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1.
Huan Jing Ke Xue ; 44(10): 5431-5442, 2023 Oct 08.
Article in Chinese | MEDLINE | ID: mdl-37827761

ABSTRACT

Recently, China has been facing the dual challenges of air pollution control and carbon emission reduction. Pollution and carbon reduction have become a breakthrough point for green socio-economic transformation. Air pollutant and CO2 emission inventories provide a tool for monitoring pollution and carbon reduction; however, there have been some problems in previous studies, including incomplete species coverage, different source classifications, and narrow time scales. Based on the unified emission source classification system and estimation method, an emission inventory was developed for Hebei Province from 2013 to 2020, and the emission trends, structure change, driving force, synergistic benefits, and spatial distribution were analyzed. Hebei Province achieved a balance during the study period in socio-economic development and anthropogenic emission control. SO2 emissions decreased rapidly during the "Ten Atmospheric Measures" period. VOCs and NH3 emissions reduction were more significant during the "Blue Sky Defense War" period. The decrease rates of NOx and PM2.5 emissions were relatively stable, and CO2 emissions increased slightly. The coal-fired treatment effectively reduced the air pollutant and CO2 emissions and strengthening the emission standards for key industries reduced SO2, NOx, and PM2.5 emissions; however, the VOCs emission control requires improvement. Power and residential sources achieved co-reduction of air pollutants and CO2 and reducing residential coal optimized the energy structure, thereby leading to greater synergistic benefits in the residential source. The key pollution and carbon reduction areas in Hebei Province were Shijiazhuang, Tangshan, Handan, Baoding, and Langfang. The methods and conclusions in this study can provide technical and decision-making references for regional pollution and carbon reduction efforts.

2.
Huan Jing Ke Xue ; 44(3): 1287-1296, 2023 Mar 08.
Article in Chinese | MEDLINE | ID: mdl-36922190

ABSTRACT

Railway transportation is one of the main modes of modern transportation. Under the dual constraints of air quality improvement and carbon neutrality achievement, clarifying the emission trend of CO2 and pollutants in railway transportation is of great significance for pollution and carbon reduction in the transport sector. In this study, the CO2 and pollutant emission characteristics of Chinese railways from 2001 to 2018 were analyzed based on the fuel life cycle method. Then, railway emission trends from 2019-2030 were assessed combined with scenario analysis. The results showed that with the advancement of railway electrification, the use of new diesel locomotives, and the continuous upgrading of fuel standards, the total CO2 and pollutant emissions in the fuel life cycle of railway transportation showed an upward and downward trend, respectively. In 2018, the total emissions of CO2, NOx, CO, BC, and SOx from railway transportation were 3780.29×104t, 11.98×104t, 3.94×104t, 0.20×104t, and 3.08×104t, respectively. Accelerating the improvement of power structure and reducing unit energy consumption were the best single control strategies to reduce railway emissions of CO2, SOx, NOx, BC, and CO, respectively. Under the comprehensive scenario of actively responding to railway pollution and carbon reduction, the emission reduction rates of CO2, NOx, CO, BC, and SOx could reach 35%, 37%, 39%, 32%, and 45%, respectively. The stagnation of power structure reform or the railway electrification process will lead to a significant increase in total emissions of railway transportation. Therefore, the pollution and carbon reduction of railway transportation requires continuous attention.

3.
Huan Jing Ke Xue ; 44(3): 1346-1356, 2023 Mar 08.
Article in Chinese | MEDLINE | ID: mdl-36922196

ABSTRACT

Vehicle emissions are an important source of anthropogenic volatile organic compound (VOCs) emissions in urban areas and are commonly quantified using vehicle emission inventories. However, most previous studies on vehicle emission inventories have incomplete emission factors and emission processes or insufficient consideration of meteorological parameters. Based on the localized full-process emission factors attained from tested data and previous studies, a method to develop a monthly vehicular VOC emission inventory of full process for the long-term was established, which covered exhaust and evaporative emissions (including running loss, diurnal breathing loss, hot soak loss, and refueling emission). Then, the method was used to develop a full-process vehicular VOC emission inventory in Tianjin from 2000 to 2020. The results showed that the total vehicular VOC emissions in Tianjin rose slowly and then gradually decreased. In 2020, the total emissions were 21400 tons. The light-duty passenger vehicles were the dominant contributors and covered 75.00% of the total emissions. Unlike the continuous decline in exhaust emissions, evaporative emissions showed an inverted U-shaped trend with an increasing contribution to total emissions yearly, accounting for 31.69% in 2020. Monthly emissions were affected by both vehicle activity and emission factors. VOC emissions were high in autumn and winter and low in spring and summer. During the COVID-19 epidemic in 2020, vehicle activity was limited by closure and control, making VOC emissions significantly lower than those during the same period in previous years. The method and data in this study can provide technical reference and a decision-making basis for air pollution prevention and control.

4.
Chin J Traumatol ; 24(4): 221-230, 2021 Jul.
Article in English | MEDLINE | ID: mdl-34099359

ABSTRACT

PURPOSE: Posttraumatic stress disorder (PTSD) is a significant global mental health concern, especially in the military. This study aims to estimate the efficacy of mindfulness meditation in the treatment of military-related PTSD, by synthesizing evidences from randomized controlled trials. METHODS: Five electronic databases (Pubmed, EBSCO Medline, Embase, PsychINFO and Cochrane Library) were searched for randomized controlled trials focusing on the treatment effect of mindfulness meditation on military-related PTSD. The selection of eligible studies was based on identical inclusion and exclusion criteria. Information about study characteristics, participant characteristics, intervention details, PTSD outcomes, as well as potential adverse effects was extracted from the included studies. Risk of bias of all the included studies was critically assessed using the Cochrane Collaboration's tool. R Statistical software was performed for data analysis. RESULTS: A total of 1902 records were initially identified and screened. After duplicates removal and title & abstract review, finally, 19 articles in English language with 1326 participants were included through strict inclusion and exclusion criteria. The results revealed that mindfulness meditation had a significantly larger effect on alleviating military-related PTSD symptoms compared with control conditions, such as treatment as usual, present-centered group therapy and PTSD health education (standardized mean difference (SMD) = -0.33; 95% CI [-0.45, -0.21]; p < 0.0001). Mindfulness interventions with different control conditions (active or non-active control, SMD = -0.33, 95% CI [-0.46, -0.19]; SMD = -0.49, 95% CI [-0.88, -0.10], respectively), formats of delivery (group-based or individual-based, SMD = -0.30, 95% CI [-0.42, -0.17], SMD = -0.49, 95% CI [-0.90, -0.08], respectively) and intervention durations (short-term or standard duration, SMD = -0.27, 95% CI [-0.46, -0.08], SMD = -0.40, 95% CI [-0.58, -0.21], respectively) were equally effective in improving military-related PTSD symptoms. CONCLUSION: Findings from this meta-analysis consolidate the efficacy and feasibility of mindfulness meditation in the treatment of military-related PTSD. Further evidence with higher quality and more rigorous design is needed in the future.


Subject(s)
Cognitive Behavioral Therapy , Meditation , Military Personnel , Mindfulness , Stress Disorders, Post-Traumatic , Humans , Randomized Controlled Trials as Topic , Stress Disorders, Post-Traumatic/therapy
5.
Chin J Traumatol ; 24(4): 187-208, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33994278

ABSTRACT

There has been a long history since human beings began to realize the existence of post-traumatic symptoms. Posttraumatic stress disorder (PTSD), a diagnostic category adopted in 1980 in the Diagnostic and Statistical Manual of Mental Disorders-Ⅲ, described typical clusters of psychiatric symptoms occurring after traumatic events. Abundant researches have helped deepen the understanding of PTSD in terms of epidemiological features, biological mechanisms, and treatment options. The prevalence of PTSD in general population ranged from 6.4% to 7.8% and was significantly higher among groups who underwent major public traumatic events. There has been a long way in the studies of animal models and genetic characteristics of PTSD. However, the high comorbidity with other stress-related psychiatric disorders and complexity in the pathogenesis of PTSD hindered the effort to find specific biological targets for PTSD. Neuroimage was widely used to elucidate the underlying neurophysiological mechanisms of PTSD. Functional MRI studies have showed that PTSD was linked to medial prefrontal cortex, anterior cingulate cortex and sub-cortical structures like amygdala and hippocampus, and to explore the functional connectivity among these brain areas which might reveal the possible neurobiological mechanism related to PTSD symptoms. For now, cognitive behavior therapy-based psychotherapy, including combination with adjunctive medication, showed evident treatment effects on PTSD. The emergence of more effective PTSD pharmacotherapies awaits novel biomarkers from further fundamental research. Several natural disasters and emergencies have inevitably increased the possibility of suffering from PTSD in the last two decades, making it critical to strengthen PTSD research in China. To boost PTSD study in China, the following suggestions might be helpful: (1) establishing a national psychological trauma recover project, and (2) exploring the mechanisms of PTSD with joint effort and strengthening the indigenized treatment of PTSD.


Subject(s)
Stress Disorders, Post-Traumatic , Animals , Brain , Comorbidity , Hippocampus , Humans , Magnetic Resonance Imaging , Stress Disorders, Post-Traumatic/epidemiology , Stress Disorders, Post-Traumatic/therapy
6.
Huan Jing Ke Xue ; 41(10): 4470-4481, 2020 Oct 08.
Article in Chinese | MEDLINE | ID: mdl-33124379

ABSTRACT

Mobile source emissions have become a major contributor to air pollution in urban areas. Most of the previous studies focus on the emissions from a single source such as on-road mobile source (vehicles) or non-road mobile source (construction machinery, agricultural machinery, ships, railway diesel locomotives, aircraft), but few studies investigate the mobile source emissions as a whole. In this study, we introduced a method for developing mobile source emission inventory with high spatiotemporal resolution, and applied this method in Tianjin in 2017 to analyze the emission compositions and spatiotemporal characteristics there. The results showed that the CO, VOCs, NOx, and PM10 emissions from the mobile sources were 183.03, 64.18, 149.85, and 8.36 thousand tons, respectively. The on-road mobile source was the main contributor to CO and VOCs emissions, accounting for 85.38% and 86.60%, respectively. The non-road mobile source was the main contributor to NOx and PM10 emissions, accounting for 57.32% and 66.95%, respectively. According to the temporal distributions, the mobile source emissions were lowest in February for all pollutants. Moreover, they were highest in October for CO and VOCs and in August for NOx and PM10. Holidays (such as Spring Festival and National Day) have a significant impact on the temporal distribution of the mobile source emissions. According to the spatial distributions, the CO and VOCs emissions were concentrated in urban areas and roads with heavy traffic flow (highways and national highways), and the NOx and PM10 were concentrated in urban areas and port areas. The spatial distributions of different pollutants were determined by the location of their major contributors. This study can provide the required data for fine air pollution control and air quality simulation in Tianjin. Moreover, this method can be applied to the other areas where a mobile source emission inventory needs to be developed.


Subject(s)
Air Pollutants , Air Pollution , Agriculture , Air Pollutants/analysis , Air Pollution/analysis , Environmental Monitoring , Vehicle Emissions/analysis
7.
Huan Jing Ke Xue ; 40(1): 104-113, 2019 Jan 08.
Article in Chinese | MEDLINE | ID: mdl-30628264

ABSTRACT

The pollution characteristics and emission factors (EFs) of the volatile organic compounds (VOCs) of vehicles were investigated using the tunnel test method on weekdays and weekends in the Wujinglu Tunnel in Tianjin, China. Gas samples in the tunnel were collected with 3.2 L stainless steel canisters and 99 VOCs species were analyzed by gas chromatography-mass spectrometry (GC-MS). The concentration levels, variation characteristics, and EFs of the VOCs were analyzed. The ozone formation potentials (OFPs) and secondary organic aerosol formation potentials (SOAFPs) of the VOCs in the tunnel were calculated. Moreover, a comparison of the study results with current literature was conducted. The total concentrations of VOCs at the inlet and midpoint are (190.85±51.15) µg·m-3 and (257.44±62.02) µg·m-3, respectively. The total EFs are (45.12±10.97) mg·(km·veh)-1 and the EFs for alkanes, alkenes, alkynes, aromatics, halocarbons, and oxygenated volatile organic compounds (OVOCs) are (22.79±7.15), (5.04±1.20), (0.78±0.34), (9.86±2.81), (0.26±0.17), and (6.25±2.27) mg·(km·veh)-1, respectively. They are notably smaller than the values obtained in a previous test in 2009. Isopentane, toluene, ethylene, methyl tert-butyl ether (MTBE), and ethane were the top five species among the VOC EFs. The ratios of methyl tert-butyl ether/benzene (MTBE/B) and methyl tert-butyl ether/toluene (MTBE/T) are 1.07 and 0.77, respectively. This implies that the contribution of evaporative emissions from vehicles to VOCs emissions cannot be ignored. The OFPs and SOAFPs in the tunnel are (145.50±37.85) and (43.87±12.75) mg·(km·veh)-1, respectively. Compared with the test in 2009, the OFPs and SOAFPs are 94.23% and 90.88% smaller, respectively. The sharp decrease of the OFPs and SOAFPs is closely related to stricter emission standards and the upgrade of oil products.

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