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The emissions reduction of CO 2 and air pollutants are the main task in China. The two have the same roots and they interact with each other. However, CO 2 and air pollutants are quite different in space, so it is of great practical significance to explore the spatial differences of their synergy. As PM 2.5 and O 3 are more concerned at present, thus, this paper examined the decoupling of CO 2 , PM 2.5 and O 3 from GDP in China's 296 cities using the latest available data from 2015 to 2016. And the spatial differences of synergy among CO 2 , PM 2.5 and O 3 were quantitatively analyzed by using spatial autocorrelation analysis and geographically weighted regression model. The results showed that: (1) The cities achieving the three synergy emissions reduction were mainly in the southeast of China. (2) Only 26 cities had achieved the strong decoupling of CO 2 , PM 2.5 and O 3 from GDP. (3) The synergy characteristics between CO 2 and PM 2.5 , CO 2 and O 3 were different. This paper put forward the policies according to the conclusions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

China implemented the Promoting the Big and Quashing the Small Policy (PBQSP) in 2007 to alleviate air pollution due to coal-fired power plants (CFPPs). However, how the policy affected the air pollutant emissions remains poorly understood. We compared the air pollutant emissions between decommissioned and newly-built CFPPs under the PBQSP by developing a plant-level supply chain emission inventory model, taking Shandong, China's top provincial-level coal power producer, as the case area. The results indicated that compared to a 27.4% increase in electricity produced in Shandong from 2010 to 2014, the NOx, particulate matter (PM), Hg, and SO 2 emissions disproportionately increased by 10.3%, 11.7%, 11.8% and 0.5%, respectively. It was found that the PBQSP policy has made great contribution to air pollution mitigation, as the supply chain emission intensities (emissions per kilowatt-hour) of NO X , PM, Hg and SO 2 of the newly-built CFPPs are three-quarters, two-fifths, three-fifths, and four-fifths lower, respectively, than those of the decommissioned CFPPs. However, coal transport route changes caused an increase in NO X , PM, and SO 2 emissions by 44.0%, 45.5%, and 55.6%, respectively, during the transportation stage, which offset the PBQSP overall mitigation effect. By building a comprehensive assessment framework for air pollutant control policies, our study provides insights for formulating coordinated mitigation measures for the pollutant-intensive industries, such as promoting efficient air pollutant control technologies including the spray dust suppression devices., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Estimating accurately airborne pollutant emissions source information (source strength and location) is important for achieving effective air pollution management or adequate emergency responses to accidents. Inversion method is one of the useful tools to identify the source parameters. The atmospheric dispersion scheme has been proven to be the key to determining the source inversion performance by influencing the accuracy of the dispersion models. Modifying the atmospheric dispersion scheme is an important potential method to improve the inversion performance, but this has not been studied previously. To fill this gap, a novel approach for parameter sensitivity analysis combined with an optimization method was proposed to improve the source inversion performance by optimizing empirical scheme. The dispersion coefficients σ y and σ z of the typical BRIGGS scheme under different atmospheric dispersion conditions were optimized and used for air pollutant dispersion and source inversion. The results showed that the prediction performance of the air pollutant concentrations was greatly improved with statistical indices |FB| and NMSE decreased by 0.22 and 2.07, respectively; FAC2 and R increased by 0.10, and 0.08, respectively. For source inversion, the results of the significance analysis suggested that the accuracy in the source strength and location parameter (x0) were both significantly improved by ∼271% (relative deviation reduced from 60.0% to 16.2%) and ∼121% (absolute deviation reduced from 27.6 to 12.5 m). The improvement of source strength inversion accuracy was more significant under unstable atmospheric conditions (stability class A, B, and C); the mean absolute relative deviation was reduced by 97.5%. These results can help to obtain more accurate source information and to provide reliable reference for air pollution managements or emergency response to accidents. This study provides a novel and versatile approach to improve estimation performance of pollutant emission sources and enhances our understanding of source inversion., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Meteorology and long-term trends in air pollutant concentrations may obscure the results from short-term policies implemented to improve air quality. This study presents changes in CO, NO 2 , O 3 , SO 2 , PM 10 , and PM 2.5 based on their anomalies during the COVID-19 partial (Phase 2) and total (Phase 3) lockdowns in Mexico City (MCMA). To minimise the impact of the air pollutant long-term trends, pollutant anomalies were calculated using as baseline truncated Fourier series, fitted with data from 2016 to 2019, and then compared with those from the lockdown. Additionally, days with stagnant conditions and heavy rain were excluded to reduce the impact of extreme weather changes. Satellite observations for NO 2 and CO were used to contrast the ground-based derived results. During the lockdown Phase 2, only NO 2 exhibited significant decreases ( p < 0.05) of between 10 and 23% due to reductions in motor vehicle emissions. By contrast, O 3 increased ( p < 0.05) between 16 and 40% at the same sites where NO 2 decreased. During Phase 3, significant decreases ( p < 0.05) were observed for NO 2 (43%), PM 10 (20%), and PM 2.5 (32%) in response to the total lockdown. Although O 3 concentrations were lower in Phase 3 than during Phase 2, those did not decrease ( p < 0.05) from the baseline at any site despite the total lockdown. SO 2 decreased only during Phase 3 in a near-road environment. Satellite observations confirmed that NO 2 decreased and CO stabilised during the total lockdown. Air pollutant changes during the lockdown could be overestimated between 2 and 10-fold without accounting for the influences of meteorology and long-term trends in pollutant concentrations. Air quality improved significantly during the lockdown driven by reduced NO 2 and PM 2.5 emissions despite increases in O 3 , resulting in health benefits for the MCMA population. A health assessment conducted suggested that around 588 deaths related to air pollution exposure were averted during the lockdown. Our results show that to reduce O 3 within the MCMA, policies must focus on reducing VOCs emissions from non-mobile sources. The measures implemented during the COVID-19 lockdowns provide valuable information to reduce air pollution through a range of abatement strategies for emissions other than from motor vehicles., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Hernández-Paniagua, Valdez, Almanza, Rivera-Cárdenas, Grutter, Stremme, García-Reynoso and Ruiz-Suárez.)

On December 31, 2019, the Chinese authorities reported to the World Health Organization (WHO) the outbreak of a new strain of coronavirus that causes a serious disease in the city of Wuhan, China. This outbreak was classified as SARS-CoV2 and is the cause of the COVID-19 disease. On March 11, 2020, the WHO declares it a Pandemic and today it is considered the greatest challenge in global health that humanity has faced since World War II and it is estimated that between 40 and 60% of the population worldwide will catch the virus. This has caused enormous challenges in countries around the world in social, economic, environmental and obviously health issues. These challenges are mainly due to the effects of the established quarantines in almost all capitals and major cities around the world, from Asia, Europe to America. However, these lockdown which began worldwide from January 23, have had a significant impact on the environment and on the air quality of cities as recently reported by NASA (National Aeronautics and Space Administration) and ESA (European Space Agency), with reductions according to them of up to 30% in some of the epicenters such as the case of Wuhan. Knowing that air pollution causes approximately 29% of lung cancer deaths, 43% of COPD deaths, and 25% of ischemic heart disease deaths, it is important to know the effects of quarantines in cities regarding air quality to take measures that favor populations and urban ecosystems when the emergency ends. Therefore, this paper describes the behavior of PM 2.5 emissions particulate matter from the 50 most polluted capital cities in the world according to the WHO, measured before-after the start of the quarantine. Likewise, the impact at the local and global level of this emissions behavior, which averaged 12% of PM 2.5 decrease in these cities., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The active use of solid fossil fuels (coal) in the production of heat and electricity has led to significant pollution, climate change, environmental degradation, and an increase in morbidity and mortality. Many countries (in particular, European ones, China, Japan, the USA, Canada, etc.) have launched programs for using plant and agricultural raw materials to produce heat and electricity by burning them instead of or together with traditional fuels. It is a promising solution to produce slurry fuels, based on a mixture of coal processing, oil refining and agricultural waste. This paper presents the results of experimental research into the formation and assessment of the most hazardous emissions (sulfur and nitrogen oxides) from the combustion of promising coal slurry fuels with straw, sunflower and algae additives, i.e. the most common agricultural waste. A comparative analysis has been carried out to identify the differences in the concentrations of sulfur and nitrogen oxides from the combustion of typical coal, coal processing waste, as well as fuel slurries with and without plant additives. It has been shown that the concentration of sulfur and nitrogen oxides can be reduced by 62-87% and 12-57%, respectively, when using small masses of plant additives (no more than 10 wt%) and maintaining high combustion heat of the slurry fuel. However, the use of algae and straw in the slurry composition can increase the HCl emissions, which requires extra measures to fight corrosion. A generalizing criterion of slurry fuel vs. coal efficiency has been formulated to illustrate significant benefits of adding plant solid waste to coal-water slurries containing petrochemicals. Straw and sunflower waste (10 wt%) were found to be the best additives to reduce the air pollutant emissions., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Environmental pollution and the associated societal health issues have attracted recent research attention. While most research has focused on the effect of air pollution on human health and local economies, few articles have discussed the environment, health, and economic development in in an integrated analysis. This paper used a Dynamic Network SBM Model to evaluate production and health efficiencies in Chinese cities and found that the production efficiency scores were slightly higher than the health efficiency scores, with the two-stage efficiency scores in most cities having significant fluctuations. Labor, fixed assets, energy, GDP, and lung disease and mortality reduction efficiencies in the first stage were generally high; however, the medical input efficiencies in the second stage were low, indicating that there was there significant room for improvement in many cities.

Pollutant emissions from incomplete combustion of raw coal in low-efficiency residential heating stoves greatly contribute to winter haze in China. Semi-coke coals and improved heating stoves are expected to lower air pollutant emissions and are vigorously promoted by the Chinese government in many national and local plans. In this study, the thermal performance and air pollutant emissions from semi-coke combustion in improved heating stoves were measured in a pilot rural county and compared to the baseline of burning raw coal to quantify the mitigation potential of air pollutant emissions. A total of five stove-fuel combinations were tested, and 27 samples from 27 different volunteered households were obtained. The heating efficiency of improved stoves increased, but fuel consumption appeared higher with more useful energy output compared to traditional stoves. The emission factors of PM 2.5 , SO 2 , and CO 2 of semi-coke burning in specified improved stoves were lower than the baseline of burning raw coal chunk, but no significant NOx and CO decreases were observed. The total amount of PM 2.5 and SO 2 emissions per household in one heating season was lower, but CO, CO 2 , and NOx increased when semi-coke coal and specified improved stoves were deployed. Most differences were not statistically significant due to the limited samples and large variation, indicating that further evaluation would be needed to make conclusions that could be considered for policy., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The increasing number of vehicles operating in Poland, especially passenger vehicles, justifies the need to conduct air pollution emission tests in the context of the impact of vehicles on the natural environment. Firstly, this article reviews the publications related to air pollutant emissions and passenger vehicles traveling on Polish roads. However, it presents a special method using advanced research equipment to determine air pollutant emissions. The above research methods are justified in implementing clean transport zones. Real Driving Emissions represent an essential procedure in the implementation of clean transport zones in Poland, verifying the actual emissions of air pollutants and modeling this phenomenon using the results of real air pollutant emissions. The results of this research state that establishing a link between a vehicle's air pollutant emissions and its age can support making transport or delivery planning more sustainable and choosing less carbon-intensive means of transport to reduce the negative impact of transport on the environment. The scientific novelty of the proposed solutions is the verification of the actual emissions of Euro 6 vehicles and the modeling of air pollutant emissions as a function of speed and acceleration. The research results are included in this article and will become input data for further analysis in examining the impact of vehicle operating age on air pollution emissions. Consequently, the novelty of the present research also lies in its focus on the verification of the impact of operating age, particularly in the context of vehicles exceeding 15 years of age, on air pollutant emissions. By establishing a correlation between a vehicle's air pollutant emissions and its operating age, it becomes possible to make transport or delivery planning more sustainable. Furthermore, the selection of less carbon-intensive means of transport can contribute to reducing the negative impact of transport on the environment. [ABSTRACT FROM AUTHOR]

In China's energy consumption, about 50% of coal is used for power generation conversion, and the resulting environmental impact and air pollution problems cannot be ignored. Therefore, it is of great practical significance to improve the level of clean coal utilization. Based on the background that the country currently grants a subsidy of RMB 0.01/kWh for the "near-zero emission" of thermal power, this paper applies system dynamics (SD) modeling to simulate the impact of different policy scenarios on the promotion and effects of "near-zero emission" of thermal power. From the perspective of promotion speed and emission reduction contribution, simulation analysis found that thermal power "near-zero emission" technology can bring more significant environmental benefits and has promotion value. The main conclusions are as follows: (1) After 2020, if the current subsidy of RMB 0.01/kWh continues to be implemented, the "near-zero emission" retrofit of stock units can be fully completed in early 2026. (2) Compared with no policy subsidies, the cumulative emission reduction of sulfur dioxide, nitrogen oxides and soot will be approximately 15.13 million tons, 15.13 million tons and 2.37 million tons from the beginning of 2016 to the beginning of 2026, respectively. [ABSTRACT FROM AUTHOR]

With fast economic development, industrialization and urbanization, China faces increasing pressures on carbon emission reduction, and especially on air pollutants (SO 2 , NOx, PM) reduction, particularly the notorious haze issue caused by air pollution in recent years. Pursuing co-benefits is an effective approach to simultaneously respond to both carbon and air pollutant problems. In this paper, the AIM/CGE (Asia–Pacific Integrated Assessment Model/Computational General Equilibrium) model and GAINS (Greenhouse Gas and Air Pollution Interactions and Synergies)-China model are combined together to project future CO 2 and air pollutants emissions in China, as well as reduction costs and co-benefit effects. Considering implementation of carbon mitigation policy and air pollutant mitigation technologies, four scenarios (S1, S2, S3 and S4) are analyzed. Results indicate that by implementing both carbon and air pollutant mitigation (S4), CO 2 emission per GDP can be reduced by 41% by 2020, compared with the 2005 level, and SO 2 , NOx and PM2.5 emissions would change by a factor 0.8, 1.26 and 1.0 of the 2005 level, respectively in 2030. The real co-benefits of emission reductions (S2 minus S4) for SO 2 , NOx and PM2.5 are 2.4 Mt, 2.1 Mt and 0.3 Mt in 2020, and the corresponding cost reduction co-benefits are 4, 0.11, and 0.8 billion €, respectively. Provincial disparity analysis reveals that regions with higher co-benefits are those with higher GDP such as Guangdong, Shandong and Jiangsu, energy production bases such as Inner Mongolia and Shanxi, low coal quality provinces such as Sichuan (for SO 2 ), and industrial base provinces such as Liaoning. Cost-effectiveness is finally discussed for policy implications, which suggests that investment in less developed western regions is more cost-effective and easier in reducing CO 2 or air pollutant emissions than in developed eastern regions. [ABSTRACT FROM AUTHOR]

This study examines the stochastic conditional convergence of sulphur dioxide (SO2) emissions using the Residual Augmented Least Squares–Lagrange Multiplier (RALS–LM) unit root test with structural breaks. This procedure allows the data to account for trend breaks and nonnormal errors that have been ignored or deemphasized in previous studies. The study finds that per capita sulphur dioxide emissions exhibits stochastic conditional convergence across US states. [ABSTRACT FROM AUTHOR]

Construction operations generate significant air pollutant emissions, including carbon emissions and diesel exhaust emissions. Controlling operational efficiency is the most important strategy for reducing air pollutants emitted from construction operations. However, current practices to assess air pollutant emissions from construction operations tend to ignore the variability of the operational efficiency that results from different resource allotting and scheduling. In this context, this paper presents a methodology for incorporating the analysis of operational efficiency into quantifying the amount of exhaust emission from construction operations. Case studies are presented to examine how and to what extent planning decisions affect the amount of air pollutants emitted from construction operations and to identify the impact that possible alternatives have on the schedule and cost of projects. The findings of case studies indicate that considering environmental aspects in the planning stage could contribute to a project's increased integrated value, which includes schedule, cost, and environmental impact. [ABSTRACT FROM AUTHOR]

In view of energy shortage and air pollution, ethanol-gasoline blended fuel used for motorcycle engine was studied in this work. The emissions of carbon monoxide (CO), nitrogen oxides (NOX) and engine performance of a 125 cc four-stroke motorcycle engine with original carburetor using ethanol-gasoline fuels were investigated. The model of three-variable Box Behnken design (BBD) was used for experimental design, the ethanol blend ratios were prepared at 0, 10, 20 vol%; the speeds of motorcycle were selected as 30, 45, 60 km/h; and the throttle positions were set at 30, 60, 90 %. Both engine performance and air pollutant emissions were then analyzed by response surface method (RSM) to yield optimum operation parameters for tolerable pollutant emissions and maximum engine performance. The RSM optimization analysis indicated that the most suitable ethanol-gasoline blended ratio was found at the range of 3.92–4.12 vol% to yield a comparable fuel conversion efficiency, while considerable reductions of exhaust pollutant emissions of CO (-29 %) and NOX (-12 %) when compared to pure gasoline fuel. This study demonstrated low ethanol-gasoline blended fuels could be used in motorcycle carburetor engines without any modification to keep engine power while reducing exhaust pollutants. [ABSTRACT FROM AUTHOR]

Abstract: During the last decades, the Greater Athens Area (GAA), among many other urban agglomerations, faces atmospheric pollution problems mainly associated with high levels of particulates, nitrogen dioxide and ozone. The major pollution source for the GAA is road transportation. In this sense, the aim of this work was to investigate the existence of a direct relationship linking air pollutant concentration levels and road traffic emissions. To this aim, air pollutant emissions from road traffic were calculated for the period 1990–2009 and then the relationship with the corresponding air pollutant concentrations was investigated. The calculated results have revealed that all pollutants examined show a strong decreasing trend whereas the age of the vehicles and the corresponding engine technology determine the amount of the pollutants emitted. In addition, the NO2/NOx emission ratio presents a constant increase in the course of the years, according to the respective NO2/NOx concentration ratio. Furthermore, the comparison between emission calculations and the corresponding measured concentrations shows a highly significant correlation providing therefore evidence to policy makers that all pollution abatement measures can be defined and assessed with regard to their anticipated effect on air pollutant emissions. Detailed analysis of the 2009 emissions shows that, in general, passenger cars are the major polluters for CO, NMVOCs and CH4, whereas PM10 and NOx are mostly associated with heavy duty vehicles (HDVs). Finally, it appears that vehicles aged more than 15years are responsible for the major part of the air pollutants emitted. [Copyright &y& Elsevier]

Rice is a widely grown crop in Asia. China (30%) and India (21%) contribute to about half of the world''s total rice production. In this study, three major rice-producing countries in Asia are considered, India, Thailand and the Philippines (the later two contributing 4% and 2% of the world''s rice production). Rice straw is one of the main field based residues produced along with this commodity and its applications vary widely in the region. Although rice production practises vary from one country to another, open burning of straw is a common practice in these countries. In this study, an approach was followed aiming at (a) determining the quantity of rice straw being subject to open field burning in those countries, (b) congregating pollutant specific emissions factors for rice straw burning, and (c) quantifying the resulting air pollutant emissions. Uncertainties in the results obtained as compared to a global approach are also discussed. [Copyright &y& Elsevier]

Abstract: This paper reports the development of the maritime module within the framework of the Transport and Environment Database System (TRENDS) project. A detailed database has been constructed for the calculation of energy consumption and air pollutant emissions. Based on an in-house database of commercial vessels kept at the Technical University of Denmark, relationships between the fuel consumption and size of different vessels have been developed, taking into account the fleet''s age and service speed. The technical assumptions and factors incorporated in the database are presented, including changes from findings reported in Methodologies for Estimating air pollutant Emissions from Transport (MEET). The database operates on statistical data provided by Eurostat, which describe vessel and freight movements from and towards EU 15 major ports. Data are at port to Maritime Coastal Area (MCA) level, so a bottom-up approach is used. A port to MCA distance database has also been constructed for the purpose of the study. This was the first attempt to use Eurostat maritime statistics for emission modelling; and the problems encountered, since the statistical data collection was not undertaken with a view to this purpose, are mentioned. Examples of the results obtained by the database are presented. These include detailed air pollutant emission calculations for bulk carriers entering the port of Helsinki, as an example of the database operation, and aggregate results for different types of movements for France. Overall estimates of SO x and NO x emission caused by shipping traffic between the EU 15 countries are in the area of 1 and 1.5 million tonnes, respectively. [Copyright &y& Elsevier]

Vehicles typically deteriorate with accumulating mileage and emit more tailpipe air pollutants per mile. Although incentive programs for scrapping old, high-emitting vehicles have been implemented to reduce urban air pollutants and greenhouse gases, these policies may create additional sales of new vehicles as well. From a life cycle perspective, the emissions from both the additional vehicle production and scrapping need to be addressed when evaluating the benefits of scrapping older vehicles. This study explores an optimal fleet conversion policy based on mid-sized internal combustion engine vehicles in the US, defined as one that minimizes total life cycle emissions from the entire fleet of new and used vehicles. To describe vehicles'' lifetime emission profiles as functions of accumulated mileage, a series of life cycle inventories characterizing environmental performance for vehicle production, use, and retirement was developed for each model year between 1981 and 2020. A simulation program is developed to investigate ideal and practical fleet conversion policies separately for three regulated pollutants (CO, NMHC, and NOx) and for CO2. According to the simulation results, accelerated scrapping policies are generally recommended to reduce regulated emissions, but they may increase greenhouse gases. Multi-objective analysis based on economic valuation methods was used to investigate trade-offs among emissions of different pollutants for optimal fleet conversion policies. [Copyright &y& Elsevier]

Construction operations are highly energy-intensive and account for significant environmental impacts, including greenhouse gases (GHG) and other engine exhaust associated with material procurement/delivery and on-site construction activities. The opportunities for mitigating air pollutant emissions from construction operations can be captured by estimating and benchmarking during the preconstruction phase and then monitoring during the construction phase. However, a formal process model to manage the environmental aspects of on-site construction activities has yet to be clearly delineated, although recently several research efforts have appeared in relevant areas such as the development of in-use emission factors of construction equipment, methods for reliably estimating emissions at the project level, embodied carbon footprint benchmarking methods, and practical monitoring tools. Such a lack of a formal process model causes the misinterpretation of the benefits from recent research efforts in each area and hinders their implementation in practice. In this context, this paper aims to establish a framework model that could be a systematic and generic reference to the management of pollutant emissions from construction operations with state-of-the-art methods and tools. To do so, the paper identifies a generic process to be supported by research efforts in each area and presents an integrated framework based on the analysis of data connectivity between processes. An example of the indirect emission measurement is presented to demonstrate how data connectivity can be ensured between processes within the framework. [ABSTRACT FROM AUTHOR]