Contribution Of Coal Combustion Research Articles

Nitrogen isotope fractionation during gas-to-particle conversion of NO<sub><i>x</i></sub> to NO<sub>3</sub><sup>−</sup> in the atmosphere – implications for isotope-based NO<sub><i>x</i></sub> source apportionment

Abstract. Atmospheric fine-particle (PM2.5) pollution is frequently associated with the formation of particulate nitrate (pNO3−), the end product of the oxidation of NOx gases (NO + NO2) in the upper troposphere. The application of stable nitrogen (N) (and oxygen) isotope analyses of pNO3− to constrain NOx source partitioning in the atmosphere requires knowledge of the isotope fractionation during the reactions leading to nitrate formation. Here we determined the δ15N values of fresh pNO3− (δ15N–pNO3−) in PM2.5 at a rural site in northern China, where atmospheric pNO3− can be attributed exclusively to biomass burning. The observed δ15N–pNO3− (12.17±1.55 ‰; n = 8) was much higher than the N isotopic source signature of NOx from biomass burning (1.04±4.13 ‰). The large difference between δ15N–pNO3− and δ15N–NOx (Δ(δ15N)) can be reconciled by the net N isotope effect (εN) associated with the gas–particle conversion from NOx to NO3−. For the biomass burning site, a mean εN( ≈ Δ(δ15N)) of 10.99±0.74 ‰ was assessed through a newly developed computational quantum chemistry (CQC) module. εN depends on the relative importance of the two dominant N isotope exchange reactions involved (NO2 reaction with OH versus hydrolysis of dinitrogen pentoxide (N2O5) with H2O) and varies between regions and on a diurnal basis. A second, slightly higher CQC-based mean value for εN (15.33±4.90 ‰) was estimated for an urban site with intense traffic in eastern China and integrated in a Bayesian isotope mixing model to make isotope-based source apportionment estimates for NOx at this site. Based on the δ15N values (10.93±3.32 ‰; n = 43) of ambient pNO3− determined for the urban site, and considering the location-specific estimate for εN, our results reveal that the relative contribution of coal combustion and road traffic to urban NOx is 32 % ± 11 % and 68 %± 11 %, respectively. This finding agrees well with a regional bottom-up emission inventory of NOx. Moreover, the variation pattern of OH contribution to ambient pNO3− formation calculated by the CQC module is consistent with that simulated by the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem), further confirming the robustness of our estimates. Our investigations also show that, without the consideration of the N isotope effect during pNO3− formation, the observed δ15N–pNO3− at the study site would erroneously imply that NOx is derived almost entirely from coal combustion. Similarly, reanalysis of reported δ15N–NO3− data throughout China and its neighboring areas suggests that NOx emissions from coal combustion may be substantively overestimated (by > 30 %) when the N isotope fractionation during atmospheric pNO3− formation is neglected.

Emission control priority of PM2.5-bound heavy metals in different seasons: A comprehensive analysis from health risk perspective

Source-specific health risks of PM2.5-bound metals were analyzed for emission control by integrating source apportionment with health risk assessments of residents affected via inhalation pathways. A total of 218 daily PM2.5 samples were collected in 2016 in the central urban district of Beijing, China. Analyses showed that the mean annual concentrations of total heavy metals (THMs) and PM2.5 were 0.39 and 104.37 μg m−3, respectively. The heating season had significantly higher concentrations of THMs and PM2.5 (0.61, 134 μg m−3) than the non-heating season (0.27, 88.1 μg m−3) (p < 0.05). Among all metals, arsenic had the largest incremental cancer risk of 7.04 × 10−6. Six sources were identified by positive matrix factorization combined with conditional probability function and potential source contribution function analyses. The order of contribution to PM2.5-bound metal concentrations was resuspended dust (61.0%), traffic emission (16.3%), Cu-related industry (14.1%), coal combustion (3.7%), Cr-related industry (3.4%), and fuel oil combustion (1.6%). During the heating season, the contribution of coal combustion decreased slightly, which may have been due to the countermeasure of substituting coal for gas or electric heat in 2016. However, in terms of cancer risk contribution, coal combustion was the top contributor in both heating (3.5 × 10−6, 51.6%) and non-heating (2.7 × 10−6, 59.6%) seasons due to high attributable contents of the toxic metals, As, Cd and Pb. The Cr-related and Cu-related industries were the next controlled sources in the heating and non-heating seasons, respectively. Thus, these sources should receive priority in the development of control measures.

Optical characteristics and source apportionment of brown carbon in winter PM2.5 over Yulin in Northern China

In this study, daily PM2.5 samples were collected at an urban site in Yulin of Northern China during a winter season. Eight carbon fractions, 13 kinds of polycyclic aromatic hydrocarbons (PAHs), and nine water-soluble ions in PM2.5 were measured. The light-absorption characteristics of brown carbon (BrC) both in water and in methanol extracts were evaluated and quantified. The total quantified PAHs exhibited high concentrations (228.4 ± 52.6 ng m−3), contributing 0.2% of the PM2.5 mass. High indeno[1,2,3-cd]pyrene/(indeno[1,2,3-cd]pyrene + benzo[ghi]-perylene) ratio but low NO3−/SO42− ratio revealed the important contribution of coal combustion to PM2.5. The absorption coefficient (babs) for methanol extracts measured at 365 nm averaged 27.5 ± 12.0 Mm−1. Light absorption by methanol extracts exhibited strong wavelength dependence, with an average absorption Ångström exponent of 5.2 in the 330–400 nm range. The mass absorption cross section (for methanol extracts averaged 1.4 ± 0.4 m2 g−1 by normalizing babs measured at 365 nm to organic carbon mass. A relatively strong positive relationship between babs, methanol and benzo[a]pyrene as well as with six carbon fractions indicated the important contribution of coal burning to BrC. Source apportionment based on the positive matrix factorization receptor model and multiple linear regression showed that residential coal combustion accounted for 37.4% of babs365,methanol. The estimated relative radiative forcing by methanol-soluble organic carbon relative to elemental carbon was 36.9% at 300–400 nm.

Large contribution of fossil fuel derived secondary organic carbon to water soluble organic aerosols in winter haze in China

Abstract. Water-soluble organic carbon (WSOC) is a large fraction of organic aerosols (OA) globally and has significant impacts on climate and human health. The sources of WSOC remain very uncertain in polluted regions. Here we present a quantitative source apportionment of WSOC, isolated from aerosols in China using radiocarbon (14C) and offline high-resolution time-of-flight aerosol mass spectrometer measurements. Fossil emissions on average accounted for 32–47 % of WSOC. Secondary organic carbon (SOC) dominated both the non-fossil and fossil derived WSOC, highlighting the importance of secondary formation to WSOC in severe winter haze episodes. Contributions from fossil emissions to SOC were 61 ± 4 and 50 ± 9 % in Shanghai and Beijing, respectively, significantly larger than those in Guangzhou (36 ± 9 %) and Xi'an (26 ± 9 %). The most important primary sources were biomass burning emissions, contributing 17–26 % of WSOC. The remaining primary sources such as coal combustion, cooking and traffic were generally very small but not negligible contributors, as coal combustion contribution could exceed 10 %. Taken together with earlier 14C source apportionment studies in urban, rural, semi-urban and background regions in Asia, Europe and the USA, we demonstrated a dominant contribution of non-fossil emissions (i.e., 75 ± 11 %) to WSOC aerosols in the Northern Hemisphere; however, the fossil fraction is substantially larger in aerosols from East Asia and the eastern Asian pollution outflow, especially during winter, due to increasing coal combustion. Inclusion of our findings can improve a modelling of effects of WSOC aerosols on climate, atmospheric chemistry and public health.

Lead Isotopic Compositions of Selected Coals, Pb/Zn Ores and Fuels in China and the Application for Source Tracing.

Lead (Pb) pollution emission from China is becoming a potential worldwide threat. Pb isotopic composition analysis is a useful tool to accurately trace the Pb sources of aerosols in atmosphere. In this study, a comprehensive data set of Pb isotopes for coals, Pb/Zn ores, and fuels from China was presented. The ratios of 206Pb/207Pb and 208Pb/206Pb in the coals were in the range of 1.114-1.383 and 1.791-2.317, similar to those from Europe, Oceania, and South Asia, but different from those from America (p < 0.01). The Pb/Zn ores had 206Pb/207Pb and 208Pb/206Pb in 1.020-1.183 and 2.088-2.309, less radiogenic than the coals. Leaded gasolines showed similar Pb isotopic compositions to Pb/Zn ores, with unleaded gasolines and diesels being mixed sources. The average Pb isotopic ratios of gasolines and diesels were significantly different (p < 0.01) from those of coals in China, leading to the possibility to discriminate Pb in fuels from in coals. Urban aerosols demonstrated similar Pb isotopic compositions to coals, Pb/Zn ores, and fuels in China. After removing the leaded gasoline, the Pb in aerosols is more radiogenic, supporting the heavy contribution of coal combustion to the atmospheric Pb pollution.

Source apportionment of PM2.5 pollution in the central six districts of Beijing, China

Fine particulate matter (PM2.5) has become the primary atmospheric pollutant in Beijing in recent years, causing widespread concern in society. Understanding the origin of PM2.5 is essential for developing effective strategies to reduce PM2.5. In this study, we used the Particulate Matter Source Apportionment Technology (PSAT) in Comprehensive Air Quality Model with Extensions (CAMx) to quantify the contributions of different source regions and emission categories to the PM2.5 concentration in the central six districts of Beijing in January, April, July and October, representing four seasons in 2014. The annual contribution ratios from local, suburb and the surrounding regions of Beijing as well as the outside of boundary region were 47.6, 19.3, 11.4, and 21.7%, respectively, showing significant contribution of regional transport to the PM2.5 pollution in the central six districts of Beijing. The emission category apportionment results in the central six districts showed distinct seasonal variations with important contribution of coal combustion in winter but minor contribution in the other seasons, dominant contribution of dust in spring, and dominant contribution of the vehicle related sources in the other seasons. Moreover, the detailed contribution proportion of the five emission categories showed clear spatial variation in the suburbs and the surrounding regions. Based on the sensitivity analysis of local emission reduction, the control of the vehicle related sources was the most efficient mitigation measure for the reduction of PM2.5 during the case study period in autumn, but the efficiency of the local mitigation measures was greatly reduced in the period of heavy PM2.5 pollution.

Source profiles and contributions of biofuel combustion for PM2.5, PM10 and their compositions, in a city influenced by biofuel stoves

Source and ambient samples were collected in a city in China that uses considerable biofuel, to assess influence of biofuel combustion and other sources on particulate matter (PM). Profiles and size distribution of biofuel combustion were investigated. Higher levels in source profiles, a significant increase in heavy-biomass ambient and stronger correlations of K+, Cl−, OC and EC suggest that they can be tracers of biofuel combustion. And char-EC/soot-EC (8.5 for PM2.5 and 15.8 for PM10 of source samples) can also be used to distinguish it. In source samples, water-soluble organic carbon (WSOC) were approximately 28.0%–68.8% (PM2.5) and 27.2%–43.8% (PM10) of OC. For size distribution, biofuel combustion mainly produces smaller particles. OC1, OC2, EC1 and EC2 abundances showed two peaks with one below 1 μm and one above 2 μm. An advanced three-way factory analysis model was applied to quantify source contributions to ambient PM2.5 and PM10. Higher contributions of coal combustion, vehicular emission, nitrate and biofuel combustion occurred during the heavy-biomass period, and higher contributions of sulfate and crustal dust were observed during the light-biomass period. Mass and percentage contributions of biofuel combustion were significantly higher in heavy-biomass period. The biofuel combustion attributed above 45% of K+ and Cl−, above 30% of EC and about 20% of OC. In addition, through analysis of source profiles and contributions, they were consistently evident that biofuel combustion and crustal dust contributed more to cation than to anion, while sulfate & SOC and nitrate showed stronger influence on anion than on cation.

Characteristics and sources of the fine carbonaceous aerosols in Haikou, China

Ambient PM2.5 samples were collected from January to September 2015 in Haikou. The carbonaceous fractions included OC, EC, OC1, OC2, OC3, OC4, EC1, EC2, EC3, Char-EC (EC1 minus POC) and Soot-EC (EC2 plus EC3) were analysed in this study. The results indicate that the mean concentrations of OC and EC are 5.6 and 2.5μg/m3 during the sampling period, respectively; and the concentrations of most of carbonaceous fractions are the highest in winter and the lowest in spring. The seasonal variations of Soot-EC and Char-EC concentrations show distinct differences. The concentrations of Char-EC are higher in winter and lower in spring; while those of Soot-EC are lower in winter and higher in summer. Compared to Char-EC, the concentrations of Soot-EC show smaller seasonal-variation in Haikou. The Char-EC has the higher correlations with OC and EC (r=0.91 and 0.95, P<0.01), while the correlation between the Soot-EC and either OC or EC is absent (r=0.15 and 0.11, P>0.05). The average ratios of Char-EC/Soot-EC are in the order of winter (15.9)>autumn (4.9)>summer (4.0)>spring (3.6), with an average value of 7.1. According to error estimation (EE) diagnostics analysis, four factors are revealed in Positive Matrix Factorization (PMF) analysis during each season. The combined gasoline/diesel vehicle exhaust, coal combustion, biomass burning and specific diesel vehicle exhaust are identified as the major sources of carbonaceous aerosols, and their contributions during the whole year are up to 29.3%, 27.4%, 17.9% and 15.9%, respectively. The transport trajectories of the air masses illustrate distinct differences during different seasons, and the transport trajectories are mainly derived from the mainland China (i.e. Jiangxi, Fujian and Guangdong provinces) in winter, likely caused by higher contribution of coal combustion.

The Distribution Variation of Polycyclic Aromatic Hydrocarbons Between Fresh Snow and Seasonal Snowpack in Campus in Changchun City, Northeast China

Polycyclic aromatic hydrocarbons (PAHs) are scavenged from the atmosphere during snowfall, stored in the seasonal snowpack, and exchanged with PAHs in atmosphere. Thus, the PAHs in fresh snow and snowpack could reflect the PAH levels in atmosphere. This study investigated the concentrations and compositions of 16 priority-controlled PAHs in fresh snow and seasonal snowpack, as well as PAH levels in underlying soils before and after snow melting. The total concentrations of PAHs in fresh snow and snowpack ranged from 26.6 ± 4.2 to 36.9 ± 1.7 μg L−1 and from 40.3 ± 4.4 to 105.9 ± 6.9 μg L−1, respectively. The higher concentrations of PAHs in fresh snow compared with other areas indicated a high PAH level in atmosphere in Changchun city, presenting a potential risk to human health. Higher concentrations of total PAHs in snowpack than those in fresh snow indicated the prominent deposition of PAHs from atmosphere to snowpack in winter. In contrast, a specific reduction of five- to six-ring PAHs in the snowpack suggested that strong photolysis of five- to six-ring PAHs occurred in snowpack. The variation of PAHs in different snowpacks suggested that the deposition may be largely affected by local environment. The results of diagnostic ratios and principal component analysis (PCA) suggested that the PAHs in fresh snow and snowpack are both from a mixed source of coal combustion and from vehicle emissions. However, nonmetric multidimensional scaling (NMDS) divided fresh snow and snowpack into two groups, indicating the different contributions of coal combustion and vehicle emissions to PAHs in fresh snow and snowpack. After snowpack melting, three- to four-ring PAH levels in underlying soils showed no change, indicating that the three- to four-ring PAHs were volatilized to the atmosphere. This study indicated a risk of atmospheric PAHs in Changchun city in winter and in the beginning of spring.

Impacts of coal burning on ambient PM&amp;lt;sub&amp;gt;2.5&amp;lt;/sub&amp;gt; pollution in China

Abstract. High concentration of fine particles (PM2.5), the primary concern about air quality in China, is believed to closely relate to China's large consumption of coal. In order to quantitatively identify the contributions of coal combustion in different sectors to ambient PM2. 5, we developed an emission inventory for the year 2013 using up-to-date information on energy consumption and emission controls, and we conducted standard and sensitivity simulations using the chemical transport model GEOS-Chem. According to the simulation, coal combustion contributes 22 µg m−3 (40 %) to the total PM2. 5 concentration at national level (averaged in 74 major cities) and up to 37 µg m−3 (50 %) in the Sichuan Basin. Among major coal-burning sectors, industrial coal burning is the dominant contributor, with a national average contribution of 10 µg m−3 (17 %), followed by coal combustion in power plants and the domestic sector. The national average contribution due to coal combustion is estimated to be 18 µg m−3 (46 %) in summer and 28 µg m−3 (35 %) in winter. While the contribution of domestic coal burning shows an obvious reduction from winter to summer, contributions of coal combustion in power plants and the industrial sector remain at relatively constant levels throughout the year.

Changes in concentration, composition and source contribution of atmospheric organic aerosols by shifting coal to natural gas in Urumqi

Size-segregated aerosols were collected in Urumqi, a megacity in northwest China, during two heating seasons, i.e., before (heating season І: January–March 2012) and after (heating season II: January–March 2014) the project “shifting coal to natural gas”, and determined for n-alkanes, PAHs and oxygenated PAHs to investigate the impact of replacement of coal by natural gas on organic aerosols in the urban atmosphere. Our results showed that compared to those in heating season I concentrations of n-alkanes, PAHs and OPAHs decreased by 74%, 74% and 82% in heating season II, respectively. Source apportionment analysis suggested that coal combustion, traffic emission and biomass burning are the major sources of the determined organics during the heating seasons in Urumqi. Traffic emission is the main source for n-alkanes in the city. Coal combustion is the dominant source of PAHs and OPAHs in heating season І, but traffic emission becomes their major source in heating season ІI. Relative contributions of coal combustion to n-alkanes, PAHs and OPAHs in Urumqi decreased from 21 to 75% in heating season I to 4.0–21% in heating season II due to the replacement of coal with natural gas for house heating. Health risk assessment further indicated that compared with that in heating season I the number of lung cancer related to PAHs exposure in Urumqi decreased by 73% during heating season II due to the project implementation. Our results suggest that replacing coal by clean energy sources for house heating will significantly mitigate air pollution and improve human health in China.

How can bioaccessibility testing add value in the inhalation hazard assessment?

Highly time-resolved data for volatile organic compounds (VOCs) can now be monitored. Source analyses of such high time-resolved concentrations provides key information for controlling VOC emissions. This work reviewed the literature on VOCs source analyses published from 2015 to 2021, and assesses the state-of-the-art and the existing issues with these studies. Gas chromatography system and direct-inlet mass spectrometry are the main monitoring tools. Quality control (QC) of the monitoring process is critical prior to analysis. QC includes inspection and replacement of instrument consumables, calibration curve corrections, and reviewing the data. Approximately 54% published papers lacked details on the quantitative evaluation of the effectiveness of QC measures. Among the reviewed works, the number of monitored species varied from 5 to 119, and fraction of papers with more than 90 monitored species increased yearly. US EPA PMF v5.0 was the most commonly used (∼86%) for VOC source analyses. However, conventional source apportionment directly uses the measured VOCs and may be problematic given the impacts of dispersion and photochemical losses, uncertainty setting of VOCs data, factor resolution, and factor identification. Excluding species with high-reactivity or estimation of corrected concentrations were often applied to reduce the influence of photochemical reactions on the results. However, most reports did not specify the selection criteria or the specific error fraction values in the uncertainty estimation. Model diagnostic indexes were used in 99% of the reports for PMF analysis to determine the factor resolution. Due to lack of known local source profiles, factor identification was mainly achieved using marker species and characteristic species ratios. However, multiple sources had high-collinearity and the same species were often used to identify different sources. Vehicle emissions and fuel evaporation were the primary contributors to VOCs around the world. Contribution of coal combustion in China was substantially higher than in other countries.

Fine Particulate Matter in Beijing: Sources and Health Impacts

Introduction: High concentration of atmospheric fine particulate matter (PM2.5) could deteriorate air quality, reduce visibility, influence climate change, and affect human health. PM2.5 has attracted increasing attention in Beijing, China, as there are frequent haze episodes in recent years. Health impact of PM2.5 is still a great concern of the public. To better understand the health effects of PM2.5 and develop effective policies to control fine particulate pollutants, research on sources of particulate matter and its associated health effects are in urgent need. Methods: PM2.5 was collected on filters at a representative urban site in Beijing in different seasons, including haze and non-haze days. Detailed chemical composition including carbonaceous components, ions, and metals in fine particles was measured. Receptor-model based source apportionment of PM2.5 was performed to determine source contributions. The production of reactive oxygen species by fine particles was determined based on the cell-free surrogated lung fluid solution method. Results: Sources of fine particle in Beijing exhibited seasonal variations, with higher biomass burning contribution in summer and fall, and higher coal combustion contribution in winter. Secondary sources played a dominant role in most of the haze episodes. However, reactive oxygen species produced by per PM2.5 mass was much higher in clean days compared to haze days, and was found to be well correlated with trace metals such as Fe, Mn and Cu. Conclusions: Chemical characteristics and sources of PM2.5 in Beijing have clear difference between haze and non-haze days and between seasons. Correlations between chemical compositions and sources with health effects have been investigated through reactive oxygen species. The study of sources and health impacts of fine particles during severe haze episodes in Beijing is very important, which requires more research in the future.

Regional air quality in Leipzig, Germany: detailed source apportionment of size-resolved aerosol particles and comparison with the year 2000.

A detailed source apportionment of size-resolved aerosol particles in the area of Leipzig, Germany, was performed. Sampling took place at four sites (traffic, traffic/residential, urban background, regional background) in parallel during summer 2013 and the winters 2013/14/15. Twenty-one samples were taken per season with a 5-stage Berner impactor and analysed for particulate mass, inorganic ions, organic and elemental carbon, water-soluble organic carbon, trace metals, and a wide range of organic species. The compositional data were used to estimate source contributions to particulate matter (PM) in quasi-ultrafine (up to 140 nm), accumulation mode, and coarse size ranges using Positive Matrix Factorisation (PMF) receptor modelling. Traffic (exhaust and general traffic emissions), coal combustion, biomass combustion, photochemistry, general secondary formation, cooking, fungal spores, urban dust, fresh sea/road salt, and aged sea salt were all found to contribute to different extents to observed PM concentrations. PMF derived estimates agreed reasonably with estimates from established macrotracer approaches. Quasi-ultrafine PM originated mainly from traffic (20-50%) and photochemistry (30-50%) in summer, while it was dominated by solid fuel (mainly biomass) combustion in winter (50-70%). Tentatively identified cooking aerosol contributed up to 36% on average at the residential site. For accumulation mode particles, two secondary sources typically contributed 40-90% to particle mass. In winter, biomass and coal combustion contributions were up to ca. 25% and 45%, respectively. Main sources of coarse particles were diverse and included nearly all PMF-resolved ones depending on season and air mass origin. For PM10, traffic (typically 20-40% at kerbside sites), secondary formation (30-60%), biomass combustion (10-15% in winter), and coal combustion (30-40% in winter with eastern air mass inflow) were the main quantified sources. At the residential site, contributions from biomass combustion derived up to 60% from local emissions. Coal combustion as a significant source was only present during eastern air mass inflow and showed very similar concentrations at all sites, indicating the importance of trans-boundary air pollution transport in the study area. Overall, nearly half of the PM10 mass was attributed to urban sources by a simple subtractive approach with highest reduction potentials of up to 80% for local (urban) mitigation measures in ultrafine and coarse particles. Local increments of elemental carbon have decreased by about 50% as compared to the year 2000, corroborating results from a former study on the positive effects of a low emission zone, implemented in Leipzig in 2011.

Characteristics of hopanoid hydrocarbons in ambient PM10 and motor vehicle emissions and coal ash in Taiyuan, China

Hopanoid hydrocarbon content in ambient particulate matter (PM) of less than or equal to 10 μm aerodynamic diameter (PM10) was sampled at seven sites representative of different functional districts, and measured by gas chromatography-mass spectrometry. 17α(H),21β(H)-hopane (C30αβ) and 17α(H),21β(H)-30-norhopane (C29αβ) were dominant in all samples. Hopanes in motor vehicle emissions from various fuel-type engines (gasoline, diesel and natural gas) and coal ash were qualitatively measured, and the amount of C30αβ was about two to three times greater than that of C29αβ. Distinct seasonal variations (winter/summer differences) were observed at higher concentrations (45.54-108.29 ng/m(3)) of total hopanes in winter and lower (2.59-28.26 ng/m(3)) in summer. There were also clear spatial variations of hopanes in Taiyuan, with samples with greater hopane concentrations in downtown areas, but less in summer. The spatial distribution reversed in winter. Distributions and relative abundances of selected hopanes from PM10 and source emissions indicated that in summer, vehicle exhaust was the dominant fossil fuel combustion source (C30αβ was >C29αβ), and that the contribution of coal combustion was slightly greater at suburban sites. However, the contribution of coal combustion sources increased significantly at all sites in winter, especially in suburban areas, where C29αβ exceeded C30αβ. Hopanoid indexes revealed a classification of vehicle exhaust and coal combustion emissions in PM10. The results imply that during rapid urbanization, it is crucial to strengthen the construction of infrastructure such as central heating in new city districts and to increase the use of natural gas instead of residential coal burning.

Quantifying The Burden Of Disease From Ambient Air Pollution And Its Major Sources: GBD 2013 And GBD Maps

Background Ambient air pollution (AAP) threatens global health. The Global Burden of Disease (GBD) 2010 study estimated that exposure to ambient fine particulate air pollution, PM2.5, contributed to 3 million premature deaths and 74 million lost years of healthy life in 2010, with two-thirds occurring in low- and middle income countries (LMIC) in Asia. Major sources in Asia include coal-burning for power generation and other uses, household burning of solid fuels, and road transport. Estimating the burden of disease attributable to AAP from major sources is critical to support the control of both air pollution and climate-forcing emissions. Methods GBD 2013 extends methods and datasets used in GBD 2010 to estimate the burden of disease attributable to AAP for 1990-2013 in 188 countries and at sub-national levels for China, the UK and Mexico. GBD MAPS will estimate the burden of disease attributable to PM2.5 from major sources of air pollution in China, India and Eastern Europe, using emissions data to estimate source-specific PM2.5 levels. Results We will present estimates of global exposure to AAP, and its burden of disease, and preliminary results of GBD MAPS in China, including the contribution of coal combustion to PM2.5 exposure and current and predicted disease burden under future (ca. 2030) policy-relevant scenarios. Discussion We expect to confirm the importance of AAP as a global risk factor, particularly in LMIC, and to observe divergent trends in both exposure and burden between high-income countries and LMIC. The burden attributable to coal-burning in China will likely be substantial, with large health benefits possible from reducing coal burning.

Source Apportionment of Elemental Carbon in Beijing, China: Insights from Radiocarbon and Organic Marker Measurements.

Elemental carbon (EC) or black carbon (BC) in the atmosphere has a strong influence on both climate and human health. In this study, radiocarbon ((14)C) based source apportionment is used to distinguish between fossil fuel and biomass burning sources of EC isolated from aerosol filter samples collected in Beijing from June 2010 to May 2011. The (14)C results demonstrate that EC is consistently dominated by fossil-fuel combustion throughout the whole year with a mean contribution of 79% ± 6% (ranging from 70% to 91%), though EC has a higher mean and peak concentrations in the cold season. The seasonal molecular pattern of hopanes (i.e., a class of organic markers mainly emitted during the combustion of different fossil fuels) indicates that traffic-related emissions are the most important fossil source in the warm period and coal combustion emissions are significantly increased in the cold season. By combining (14)C based source apportionment results and picene (i.e., an organic marker for coal emissions) concentrations, relative contributions from coal (mainly from residential bituminous coal) and vehicle to EC in the cold period were estimated as 25 ± 4% and 50 ± 7%, respectively, whereas the coal combustion contribution was negligible or very small in the warm period.

Atmospheric lead in urban Guiyang, Southwest China: Isotopic source signatures

Total suspended particles (TSP) and their source-related samples from Guiyang, Southwest China, were collected and analyzed for their lead (Pb) concentrations and Pb isotopic compositions, to identify the sources of atmosphere lead in urban Guiyang. Coals from Guizhou Province had significantly high radiogenic Pb, different to those from North China. Local vehicle exhaust had similar Pb isotope ratios to those of other areas in China. Pb isotopic compositions of atmospheric aerosols, rainwaters, plant samples, and acid-soluble fraction of street dusts were similar to each other. The results clearly suggest that the Pb–Zn ore-related industrial emission, and/or vehicle exhaust, rather than the local coal combustion, are the main sources of atmospheric Pb in Guiyang. Furthermore, binary mixing model indicates that the contribution of coal combustion to the local atmospheric Pb decreased from about 40% in 1988 to about 10% in 2013.

Investigation of spatial and temporal metal atmospheric deposition in France through lichen and moss bioaccumulation over one century

Lichens and mosses were used as biomonitors to assess the atmospheric deposition of metals in forested ecosystems in various regions of France. The concentrations of 17 metals/metalloids (Al, As, Cd, Co, Cr, Cs, Cu, Fe, Mn, Ni, Pb, Sb, Sn, Sr, Ti, V, and Zn) indicated overall low atmospheric contamination in these forested environments, but a regionalism emerged from local contributions (anthropogenic activities, as well as local lithology). Taking into account the geochemical background and comparing to Italian data, the elements from both natural and anthropogenic activities, such as Cd, Pb, or Zn, did not show any obvious anomalies. However, elements mainly originating from lithogenic dust (e.g., Al, Fe, Ti) were more prevalent in sparse forests and in the Southern regions of France, whereas samples from dense forests showed an accumulation of elements from biological recycling (Mn and Zn). The combination of enrichment factors and Pb isotope ratios between current and herbarium samples indicated the historical evolution of metal atmospheric contamination: the high contribution of coal combustion beginning 150years ago decreased at the end of the 20th century, and the influence of car traffic during the latter observed period decreased in the last few decades. In the South of France, obvious local influences were well preserved during the last century.

Chemical characteristics of submicron particulates (PM1.0) in Wuhan, Central China

Submicron particulate matter (PM1.0) samples were collected at a suburban site in Wuhan from Sept., 2012 to Aug., 2013. Concentration, composition, potential sources and acidity of the PM1.0 were investigated. The results indicated that the annual average concentration of PM1.0 was 81.7μg/m3, with the highest and lowest values occurring in winter and summer, respectively. Inorganic water soluble ions constituted 48.9% of the PM1.0, and dominated by secondary species in the form of NH4NO3 and NH4HSO4. The high concentration of Pb (128.4ng/m3) and greatly enriched Pb, Cd and Se in PM1.0 indicated contribution of coal combustion to PM1.0. Ratios of SO42−/NO3− (1.3) and Cl−/Na+ (2.7) revealed the dominant stationary emissions, further confirming the coal combustion source in Wuhan. According to the chemical and meteorological analyses, biomass burning and stagnant weather were proposed to be the main causes to the haze episodes in autumn and winter, respectively.