huan Jing Ke Xue ; 43(1): 46-60, 2022 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-34989489

RESUMO

In order to investigate the chemical composition and source apportionment of aerosols during winter in the Beijing-Tianjin-Heibei region, the particular matter (PM) and aerosol chemical composition at Mt. Haituo were observed by using a GRIMM 180, a single-particle soot photometer (SP2), and a high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS) from December 28, 2020 to February 3, 2021. Combining these observations with meteorological data and the HYSPLIT model, we calculated the potential source contribution factor (PSCF) and concentration weighted trajectory (CWT) and analyzed the temporal evolution and potential sources apportionment of PM and aerosol chemical composition under different pollution processes. The results showed that the dust storm process mainly affected PM10 and PM2.5 in Mt. Haituo during the winter and had a small impact on PM1; by contrast, haze pollution mainly affected PM1. Chemical components of aerosol accounted for 85.0% and 73.4% of PM1 on clean and haze days, respectively, but only 47.4% of PM1 in dust storm processes. NO3- was the chemical component with the largest mass concentration in haze, accounting for 25.2% of PM1; black carbon (BC) had the largest mass concentration on clean and dust storm days, accounting for 24.1% and 12.8% of PM1, respectively. The median diameters of BC were 209.7, 207.5, and 204.7 nm on clean, dust storm, and haze days, respectively. Dp/Dc was 2.15 in haze pollution, which was 1.38 and 1.39 times that on dust storm and clean days, respectively. Diurnal variations in PM and aerosol chemical components were different during the different processes. PM10 and PM2.5had high mass concentrations at night and low mass concentrations during the daytime on clean and dust storm days and had a unimodal distribution with a peak at 14:00 in haze. Diurnal variations in chemical composition had a unimodal distribution on clean days and a bimodal distribution on dust storm and haze days. The chemical compositions of the BC coating layer were different under different processes. The coating layers of BC were mainly NH4NO3, (NH4)2SO4, and organic matter on the clean, dust storm, and haze days, respectively. The distribution of potential sources of PM1 and its chemical components were different under different processes. The high-value area of the potential sources was mainly concentrated in the Beijing-Baoding-Shijiazhuang-Yangquan area in the southwestern portion of the site during dust storms and was mainly concentrated in Yanqing, Huailai, and Changping in the areas around the site during haze.


Assuntos
Poluentes Atmosféricos , Aerossóis/análise , Poluentes Atmosféricos/análise , Pequim , China , Monitoramento Ambiental , Material Particulado/análise , Estações do Ano
6.
Huan Jing Ke Xue ; 43(1): 247-255, 2022 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-34989509

RESUMO

Macrobenthos can reflect the cumulative effect of various ecological threats on the water environment and are closely related to the health of river ecosystems. In this study, taking the North Canal River basin, a typical basin in Beijing, as an example, ecological data from 34 stations were investigated in the summer of 2015. Characteristics of the macrobenthos communities were analyzed, and driving environmental factors were identified using typical correspondence analysis. Thresholds and response species of those driving environmental factors were conducted using the thresholds indicator taxa analysis (TITAN). In this study, the health status of the river ecosystem was evaluated by the multi-metrics method and benthic index of biotic integrity (B-IBI). The benthic community was dominated by pollution-tolerant aquatic insects and mollusks, with a low-level Shannon-wiener diversity index between 0-1.01; fluoride, biochemical oxygen demand, ammonia-nitrogen, and total phosphorus were driving environmental factors influencing the community structure of macrobenthos. Indicator species of ammonia-nitrogen were identified by the TITAN in the North Canal River basin with a threshold range of 1.09-6.94 mg·L-1; three indicator species of total phosphorus were identified with a threshold range of 0.48-1.27 mg·L-1, which were all positive response species. According to the health assessment, the river ecosystem in the North Canal River basin was generally unhealthy, and the upstream ecosystem was better than that downstream; the health conditions in the mountainous areas of Changping district were the best, whereas those in Chaoyang and central city districts were the worst. This study can provide a basis for ecological restoration and pollution control of rivers and also provide a reference for the water ecological civilization construction in other cities.


Assuntos
Ecossistema , Água , Pequim , China , Monitoramento Ambiental , Rios
7.
Sci Total Environ ; 806(Pt 2): 150430, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34852427

RESUMO

This study aims to provide a comprehensive understanding of the role of urban waterbodies in avian ecology, which is instructive for both biodiversity conservation and urban planning. Based on bird surveys conducted in 41 urban parks in Beijing during the breeding and wintering seasons of 2018-2019, and using standardized regression analyses, we identified the specific effects of waterbody attributes on the full avian community and forest bird guilds. We assessed this at multiple spatial scales, first within the focal parks, and then within buffer zones with radius of 200 m and 1000 m. We found that waterbodies can serve as avian diversity "hotspots" in the urban landscape. More specifically, they support avian diversity in the following ways: (1) Parks with waterbodies maintain a higher number of bird species than parks without waterbodies during the breeding season and attract resident forest birds during the wintering season. (2) When not frozen, waterbodies inside and outside parks contribute equally to resident forest bird species richness, while more individuals were attracted by waterbodies within neighborhoods. (3) In parks without waterbodies, the number of forest bird species significantly increases with the number of waterbody patches within neighborhoods, while the corresponding relationship for parks with waterbodies is insignificant. These findings suggest a preference for habitats nearby waterbodies among forest birds residing highly urbanized areas. This study provides new insights into avian ecology in urban landscapes and scientific support for the idea that creating and maintaining urban waterbodies can conserve biodiversity.


Assuntos
Biodiversidade , Aves , Animais , Pequim , Conservação dos Recursos Naturais , Ecossistema , Florestas , Humanos
8.
Sci Total Environ ; 811: 152323, 2022 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-34910946

RESUMO

Driving behavior and speed enforcement are both important to road safety and affect vehicle exhaust emissions. Relationships between driving characteristics and safety or emissions have been assessed in multiple studies. However, there is scant information on whether safe driving also reduces emissions and how this relationship changes across urban areas. This study makes use of two similar GPS datasets collected in the metropolitan areas of Toronto and Beijing to conduct a comparative analysis of driving characteristics, speed limit violations, and emissions. Emissions for all trips were computed using the same emission rate database derived from a Portable Emissions Monitoring System (PEMS). We observe that the average speeds in the two cities are close to 25 km/h. In Toronto, the fraction of time spent at speeds over 80 km/h on expressways is 40% higher than in Beijing. We also note a higher level of accelerations in Toronto. The trips in Beijing have approximately 14%, 57%, 14%, and 21% lower emissions of carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOx), and particle number (PN), respectively. Drivers in Toronto violate speed limits in 93% of their trips for 21% of trip travel time while the numbers for Beijing are 43% and 4%. These differences are not necessarily due to driving behavior, but rather to driving characteristics, which encompass the effects of behavior, road network design, traffic congestion, trip patterns, and speed enforcement. A scenario was evaluated by reconstructing drive-cycles to assess the effects of speed limit enforcement for trips where violations were detected. In Toronto, if obeying the speed limit, the mean trip travel time was estimated to increase by 1.8 min. In contrast, trip emissions of CO2, CO, NOx, and PN were found to decrease, on average, by 5.2%, 19.1%, 5.2%, and 2.9%, respectively. Speed limit enforcement can result in lower emissions, by reducing aggressive accelerations.


Assuntos
Poluentes Atmosféricos , Poluentes Atmosféricos/análise , Pequim , Cidades , Óxidos de Nitrogênio/análise , Emissões de Veículos/análise
9.
Environ Res ; 204(Pt A): 111982, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34478729

RESUMO

Nitrated aromatic compounds (NACs) constitute a key segment of brown carbon (BrC), thereby contributing to the light-absorbing characteristics of aerosols in the atmosphere. However, until recently, there is a scarcity of research on their generation in the urban environment. The current study is based upon an extensive field study of NACs from fine particle samples obtained at an urban location in Beijing in the spring and summer of 2017, which was characterized by both high anthropogenic volatile organic compounds (VOCs) and high-NOx dominated conditions. The mean total concentration of the nine NACs was 8.58 ng m-3 in spring and 8.54 ng m-3 in summer. In the spring, the most abundant NACs were 4-nitrophenol (33.7%) and 4-nitrocatechol (19.3%), while in the summer, the most abundant NACs were 4-nitroguaiacol (34.9%) and 2, 4-dinitrophenol (23%). Atmospheric NACs were primarily produced from coal combustion (52%) and biomass burning (32%) in spring, and originated from the secondary formation (37%) and traffic (35%) in summer. NO2 could promote the formation of NACs with a significant effect on their compositions, especially for nitrophenols and nitrocatechols. It can also affect the formation of nitrated aerosols and their existing form. Inorganic nitrates were increased to conversion in the daytime when NO2 concentrations were higher than 30 ppb, but the corresponding oxidation products shifted to primarily organic ones at night. The transition was VOC-sensitive regimes for NAC formation, and nitration of toluene was a more important pathway during the campaign in Beijing.


Assuntos
Poluentes Atmosféricos , Poluentes Ambientais , Compostos Orgânicos Voláteis , Aerossóis/análise , Poluentes Atmosféricos/análise , Pequim , China , Carvão Mineral , Monitoramento Ambiental , Material Particulado/análise , Estações do Ano
10.
J Hazard Mater ; 423(Pt B): 127142, 2022 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-34537636

RESUMO

Screening and prioritizing hazardous substances in groundwater is crucial to monitor and control groundwater quality. Total of 283 substances were determined in 213 groundwater samples from the Beijing-Tianjin-Hebei region during 2019-2020. 184 substances were screened as candidates. 22 prioritizing indicators were evaluated and scored for the candidates to reflect their occurrence, mobility, persistence, bioaccumulation, acute and chronic ecotoxicities with different trophic levels, and long-term human health effects. Multi-attribute decision-making technologies were applied to prioritize these candidates, including analytic hierarchy process (AHP), TOPSIS and VIKOR. Greater weightings in AHP were assigned to attributes of occurrence and acute toxicity by experts' judgment. Hierarchical cluster analysis and principal component analysis were used to transform initial matrix with the 22 indicators into an orthogonalized matrix with 6 principal components, which represented general toxicity to aquatic organism and mammal, bioaccumulation, carcinogenicity & mutagenicity, persistence, and teratogenicity & endocrine, respectively. VIKOR and TOPSIS results were similar, but different from the AHP ranking. Two filter criteria harmonized their difference. Twenty-three substances were proposed as the priority substance with high hazard and potential exposure, and nitrate-nitrogen and ammonia-nitrogen were selected as additional priority substance frequently and extensively exceeding official groundwater quality standard on the regional scale.


Assuntos
Monitoramento Ambiental , Água Subterrânea , Animais , Pequim , China , Humanos , Nitratos
11.
Microb Pathog ; 162: 105366, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34968645

RESUMO

BACKGROUND: Mycobacterium tuberculosis Beijing genotype was associated with tuberculosis outbreaks and increased transmissibility. To understand the variation in virulence between Beijing and non-Beijing clinical isolates of M.tuberculosis genotypes, the esat-6 gene sequencing, and its expression was compared in the macrophage environment. MATERIALS & METHODS: Among 64 nonrepetitive, culture-positive M.tuberculosis, DNA extraction of 24 and 40 pure confirmed Beijing and non-Beijing isolates was accompanied by the boiling method. esat-6 gene PCR amplification and their sequencing were carried out by specific primers and its expression was performed on human macrophage cell line U937 after 6, 12, and 18 h of exposure to bacilli. The esat-6 mRNA transcription and expression in M. tuberculosis treated macrophage by Real-Time PCR and Western blot method. RESULTS: Data analysis based on sequencing of the east-6 gene PCR product showed that this gene exists in all isolates and there are no changes or single nucleotide variation between the Beijing and non-Beijing isolates. In Beijing strains, the esat-6 expression was increased during the study times, but it was constant in non-Beijing isolates. esat-6 gene expression in Beijing isolates reached to about 44.9 times more than non-Beijing isolates after 18 h incubation on the macrophages cell line. CONCLUSION: esat-6 is a conserved gene both in Beijing and non-Beijing isolates of M.tuberculosis. More expression of the east-6 gene in the macrophage model may indicate that this gene is likely to play a more important role in increasing the pathogenicity of Beijing strains.


Assuntos
Mycobacterium tuberculosis , Pequim , Genótipo , Humanos , Mycobacterium tuberculosis/genética , Reação em Cadeia da Polimerase em Tempo Real , Virulência
12.
J Environ Sci (China) ; 112: 210-217, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34955205

RESUMO

High loads of ground-level ozone have occurred with the implementation of the Air Pollution Prevention and Control Action Plan. However, the long temporal variation in precursor nonmethane hydrocarbons (NMHCs) has rarely been studied. In this study, we examined the evolution of NMHCs in Beijing based on ambient measurements from 2000 to 2019. The results indicated that the annual variation of ambient NMHCs during 2000 and 2019 could be divided into two stages. The mixing ratios of NMHCs rapidly rose during 2000 and 2009 (1.76 ppbv/year) but exhibited a downward trend from 2009 to 2019 at rate of 0.80 ppbv/yr. Moreover, the notable decrease in alkenes and aromatics after 2009 led to a sharp decrease in the propylene-equivalent concentration (PEC) (-0.80 ppbv/year). Implementation of emission reduction measures in Beijing have effectively reduced the contribution of vehicle-related sources, but the contribution of solvent usage and fuel consumption increased, which will become the focus of VOC control in Beijing in the future.


Assuntos
Poluentes Atmosféricos , Ozônio , Compostos Orgânicos Voláteis , Poluentes Atmosféricos/análise , Pequim , China , Monitoramento Ambiental , Hidrocarbonetos/análise , Ozônio/análise , Compostos Orgânicos Voláteis/análise
13.
J Environ Sci (China) ; 112: 25-37, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34955209

RESUMO

Submicron aerosol is of extensive concern not only due to its significant impact on air quality but also because it is detrimental to human health. In this study, we investigated the characteristics, sources and chemical processes of submicron aerosol based on real-time online measurements of submicron aerosols (NR-PM1) during December 2015 at an urban site in Beijing. The average mass concentration of NR-PM1 was 92.5±84.9 µg/m3, the hourly maximum was 459.1 µg/m3 during the entire observation. The organic aerosol (OA) (55%) was the largest contributor to NR-PM1. The average mass concentration of PAHs was 0.217±0.247 µg/m3, exhibiting the highest concentration at night and the lowest levels in the daytime. The average mass concentration of organic nitrate was 2.52±2.36 µg/m3 and that of inorganic nitrate was 7.62±8.22 µg/m3, accounting for 36% and 64%, respectively, of the total nitrate mass. Positive matrix factorization (PMF) differentiated the OA into five chemical components including LV-OOA, SV-OOA, COA, HOA and CCOA, accounting for 22%, 16%, 13%, 25% and 24% respectively, of the total OA. The average NR-PM1 mass concentration on the heavy polluted days (HPD) was 182.8±70.2 µg/m3, which was approximately 9 times that on clean days (CD). The enhanced secondary formation of SNA was evident on HPD, especially the rapid increase of sulfate (23%) and nitrate (19%).


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Aerossóis/análise , Poluentes Atmosféricos/análise , Pequim , Monitoramento Ambiental , Humanos , Material Particulado/análise , Estações do Ano
14.
Environ Pollut ; 292(Pt A): 118359, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34648842

RESUMO

Rapid urbanization and the aggregation of human activities in cities have resulted in large amounts of anthropogenic heat (AH) emission, which affects urban climate. Quantifying and assessing the AH emission values accurately and analyzing their spatial distribution characteristics is important to understand the energy exchange processes of urban areas. In this study, the high spatial resolution anthropogenic heat flux (AHF) quantification and spatial distribution analysis were conducted using multi-source data in the Beijing-Tianjin-Hebei region (BTH region) of China. First, the AH emission in district and city level were estimated using inventory method based on energy consumption and socio-economic statistical data; Then, AHF spatial quantification models were constructed based on high spatial resolution nighttime light (NTL) data and Point of interests (POI) data, and 130 m × 130 m gridded AHF quantification result in BTH region was realized; Finally, the potential numerical and spatial distribution patterns of AHF were analyzed using various indicators including contribution rate and aggregation index. The results show that: (1) The parameterized index constructed based on NTL and POI data shows a strong correlation with AHF, with R2 ranging from 0.79 to 0.94 and a mean absolute error (MAE) value of 0.72 w·m-2, which can be applied to the quantification of gridded AHF values with high resolution. The highest total AHF in the study area is 214 w·m-2, and the average value is 2.24 w·m-2. (2) Considering the sources of AHF, industrial emission sources in BTH region contribute the most to the total AHF, but commercial building emission sources in Beijing have a higher contribution, which can reach 33.8%. (3) Different types of AHF have different spatial aggregation levels. Commercial building emission and human metabolic emission have the highest aggregation level, and transportation emission has the lowest aggregation level.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Pequim , China , Cidades , Monitoramento Ambiental , Temperatura Alta , Humanos , Material Particulado/análise
15.
Sci Total Environ ; 804: 150028, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34798715

RESUMO

Estazolam (EZ) is a long-acting benzodiazepine (BZD) drug with high clinical consumption in China to treat anxiety, depression and other syndromes. Recently, it has been found as a leading potentially inappropriate medication among hospitalized elderly patients, increasing the risk of falls. It is discharged into the aquatic environment after use and has been frequently detected, ultimately affecting the safety of drinking water. In the present study, the reaction of EZ during chlorination disinfection was investigated in detail with regard to its transformation and kinetics. By means of ultra-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-QTOF-MS), four main disinfection byproducts (DBPs) were tentatively identified, and the transformation pathways were speculated to be cleavage at the imine linkage and oxidation on the diazepinone ring. The chlorination reaction rate in the pseudo-first-order kinetic model was significantly affected by free available chlorine (FAC) and pH. The increase in pH value led to a decrease in the reaction rate, while a higher dosage of chlorine resulted in a faster kinetic rate. We further estimated the potential toxicities of EZ and its DBPs using quantitative structure-activity relationship (QSAR) software tools. DBPs exhibited much higher toxicity than EZ and exhibited developmental toxicity and mutagenicity. Finally, a total of 108 drinking water samples were collected in the wet and dry seasons to determine actual residue changes in real environmental conditions. The detection frequency was 29% for EZ, and the highest concentration of 0.60 ng L-1 was found for its DBPs in tap water. No seasonal variations in concentration were observed. Overall, the results indicate that EZ and its DBPs may persist in drinking water, posing potential risks to public health.


Assuntos
Desinfetantes , Água Potável , Preparações Farmacêuticas , Poluentes Químicos da Água , Purificação da Água , Idoso , Pequim , Benzodiazepinas , Cloro , Desinfecção , Estazolam , Halogenação , Humanos , Poluentes Químicos da Água/análise
16.
Sci Total Environ ; 802: 149695, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34438127

RESUMO

Particle number size distribution (PNSD) is of importance for understanding the mechanisms of particle growth, haze formation and climate impacts. However, the measurements of PNSD aloft in megacities are very limited. Here we report the first simultaneous winter measurements of size-resolved particle number concentrations along with collocated gaseous species and aerosol composition at ground level and 260 m in Beijing. Our study showed that the vertical differences of particle number concentrations between ground level and aloft varied significantly as a function of particle size throughout the study. Further analysis illustrated the impacts of boundary dynamics and meteorological conditions on the vertical differences of PNSD. In particular, the temperature and relative humidity inversions were one of the most important factors by decoupling the boundary layer into different sources and processes. Positive matrix factorization analysis identified six sources of PNSD at both ground level and city aloft. The local source emissions dominantly contributed to Aitken-mode particles, and showed the largest vertical gradients in the city. Comparatively, the regional particles were highly correlated between ground level and city aloft, and the vertical differences were relatively stable throughout the day. Our results point towards a complex vertical evolution of PNSD due to the changes in boundary layer dynamics, meteorological conditions, sources, and processes in megacities.


Assuntos
Poluentes Atmosféricos , Aerossóis/análise , Poluentes Atmosféricos/análise , Pequim , China , Monitoramento Ambiental , Tamanho da Partícula , Material Particulado/análise , Estações do Ano
17.
Sci Total Environ ; 802: 149849, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34455273

RESUMO

Promoting land use planning through ecosystem service (ES) protection is a crucial approach for maintaining landscape sustainability. Identifying ES bundles to serve landscape functional zoning can provide a new perspective for sustainable land use planning. Taking the Beijing metropolitan region as a study area, we quantitatively assessed the spatiotemporal distributions of multiple ESs, from 1980 to 2017, based on land use changes. By combining ES patterns and comprehensive ecosystem service (CES), distinct ES bundles were identified through the clustering method. Based on the ES bundles, landscape functional zones were then established. We further developed improved land use scenarios to conserve ESs in selected towns of different functional zones by exploring dominant factors influencing ESs. Results showed that most of ESs decreased due to the expansion of developed lands. According to the classification of ES bundles, Beijing can be classified into three landscape functional zones at town level: the ecological conservation region (ECR), food production region (FPR), and urban development region (UDR). For each landscape functional zone, the town with the greatest decline in CES value was selected. Associated with the influencing factors of ESs, local land use patterns, and ecological protection policies, corresponding multi-step improved land use scenarios were designed. These scenarios were demonstrated to be effective in conserving ESs in the selected towns: (1) the agricultural expansion scenario, which enhanced food provision services in the ECR; (2) the forest conservation scenario, which enhanced habitat and recreational services in the FPR; and (3) the developed land optimization scenario, which enhanced a range of regulating services in the UDR. Overall, this study used landscape functional zoning as a nexus to connect ES patterns and land use management. The optimized land use strategies can provide references for conserving ESs and enhancing landscape sustainability in Beijing and other similar metropolitan areas worldwide.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Pequim , China , Florestas
18.
Sci Total Environ ; 803: 149735, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34492490

RESUMO

Currently, most regional thermal environment (RTE) studies in urban agglomerations focus on developing countries, especially China. However, there is still a lack of comparative studies on the RTEs of urban agglomerations between China and other developed countries, such as the United States. This paper used the Beijing-Tianjin-Hebei (BTH) agglomeration in China and Boswash (the highly urbanized area extending from Boston to Washington) in the United States as examples to investigate the differences in land development patterns, RTEs and their relationship between the agglomerations of China and America. The results showed that the land development patterns of BTH and Boswash were different, as evidenced by the spatial pattern of land development intensity (LDI) and impervious surface configuration. In terms of the RTE, the sub-high land surface temperature (LST) zones were aggregated in a large and compact patch in central and northern BTH. However, the sub-high zones of the cities in Boswash were relatively separate. Moreover, the land development pattern of Boswash showed a stronger relationship with the RTE than that of BTH did. Global Moran's I between the LDI and LST in Boswash was higher than that in BTH. In addition, the correlation between impervious surface configuration and LST in Boswash was stronger than that in BTH, and this correlation was more controlled by LDI in Boswash. This study also indicated that BTH should change the land development pattern to prevent the further expansion of aggregated sub-high LST zones and control the proximity of high LST zones in cities in central and southern BTH, however, Boswash should adopt some local heat management approaches (installing cool and green roofs and creating more green space) in the core areas to help reduce the very high temperatures in the already highly developed areas where the largest fraction of people live.


Assuntos
Monitoramento Ambiental , Pequim , Boston , China , Cidades , Humanos , Washington
19.
Sci Total Environ ; 803: 150079, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34525721

RESUMO

Characterizing the relationship between vegetation phenology and urbanization indicators is essential to understand the impacts of human activities on urban ecosystems. In this study, we explored the response of vegetation phenology to urbanization in Beijing (China) during 2001-2018, using impervious surface area (ISA) and the information of urban-rural gradients (i.e., concentric rings from the urban core to surrounding rural areas) as the urbanization indicators. We found the change rates of vegetation phenology in urban areas are 1.3 and 1.1 days per year for start of season (SOS) and end of season (EOS), respectively, about three times faster than that in forest. Moreover, we found a divergent response of SOS with the increase of ISA, which differs from previous results with advanced SOS in the urban environment than surrounding rural areas. This might be attributed to the mixed land cover types and the thermal environment caused by the urban heat island in the urban environment. Similarly, a divergent pattern of phenological indicators along the urban-rural gradient shows a non-linear response of vegetation phenology to urbanization. These findings provide new insights into the complicated interactions between vegetation phenology and urban environments. High-resolution weather data are required to support process-based vegetation phenology models in the future, particularly under different global urbanization and climate change scenarios.


Assuntos
Ecossistema , Urbanização , Pequim , China , Cidades , Temperatura Alta , Humanos , Desenvolvimento Vegetal
20.
Sci Total Environ ; 803: 149980, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34525764

RESUMO

Dust storm particles have been one of the important contributors to global aerosol loading, affecting human health and climate system. Beijing, a megapolitan city, experienced two severe dust storms in spring of 2015, with maximum hourly-mean PM10 mass concentrations exceeding 1000 µg/m3. The first dust storm (Dust 1) was from east area of Gobi Desert about 850 km in the north of Beijing and the second (Dust 2) was from west area of Gobi Desert about 1500 km in the northwest of Beijing. Morphologies and elemental compositions of dust particles were identified using high-resolution electron microscopy. The statistical analysis showed that the number fractions of mineral dust particles during the two dust storm episodes were 85.3% and 95.4%, respectively. Clay minerals were the most abundant among mineral particles, with a number fraction larger than 50%, followed by quartz particles (17.3% and 14.8%) and feldspar. Feldspar and carbonate particles accounted for 14.8% and 3.4% of mineral particles in Dust 1, and 9.9% and 13.6% in Dust 2, with the difference due to the different source areas. When the dust storms directly migrated to Beijing, the occurrence of S-containing mineral particles and the relative weight ratio of S in individual mineral particles were extremely low, indicating limited production of sulfate on the dust-storm particles in the atmosphere, regardless of the differences of source areas, migration paths, and mineralogical components. After the peaks of dust storms passed, the occurrence of S on the mineral particles were much higher, although the relative weight ratios of S in the mineral particles was still very small. This result suggests that most of the mineral particles underwent heterogeneous reactions, but the reaction rates were low.


Assuntos
Poluentes Atmosféricos , Aerossóis/análise , Poluentes Atmosféricos/análise , Pequim , Poeira/análise , Monitoramento Ambiental , Humanos , Minerais/análise , Tamanho da Partícula
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