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1.
Environ Monit Assess ; 194(2): 91, 2022 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-35024963

RESUMEN

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.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Beijing , China , Ciudades , Conservación de los Recursos Naturales , Monitoreo del Ambiente , Política Ambiental , Contaminación Ambiental , Material Particulado/análisis
2.
BMC Infect Dis ; 22(1): 22, 2022 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-34983383

RESUMEN

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.


Asunto(s)
Virus de la Hepatitis A , Hepatitis A , Beijing/epidemiología , Genotipo , Hepatitis A/epidemiología , Virus de la Hepatitis A/genética , Humanos , Masculino , Epidemiología Molecular , Filogenia , ARN Viral/genética
3.
Zhonghua Er Ke Za Zhi ; 60(1): 30-35, 2022 Jan 02.
Artículo en Chino | MEDLINE | ID: mdl-34986620

RESUMEN

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.


Asunto(s)
Infecciones por Adenovirus Humanos , Adenovirus Humanos , Infecciones del Sistema Respiratorio , Infecciones por Adenovirus Humanos/epidemiología , Adenovirus Humanos/genética , Beijing/epidemiología , Niño , Niño Hospitalizado , Estudios Transversales , Femenino , Humanos , Lactante , Masculino , Filogenia , Infecciones del Sistema Respiratorio/epidemiología
4.
Huan Jing Ke Xue ; 43(1): 46-60, 2022 Jan 08.
Artículo en Chino | MEDLINE | ID: mdl-34989489

RESUMEN

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.


Asunto(s)
Contaminantes Atmosféricos , Aerosoles/análisis , Contaminantes Atmosféricos/análisis , Beijing , China , Monitoreo del Ambiente , Material Particulado/análisis , Estaciones del Año
5.
Huan Jing Ke Xue ; 43(1): 247-255, 2022 Jan 08.
Artículo en Chino | MEDLINE | ID: mdl-34989509

RESUMEN

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.


Asunto(s)
Ecosistema , Agua , Beijing , China , Monitoreo del Ambiente , Ríos
6.
BMC Infect Dis ; 22(1): 59, 2022 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-35039000

RESUMEN

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.


Asunto(s)
COVID-19 , Beijing/epidemiología , China/epidemiología , Humanos , Pandemias , Estudios Retrospectivos , SARS-CoV-2
7.
Sci Total Environ ; 802: 149695, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34438127

RESUMEN

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.


Asunto(s)
Contaminantes Atmosféricos , Aerosoles/análisis , Contaminantes Atmosféricos/análisis , Beijing , China , Monitoreo del Ambiente , Tamaño de la Partícula , Material Particulado/análisis , Estaciones del Año
8.
Microb Pathog ; 162: 105366, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34968645

RESUMEN

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.


Asunto(s)
Mycobacterium tuberculosis , Beijing , Genotipo , Humanos , Mycobacterium tuberculosis/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Virulencia
9.
Environ Res ; 204(Pt A): 111982, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34478729

RESUMEN

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.


Asunto(s)
Contaminantes Atmosféricos , Contaminantes Ambientales , Compuestos Orgánicos Volátiles , Aerosoles/análisis , Contaminantes Atmosféricos/análisis , Beijing , China , Carbón Mineral , Monitoreo del Ambiente , Material Particulado/análisis , Estaciones del Año
10.
Environ Sci Technol ; 56(1): 155-164, 2022 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-34910459

RESUMEN

During the SARS period in 2003 and COVID-19 pandemic period in 2020, unexpected severe particulate matter pollution occurred in northern China, although the anthropogenic activities and associated emissions have assumed to be reduced dramatically. This anomalistic increase in PM2.5 pollution raises a question about how source emissions impact the air quality during these pandemic periods. In this study, we investigated the stable Cu and Si isotopic compositions and typical source-specific fingerprints of PM2.5 and its sources. We show that the primary PM2.5 emissions (PM2.5 emitted directly from sources) actually had no reduction but redistribution during these pandemic periods, rather than the previous thought of being greatly reduced. This finding provided critical evidence to interpret the anomalistic PM2.5 increase during the pandemic periods in north China. Our results also suggested that both the energy structure adjustment and stringent regulations on primary emissions should be synergistically implemented in a regional scale for clean air actions in China.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , COVID-19 , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Beijing , China , Monitoreo del Ambiente , Humanos , Pandemias , Material Particulado/análisis , SARS-CoV-2
11.
J Environ Sci (China) ; 112: 210-217, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34955205

RESUMEN

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.


Asunto(s)
Contaminantes Atmosféricos , Ozono , Compuestos Orgánicos Volátiles , Contaminantes Atmosféricos/análisis , Beijing , China , Monitoreo del Ambiente , Hidrocarburos/análisis , Ozono/análisis , Compuestos Orgánicos Volátiles/análisis
12.
J Environ Sci (China) ; 112: 25-37, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34955209

RESUMEN

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%).


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Aerosoles/análisis , Contaminantes Atmosféricos/análisis , Beijing , Monitoreo del Ambiente , Humanos , Material Particulado/análisis , Estaciones del Año
13.
J Environ Sci (China) ; 115: 277-285, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-34969455

RESUMEN

The production and application of organophosphate esters (OPEs) have dramatically increased in recent years due to their use as a replacement for brominated flame retardants. In this study, 13 OPEs (Σ13OPEs) were analyzed in indoor air samples from kitchens and living rooms in 14 residential homes in Beijing, China. The concentrations of Σ13OPEs in kitchen air samples (mean: 13 ng/m3) were significantly (p < 0.05) higher than in living room air samples (5.0 ng/m3). In addition, paired window surface organic film samples were collected and analyzed to investigate film-air partitioning, exhibiting a mean concentration of Σ13OPEs of 4100 ng/m2. The congener profiles showed that tris(2-chloroisopropyl) phosphate (TCPP) was the predominant compound in both window film samples (48%) and the corresponding indoor air sample (56%). The estimated daily intakes (EDI) of OPEs via indoor air inhalation were 2.8 and 1.4 ng/kg/day for infants and adults, respectively, both of which are below the reference dose values (RfDs). Overall, these findings indicate that OPEs in the indoor air environment of residential homes in Beijing are not likely to pose a health risk to the general population.


Asunto(s)
Contaminación del Aire Interior , Retardadores de Llama , Adulto , Contaminación del Aire Interior/análisis , Beijing , China , Polvo/análisis , Monitoreo del Ambiente , Ésteres/análisis , Retardadores de Llama/análisis , Humanos , Organofosfatos/análisis
14.
J Environ Sci (China) ; 115: 432-442, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-34969471

RESUMEN

Carbon monoxide (CO) is primarily the result of incomplete combustion, which has important impacts on the atmospheric chemical cycle and climate. Improved quantitative characterization of long-term CO trends is important for both atmospheric modeling and the design and implementation of policies to efficiently control multiple pollutants. Due to the limitations of high time-resolution and high-quality long-term observational data, studies on long-term trends in the CO concentration in China are quite limited. In this study, the observational data of the concentration of CO in a rural site of Beijing during 2006-2018 was used to analyze the long-term trend in CO concentration in Beijing. The Theil-Sen method and the generalized additive model (GAM)-based method, were used to conduct the trend estimation analysis. We found that the concentration of CO at the Shangdianzi site showed a significant downward trend during 2006-2018, with a decline rate of 22.8 ± 5.1 ppbV per year. The declining trend in CO also showed phasic characteristics, with a fast decreasing rate during the period of 2006-2008, stable variations during the period of 2009-2013 and a continuous downward trend after 2013. The declining trend in the CO concentration in the south to west (S-W) sectors where the polluted air masses come from is more rapid than that in the sectors where the clean air masses come from. The declining trend in the CO concentration implies the improved combustion efficiency and the successful air pollution control policies in Beijing and the surrounding area.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Contaminación del Aire/prevención & control , Beijing , Monóxido de Carbono/análisis , China , Monitoreo del Ambiente , Material Particulado/análisis
15.
J Environ Sci (China) ; 115: 65-75, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-34969478

RESUMEN

Accurately quantifying the concentration and transport flux of atmospheric fine particulate matter (PM2.5) is vital when attempting to thoroughly identify the pollution formation mechanism. In this study, the mobile lidar measurements in Beijing on heavily polluted days in December from 2015 to 2018 are presented. The lidar was mounted on a vehicle, which could perform measurements along designated routes. On the basis of mobile lidar measurements along closed circuits of the 6th Ring Road around Beijing, the spatial distribution and transport flux of PM2.5 in Beijing were determined with information of wind field. In the spatial distribution, both the concentration and transport of PM2.5 were revealed to be more significant in the southern section of Beijing. The regional transport layer at heights < 1.3 km plays an important role in pollution formation. The maximum transport flux reached 1600 µg/(m2*sec) on 11 December 2016. With the aerosol boundary layer height determined from the image edge detection (IED) method, the inter-annual variations of the aerosol boundary layer height (ABLH) were also analysed. The ABLH decreased from 0.73 to 0.46 km during the same heavy pollution period from 2015 to 2018. Increasingly adverse aerosol boundary layer (ABL) meteorological factors, including lower ABLH, light winds, temperature inversions, and accumulated moisture, have become necessary for pollution formation in Beijing.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Aerosoles/análisis , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Beijing , China , Monitoreo del Ambiente , Material Particulado/análisis , Estaciones del Año
16.
Chemosphere ; 288(Pt 1): 132377, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34600012

RESUMEN

Volatile methyl siloxanes (VMS) have been widely used in personal care products and industrial applications, and are an important component of VOCs (volatile organic compounds) indoors. They have sufficiently long lifetimes to undergo long-range transport and to form secondary aerosols through atmospheric oxidation. To investigate these silicon-containing secondary organic aerosols (Si-SOA), we collected PM2.5 samples during 8th-21st August 2018 (summer) and 3rd-23rd January 2019 (winter) at an urban site of Beijing. As the oxidation of VMS mainly results in hydrophilic polar semi-volatile and non-volatile oxidation products, the differences between total water-soluble Si and total water-soluble inorganic Si were used to estimate water-soluble organic Si, considered to be secondary organic Si (SO-Si). The average concentrations of SO-Si during the summer and winter campaigns were 4.6 ± 3.7 and 13.2 ± 8.6 ng m-3, accounting for approximately 80.1 ± 10.1% and 80.2 ± 8.7% of the total water-soluble Si, and 1.2 ± 1.2% and 5.0 ± 6.9% of total Si in PM2.5, respectively. The estimated Si-SOA concentrations were 12.7 ± 10.2 ng m-3 and 36.6 ± 23.9 ng m-3 on average in summer and winter, which accounted for 0.06 ± 0.07% and 0.16 ± 0.22% of PM2.5 mass, but increased to 0.26% and 0.92% on certain days. We found that net solar radiation is positively correlated with SO-Si levels in the summer but not in winter, suggesting seasonally different formation mechanisms.


Asunto(s)
Contaminantes Atmosféricos , Compuestos Orgánicos Volátiles , Aerosoles/análisis , Contaminantes Atmosféricos/análisis , Beijing , Monitoreo del Ambiente , Material Particulado/análisis , Silicio , Compuestos Orgánicos Volátiles/análisis
17.
Environ Pollut ; 292(Pt B): 118407, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34715272

RESUMEN

Benefiting from the pollution controls implemented by the Chinese government, the concentrations of PM2.5, SO2, NO2 and CO showed a significant decrease in Beijing during 2013-2017. In this study, an observation-based method was employed to estimate the relative contributions of regional transport (MaxRTC) and local emissions (MinLEC) to air pollutant levels during 2013-2017 in Beijing. The results showed that the MaxRTC to SO2 and PM2.5 increased significantly over the five years, while those to CO and NO2 changed little. Furthermore, the difference in the emissions control efficiency (ΔECE) between Beijing (receptor region) and Shijiazhuang (source region), which refers to the concentration changes corresponding to unit emission changes of a certain air pollutant between the two regions, was introduced to verify the estimated variation in MaxRTC and MinLEC over 2013-2017. The negative value of ΔECE found for PM2.5 and SO2 supports the conclusion of an increasing effect of regional transport. This implies that local emissions control alone is not adequate for mitigating Beijing's air pollution, especially with the demand for continuously improving air quality. Joint prevention and control with regard to air quality on a regional scale is more important and urgent in the next Five-Year Plan.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Beijing , China , Monitoreo del Ambiente , Material Particulado/análisis
18.
J Environ Manage ; 302(Pt A): 113993, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34715614

RESUMEN

China's mega-urban agglomerations have experienced severe particulate matter pollution that is accompanied by rapid economic growth and extensive administrative division adjustment (ADA). However, the precise roles of ADA on the environmental quality are unknown. Using the geographical detector and evolution tree model, this study quantifies the effects and mechanisms of ADA on the changes in PM2.5 concentration in three mega-urban agglomerations: Beijing-Tianjin-Hebei (BTH), Yangtze River Delta (YRD), and Pearl River Delta (PRD) during 2000-2017. Our results showed that: (1) ADA had strong positive effects on PM2.5 concentrations in the 0-6 years lag and negative effects in the 7-10 years lag; (2) During 2000-2009, ADA elevated PM2.5 concentration by 5.93% via stimulating the development and transfer of heavy industry and urban sprawl in the BTH; (3) YRD and PRD respectively reduced the ADA's exacerbating effect to 5.26% and 4.98% via reasonable industrial structures and comprehensive cooperation mechanisms; (4) During 2009-2017, BTH and YRD integrated industrial transformation and environmental protection services through ADA, which alleviated 9.51% and 8.49% of PM2.5 pollution. PRD, meanwhile, accomplished orderly population dispersal and urban expansion by combining ADA with urban planning, thus reducing the PM2.5 concentration by 8.01%. We located three agglomerations in the evolution tree, which provide a basis for formulating relevant policies and region-oriented air pollution joint prevention control strategies.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Beijing , China , Ciudades , Monitoreo del Ambiente , Material Particulado/análisis
19.
J Affect Disord ; 298(Pt A): 80-85, 2022 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-34728284

RESUMEN

PURPOSE: The global coronavirus disease 2019 (COVID-19) epidemic has significantly impacted people's lives. This study aimed to examine the influence of the unexpected second wave of COVID-19 on sleep quality and anxiety of Chinese residents in Beijing in June 2020, compared with the initial outbreak at the beginning of 2020, and to investigate the associated factors. METHODS: Using a web-based cross-sectional survey, we collected data from 1,511 participants. assessed with demographic information, sleep quality and anxiety symptoms. The participants were asked to compare their recent sleep and sleep during the first outbreak. The Zung's Self-rating Anxiety Scale (SAS) was used to assess their current insomnia severity. Multivariable logistic regression models were used to analyze the association between COVID-19 epidemic and risk of sleep disturbance and anxiety symptom. RESULTS: The overall prevalence of sleep disturbance and anxiety symptoms were 50.8% and 15.3% respectively. People had significantly shorter sleep duration during the second wave of COVID-19(7.3 ± 1.3) h than the first outbreak (7.5 ± 1.4)h (p < 0.001). During the second outbreak, people were less concerned about infection and more concerned about financial stress and occupational inferference. Beijing residents did not have significant differences in sleep disturbance and anxiety compared with other regions, nor were occupations and nucleic acid testing associated risk factors. Home quarantine, health administrators, history of insomnia and anxiety-depression were significantly associated with sleep disturbance. Female gender, home quarantine, history of insomnia and anxiety-depression were significantly associated with anxiety. CONCLUSION: High prevalence of sleep disturbance and depression symptom was common during the second wave of COVID-19 crisis in Beijing. Home quarantine and previous history of insomnia and anxiety-depressive risk factors were associated with sleep disturbance and anxiety. Female gender was impacting predictor of anxiety. We need continuous assessment of the sleep quality and anxiety symptoms of this epidemic.


Asunto(s)
COVID-19 , Ansiedad/epidemiología , Beijing , Estudios Transversales , Femenino , Humanos , Internet , SARS-CoV-2 , Sueño
20.
Sci Total Environ ; 806(Pt 4): 151484, 2022 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-34742807

RESUMEN

Planetary boundaries define the safe operating space of human beings relative to the Earth's system, which is of great significance in helping human beings predict environmental safety limits. However, ecological boundaries have not been presented or downscaled to regional levels. Moreover, a method has not been developed to quantitatively measure the gap between the value of the services provided by the ecosystem and the size of the urban population and economy that the ecosystem can carry. Herein, we propose the concept and calculation model of the "ecological boundary" to quantitatively assess the ecosystem security gap size transgressed by humans. Ecological boundaries are defined as the maximum population and economic scale that a certain area can support under a certain ecologically productive area. The purpose of this paper is to investigate the ecological boundary in megacities, and Beijing is considered as a specific case. The results show that the consumption of natural resources has transgressed its ecological boundary in Beijing. The direct consequence is that the ecological well-being per capita continues to decrease. Fortunately, with decreases in the ecological footprint and land use/land cover change dynamic degree, the ecological boundary gap is gradually tightening. Moreover, the role of ecological boundaries as early warning signals of undesirable urban ecological environmental changes is discussed, the significance of the monetization of ecological boundaries is described, the factors underlying the ecological boundary gap in the process of accelerating urbanization in China are analyzed, and policy recommendations for resolving the threat to ecological security boundaries by megacities are presented. The primary purpose of our study is provide policymakers with information on the gap between the current well-being of humankind and critical capacity thresholds, which can help determine whether human activities have fallen into an unsustainable state that may result in undesirable eco-environmental changes that could have detrimental or even disastrous consequences for the population of a region.


Asunto(s)
Conservación de los Recursos Naturales , Ecosistema , Beijing , China , Ciudades , Ecología , Humanos
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