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Globally, the energy supply in the market is tight and the oil price fluctuates sharply. With the increasing degree of environmental pollution, both developed and developing countries pay special attention to the development of new energy, and energy conservation and emission reduction have been put on the agenda. As new energy vehicles have the advantages of energy conservation and environmental protection, they are strongly supported by governments. Many countries regard new energy vehicles as substitutes for traditional vehicles, and their development has ushered in a good opportunity. Under the background that the government and enterprises pay more attention to the development of new energy vehicles, it is of positive significance to study the intelligent manufacturing enterprises of new energy vehicles in a province. This paper studies the manufacturing of new energy vehicles through soft computing. Next, this paper also analyzes the financial market. Enterprise risk is closely related to investor income and social healthy development, which is a hot issue concerned by the public and the government. However, in recent years, there have been a series of cases in which enterprises have suffered huge losses using "hedging" to avoid operational risks, which has aroused public concern about the motivation of enterprises to use derivative financial products. Based on the leverage characteristics of derivative financial instruments, scholars believe that the high leverage profit in the capital market is the main incentive for enterprises to use hedging for hedging speculation. Existing studies pay more attention to the consequences of enterprise hedging, and they analyze the impact of enterprise hedging, focus on the result level after enterprise hedging, and seek the significance of enterprise hedging. Through the research on soft computing, this paper will apply it to the intelligent manufacturing of new energy vehicles and promote the development of hedging in China's financial market [ABSTRACT FROM AUTHOR]

China has already committed to peaking carbon dioxide emissions by 2030 and achieving carbon neutrality by 2060 (referred to as the 30·60 Target), which has brought both daunting challenges and great opportunities to the automobile industry in China. However, there is still a lack of comprehensive and in-depth studies on the challenges, paths, and strategies for reducing carbon emissions to fulfill the 30·60 Target in automobile industries. Therefore, this paper proposes low-carbon development strategies for China's automobile industry. This study's method is to integrate the results from different literature to summarize the status, challenges, opportunities, and refine the coping strategies for carbon emission of the automobile industry. The results indicated that the paths for achieving the 30·60 Target include joint carbon emission reduction by upstream and downstream enterprises inside the industry. It also needs cross-industry and cross-sector coordinated decarbonization outside the industry. Meanwhile, the low-carbon policy and regulation system should be established to provide a direct driving force and fundamental guarantee for the low-carbon development of China's automobile industry. [ABSTRACT FROM AUTHOR]

This paper explores the effects of consumption-tax and fuel-tax adjustments in the Chinese automobile industry. Applying the model and simulation method of Berry, Levinson, and Pakes (1995), we conduct a comparative static analysis of equilibrium prices and sales, fuel consumption, and social welfare before and after tax adjustments. For the first time, we compare the progressivity of both taxes. Our empirical findings suggest that the fuel tax is effective in decreasing fuel consumption at the expense of social welfare, while the consumption tax does not significantly affect either fuel consumption or social welfare. [ABSTRACT FROM AUTHOR]

China’s transport sector is facing enormous challenges from soaring energy consumption and greenhouse gas (GHG) emissions. Transport electrification has been viewed as a major solution to transportation decarbonization, and electric vehicles (EVs) have attracted considerable attention from policymakers. This paper analyzes the effects of the introduction of EVs in China. A system dynamics model is developed and applied to assess the energy-saving and emission-reducing impacts of the projected penetration of EVs until the year 2030. Five types of scenarios of various EV penetration rates, electricity generation mixes, and the speed of technological improvement are discussed. Results confirm that reductions in transport GHG emissions and gasoline and diesel consumption by 3.0%–16.2%, 4.4%–16.1%, and 15.8%–34.3%, respectively, will be achieved by 2030 under China’s projected EV penetration scenarios. Results also confirm that if EV penetration is accompanied by decarbonized electricity generation, that is, the use of 55% coal by 2030, then total transport GHG emissions will be further reduced by 0.8%–4.4%. Moreover, further reductions of GHG emissions of up to 5.6% could be achieved through technological improvement. The promotion of EVs could substantially affect the reduction of transport GHG emissions in China, despite the uncertainty of the influence intensity, which is dependent on the penetration rate of EVs, the decarbonization of the power sector, and the technological improvement efficiency of EVs and internal combustion engine vehicles. [ABSTRACT FROM AUTHOR]

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The impacts of heavy metal pollution in arable soil on agricultural production, environmental health, and the wellbeing of urban and rural residents cannot be overlooked. It has become a significant bottleneck in achieving comprehensive rural revitalization. To accurately grasp the characteristics of heavy metal pollution in suburban cultivated soil, Tangwang Village (a suburb of Huainan City) was subjected to scrutiny. The contents of heavy metals (Hg, Cu, Hg, As, Pb, Cr, Cd, and Zn) in the topsoil of cultivated land in this area were detected, and their spatial distribution characteristics were analyzed using inverse distance spatial interpolation. (1) After conducting a comprehensive analysis and thorough examination of the PMF model sources, it was determined that Cu, Cd, and Zn exhibit a direct correlation with agricultural practices, collectively contributing to a cumulative percentage of 21.10%. Meanwhile, Cr is derived from a combination of sources, including both natural parent materials and human activities, accounting for a total proportion of 24.45%. Notably, lead emissions from automobile exhausts constitute a significant source, while arsenic is primarily associated with dispersed factories and their respective operations, contributing to respective proportions of 36.38% and 18.07%. It is evident that agricultural practices, transportation, and industrial activities are the main reasons for heavy metal pollution in arable soil. (2) The evaluation of geological accumulation indicators reveals that the level of soil arsenic accumulation pollution is mild to moderate (1.199). On the other hand, the cumulative pollution level of Cd, Hg, Cr, and Cu was relatively low (0.462→0.186), whereas the levels of Pb and Zn were below the threshold. (3) The assessment of the ecological risk index revealed that the predominant elements posing potential ecological risks in the investigated region were Hg, As, and Cd, with average Ei values of E(Hg) = 86.81, E(As) = 80.67, and E(Cd) = 67.83, respectively. (4) The human health risk assessment revealed significant differences in the single non-carcinogenic risk values of heavy metals generated by different exposure pathways, with oral ingestion > dermal contact > oral nasal inhalation. Children were more susceptible to the toxic effects of heavy metals compared to adults. Both As and Cr caused an increased risk of cancer in both children and adults, which is a matter of great concern. The results of this study contribute to a more accurate description of the sources of heavy metals in farmland soil. This study indicates that the application of PMF for soil source analysis yields clear results that can be further applied. This research also has potential policy significance as it can help to improve the sustainability of ecosystems by coordinating both environmental and human activities. [ABSTRACT FROM AUTHOR]

Vehicle ownership is one of the most important factors affecting fuel demand. Based on the forecast of China's vehicle ownership, this paper estimates China's fuel demand in 2035 and explores the impact of new energy vehicles replacing fossil fuel vehicles. The paper contributes to the existing literature by taking into account the heterogeneity of provinces when using the Gompertz model to forecast future vehicle ownership. On that basis, the fuel demand of each province in 2035 is calculated. The results show that: (1) The vehicle ownership rate of each province conforms to the S-shape trend with the growth of real GDP per capita. At present, most provinces are at a stage of accelerating growth. However, the time for the vehicle ownership rate of each province to reach the inflection point is quite different. (2) Without considering the replacement of new energy vehicles, China's auto fuel demand is expected to be 746.69 million tonnes (Mt) in 2035. Guangdong, Henan, and Shandong are the top three provinces with the highest fuel demand due to economic and demographic factors. The fuel demand is expected to be 76.76, 64.91, and 63.95 Mt, respectively. (3) Considering the replacement of new energy vehicles, China's fuel demand in 2035 will be 709.35, 634.68, and 560.02 Mt, respectively, under the scenarios of slow, medium, and fast substitution—and the replacement levels are 37.34, 112.01, and 186.67 Mt, respectively. Under the scenario of rapid substitution, the reduction in fuel demand will reach 52.2% of China's net oil imports in 2016. Therefore, the withdrawal of fuel vehicles will greatly reduce the oil demand and the dependence on foreign oil of China. Faced with the dual pressure of environmental crisis and energy crisis, the forecast results of this paper provide practical reference for policy makers to rationally design the future fuel vehicle exit plan and solve related environmental issues. [ABSTRACT FROM AUTHOR]

Abstract: This paper investigates numerical method for predicting wind field and pollutant dispersion in an urban area with crowded buildings and heavy traffic. Large eddy simulation is employed in numerical computation with Lagrangian dynamic model to close the subgrid scale stress. The fine grids are required in numerical simulation of micro-atmospheric flows in an urban area with crowded and complex building-streets. To realize the numerical simulation on available computer resources a domain decomposition method and a combined model for the building-street layout are proposed that the computed domain of an urban area is decomposed into a central area, where the pollution is the major concern and a surrounding region where the pollutant distribution is not concerned. The combined flow model is proposed for the complex building-street layout that the fine grid mesh and exact flow boundary conditions are prescribed in the central area while the buildings are treated as roughness elements in the surrounding region where the coarse grids are used. The proposed numerical method is applied to simulate the wind field and pollutant dispersion from vehicle exhaust in the Rua Do Campo area of Macau (referred to the site hereafter). The wind speed and temperature fields are computed from 7 am on September 6 2005 to 7 am of the next day and the pollutant concentration field is computed from 7 am to 6 pm on September 6 2005. The results show fairly good agreement with the field observation. The wind field and pollutant concentration distribution are demonstrated in the site by proposed combined model and they are compared with those computed by drag element model in whole computational domain. The results show that the combined model is an appropriate method for predicting wind field and pollutant dispersion in the crowded building area. The paper also reveals the relevance of buoyancy effect in the prediction of urban atmospheric environment. [Copyright &y& Elsevier]

Abstract Urban air pollution has become a major concern in China. In the heavily populated and developed Beijing-Tianjin-Hebei (BTH) region, vehicle emissions are major pollution contributors. This paper aims to establish 2014 vehicle emission inventories for five major air pollutants in the BTH region: CO, HC, NO x , PM 10 and PM 2.5 and carry out an emission control policy scenario analysis based on the newly developed inventories. Results showed that total emissions of CO, HC, NO x , PM 10 and PM 2.5 from vehicles in the BTH region were 1622.4 kt, 187.5 kt, 544.7 kt, 23.5 kt, and 26.1 kt, respectively. Based on the emission inventory, high-resolution emission distribution maps of the study area were created at a scale of 1 km × 1 km by incorporating local traffic flow data. The CO, HC and NO x emission levels were higher in the southeast, while the PM 10 and PM 2.5 levels were relatively evenly distributed throughout the BTH region. Based on the emission inventories, four policy scenarios were set to simulate the emission changes, and results showed that eliminating old vehicles and upgrading oil quality could reduce emission efficiently. A policy of eliminating old vehicles was selected to calculate the economic cost. Results showed that the emission reduction efficiencies of unit cost decreased from Hebei, Tianjin to Beijing. The results of this study could help policy makers identify pollution sources and design appropriate control measures. Highlights • We calculated vehicle emission factors in the Beijing-Tianjin-Hebei region. • We generated high spatial resolution emission maps based on traffic flow data. • We set various policy scenarios to evaluate vehicle pollution control measures. • We analyzed governmental and social costs of typical policy scenario. [ABSTRACT FROM AUTHOR]

For over ten years, China has been the largest vehicle market in the world. In order to address energy security and air quality concerns, China issued the Dual Credit policy to improve vehicle efficiency and accelerate New Energy Vehicle adoption. In this paper, a market-penetration model is combined with a vehicle fleet model to assess implications on greenhouse gas (GHG) emissions and energy demand. Here we use this integrated modeling framework to study several scenarios, including hypothetical policy tweaks, oil price, battery cost and charging infrastructure for the Chinese passenger vehicle fleet. The model shows that the total GHGs of the Chinese passenger vehicle fleet are expected to peak in 2032 under the Dual Credit policy. A significant reduction in GHG emissions is possible if more efficient internal combustion engines continue to be part of the technology mix in the short term with more New Energy Vehicle penetration in the long term. China issued the Dual Credit policy to improve vehicle efficiency and accelerate new energy vehicle adoption. Here the authors show that the total Greenhouse gas emissions (GHGs) of the Chinese passenger vehicle fleet are expected to peak in 2032 and a significant reduction in GHG emissions is possible by optimizing the Dual Credit policy. [ABSTRACT FROM AUTHOR]

In order to explore the characteristics of water-soluble inorganic ions (WSIIs) in the atmosphere of Wanzhou, a small mountainous city in Chongqing, four representative seasonal PM2.5 samples and gaseous precursors (SO2 and NO2) were collected from April 2016 to January 2017. The WSIIs (including Cl−, NO3−, SO42−, Na+, NH4 +, K+, Mg2+, and Ca2+) were analyzed by ion chromatography. During the sampling period, daily PM2.5 concentration varied from 3.47 to 156.30 μg·m−3, with an average value of 33.38 μg·m−3, which was lower than the second-level annual limit of NAAQS-China. WSIIs accounted for 55.6% of PM2.5, and 83.1% of them were secondary inorganic ions (SNA, including SO42−, NO3−, and NH4+). The seasonal variations of PM2.5 and WSIIs were similar, with the minimum in summer and the maximum in winter. PM2.5 samples were the most alkaline in summer, weakly alkaline in spring and winter, and close to neutral in fall. The annual average ratio of NO3−/SO42− was 0.54, indicating predominant stationary sources for SNA in Wanzhou. NO3−, SO42−, and NH4+ mainly existed in the form of (NH4)2SO4 and NH4NO3. The results of the principal component analysis (PCA) showed that the major sources of WSIIs in Wanzhou were the mixture of secondary inorganic aerosols, coal combustion, automobile exhaust (49.53%), dust (23.16%), and agriculture activities (9.68%). The results of the backward trajectory analysis showed that aerosol pollution in Wanzhou was mainly caused by local emissions. The enhanced formation of SNA through homogeneous and heterogeneous reactions contributed to the winter PM2.5 pollution event in Wanzhou. [ABSTRACT FROM AUTHOR]

In order to fulfill the commitment of China to achieve carbon peak by 2030 and carbon neutrality by 2060, all industries have been taking their respective carbon reduction actions. The transportation industry accounts for 11% of CO2 emission of the whole society, and its energy conservation and carbon reduction benefit is of great significance to the national carbon reduction process. New energy vehicles are undoubtedly one of the most important means of carbon emission reduction in the transportation sector. However, electric vehicles still have CO2 emissions, as the fossil fuel use comes from upstream power. To systematically and comprehensively evaluate the CO2 emissions of HEV, PHEV and BEV in the whole process, this study introduces the life-cycle method to research on the past and current situations, and predict future scenarios for ICEV and EV light-duty vehicles at the national and regional levels, by deeply analyzing the generation mix and generating efficiency from the WTT stage, and fuel economy from the TTW stage. The study shows that compared with ICEV, HEV and PHEV could reduce around 30% of CO2 emissions. Currently, BEV could reduce 37% of CO2 emission in the region where the proportion of coal-fired power is high, and 90% of CO2 emission in the region where the proportion of hydro power is high. This study discusses the impact of the proportion of renewable energy application on the carbon emissions from electric vehicles, analyzes the environmental benefits of promoting electric vehicles in different regions, and lays a foundation for the promotion strategy of electric vehicles for different regions in the future. [ABSTRACT FROM AUTHOR]

In this paper, by analysis of emissions throughout the life cycle of new energy vehicles, pointing out that new energy automobile emissions is not only arising in its using process but also including emissions from its production process. Finally concluded that China's development of new energy vehicles is inevitable, but it should be strictly controlled of critical emissions during its life cycle. [ABSTRACT FROM AUTHOR]

Mining activities have led to severe air pollution problems while they make great contributions to economic construction. Therefore, as a typical steel-industry city in southwest China, Panzhihua, its air pollution has received extensive attention. The characteristics of PM1 in different functional areas of Panzhihua from 2018 to 2019, and the changes of its microstructure and potentially toxic elements (PTEs) and the sources of PM1 were analyzed. The results showed that the mass concentrations of PM1 in the heavy pollution area of Nongnongping (NNP) and the complex industrial pollution area of Hemenkou (HMK) were 12.12–145.30 μg/m3 and 14.38–67.02 μg/m3, respectively. Seasonal PM1 mass concentrations in the two functional areas could be arranged in the following order: winter > autumn > spring > summer. The main particle types in PM1 were fly ash, soot, sulphate particles, aluminosilicate particles and metal particles. Potential sources of PM1 in Panzhihua included coal burning, biomass combustion, automobile exhaust and mining activities. At the same time, the average concentrations of PTEs at NNP were also higher than those at HMK because of smelting activities. Enrichment factor analysis showed that most of the PTEs came from human sources. The results could provide theoretical guidance for environmental management. [ABSTRACT FROM AUTHOR]

A total of 28,095 surface soil samples were collected in areas with high natural background levels; the potential ecological risk is generally low, and the high-risk area is small and mainly affected by lead–zinc mines. The contribution to the potential ecological risk factor (RI) is as follows: Hg > Cd > As > Pb > Cu > Ni > Cr > Zn, with noncarcinogenic chronic risks of Cr > As > Cd > Pb > Ni > Cu > Hg > Zn; furthermore, dermal contact is the main pathway of exposure causing health risks. The total carcinogenic risks caused by heavy metals were as follows: Cr > Cd > As > Pb; and the risks posed by Cr, Cd, and As were higher than the threshold value (1.0 × 10−4); people face a higher threat to heavy metals in soils in Zhenxiong, Ludian, Huize, Weixin, and Zhaoyang. The evaluation result of the EPA PMF model shows that the soil heavy metals are mainly composed of five sources, of which basalt, Permian, and Triassic carbonate rock parent material constitute the natural background source, while the mining activities of lead–zinc mines and the emissions of coal burning by residents constitute the anthropogenic source. The contribution was ranked in order of lead–zinc mining (26.7%) > Triassic carbonate (23.7%) > basalt (20.9%) > coal burning and automobile emissions (16.1%) > Permian carbonate (12.6%). [ABSTRACT FROM AUTHOR]

In this paper, we report the results and analysis of a recent field campaign in August 2007 investigating the impacts of emissions from transportation on air quality and community concentrations in Beijing, China. We conducted measurements in three different environments, on-road, roadside and ambient. The carbon monoxide, black carbon and ultrafine particle number emission factors for on-road light-duty vehicles are derived to be 95gkg−1-fuel, 0.3gkg−1-fuel and 1.8×1015 particleskg−1-fuel, respectively. The emission factors for on-road heavy-duty vehicles are 50gkg−1-fuel, 1.3gkg−1-fuel and 1.1×1016 particleskg−1-fuel, respectively. The carbon monoxide emission factors from this study agree with those derived from remote sensing and on-board vehicle emission testing systems in China. The on-road black carbon and particle number emission factors for Chinese vehicles are reported for the first time in the literature. Strong traffic impacts can be observed from the concentrations measured in these different environments. Most clear is a reflection of diesel truck traffic activity in black carbon concentrations. The comparison of the particle size distributions measured at the three environments suggests that the traffic is a major source of ultrafine particles. A four-day traffic control experiment conducted by the Beijing Government as a pilot to test the effectiveness of proposed controls was found to be effective in reducing extreme concentrations that occurred at both on-road and ambient environments. [Copyright &y& Elsevier]

Urumchi suffered serious air quality problem in recent years. Although the main air pollutants and wet deposition monitoring have been undertaken by Urumchi Environmental Monitoring Center for many years, researches on chemical composition and variations of wet deposition were not there till now. In this paper, wet deposition monitoring data in Urumchi from 2000 and 2005 were selected to perform this evaluation based on data quality and data integrity. The volume-weighted mean (VWM) concentrations of parameters of wet deposition, namely pH, conductivity, SO4 2−, NO3 −, F−, Cl−, NH4 +,Ca2+, Mg2+, Na+ and K+ concentrations, were 6.86 and 91.04μscm−1, 14.3, 1.63, 0.37, 3.78, 1.22, 4.79, 0.59, 1.05, 0.74mgL−1, respectively. Acid precipitation appeared only in wintertime in few cases, and its extreme value was 4.96; the maximum emerged during sand storm event in the non-winter season with the value of 9.35. Wet deposition and air pollution characteristics varied with seasons. In order to make a certainty of possible sources of ions in different seasons, principal component analysis was applied, and conclusions were drawn that in wintertime, the predominant contributor to the wet deposition was coal combustion for residential heating; however, in the non-winter season, the situation was more complicated, dust and soil from outside the urban, dust re-suspension, local industries process, motor vehicle emissions all played their roles. [Copyright &y& Elsevier]

Several civilian vehicles in China operate in urban traffic conditions and have their motor oil changed every 5,000 km. This study investigates the variations in oil properties after servicing at 5,000 km, based on systematic road tests (including a repeated test, a parallel test, and a new vehicle test). The physicochemical properties, changes in components, oxidation stability, detergent-dispersant performance, and tribological properties of motor oils were analyzed. The results showed that the total acid number (TAN) of oils increased with the operation mileage, by up to 1.41 mgKOH/g. The total base number (TBN) decreased after the road tests were completed, and the decrease was less than 44.6%. The kinematic viscosity (KV) of most oils decreased initially and then stabilized in the middle stage, before starting to increase later in the experiment. The change in KV at 100 °C was less than 15.96%. The oxidation onset temperature (OOT) of the oils diminished gradually with the operation mileage. All OOT values of the used oils were higher than 210 °C. A spot test indicated that the used oils retained their detergent-dispersant performance to an appropriate extent. The four-ball wear scar diameters and friction coefficient of the used oils did not increase significantly after the road tests were completed. This study can serve as a reference for end-users when changing motor oils. [ABSTRACT FROM AUTHOR]

The Chinese government has instituted a number of policies to actively promote the diffusion of new energy vehicles (NEVs). There is widespread consensus that policy mixes can drive NEV diffusion effectively. To verify this consensus, we construct a two-dimensional framework of NEV policy instruments: producer-orientation versus consumer-orientation instruments, economic in cash versus regulatory instruments and classify NEV policy mixes. Then, we analyse the impact of policy mixes on NEV diffusion among enterprises and consumers by building an evolutionary game model. And according to the concept of stable area in the evolutionary game, we propose a definition of policy effect. The results show: (1) Policy mixes can reduce the saddle point of the auto market game and accelerate the spread of NEVs. In the early stages of the NEV industry, the government should take the policy mix strategy with four policies, and economic in cash instrument should be the main policy. (2) Policy mixes composed of producer-orientation and consumer-orientation instruments have a synergy or complementarity to promote NEV diffusion effectively. (3) With the increasing rate of NEV production and consumption, the government should adopt policy mixes mainly composed of regulatory instruments and rather than economic instruments. [ABSTRACT FROM AUTHOR]

Automobile exhaust pollution is one of the major contributors to the severe air pollution in China, and policies have been issued by the Chinese government to mitigate this problem. In this paper, we evaluate the impact of a recently implemented policy to upgrade the quality of gasoline on reducing the fine particulate matter (PM) concentration. Based on regression discontinuity (RD) design, we systematically analyze the policy effect on the PM 10 and PM 2.5 concentrations at three scales, namely, the macro-, meso-, and microscales. Macroscale analysis measures the impact on all cities, and mesoscale analysis measures it on all monitoring stations, while microscale analysis focuses on the rush hours at each station. Our results show that the policy has little effect on reducing particulate matter pollution at the macro- or mesoscale, while positive evidence does exist at the microscale when focusing on pollution reduction during rush hours, especially for areas near main roads or junctions with heavy traffic. Our research suggests that the policy impact is affected by the heterogeneous pollution sources, and the potential of mitigating air pollution by continually upgrading the quality of gasoline will be limited after five stages of upgrades. In addition, one single policy can hardly completely solve particulate matter pollution in China, and a systematic design consisting of a series of policies is needed to mitigate this problem. [ABSTRACT FROM AUTHOR]

BACKGROUND: In 2013, China released the Air Pollution Prevention and Control Action Plan (Action Plan), which set the roadmap for national air pollution control actions for the period of 2013 to 2017. A decrease in the fine particulate matter with aerodynamic diameter ≤2:5 lm (PM2:5) concentration may lead to a substantial benefit for human health. OBJECTIVE: We aimed to quantify the relative contributions four factors: emission reductions, changed meteorology, population growth, and a change in baseline mortality rates to the reduced PM2:5-related mortality (PM2:5-mortality) during the 2013-2017 period and evaluate the importance of emission controls for human health protection in China. METHODS: The integrated exposure-response function was adopted to estimate the chronic health effects of PM2:5. The annual PM2:5 concentrations were estimated from chemical transport model simulations combined with surface observations for 2013 and 2017. Relative contributions to PM2:5-mortality from emission reductions and the three factors were individually quantified through scenario analysis. RESULTS: The estimated total PM2:5-mortality in China was 1.389 million [95% confidence interval (CI): 1.005 million, 1.631 million] in 2013 but was substantially reduced to 1.102 million (95% CI: 0.755 million, 1.337 million) in 2017. Emission controls contributed 88.7% to this reduction in PM2:5-mortality, while changed meteorology, the change in baseline mortality rates, and population growth during 2013-2017 contributed 9.6, 3.8, and -2:2%, respectively. CONCLUSIONS: The implementation of the Action Plan has significantly reduced the PM2:5 concentration in regions of China where population density is high, dominating the decline in PM2:5-mortality during 2013-2017. However, the health burden of PM2:5 pollution in China is still extremely high compared with that in other developed countries. An aggressive air pollution control strategy should be implemented in densely populated areas to further reduce the health burden. [ABSTRACT FROM AUTHOR]

In January 2013, February 2014, December 2015 and December 2016 to 10 January 2017, 12 persistent heavy aerosol pollution episodes (HPEs) occurred in Beijing, which received special attention from the public. During the HPEs, the precise cause of PM2:5 explosive growth (mass concentration at least doubled in several hours to 10 h) is uncertain. Here, we analyzed and estimated relative contributions of boundary-layer meteorological factors to such growth, using ground and vertical meteorological data. Beijing HPEs are generally characterized by the transport stage (TS), whose aerosol pollution formation is primarily caused by pollutants transported from the south of Beijing, and the cumulative stage (CS), in which the cumulative explosive growth of PM2:5 mass is dominated by stable atmospheric stratification characteristics of southerly slight or calm winds, near-ground anomalous inversion, and moisture accumulation. During the CSs, observed southerly weak winds facilitate local pollutant accumulation by minimizing horizontal pollutant diffusion. Established by TSs, elevated PM2:5 levels scatter more solar radiation back to space to reduce near-ground temperature, which very likely causes anomalous inversion. This surface cooling by PM2:5 decreases near-ground saturation vapor pressure and increases relative humidity significantly; the inversion subsequently reduces vertical turbulent diffusion and boundary-layer height to trap pollutants and accumulate water vapor. Appreciable near-ground moisture accumulation (relative humidity> 80 %) would further enhance aerosol hygroscopic growth and accelerate liquid-phase and heterogeneous reactions, in which incompletely quantified chemical mechanisms need more investigation. The positive meteorological feedback noted on PM2:5 mass explains over 70% of cumulative explosive growth. [ABSTRACT FROM AUTHOR]

With the exponential growth of the national vehicle fleet in the last three decades, most cities in China are facing mounting pressure to tackle congestion and air pollution problems caused by motor vehicles. Beijing, the capital city, is a good case to study how municipal governments address those issues. To alleviate road congestion and pollution, the government has invested heavily in road infrastructure, advanced traffic management technology and also introduced stringent standards on vehicular emissions. However, city planners have been over-relying on command and control measures including travel demand management, which have proven to be costly and inefficient in controlling motor vehicle ownership and usage-the fundamental causes of congestion and emissions. Economic measures including road pricing and vehicle registration auction schemes are superior and should be adopted in travel demand management in the future. [ABSTRACT FROM AUTHOR]

Surface soil samples from 467 sample sites were collected in urban area of Wuhan City in 2013, and total concentrations of five trace metals (Pb, Zn, Cu, Cr, and Cd) were measured. Multivariate and geostatistical analyses showed that concentrations of Pb, Zn, and Cu are higher along Yangtze River in the northern area of Wuhan, gradually decrease from city center to suburbs, and are mainly controlled by anthropogenic activities, while those of Cr and Cd are relatively spatially homogenous and mainly controlled by soil parent materials. Pb, Zn, Cu, and Cd have generally higher concentrations in roadsides, industrial areas, and residential areas than in school areas, greenbelts, and agricultural areas. Areas with higher road and population densities and longer urban construction history usually have higher trace metal concentrations. According to estimated results of the potential ecological risk index and Nemero synthesis pollution index, almost the whole urban area of Wuhan is facing considerable potential ecological risk caused by soil trace metals. These results reveal obvious trends of trace metal pollution, and an important impact of anthropogenic activities on the accumulation of trace metals in soil in Wuhan. Vehicular emission, industrial activities, and household wastes may be the three main sources for trace metal accumulation. Increasing vegetation cover may reduce this threat. It should be pointed out that Cd, which is strongly accumulated in soil, could be the largest soil pollution factor in Wuhan. Effective measures should be taken as soon as possible to deal with Cd enrichment, and other trace metals in soil should also be reduced, so as to protect human health in this important large city. [ABSTRACT FROM AUTHOR]