Air Pollution Control Strategies Research Articles

Decade-long trends in chemical component properties of PM2.5 in Beijing, China (2011−2020)

A 10-year-long measurement of water-soluble inorganic ions in PM2.5 was made in Beijing from June 2011 to December 2020, to investigate the interannual trends of chemical characteristics of PM2.5 and to provide insights into the future prevention and control of PM2.5 pollution. From 2011 to 2020, with the implementation of strict air pollution control strategies, significant changes of PM2.5 have been observed in Beijing, with NO3−, SO42− and NH4+ decreasing at rates of 5.10, 8.80 and 7.64% yr−1 respectively. The percentages of NO3− and SO42− under elevated pollution levels were investigated. When PM2.5 values fell in the range of 0–400 μg m−3, NO3−/ SO42− values were mostly higher than 1 and showed upward trends from 2011 to 2020. However, under extremely heavy haze conditions, SO42− dominated PM2.5 formation. This result was closely related to the change characteristics of the oxidation ratio of sulfate (SOR), the oxidation ratio of nitrate (NOR) and gaseous precursors under different pollution levels. The change characteristics of NOR and SOR under elevated PM2.5 levels indicated that the aqueous phase oxidation was the key process driving SO42− formation; while as for NO3−, in addition to the availability of NH4+, the atmospheric oxidation capacity made crucial roles. The analysis of typical haze episodes during the past decade indicated that the emission reduction of gaseous pollutants, especially SO2, made great contributions to the improved PM2.5 air quality in Beijing. We highlighted that future efforts should focus on enhanced reduction of NO2 emission and control of atmospheric oxidation capacity to further reduce particulate nitrate formation.

Evaluating cost and benefit of air pollution control policies in China: A systematic review

China has put great efforts into air pollution control over the past years and recently committed to its most ambitious climate target. Cost and benefit analysis has been widely used to evaluate the control policies in terms of past performance, future reduction potential, and direct and indirect impacts. To understand the cost and benefit analysis for air pollution control in China, we conducted a bibliometric review of more than 100 studies published over the past two decades, including the current research progress, most commonly adopted methods, and core findings. The control target in cost and benefit analysis has shifted in three stages, from individual and primary pollution control, moving to joint prevention of multiple and secondary pollutants, and then towards synergistic control of air pollution and carbon. With the expansion of the research scope, the integrated assessment model has gradually demonstrated the necessity for long-term ex-anti policy simulation, especially for dealing with complex factors. To ensure long-term air quality, climate, public health, and sustainable economic development, substantial evidence from published studies has suggested that China needs to continue its efforts in the upstream adjustment of the energy system and industrial structure with multi-regional and -sector collaboration. This cost and benefit review paper provides decision-makers with the fundamental information and knowledge gaps in air pollution control strategies in China, and direction for facing future challenges.

Pollution characteristics and health risk assessment of PM2.5-bound arsenic: a 7-year observation in the urban area of Jinan, China.

The aim of the study was to analyze the temporal trends, pollution sources, and carcinogenic health risks associated with PM2.5-bound arsenic (As). A total of 588 PM2.5 samples were collected in Jinan during January 2014-December 2020. The content and distribution characteristics were determined for As and Al in PM2.5, and the pollution sources were identified based on enrichment factors (EFs). The health risk of inhalation exposure to As was estimated using the risk assessment methods recommended by the United States Environmental Protection Agency (US EPA). The annual average concentration of As in PM2.5 was 4.5-17.5ngm-3, which was 0.8-2.9 times higher than the limit ruled by the European Union and China's Ambient Air Quality Standards (6ngm-3). From 2014 to 2020, the As concentration gradually decreased from 17.5 to 4.9ngm-3. After 2017, the concentration was close to the level required by the atmospheric quality standard (6ngm-3). The PM2.5 and arsenic concentrations in the heating season were significantly higher than those in the non-heating season. The EF of As ranged from 144 to 607, which was higher than 10. The cancer risk of As in PM2.5 decreased to the lowest values (heating season 1.0 × 10-5 and non-heating season 7.1 × 10-6, respectively) in 2019. As in Jinan mainly came from anthropogenic pollution. The level of As pollution has been significantly reduced in recent years, but there is still a high risk of carcinogenesis. Air pollution control strategies and guidelines need to be implemented in urban areas, especially during the heating season in winter and spring.

Prediction of Carbon Monoxide Concentration with Variation of Support Vector Regression Kernel Parameter Value

Human and industrial activities produce air pollutants that can cause a decline in air quality. In urban areas, transportation activities are the main source of air pollution. One of the emitted air pollutants produced by transportation is carbon monoxide (CO). The understanding of CO concentration is crucial since its overabundance beyond a certain limit will have a negative impact on human health and the environment. In this study, the support vector regression (SVR) method was used to predict CO concentration. The purpose of this study was to predict the hourly CO concentration in the Ujung Berung district, Bandung City, West Java, Indonesia with optimal prediction accuracy. An experiment was carried out by modeling the CO concentration with varying kernel parameter values to obtain accurate prediction results. The suitability of the values between error (ɛ), a trade-off constant (C), and variation mismatch (γ) is vital to obtain optimal prediction results. The results showed that the best prediction accuracy value was 97.68% with kernel parameter values ɛ = 0.02, γ = 30, and C = 0.006. These results may lead to proper decision making on environmental issues and can improve air pollution control strategies.

Assessment of COVID-19 Lockdown Impact on the Air Quality in Eastern Spain: PM and BTX in Urban, Suburban and Rural Sites Exposed to Different Emissions

In early 2020, the COVID-19 pandemic spread globally, and severe measures to control it were implemented. This study investigates the impact of the lockdown on the air quality of three provinces in the Valencia region, eastern Spain, in the years 2015–2020, focusing on particulate matter (PM). A thorough statistical analysis using different approaches is conducted. Hourly patterns are also assessed. In addition, the role of meteorological parameters on PM is explored. The results indicate an overall PM10 reduction of 16.5% when comparing the lockdown in 2020 and the 2015–2019 period, while PM2.5 increased by 3.1%. As expected, urban zones experienced higher reductions than suburban zones, which experienced a PM concentration increase. The impact of the drastic drops of benzene, toluene and xylene (77.4%, 58.0% and 61.8%, respectively) on the PM values observed in urban sites is discussed. Our study provides insights on the effect of activity changes over a wide region covering a variety of air quality stations, urban, suburban and rural, and different emission types. The results of this work are a valuable reference and suggest the need for considering different factors when establishing scientific air pollution control strategies.

Internalising health-economic impacts of air pollution into climate policy: a global modelling study

Climate change and air pollution are two major societal problems. Their complex interplay calls for an advanced evaluation framework that can support decision making. Previous assessments have looked at the co-benefits of climate policies for air pollution, but few have optimised air pollution benefits. In our study, we lay out a modelling framework that internalises air pollution's economic impacts on human mortality, while considering climate constraints and aerosol feedback. We developed a modelling framework based on an integrated assessment model (World Induced Technical Change Hybrid [WITCH]) designed to assess optimal climate change mitigation policies. We included structural and end-of-pipe measures in a detailed process integrated assessment model, that is hard-linked to air pollution and climate models. We analysed a large set of baseline scenarios, including five shared socioeconomic pathways (SSPs). SSP scenarios were also tested with three different levels of value per statistical life, and were combined with the Paris Agreement temperature targets (TTs), focusing on the 2°C and 1·5°C TTs by the end of the century. We found that, in the baseline scenarios, where no policies are applied, the number of annual premature deaths grew before declining slightly to 4·45 (range 3·86-6·11) million annual premature deaths by 2050. Reaching the Paris Agreement TT decreases mortality by approximately 0·47 million premature deaths by 2050 (up to 1·28 million premature deaths in SSP3 -1·5°C) with respect to the baseline. We showed that welfare-maximising policies accounting for air pollution benefits reduces premature mortality by 1·62 million deaths annually. This is three times greater than the co-benefits of climate policies. China is the region where most of the avoided mortality is possible, whereas the reforming economies (ie, non-EU eastern European countries, including Russia) region has the greatest welfare benefits. We find that global and regional welfare increases when air pollution impacts are internalised, with no negative repercussions on global inequality. Air pollution control strategies are found to be an important complement to structural emission reductions. Accounting for air pollution impacts reduces climate mitigation costs and inequality and increases global and regional welfare. Results are robust to a broad set of scenarios and assumptions, including debated normative choices on how to value improved health. EU Commission projects: INNOPATHS, NAVIGATE, ENGAGE, and COMMIT.

Characteristics of VOCs and their Potentials for O3 and SOA Formation in a Medium-sized City in Eastern China

To understand the characteristics and environmental effects of volatile organic compounds (VOCs) in a typical medium-sized city in China, manual measurements including 56 species of the nonmethane hydrocarbons (NMHCs) were taken at three urban and suburban sites in Huai’an from April to September 2019, and automatic measurements including 106 species of VOCs were taken at the urban center in May and August 2019. Spatial and temporal characteristics of the VOC concentrations were analyzed. Positive matrix factorization (PMF) model was applied to apportion VOC sources. Ozone (O3) formation potentials (OFPs) and secondary organic aerosol (SOA) formation potentials (SOAFPs) were calculated. The results show that the mean VOC concentration was much lower in the urban center than in the suburbs. Generally, proportions of both alkenes and aromatic hydrocarbons were higher and proportion of alkanes was lower in Huai’an than that in big cities, indicating emissions from solvent usage and industrial process play a more important role in the medium-sized city. The results of source apportionment show that solvent usage and industrial process together contributed 53%, and vehicle emission contributed 27% to the ambient VOCs. The dependence of VOC concentrations on temperature indicates that a considerable part of VOCs may come from fugitive emissions. The two-peak pattern of diurnal variation suggests near-surface emissions contributed a lot to the VOCs. Aromatic hydrocarbons were identified as the key component to the formation of O3 and SOA. Furthermore, biogenic emission could contribute greatly (> 20%) to the ambient VOCs during daytime in summer, which may have significant effects on O3 formation. Aromatic hydrocarbons were identified as the key component to the formation of O3 and SOA, which should be given more attention in developing air pollution control strategies.

The Modeling Study about Impacts of Emission Control Policies for Chinese 14th Five-Year Plan on PM2.5 and O3 in Yangtze River Delta, China

The Chinese government has made great efforts to combat air pollution through the reductions in SO2, NOx and VOCs emissions, as part of its socioeconomic Five-Year Plans (FYPs). China aims to further reduce the emissions of VOCs and NOx by 10% in its upcoming 14th FYP (2021–2025). Here, we used a regional chemical transport model (e.g., WRF/CMAQ) to examine the responses of PM2.5 and O3 to emission control policies of the 14th FYP in the Yangtze River Delta (YRD) region. The simulation results under the 4 emission control scenarios in the 2 winter months in 2025 indicate that the average concentrations of city mean PM2.5 in 41 cities in the YRD were predicted to only decrease by 10% under both S1 and S1_E scenarios, whereas the enhanced emission control scenarios (i.e., S2_E and S3_E) could reduce PM2.5 in each city by more than 20%. The model simulation results for O3 in the 3 summer months in 2025 show that the O3 responses to the emission controls under the S1 and S1_E scenarios show different control effects on O3 concentrations in the YRD with the increase and decrease effects, respectively. The study found that both enhanced emission control scenarios (S2_E and S3_E) could decrease O3 in each city by more than 20% with more reductions in O3 under the S3_E emission control scenario because of its higher control strengths for both NOx and VOCs emissions. It was found that emission reduction policies for controlling high emission sectors of NOx and VOCs such as S2_E and S3_E were more effective for decreasing both PM2.5 and O3 in the YRD. This study shows that O3 controls will benefit from well-designed air pollution control strategies for reasonable control ratios of NOx and VOCs emissions.

Air Pollution Control by Using Advanced Oxidation Processes (AOPs)

Among air pollution control strategies, air cleaning with Advanced Oxidation Processes (AOPs) has been drawing more and more attention because of the restraints in the production of secondary pollution. AOPs have a wide range of applications such as air (odour elimination, purification), soil (remediation) and water decontamination. Ideally, the photo catalyst, titanium dioxide, is introduced in the top layer of the concrete pavement for best results. In addition, the combination of TiO2 with cement-based products offers some synergistic advantages, as the reaction products can be adsorbed at the surface and subsequently be washed away by rain. The main aim of this research work is to measure the effect of titanium dioxide as photo catalyst in purifying nitrogen oxide (NOX) and Carbon Oxides (COX) on pavement surface and outdoor environment condition. For that, TiO2 is replaced for cement at different proportions of 5%, 10% & 15% in terms of weight in the cement concrete moulds of 10 mm uniform thickness and curing is done for seven days, then same were exposed to the sunlight at Ijoor circle sampling point Rama Nagar Town for 21 days of observation. From the Energy Dispersive Spectroscopy (EDS) analysis, result it is observed that atom percentage increased maximum of 59.05 for carbon atoms for 10% proportion specimen. Then, check the amount of percentage for carbon atoms adsorbed by 10% proportion specimen at police/Kandaya Bhavan circle and Railway station circle sampling points of Rama Nagar Town for 21 days of observations and the results shows that, carbon atom percentage increased maximum of 42.99 and 58.69 for carbon atoms respectively at above sampling points. From this work, it is conclude that the Carbon atoms and Nitrogen atoms present in the atmosphere will be reduce up to some level when replace 10% of Titanium dioxide with cement in the concrete moulds of 10 mm thickness by Photo catalytic activity.

Health and Economic Impact Assessment of Transport and Industry PM2.5 Control Policy in Guangdong Province

PM2.5 pollution-related diseases lead to additional medical expenses and the loss of working hours, thus affecting the macro-economy. To evaluate the health-related economic impacts of PM2.5, the Integrated Assessment Model of Climate, Economic, and Environment (ICEEH), combined with the Computable General Equilibrium (CGE) model, the Greenhouse Gas and Air Pollution Interactions and Synergies (GAINS) model, and a health impact assessment module was constructed. The impact of different air pollution control strategies was analyzed in Guangdong Province by establishing a Without Control (WOC) scenario, an Air Control (AIC) scenario, and a Blue Sky (BLK) scenario. The results show that in the WOC scenario for 2035, the death rate for Guangdong Province is 71,690 persons/year and the loss of working hours is 0.67 h/person/year. In the AIC and BLK scenarios compared with WOC for 2035, the loss of working hours is reduced by 29.8% and 34.3%, and premature deaths are reduced by 33.0% and 37.5%, respectively; GDP would increase by 0.05% and 0.11%, respectively, through strict pollution control policies. Furthermore, improved labor force quality induced by better air conditions would promote the added value in labor-intensive industries, such as agriculture (0.233%), other manufacturing (0.172%), textiles (0.181%), food (0.176%), railways transport (0.137%), and services (0.129%). The added value in the waste (−0.073%), nature gas (−0.076%), and crude oil sectors (−0.072%) would decrease because of the increased investment installment in PM2.5 treatment equipment.

Sources of cellular oxidative potential of water-soluble fine ambient particulate matter in the Midwestern United States

We investigated the spatiotemporal distribution and sources of cellular oxidative potential (OP) in the Midwest US. Weekly samples were collected from three urban [Chicago (IL), Indianapolis (IN), and St. Louis (MO)], one rural [Bondville (IL], and one roadside site [Champaign (IL)] for a year (May 2018 to May 2019), and analyzed for water-soluble cellular OP using a macrophage reactive oxygen species (ROS) assay. Chemical composition of the samples including several carbonaceous components, inorganic ions, and water-soluble elementals, were also analyzed. The emission sources contributing to water-soluble cellular OP and PM2.5 mass were analyzed using positive matrix factorization. The secondary organic aerosols contributed substantially (≥54%) to PM2.5 cellular OP at urban sites, while the roadside and rural OP were dominated by road dust (54%) and agricultural activities (62%), respectively. However, none of these sources contributed substantially to the PM2.5 mass (≤21%). Other sources contributing significantly to the PM2.5 mass, i.e., secondary sulfate and nitrate, biomass burning and coal combustion (14–26%) contributed minimally to the cellular OP (≤13%). Such divergent profiles of the emission sources contributing to cellular OP vs. PM2.5 mass demonstrate the need of considering more health-relevant metrics such as OP in the design of air pollution control strategies.

Impact of air pollution exposure on the risk of Alzheimer's disease in China: A community-based cohort study

Alzheimer's disease (AD) is the most common type of dementia. Impact of air pollution (AP) on the risk of AD is unclear. It is unknown which air pollutants are independently associated with AD and whether fish consumption mitigated the association. We carried out a community-based cohort of 6115 participants aged ≥60 years in China to examine the association of PM2.5, PM10, CO, NO2, SO2 and O3 exposure with AD, and differences in the association between people with low and high consumption of fish. The participants were randomly recruited from six counties in Zhejiang province for health survey to document socio-demographic and disease risk factors in 2014, and were followed up to diagnose AD in 2019. A total of 986 cohort members were diagnosed with AD. Based on the daily mean air pollutants monitored in 2013–2015 in the counties, participants were divided into low, middle and high AP exposure groups for subsequent analysis. The multiple adjusted odds ratio (OR) of AD in participants living with the middle and high levels of PM2.5 exposure versus the low exposure were 1.50 (95% CI 0.90–2.50) and 3.92 (2.09–7.37). The increased ORs were also with PM10 (1.74, 0.65–4.64; 3.00, 1.22–7.41) and CO (2.86, 1.32–6.20; 1.19, 0.45–3.18), but not with NO2 (0.63, 0.17–2.27; 0.95, 0.28–3.19), SO2 (0.44, 0.19–1.001; 1.21, 0.56–2.62), and O3 (0.38, 0.20–0.74; 0.50, 0.21–1.21). There were no significant interaction effects of AP with fish consumption on AD. However, participants with low consumption of fish appeared to have higher ORs in PM2.5 exposure (1.80, 1.39–2.33; 5.18, 3.93–6.82) than those high consumption (1.38, 0.78–2.47; 2.89, 1.50–5.59). Our findings of PM2.5, PM10 and CO exposure significantly increased the risk of AD and the potential mitigating effect of fish consumption on the association provide evidence for developing effective strategies for AD reduction and air pollution control.

Associations between long term exposures to outdoor air pollution and indoor solid fuel use and depression in China

Depression is one of the most common mental disorders. Effects of air pollution from outdoor and indoor on depression were inconsistent. We assessed 30,139 participants from Northeast China to explore the associations between long term exposures of outdoor and indoor solid fuel use and depressive symptoms. Multiple logistic regressions models as well as multiplicative interaction and additive interaction analysis were used. Outdoor exposures to air pollutants of particulate matter (with an aerodynamic diameter <2.5 μm, [PM2.5], odds ratio [OR] = 1.98 per standard deviation [SD], 95% confidence interval [CI]: 1.78, 2.19; with an aerodynamic diameter <10 μm, [PM10], OR = 1.83, 95% CI:1.68, 2.00), sulfur dioxide (SO2, OR = 1.42, 95% CI: 1.33, 1.52), and nitrogen dioxide (NO2, OR = 1.62, 95% CI: 1.49, 1.76) were significantly associated with higher occurrence of depressive symptoms. A significant linear trend for increased occurrence of depressive symptoms was observed in participants using both solid fuels for cooking and heating (P = 0.04). Indoor air pollution exposures from solid fuel use for heating (OR = 1.16, 95%CI: 1.00, 1.35) and high cooking frequency (OR = 1.17, 95%CI: 1.00, 1.37) were significantly associated with increased occurrence of depressive symptoms. We observed significant interactions of indoor solid fuel use and outdoor air pollution exposures on depressive symptoms (indoor fuel use for cooking and SO2, P value = 0.04; solid fuel use for heating and NO2, P value = 0.02). Solid fuel use for cooking weakened the associations between SO2(relative excess risk due to interaction [RERI] = −1.37, 95% CI: −1.88, −0.86) and depressive symptoms. Solid fuel use for heating weakened the associations between NO2 (RERI = −1.91, 95% CI: −2.55, −1.27) and depressive symptoms. Compared with individual associations, antagonistic interactions of outdoor air pollution and indoor solid fuel use on depressive symptoms might exist. Our findings contribute to better understandings for the associations between air pollution and depressive symptoms, which might be useful for developing effective strategies for depression prevention and air pollution control.

Urban air pollution control policies and strategies: a systematic review.

A wide range of policies, strategies, and interventions have been implemented to improve air quality all over the world. This systematic review comprehensively appraises the policies and strategies on air pollutants controls enacted in different countries, worldwide. Three databases, Web of Science, PubMed and Scopus, were used for the search. After screening, a total of 114 eligible manuscripts were selected from 2219 documents for further analysis. Selected articles were divided into two categories: (1) articles focusing on introducing the policies and strategies enacted for controlling air pollution in different countries, and (2) articles which focused on different policies and strategies to control one or more specific pollutants. In the former one, urban air pollution control strategies and policies were divided into four categories, namely, general strategies and policies, transportation, energy, and industry. In case of latter category, policies and strategies focused on controlling six pollutants (PM, SO2, NO2, VOCS, O3 and photochemical smog). The results indicated that, the most common policies and strategies enacted in most countries are pertinent to the transportation sector. Changing energy sources, in particular elimination or limited use of solid fuels, was reported as an effective action by governments to reduce air pollution. Overall, most policies enacted by governments can be divided into three general categories: (a) incentive policies such as implementing a free public transportation program to use fewer private cars, (b) supportive policies such as paying subsidies to change household fuels, and (c) punitive policies such as collecting tolls for cars to enter the congestion charging areas. Depending on the circumstances, these policies are implemented alone or jointly. In addition to the acceptance of international agreements to reduce air pollution by governments, greater use of renewable energy, clean fuels, and low-pollution or no-pollution vehicles such as electric vehicles play an important role in reducing air pollution.

IMPACT OF COVID-19 EVENT ON AIR POLLUTANTS OF PM2.5 AND PM10 IN JAKARTA, INDONESIA

As the capital city of Indonesia, the Province of Jakarta encounter a problem seriously of decreasing air quality. This study analyzes the air quality of two cities in Jakarta Province, Central Jakarta and South Jakarta, from March to June 2016–2020, and the impact of COVID-19 epidemic prevention and control actions on air quality. The combined air quality index (AQI) for two cities from 2016–2019, in the wet season, indicated that it has the lowest AQI with an average of 79, and the highest AQI occurred in the dry season with averaged 118. The distribution of the six AQI classes for two cities in dry season were 2%, 24%, 63%, 11%, 0%, and 0%, and in wet season, they were 10%, 48%, 39%, 3%, 0%, and 0%, respectively. The concentrations for PM2.5 and PM10 in March, April, May, and June 2016–2019 and those for 2020 were also analyzed in this study. Based on the data from the two cities, during March, April, May, and June 2020, the average PM2.5 decreased by 23.6%, 39.5%, 41.5%, and 13.3%, respectively, and the average PM10 decreased by 22.2%, 29.9%, 36.9%, and 29.8%, respectively, compared with that in March, April, May, and June 2016–2019. It is obvious that air quality greatly improved during the COVID-19 epidemic. This study presents beneficial information to policymakers for developing scientific air pollution control strategies and is a useful reference for future research in improving urban air quality.

Strategies towards PM2.5 attainment for non-compliant cities in China: A case study

The northern part of the Yangtze River Delta (YRD) region in China suffers from high concentrations of fine particular matter (PM2.5) during the past years yet received much less attention compared to the other parts of the YRD region. In this study, we integrated observational data, control policies and strategies, and air quality simulations to develop PM2.5 attainment demonstration by year 2030 for the city of Bengbu, which represents a typical non-compliant city in the northern YRD region. In 2018, the annual average PM2.5 concentration in Bengbu was 51.8 μg/m3, which was 48 % higher than the standard of 35 μg/m3 set by the National Ambient Air Quality Standards (NAAQS). Different future emission scenarios were developed for year 2025 as mid-term and year 2030 as long-term. Integrated meteorology and air quality modeling system together with monitoring data was applied to predict the air quality under the future emission scenarios. Results show that when a conservative emission reduction ratio of 40 % was assumed for surrounding regions, the annual average PM2.5 concentration in Bengbu could meet the target value by 2030, in which case emissions of SO2, NOx, PM2.5, VOCs, and NH3 need to be reduced by 70.6 %, 43.5 %, 47.2 %, 33.4 %, and 47.5 %, respectively. PM2.5 concentration in Bengbu is not only controlled by local emission reductions but also affected by emission reductions of surrounding regions as well as contribution from long-range transport. More attentions need to be paid to the control of VOCs emissions in the near future to avoid increase of ozone concentrations while reducing PM2.5. Our results provide scientific support for the local government to formulate future air pollution prevention and control strategies, sub-regional joint-control among surrounding cities, as well as trans-regional joint-control between the north China and the YRD region.

Effects of road grade on real-world tailpipe emissions of regulated gaseous pollutants and volatile organic compounds for a Euro 5 motorcycle

Road grade is an important variable that affects engine power demand and hence the fuel consumption and tailpipe emissions of vehicles. However, no prior works have evaluated the effects of road grade on tailpipe volatile organic compound (VOC) emissions of motorcycles. This study investigated the effects of road grade on real-world tailpipe emissions of carbon monoxide (CO), carbon dioxide (CO2), total hydrocarbons (THC), nitric oxide (NO), and speciated VOCs for a Euro 5 motorcycle. Real-world emissions of CO, CO2, THC, and NO were measured in real-time using a miniature portable emissions measurement system (mini-PEMS), while VOCs were measured in integrated exhaust samples collected during real-world driving. PEMS tests (n = 20) were conducted on urban (UR), suburban (SU), uphill (UH), and downhill (DH) routes. The road grade range encountered in this study was approximately −14 % to +14 %. The mean UH emission factors of CO, THC, and ΣVOC were 9890 ± 1619, 101.0 ± 6.7, and 18.81 ± 4.31 mg/km, respectively. Likewise, the DH emission factors were 202 ± 197 mg/km for CO, 10.3 ± 2.9 mg/km for THC, and 1.49 ± 0.68 mg/km for ΣVOC. The emission factors of all measured pollutants on the UH route were significantly higher than the DH and baseline (mean of UR and SU) emission factors. The results of the present study may help identify emission hotspots along the roads and formulate traffic air pollution control strategies.

PM2.5-associated risk for cardiovascular hospital admission and related economic burdens in Beijing, China

BackgroundThe study of ambient air particulate matter (PM2.5)-associated health and economic burdens of cardiovascular disease are crucial for air pollution control and disease prevention strategies. Quantified evidence remains inadequate. ObjectivesThis study aimed to estimate the PM2.5 associated risk in cardiovascular hospital admission as well as attributable health burdens and economic costs. MethodsA total of 2,202,244 hospital admission records of cardiovascular disease and six common clinical subtypes in Beijing were included. A time-stratified case-crossover design was applied to estimate the associations and the concentration-response curve. Then, the annual average additional hospital admissions, days of hospital stay, and hospital expenditures were evaluated from 2013 to 2017 and compared between 2017 and 2013. ResultsThe results showed that each 10 μg/m3 increase in previous-day PM2.5 concentration was associated with a risk increase of 0.44% (95%CI: 0.40%, 0.47%) for cardiovascular disease, 0.66% (95%CI: 0.58%, 0.73%) for angina pectoris, 0.53% (95%CI: 0.39%, 0.66%) for chronic ischemic heart disease, 0.48% (95%CI: 0.34%, 0.63%) for myocardial infarction, 0.44% (95%CI: 0.29%, 0.60%) for hypertensive heart disease and 0.40% (95%CI: 0.27%, 0.52%) for ischemic stroke. There were 1938 PM2.5 attributed additional hospital admissions, resulting in 21,668 additional days in hospital, along with 5527.12 and 1947.04 ten-thousand of additional total hospital cost and self-afforded cost, respectively. Compared with 2013, the above-mentioned four burdens decreased by 18.17%, 28.80%, 18.90% and 13.72% in 2017, respectively. ConclusionPM2.5 exposure was significantly associated with substantial burdens of cardiovascular hospital admission and economic expenditures. The results highlight the necessity of continuous PM2.5 control from the perspective of healthy and sustainable city development in urban China.

Reducing Planetary Health Risks Through Short-Lived Climate Forcer Mitigation.

Global air pollution and climate change are major threats to planetary health. These threats are strongly linked through the short‐lived climate forcers (SLCFs); ozone (O3), aerosols, and methane (CH4). Understanding the impacts of ambitious SLCF mitigation in different source emission sectors on planetary health indicators can help prioritize international air pollution control strategies. A global Earth system model is applied to quantify the impacts of idealized 50% sustained reductions in year 2005 emissions in the eight largest global anthropogenic source sectors on the SLCFs and three indicators of planetary health: global mean surface air temperature change (∆GSAT), avoided PM2.5‐related premature mortalities and gross primary productivity (GPP). The model represents fully coupled atmospheric chemistry, aerosols, land ecosystems and climate, and includes dynamic CH4. Avoided global warming is modest, with largest impacts from 50% cuts in domestic (−0.085 K), agriculture (−0.034 K), and waste/landfill (−0.033 K). The 50% cuts in energy, domestic, and agriculture sector emissions offer the largest opportunities to mitigate global PM2.5‐related health risk at around 5%–7% each. Such small global impacts underline the challenges ahead in achieving the World Health Organization aspirational goal of a 2/3 reduction in the number of deaths from air pollution by 2030. Uncertainty due to natural climate variability in PM2.5 is an important underplayed dimension in global health risk assessment that can vastly exceed uncertainty due to the concentration‐response functions at the large regional scale. Globally, cuts to agriculture and domestic sector emissions are the most attractive targets to achieve climate and health co‐benefits through SLCF mitigation.

Biomass-burning emissions could significantly enhance the atmospheric oxidizing capacity in continental air pollution

Volatile organic compounds (VOCs) are important precursors of photochemical pollution. However, a substantial fraction of VOCs, namely, oxygenated VOCs (OVOCs), have not been sufficiently characterized to evaluate their sources in air pollution in China. In this study, a total of 119 VOCs, including 60 OVOCs in particular, were monitored to provide a more comprehensive picture based on different online measurement techniques, proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF-MS) and online gas chromatography/mass spectrometry (GC/MS), at a receptor site in southeastern China during a photochemically active period. Positive matrix factorization (PMF) and photochemical age-based parameterization were combined to identify and quantify different sources of major VOCs during daytime hours, with the advantage of including VOC decay processes. The results revealed the unexpected role of biomass burning (21%) in terms of ozone (O3) formation potential (OFP) when including the contributions of OVOCs and large contributions (30–32%) of biomass burning to aldehydes, as more OVOCs were measured in this study. We argue that biomass burning could significantly enhance the continental atmospheric oxidizing capacity, in addition to the well-recognized contributions of primary pollutants, which should be seriously considered in photochemical models and air pollution control strategies.