Showing papers on "Particulates published in 2017"
TL;DR: This review summarizes the main findings from published papers on the characteristics and sources and processes of ozone and ozone precursors in the boundary layer of urban and rural areas of China, including concentration levels, seasonal variation, meteorology conducive to photochemistry and pollution transport, key production and loss processes, ozone dependence on nitrogen oxides and volatile organic compounds, and the effects of ozone on crops and human health.
952 citations
TL;DR: A powerful roll-to-roll hot-pressing strategy for mass production of metal-organic framework (MOF)-based filters (MOFilters) using various MOF systems with ranges of substrates is presented, which shows superior particulate matter removal efficiency under desired working temperatures.
Abstract: A powerful roll-to-roll hot-pressing strategy for mass production of metal-organic framework (MOF)-based filters (MOFilters) using various MOF systems with ranges of substrates is presented. Thus-obtained MOFilters show superior particulate matter removal efficiency under desired working temperatures. Such versatile MOFilters can be scaled up and purposely designed, which endows MOFilters with great potentials in both residential and industrial pollution control.
266 citations
TL;DR: The control policies issued before 2010 are insufficient to improve PM2.5 air quality notably in future, an optimal mix of energy-saving and end-of-pipe control measures should be implemented, more ambitious control policies for NMVOC and NH3 should be enforced, and special control measures in winter should be applied.
259 citations
TL;DR: In the oceans' largest known hydrothermal plume, extending westwards across the Pacific from the Southern East Pacific Rise, dissolved iron and manganese were shown by the GEOTRACES program to be transported halfway across the ocean.
Abstract: Hydrothermally sourced dissolved metals have been recorded in all ocean basins. In the oceans’ largest known hydrothermal plume, extending westwards across the Pacific from the Southern East Pacific Rise, dissolved iron and manganese were shown by the GEOTRACES program to be transported halfway across the Pacific. Here, we report that particulate iron and manganese in the same plume also exceed background concentrations, even 4,000 km from the vent source. Both dissolved and particulate iron deepen by more than 350 m relative to 3He—a non-reactive tracer of hydrothermal input—crossing isopycnals. Manganese shows no similar descent. Individual plume particle analyses indicate that particulate iron occurs within low-density organic matrices, consistent with its slow sinking rate of 5–10 m yr−1. Chemical speciation and isotopic composition analyses reveal that particulate iron consists of Fe(III) oxyhydroxides, whereas dissolved iron consists of nanoparticulate Fe(III) oxyhydroxides and an organically complexed iron phase. The descent of plume-dissolved iron is best explained by reversible exchange onto slowly sinking particles, probably mediated by organic compounds binding iron. We suggest that in ocean regimes with high particulate iron loadings, dissolved iron fluxes may depend on the balance between stabilization in the dissolved phase and the reversibility of exchange onto sinking particles. The largest known hydrothermal plume moves dissolved iron halfway across the Pacific. In situ measurements show that dissolved and particulate iron transport is facilitated by reversible exchange of dissolved iron onto organic compounds.
195 citations
TL;DR: In this paper, simultaneous 1-h measurements of particulate and gaseous compositions along with the ISORROPIA-II thermodynamic equilibrium model were used to study aerosol acidity during severe haze episodes in northern China.
Abstract: Aerosol acidity plays an important role in atmospheric chemistry. China emits large amounts of SO2, NOx, and NH3 into the atmosphere, but aerosol acidity is poorly characterized. In this study, simultaneous 1 h measurements of particulate and gaseous compositions along with the ISORROPIA-II thermodynamic equilibrium model were used to study aerosol acidity during severe haze episodes in northern China. The summed concentration of sulfate, nitrate, and ammonium was 135 ± 51 μg/m3 with a maximum of 250 μg/m3, and the gas-phase NH3 mixing ratio was 22 ± 9 ppb. Fine particles were moderately acidic, with a pH range of 3.0–4.9 and an average of 4.2, which was higher than those in the United States and Europe. Excess NH3 and high aerosol water content are responsible for the relatively lower aerosol acidity. These results suggest that the new pathways for sulfate production in China proposed by recent studies should be revisited.
181 citations
TL;DR: In this paper, a review of the works on the control of diesel particulate matter in both pre-combustion and postcombustions techniques employed in the past few decades is presented.
Abstract: The diesel engine is being widely used in day to day life in both mobile and stationary applications. The main drawback is the release of harmful gasses like HC, CO, NOx and particulate matter into the atmosphere. This affects both human beings and environment to a great extent and should be controlled effectively. This paper reviews the works on the control of diesel particulate matter in both pre-combustion and post-combustion techniques employed in the past few decades. The initial part of this review will discuss particulate matter composition and its structure. Then the various physical processes involved in the formation of particulate matter are discussed. Effects of fuel composition and its structure on soot formation are reported. Hazardous effects of particulate matter on both human beings and the environment are reviewed. Use of biodiesel water emulsified fuel as a fuel to control soot formation is highlighted. This review also highlights control of particulate matter by varying injection parameters like injection pressure, injection timing and auxiliary air injection. Multiple fuel injections within the same cycle to control NOx and particulate matter are also discussed. The conventional control technique of particulate matter by using Diesel particulate filter and its types are also compared with the new technologies. Various regeneration concepts to burn the collected soot are also highlighted. The major part of this review focuses on pre-combustion techniques to control particulate matter. This review paper, it is hoped, will be very useful for the researchers working on the control of diesel particulate matter.
176 citations
TL;DR: In this paper, the authors reviewed the sources, spatial and temporal variability, and toxicity of PM10, the particulate matter having particle sizes 10 micrometers or less in diameter, in world regions.
Abstract: Particulate matter (PM) is both a major driver of climate change and a source of toxicity for health. In the upper atmosphere, particulate matter modifies the earth radiation budget, cloud formation and acts as a reaction center for air pollutants. In the lower atmosphere, particulate matter changes atmospheric visibility and alters biogeochemical cycles and meteorology. Most critical effects are observed in ambient air, where particulate matter degrades human health. Here we review the sources, spatial and temporal variability, and toxicity of PM10, the particulate matter having particle sizes 10 micrometers or less in diameter, in world regions. For that we analyzed information from the world wide web and databases from government organizations after the year 2000. Findings show that PM10 is a major risk in both developed and developing countries. This risk is more severe in Asian countries compared to Europe and USA, where decreasing trends are recorded during the last two decades. Meteorological factors modify particulate matter variations at local and regional levels. PM2.5/PM10 ratio provides information of particulate matter sources under different environment conditions. Crustal matter, road traffic and combustion of fuels are major sources of particulate matter pollution. Health studies indicate that long-term exposure to particulate matter has multiple health effects in people from all age groups. Identification of possible sources and their control with regular epidemiological monitoring could decrease the impact of particulate matter pollution.
176 citations
University of North Carolina at Chapel Hill1, National Center for Atmospheric Research2, Duke University3, University of Reading4, Goddard Institute for Space Studies5, Geophysical Fluid Dynamics Laboratory6, National Institute for Environmental Studies7, Nagoya University8, Kyushu University9, Lawrence Livermore National Laboratory10, University of Edinburgh11, Centre national de la recherche scientifique12, National Institute of Water and Atmospheric Research13
TL;DR: Premature mortality from changes in air pollution attributable to climate change, under the high greenhouse gas scenario RCP8.5, is estimated to be positive in all regions except Africa, and is greatest in India and East Asia.
Abstract: The effect of ozone and fine particulate matter on human health is dependent on emissions and climate change. Here the effects of climate change on air pollution mortality are isolated, with increases predicted in all regions except Africa. Ground-level ozone and fine particulate matter (PM 2.5) are associated with premature human mortality1,2,3,4; their future concentrations depend on changes in emissions, which dominate the near-term5, and on climate change6,7. Previous global studies of the air-quality-related health effects of future climate change8,9 used single atmospheric models. However, in related studies, mortality results differ among models10,11,12. Here we use an ensemble of global chemistry–climate models13 to show that premature mortality from changes in air pollution attributable to climate change, under the high greenhouse gas scenario RCP8.5 (ref. 14), is probably positive. We estimate 3,340 (−30,300 to 47,100) ozone-related deaths in 2030, relative to 2000 climate, and 43,600 (−195,000 to 237,000) in 2100 (14% of the increase in global ozone-related mortality). For PM 2.5, we estimate 55,600 (−34,300 to 164,000) deaths in 2030 and 215,000 (−76,100 to 595,000) in 2100 (countering by 16% the global decrease in PM 2.5-related mortality). Premature mortality attributable to climate change is estimated to be positive in all regions except Africa, and is greatest in India and East Asia. Most individual models yield increased mortality from climate change, but some yield decreases, suggesting caution in interpreting results from a single model. Climate change mitigation is likely to reduce air-pollution-related mortality.
166 citations
TL;DR: In this article, the influence of dust and anthropogenic sources (e.g., fossil and biomass fuel combustion) on solar electricity generation is estimated. But, the results show that solar energy production is currently reduced by ∼17-25% across these regions, with roughly equal contributions from ambient PM and PM deposited on photovoltaic surfaces.
Abstract: Atmospheric particulate matter (PM) has the potential to diminish solar energy production by direct and indirect radiative forcing as well as by being deposited on solar panel surfaces, thereby reducing solar energy transmittance to photovoltaics. Worldwide solar energy production is expected to increase more rapidly than any other energy source into the middle of this century, especially in regions that experience high levels of dust and/or anthropogenic particulate pollutants, including large areas of India, China, and the Arabian Peninsula. Here we combine field measurements and global modeling to estimate the influence of dust and PM related to anthropogenic sources (e.g., fossil and biomass fuel combustion) on solar electricity generation. Results indicate that solar energy production is currently reduced by ∼17–25% across these regions, with roughly equal contributions from ambient PM and PM deposited on photovoltaic surfaces. Reductions due to dust and anthropogenic PM are comparable in northern In...
154 citations
TL;DR: PM2.5 pollution is a pan-India problem, with a regional character, and is not limited to urban areas or megacities, and even under the most active reductions envisioned, the 2050 mean exposure is estimated to be nearly 3 times higher than the WHO Air Quality Guideline.
Abstract: . India is currently experiencing degraded air quality, and future economic development will lead to challenges for air quality management. Scenarios of sectoral emissions of fine particulate matter and its precursors were developed and evaluated for 2015–2050, under specific pathways of diffusion of cleaner and more energy-efficient technologies. The impacts of individual source sectors on PM2.5 concentrations were assessed through systematic simulations of spatially and temporally resolved particulate matter concentrations, using the GEOS-Chem model, followed by population-weighted aggregation to national and state levels. We find that PM2.5 pollution is a pan-India problem, with a regional character, and is not limited to urban areas or megacities. Under present-day emissions, levels in most states exceeded the national PM2.5 annual standard (40 µg m−3). Sources related to human activities were responsible for the largest proportion of the present-day population exposure to PM2.5 in India. About 60 % of India's mean population-weighted PM2.5 concentrations come from anthropogenic source sectors, while the remainder are from other sources, windblown dust and extra-regional sources. Leading contributors are residential biomass combustion, power plant and industrial coal combustion and anthropogenic dust (including coal fly ash, fugitive road dust and waste burning). Transportation, brick production and distributed diesel were other contributors to PM2.5. Future evolution of emissions under regulations set at current levels and promulgated levels caused further deterioration of air quality in 2030 and 2050. Under an ambitious prospective policy scenario, promoting very large shifts away from traditional biomass technologies and coal-based electricity generation, significant reductions in PM2.5 levels are achievable in 2030 and 2050. Effective mitigation of future air pollution in India requires adoption of aggressive prospective regulation, currently not formulated, for a three-pronged switch away from (i) biomass-fuelled traditional technologies, (ii) industrial coal-burning and (iii) open burning of agricultural residue. Future air pollution is dominated by industrial process emissions, reflecting larger expansion in industrial, rather than residential energy demand. However, even under the most active reductions envisioned, the 2050 mean exposure, excluding any impact from windblown mineral dust, is estimated to be nearly 3 times higher than the WHO Air Quality Guideline.
152 citations
TL;DR: Reduction of anthropogenic sources of NOx, VOCs, and PM, for example, reduction of the motorized vehicle fleet, would have to accompany urban tree planting campaigns to make them really beneficial for urban dwellers.
Abstract: The potential of emissions from urban vegetation combined with anthropogenic emissions to produce ozone and particulate matter has long been recognized This potential increases with rising temperatures and may lead to severe problems with air quality in densely populated areas during heat waves Here, we investigate how heat waves affect emissions of volatile organic compounds from urban/suburban vegetation and corresponding ground-level ozone and particulate matter We use the Weather Research and Forecasting Model with atmospheric chemistry (WRF-Chem) with emissions of volatile organic compounds (VOCs) from vegetation simulated with MEGAN to quantify some of these feedbacks in Berlin, Germany, during the heat wave in 2006 The highest ozone concentration observed during that period was ∼200 μg/m3 (∼101 ppbV) The model simulations indicate that the contribution of biogenic VOC emissions to ozone formation is lower in June (9–11%) and August (6–9%) than in July (17–20%) On particular days within the an
TL;DR: It is demonstrated that long‐term exposure to air pollution including PM 2.5 increases the risk of major cardiovascular disease and mortality and air pollution should be considered an important modifiable environmental cardiovascular risk factor.
Abstract: BackgroundStudies have shown that long‐term exposure to air pollution such as fine particulate matter (≤2.5 μm in aerodynamic diameter [PM2.5]) increases the risk of all‐cause and cardiovascular mo...
TL;DR: Whether gasoline or Diesel cars are more polluting depends on the pollutant in question, i.e. that diesel cars are not necessarily worse polluters than gasoline cars.
Abstract: Carbonaceous particulate matter (PM), comprising black carbon (BC), primary organic aerosol (POA) and secondary organic aerosol (SOA, from atmospheric aging of precursors), is a highly toxic vehicle exhaust component. Therefore, understanding vehicle pollution requires knowledge of both primary emissions, and how these emissions age in the atmosphere. We provide a systematic examination of carbonaceous PM emissions and parameterisation of SOA formation from modern diesel and gasoline cars at different temperatures (22, −7 °C) during controlled laboratory experiments. Carbonaceous PM emission and SOA formation is markedly higher from gasoline than diesel particle filter (DPF) and catalyst-equipped diesel cars, more so at −7 °C, contrasting with nitrogen oxides (NOX). Higher SOA formation from gasoline cars and primary emission reductions for diesels implies gasoline cars will increasingly dominate vehicular total carbonaceous PM, though older non-DPF-equipped diesels will continue to dominate the primary fraction for some time. Supported by state-of-the-art source apportionment of ambient fossil fuel derived PM, our results show that whether gasoline or diesel cars are more polluting depends on the pollutant in question, i.e. that diesel cars are not necessarily worse polluters than gasoline cars.
TL;DR: In this article, the authors examined the inter-species variation of particulate capture by leaves of seventeen plant species present in a living wall at New Street railway station, Birmingham, UK.
TL;DR: The study uses data collected during a seven-year period (2009–2015) in the automatic measuring station of immissions located in Eastern Wielkopolska to analysis the average and maximum values of air pollution from the perspective of their occurrence in particular seasons and months or in relation to meteorological actors such as temperature, humidity, and wind speed.
Abstract: Seasonal variation of air pollution is associated with variety of seasons and specificity of particular months which form the so-called summer and winter season also known as the “heating” season. The occurrence of higher values of air pollution in different months of a year is associated with the type of climate, and accordingly with different atmospheric conditions in particular months, changing state of weather on a given day, and anthropogenic activity. The appearance of these conditions results in different levels of air pollution characteristic for a given period. The study uses data collected during a seven-year period (2009–2015) in the automatic measuring station of immissions located in Eastern Wielkopolska. The analysis concerns the average and maximum values of air pollution (i.e., particulate matter PM10, sulfur dioxide, nitrogen dioxide, carbon monoxide, and ozone) from the perspective of their occurrence in particular seasons and months or in relation to meteorological actors such as temperature, humidity, and wind speed.
University of Maryland, Baltimore County1, Goddard Space Flight Center2, Centre national de la recherche scientifique3, Norwegian Meteorological Institute4, University of Oslo5, Goddard Institute for Space Studies6, Columbia University7, Max Planck Society8, Universities Space Research Association9, Morgan State University10, Japan Agency for Marine-Earth Science and Technology11, Nagoya University12
TL;DR: In this paper, an assessment of global particulate nitrate and ammonium aerosol based on simulations from nine models participating in the Aerosol Comparisons between Observations and Models (AeroCom) phase-III study is presented.
Abstract: . An assessment of global particulate nitrate and ammonium aerosol based on simulations from nine models participating in the Aerosol Comparisons between Observations and Models (AeroCom) phase III study is presented. A budget analysis was conducted to understand the typical magnitude, distribution, and diversity of the aerosols and their precursors among the models. To gain confidence regarding model performance, the model results were evaluated with various observations globally, including ground station measurements over North America, Europe, and east Asia for tracer concentrations and dry and wet depositions, as well as with aircraft measurements in the Northern Hemisphere mid-to-high latitudes for tracer vertical distributions. Given the unique chemical and physical features of the nitrate occurrence, we further investigated the similarity and differentiation among the models by examining (1) the pH-dependent NH3 wet deposition; (2) the nitrate formation via heterogeneous chemistry on the surface of dust and sea salt particles or thermodynamic equilibrium calculation including dust and sea salt ions; and (3) the nitrate coarse-mode fraction (i.e., coarse/total). It is found that HNO3, which is simulated explicitly based on full O3-HOx-NOx-aerosol chemistry by all models, differs by up to a factor of 9 among the models in its global tropospheric burden. This partially contributes to a large difference in NO3−, whose atmospheric burden differs by up to a factor of 13. The atmospheric burdens of NH3 and NH4+ differ by 17 and 4, respectively. Analyses at the process level show that the large diversity in atmospheric burdens of NO3−, NH3, and NH4+ is also related to deposition processes. Wet deposition seems to be the dominant process in determining the diversity in NH3 and NH4+ lifetimes. It is critical to correctly account for contributions of heterogeneous chemical production of nitrate on dust and sea salt, because this process overwhelmingly controls atmospheric nitrate production (typically > 80 %) and determines the coarse- and fine-mode distribution of nitrate aerosol.
TL;DR: In this paper, an ultralow-emission coal-fired power plant, the emission concentrations of condensable and filterable particulate matter in the stack were 1.6 mg/nm3 and 7.9 mg/Nm3, respectively.
Abstract: Condensable particulate matter is the predominant contributor to the total particulate matter emissions of coal-fired power plants. In the studied ultralow-emission coal-fired power plant, the emission concentrations of condensable and filterable particulate matter in the stack were 1.6 mg/Nm3 and 7.9 mg/Nm3. The organic fraction in condensable particulate matter was mainly composed of alkanes, esters, and other complex organic compounds. The organic fraction comprised 54% of the total concentrations of condensable particulate matter tested at the stack. The organic fraction in condensable particulate matter might contribute significantly to the organic carbon in atmospheric PM2.5. SO42– accounted for the highest concentrations in the inorganic fraction of condensable particulate matter. Na and Ca were predominant metal elements in the inorganic fraction. The inorganic fraction of condensable particulate matter mainly contributed to the water-soluble ions in atmospheric PM2.5. The total particulate matter...
TL;DR: A combination of temporal behavior and air parcel trajectory ensemble analyses indicated that the iron-rich source was most likely a local source attributed to emissions from metal processing facilities and was local in origin.
Abstract: Fine aerosol fraction (particulate matter with aerodynamic diameter <= 1.0 μm (PM)1.0) over the Indian Institute of Technology Delhi campus was monitored day and night (10 h each) at 30 m height from November 2009 to March 2010. The samples were analyzed for 5 ions (NH4
+, NO3
−, SO4
2−, F−, and Cl−) and 12 trace elements (Na, K, Mg, Ca, Pb, Zn, Fe, Mn, Cu, Cd, Cr, and Ni). Importantly, secondary aerosol (sulfate and nitrate) formation was observed during dense foggy events, supporting the fog-smog-fog cycle. A total of 76 samples were used for source apportionment of PM mass. Six factors were resolved by PMF analyses and were identified as secondary aerosol, secondary chloride, biomass burning, soil dust, iron-rich source, and vehicular emission. The geographical location of the sources and/or preferred transport pathways was identified by conditional probability function (for local sources) and potential source contribution function (for regional sources) analyses. Medium- and small-scale metal processing (e.g. steel sheet rolling) industries in Haryana and National Capital Region (NCR) Delhi, coke and petroleum refining in Punjab, and thermal power plants in Pakistan, Punjab, and NCR Delhi were likely contributors to secondary sulfate, nitrate, and secondary chloride at the receptor site. The agricultural residue burning after harvesting season (Sept–Dec and Feb–Apr) in Punjab, and Haryana contributed to potassium at receptor site during November–December and March 2010. The soil dust from North and East Pakistan, and Rajasthan, North-East Punjab, and Haryana along with the local dust contributed to soil dust at the receptor site, during February and March 2010. A combination of temporal behavior and air parcel trajectory ensemble analyses indicated that the iron-rich source was most likely a local source attributed to emissions from metal processing facilities. Further, as expected, the vehicular emissions source did not show any seasonality and was local in origin.
TL;DR: In this paper, the authors developed a global simulation of anthropogenic fugitive, combustion, and industrial dust which, to the knowledge, is partially missing or strongly underrepresented in global models.
Abstract: Global measurements of the elemental composition of fine particulate matter across several urban locations by the Surface Particulate Matter Network reveal an enhanced fraction of anthropogenic dust compared to natural dust sources, especially over Asia. We develop a global simulation of anthropogenic fugitive, combustion, and industrial dust which, to our knowledge, is partially missing or strongly underrepresented in global models. We estimate 2-16 μg/m3 increase in fine particulate mass concentration across East and South Asia by including anthropogenic fugitive, combustion, and industrial dust emissions. A simulation including anthropogenic fugitive, combustion, and industrial dust emissions increases the correlation from 0.06 to 0.66 of simulated fine dust in comparison with Surface Particulate Matter Network measurements at 13 globally dispersed locations, and reduces the low bias by 10% in total fine particulate mass in comparison with global in situ observations. Global population-weighted PM2.5 increases by 2.9 μg/m3 (10%). Our assessment ascertains the urgent need of including this underrepresented fine anthropogenic dust source into global bottom-up emission inventories and global models.
TL;DR: Relative humidity (RH), which is of great influence on aerosol liquid water content (ALWC), played a considerable role in the formation of secondary inorganic aerosols, accelerated the secondary transformation of gaseous precursors, and further aggravated haze pollution.
TL;DR: Exposure to coarse PM was associated with increased asthma diagnosis prevalence and the estimates remained elevated across different levels of spatial confounding adjustment, suggesting the need for direct monitoring of coarse PM and reconsideration of limits on long‐term average coarse PM pollution levels.
Abstract: Rationale: Short- and long-term fine particulate matter (particulate matter ≤2.5 μm in aerodynamic diameter [PM2.5]) pollution is associated with asthma development and morbidity, but there are few...
TL;DR: Results support the conclusion of a previous epiphytic lichen biomonitor study that near-field atmospheric deposition in the AOSR is dominated by coarse fraction fugitive dust from bitumen mining and upgrading operations, and suggest that fugitive dust abatement strategies targeting the three major sources of PM10-2.5 would significantly reduce near- field atmospheric deposition gradients in theAOSR and reduce ambient PM concentrations in the Fort McKay community.
TL;DR: In this article, the authors studied the impact of urban forest vegetation on the levels of five types of air pollutants (NO 2, ground-level O 3, anthropogenic and biogenic VOCs, and particulate matter) in near-road environments during summer (June) using passive samplers in Helsinki, Finland.
TL;DR: In this article, a real-time measurement study of springtime aerosol in SMA was conducted using an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) from 14-April to 15-June 2016, as a part of the Korea-US Air Quality Study (KORUS-AQ) campaign.
Abstract: . Non-refractory submicrometer particulate matter (NR-PM1) was measured in the Seoul Metropolitan Area (SMA), Korea, using an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) from 14 April to 15 June 2016, as a part of the Korea-US Air Quality Study (KORUS-AQ) campaign. This was the first highly time-resolved, real-time measurement study of springtime aerosol in SMA and the results reveal valuable insights into the sources and atmospheric processes that contribute to PM pollution in this region. The average concentration of submicrometer aerosol (PM1 = NR-PM1 + black carbon (BC)) was 22.1 µg m−3, which was composed of 44 % organics, 20 % sulfate, 17 % nitrate, 12 % ammonium, and 7 % BC. Organics had an average atomic oxygen-to-carbon (O ∕ C) ratio of 0.49 and an average organic mass-to-carbon (OM/OC) ratio of 1.82. Four distinct sources of OA were identified via positive matrix factorization (PMF) analysis of the HR-ToF-AMS data: vehicle emissions represented by a hydrocarbon-like OA factor (HOA; O ∕ C = 0.15; 17 % of OA mass), food cooking activities represented by a cooking-influenced OA factor (COA; O ∕ C = 0.19; 22 % of OA mass), and secondary organic aerosol (SOA) represented by a semi-volatile oxygenated OA factor (SV-OOA; O ∕ C = 0.44; 27 % of OA mass) and a low-volatility oxygenated OA factor (LV-OOA; O ∕ C = 0.91; 34 % of OA mass). Our results indicate that air quality in SMA during KORUS-AQ was influenced strongly by secondary aerosol formation, with sulfate, nitrate, ammonium, SV-OOA, and LV-OOA together accounting for 76 % of the PM1 mass. In particular, the formation of LV-OOA and sulfate was mainly promoted by elevated ozone concentrations and photochemical reactions during daytime, whereas SV-OOA and nitrate formation was contributed by both nocturnal processing of VOC and nitrogen oxides, respectively, and daytime photochemical reactions. In addition, lower nighttime temperature promoted gas-to-particle partitioning of semivolatile species and formation of SV-OOA and nitrate. During a period of 4 days (from 20 to 23 May ), LV-OOA increased dramatically and accounted for up to 41 % of the PM1 mass. This intense LV-OOA formation event was associated with large enhancements of both anthropogenic and biogenic VOCs (e.g., isoprene and toluene), high concentration of Ox ( = O3 + NO2), strong solar radiation, and stagnant conditions, suggesting that it was mainly driven by local photochemical formation. We have also investigated the formation and evolution mechanisms of severe haze episodes. Unlike the winter haze events which were mainly caused by intense local emissions coupled with stagnant meteorological conditions, the spring haze events appeared to be influenced by both regional and local factors. For example, there were episodes of long-range transport of plumes followed by calm meteorology conditions, which promoted the formation and accumulation of local secondary species, leading to high concentrations of PM. Overall, our results indicate that PM pollutants in urban Korea originate from complex emission sources and atmospheric processes and that the concentrations and composition of PM are controlled by various factors, including meteorological conditions, local anthropogenic emissions, and upwind sources.
TL;DR: China has been suffering high levels of fine particulate matter (PM2.5), and residential and industrial emissions are the top two sources, with a combined contribution of 40-50% in most provinces, with higher contributions in southern provinces such as Yunnan, Hainan and Taiwan.
TL;DR: In this article, a detailed chemical speciation of traffic-related PM 2.5 (fine particles) is conducted to gain insights into the emission characteristics of trafficrelated fine aerosols.
TL;DR: In this article, the authors applied the LOTOS-EUROS model with its module to track the contributions of predefined source sectors to China for the year 2013 using the MEIC emission inventory.
TL;DR: The impact of emission changes on air quality out to the 2050s will be larger than that due to climate change, because of large reductions in emissions of O3 and PM pollutant precursor emissions and the more limited climate change response itself.
Abstract: This review examines the current literature on the effects of future emissions and climate change on particulate matter (PM) and O3 air quality and on the consequent health impacts, with a focus on Europe. There is considerable literature on the effects of climate change on O3 but fewer studies on the effects of climate change on PM concentrations. Under the latest Intergovernmental Panel on Climate Change (IPCC) 5th assessment report (AR5) Representative Concentration Pathways (RCPs), background O3 entering Europe is expected to decrease under most scenarios due to higher water vapour concentrations in a warmer climate. However, under the extreme pathway RCP8.5 higher (more than double) methane (CH4) abundances lead to increases in background O3 that offset the O3 decrease due to climate change especially for the 2100 period. Regionally, in polluted areas with high levels of nitrogen oxides (NOx), elevated surface temperatures and humidities yield increases in surface O3 – termed the O3 climate penalty – especially in southern Europe. The O3 response is larger for metrics that represent the higher end of the O3 distribution, such as daily maximum O3. Future changes in PM concentrations due to climate change are much less certain, although several recent studies also suggest a PM climate penalty due to high temperatures and humidity and reduced precipitation in northern mid-latitude land regions in 2100. A larger number of studies have examined both future climate and emissions changes under the RCP scenarios. Under these pathways the impact of emission changes on air quality out to the 2050s will be larger than that due to climate change, because of large reductions in emissions of O3 and PM pollutant precursor emissions and the more limited climate change response itself. Climate change will also affect climate extreme events such as heatwaves. Air pollution episodes are associated with stagnation events and sometimes heat waves. Air quality during the 2003 heatwave over Europe has been examined in numerous studies and mechanisms for enhancing O3 have been identified. There are few studies on health effects associated with climate change impacts alone on air quality, but these report higher O3-related health burdens in polluted populated regions and greater PM2.5 health burdens in these emission regions. Studies that examine the combined impacts of climate change and anthropogenic emissions change under the RCP scenarios report reductions in global and European premature O3-respiratory related and PM mortalities arising from the large decreases in precursor emissions. Under RCP 8.5 the large increase in CH4 leads to global and European excess O3-respiratory related mortalities in 2100. For future health effects, besides uncertainty in future O3 and particularly PM concentrations, there is also uncertainty in risk estimates such as effect modification by temperature on pollutant-response relationships and potential future adaptation that would alter exposure risk.
TL;DR: In this article, the chemical composition of PM25 was reconstructed using IMPROVE equation from the analyzed elemental composition of the PM25 mass using positive matrix factorization (PMF).
Abstract: In this paper, the chemical constitutes of PM25 mass [organic carbon (OC), elemental carbon (EC), water soluble inorganic ionic components (WSIC), and trace elements] was estimated for its chemical characteristics and source apportionment study at Delhi, India during January 2013 to May 2014 In the present case, the average mass concentration of PM25 was recorded as 1255 ± 772 μg m− 3 (range: 311–4295 μg m− 3) The average concentration of major and trace elements (Na, Mg, Al, P, S, Cl, K, Ca, Cr, Ti, AS, Br, Pb, Fe, Zn and Mn) was accounted for ~ 22% of PM25 mass Strong seasonal variation was observed in PM25 mass concentration and its chemical composition with maxima during winter and minima during monsoon seasons The chemical composition of the PM25 was reconstructed using IMPROVE equation from the analyzed elemental composition of PM25 mass In reconstructed PM25 mass, the highest contribution accounted from particulate organic matter (275%) to other components eg, soil/crustal matter (161%), ammonium sulphate (161%), ammonium nitrate (131%), sea salt (171%) and light absorbing carbon (102%) In the present study, Positive Matrix Factorization (PMF) was used for identifying the PM25 sources at the observational site of Delhi The major source of PM25 was identified as secondary aerosols (232%), soil dust (225%), vehicle emissions (185%), fossil fuel burning (131%), biomass burning (123%), industrial emissions (63%) and sea salts (41%) at Delhi
TL;DR: In this article, a year-round sampling was performed at the University of Sao Paulo campus (20m) in Brazil to evaluate the sources of particulate air pollution and related health risks, and different chemical constituents, such as carbonaceous species, polycyclic aromatic hydrocarbons (PAHs), water-soluble ions, and biomass burning tracers were identified in order to evaluate health risks and to apportion sources.
Abstract: . Sao Paulo in Brazil has relatively relaxed regulations for ambient air pollution standards and often experiences high air pollution levels due to emissions of particulate pollutants from local sources and long-range transport of air masses impacted by biomass burning. In order to evaluate the sources of particulate air pollution and related health risks, a year-round sampling was done at the University of Sao Paulo campus (20 m a.g.l.), a green area near an important expressway. The sampling was performed for PM2. 5 ( ≤ 2. 5 µm) and PM10 ( ≤ 10 µm) in 2014 through intensive (everyday sampling in wintertime) and extensive campaigns (once a week for the whole year) with 24 h of sampling. This year was characterized by having lower average precipitation compared to meteorological data, and high-pollution episodes were observed all year round, with a significant increase in pollution level in the intensive campaign, which was performed during wintertime. Different chemical constituents, such as carbonaceous species, polycyclic aromatic hydrocarbons (PAHs) and derivatives, water-soluble ions, and biomass burning tracers were identified in order to evaluate health risks and to apportion sources. The species such as PAHs, inorganic and organic ions, and monosaccharides were determined using chromatographic techniques and carbonaceous species using thermal-optical analysis. Trace elements were determined using inductively coupled plasma mass spectrometry. The risks associated with particulate matter exposure based on PAH concentrations were also assessed, along with indexes such as the benzo[a]pyrene equivalent (BaPE) and lung cancer risk (LCR). High BaPE and LCR were observed in most of the samples, rising to critical values in the wintertime. Also, biomass burning tracers and PAHs were higher in this season, while secondarily formed ions presented low variation throughout the year. Meanwhile, vehicular tracer species were also higher in the intensive campaign, suggesting the influence of lower dispersion conditions in that period. Source apportionment was performed using positive matrix factorization (PMF), which indicated five different factors: road dust, industrial emissions, vehicular exhaust, biomass burning and secondary processes. The results highlighted the contribution of vehicular emissions and the significant input from biomass combustion in wintertime, suggesting that most of the particulate matter is due to local sources, in addition to the influence of pre-harvest sugarcane burning.