Composition Of PM2 Research Articles

Comparison of PM2.5 Monitoring Data Using Light Scattering and Beta Attenuation Methods: A Case Study in Seoul Metro Subway

A study on monitoring PM2.5 concentrations at an underground subway station using light scattering and beta attenuation methods was conducted. Six optical particle counters (OPCs), which were representative of the light scattering method and had 16 size channels, were installed at different sampling sites in the waiting room and platforms to compare PM2.5 concentrations, determine PM2.5 /PM10 ratios, and characterize the size distribution based on particle number. In terms of the beta attenuation method, a beta-ray attenuation monitor (BAM) was set up at the platform to compare it with OPCs for one month. It was found that 1h-average PM2.5 concentrations varied at different sampling sites depending on PM composition, while 24h-average PM2.5 concentrations were independent of the sampling sites. There was a significant difference between the means of 1h-average PM2.5 concentrations observed by the BAM and OPC when PM2.5 contributed to less than 50% or higher than 80% of PM10. In contrast, the 24h-average PM2.5 concentrations observed by the BAM and OPC showed the same patterns as each other with an insignificant difference. Therefore, an OPC can be used to monitor the 24h-average PM2.5 concentration in an underground subway station. However, the use of OPC to measure the 1h-average PM2.5 concentration should consider PM composition and other factors. In addition, more frequent calibration is needed on a regular basis.

Staggered-peak production is a mixed blessing in the control of particulate matter pollution.

Staggered-peak production (SP)-a measure to halt industrial production in the heating season-has been implemented in North China Plain to alleviate air pollution. We compared the variations of PM1 composition in Beijing during the SP period in the 2016 heating season (SPhs) with those in the normal production (NP) periods during the 2015 heating season (NPhs) and 2016 non-heating season (NPnhs) to investigate the effectiveness of SP. The PM1 mass concentration decreased from 70.0 ± 54.4 μg m-3 in NPhs to 53.0 ± 56.4 μg m-3 in SPhs, with prominent reductions in primary emissions. However, the fraction of nitrate during SPhs (20.2%) was roughly twice that during NPhs (12.7%) despite a large decrease of NOx, suggesting an efficient transformation of NOx to nitrate during the SP period. This is consistent with the increase of oxygenated organic aerosol (OOA), which almost doubled from NPhs (22.5%) to SPhs (43.0%) in the total organic aerosol (OA) fraction, highlighting efficient secondary formation during SP. The PM1 loading was similar between SPhs (53.0 ± 56.4 μg m-3) and NPnhs (50.7 ± 49.4 μg m-3), indicating a smaller difference in PM pollution between heating and non-heating seasons after the implementation of the SP measure. In addition, a machine learning technique was used to decouple the impact of meteorology on air pollutants. The deweathered results were comparable with the observed results, indicating that meteorological conditions did not have a large impact on the comparison results. Our study indicates that the SP policy is effective in reducing primary emissions but promotes the formation of secondary species.

Small contributions of dust to PM2.5 and PM10 concentrations measured downwind of Oceano Dunes

The Oceano Dunes State Vehicular Recreation Area (ODSVRA) is a large natural source of wind-driven dust emissions that primarily consist of particulate matter (PM) for which most of the mass is greater than 1 μm. The San Luis Obispo County Air Pollution Control District (SLOAPCD) has targeted ODSVRA emissions to reduce exceedances of the state standard of 50 μg m−3 for PM smaller than 10 μm (PM10) at a coastal monitoring site located 1 mile downwind of the dune area. To evaluate the potential effectiveness of this abatement strategy, five sets of measurements were collected during the windy afternoons of high-wind months (May and October) from 2019 to 2021 to quantify the organic and elemental composition of PM10 and PM smaller than 2.5 μm (PM2.5) samples. The five-campaign average afternoon PM2.5 composition relative to Beta Attenuation Monitor (BAM) concentrations included 14 ± 12% dust, 9 ± 9% sea salt, 4 ± 5% non-sea salt sulfate, and 8 ± 8% organic components, with the difference between BAM and the measured components contributing the remaining 66 ± 16% unidentified components. The high afternoon unidentified contribution was partially attributable to water, consistent with the increasing relative humidity during warm afternoons, since there was a lower unidentified contribution for overnight samples. The remaining unidentified components are consistent with prior measurements of semivolatile contributions of ammonium nitrate and organic compounds constituting >40% of PM2.5 in central California. The organic functional group signature in Fourier Transform Infrared (FTIR) spectroscopy for PM2.5 was similar to previously reported ambient marine aerosol, consistent with a natural marine source for most of the organic mass concentration. For PM10, the dust fraction was 11 ± 8% of BAM PM10 concentration and increased to 14 ± 10% of BAM PM10 concentration during days in which hourly BAM PM10 concentration exceeded 140 μg m−3. There was no statistically significant difference (p»0.05) between dust, sea salt, sulfate, or organic PM2.5 fractions between weekend and weekday concentrations, similar to prior findings for the region. These results are consistent with national and state assessments of the good air quality of the region and suggest that semivolatile components may cause differences between BAM and gravimetric mass concentrations for sampling times shorter than 24 h. In addition, the results demonstrate that the regulated dust abatement implemented at ODSVRA is misapplied and unlikely to improve downwind air quality significantly, since ODSVRA and other nearby sandy areas contribute only 14% of BAM PM10 and have not been shown to include toxic components.

Air quality modeling in the city of Marrakech, Morocco using a local anthropogenic emission inventory

Exposure to high levels of suspended particles, and particularly dust, has been associated with increased risk of morbidity and premature mortality. The city of Marrakech is situated at a distance of only 560 km from the Sahara desert, the major dust source in the world, leading to an atmosphere rich in particulate matter all year round. In this study, we use for the first-time local scale information on anthropogenic emissions in the city of Marrakech and conduct urban-scale chemistry-transport model simulations with the CHIMERE-WRF coupled system. We compare simulated airborne particles of diameter lower to 10 μm (PM10), NO2 and O3 concentrations against surface in-situ measurements and quantify the added value of the local inventory compared to the state-of-the-art global anthropogenic emission dataset (CAMS-GLOB_ANT). We show that correlation with measurements increases and the bias decreases in all cases (pollutants, seasons and monitor sites). The major component of summertime PM10 composition is dust particles, whereas in winter PM10 consists mainly of primary organic aerosol. Comparison between simulated and observed aerosol optical depth suggests that the model reproduces accurately most of the observed summertime dust plumes. PM10 simulated concentrations are closer to in-situ surface measurements during summer than during winter with an overestimation of 13% in summer versus an underestimation of 37% in winter. Finally, we show how the Atlas range blocks at some extent the import of dust plumes in the region and the export of local air-pollution to the surrounding area leading to ozone formation at high altitude.Modeling is an important activity to predict air-quality in Africa, where monitor networks are scarce. Our results highlight the necessity of using fine scale, local information on anthropogenic emissions to assess air-quality and in particular to (i) quantify the chemical composition of atmospheric aerosol; ii) compare the relative role of dust transport compared to locally emitted or formed suspended particles and iii) provide evidence of ozone formation at high altitude.

Analytical Methods for Physicochemical Characterization and Toxicity Assessment of Atmospheric Particulate Matter: A Review

Particle-bound pollutants are a critical risk factor for human respiratory/cardiovascular conditions. A comprehensive analysis of the physicochemical characteristics of PM is often challenging since it requires combining different practical methods with a good understanding the of characterization outputs. The present review aims to (1) provide a comprehensive assessment of the underlying mechanisms of PM cytotoxicity and the related biological response; (2) evaluate the selected methods for PM characterization in terms of outputs, technical aspects, challenges, and sample preparation; (3) present effective means of studying PM physicochemical toxicity and composition; and (4) provide recommendations for enhancing the human health risk assessment. The cellular response to potentially toxic elements in PM is complex to understand as exposure includes systemic inflammation, increased ROS accumulation, and oxidative stress. A comprehensive toxicity assessment requires blending morphological features and chemical composition data. For the morphological/chemical characterization, we recommend first using SEM-EDS as a practical method for the single-particle analysis. Then, the bulk chemistry of PM can be further studied using either a dry analysis (e.g., XRF) or wet analysis techniques (e.g., ICP and IC). Finally, when used on a need basis, the reviewed complementary laboratory methods may further add valuable information to the characterization. The accuracy of the human health risk assessment may be improved using bioaccessible/soluble fractions of the contaminants instead of the total contaminant concentration. Having an integrated understanding of the covered analytical methods along with the health risk assessment guidelines would contribute to research on atmospheric chemistry, molecular biology, and public health while helping researchers better characterize human exposure to PM and the associated adverse health effects.

Atmospheric saccharide composition and its possible linkage with marine phytoplankton from North Pacific to the Antarctic regions

Saccharide compounds can distinguish the influence of both biogenic emissions and anthropogenic sources. In this study, the spatial distribution of 10 saccharide compounds was observed to determine the major factor for the production of organic aerosols in the pristine marine regions from the North Pacific Ocean to the Antarctic Ocean. The pristine marine atmospheric PM2.5 (Particle matter with an aerodynamic diameter equal to or less than nominal 2.5 μm) samples were collected using a high-volume air sampler connected to a wind sector controller installed in the Korean Ice-breaking Research Vessel (IBRV) during the cruise through the Pacific Ocean: from the Yellow Sea, Korea on October 31, 2018 to the Antarctic Ocean on December 14, 2018.In the pristine marine region, the total saccharides concentrations varied greatly from 0.16 to 16.57 ng/m3 (mean: 3.02 ± 4.76 ng/m3). The compositions of 10 saccharide compounds in each PM2.5 sample changed when the marine geographic characteristics changed. The contribution of levoglucosan in the sample collected near land was higher than the sample collected in the open ocean. In addition, saccharides concentrations had a strong positive correlation with OC (Organic carbon), indicating that the increase of saccharides concentrations strongly contributes to the increase in OC concentration in the pristine marine region. The highest concentration of saccharides was observed near the New Zealand coast, which also showed highest air mass exposure to marine biology. We also found that the spatial distribution of saccharide composition was correlated with the spatial distribution of phytoplankton. From these observations, we concluded that 1) marine phytoplankton can be a significant source of organic aerosol production and 2) the type of phytoplankton in a region affects the change of saccharides composition in PM2.5.

Contrasting mass absorption efficiency of carbonaceous aerosols between PM1 and PM2.5 in urban Beijing

Carbonaceous aerosol, mainly comprising elemental carbon (EC) and organic carbon (OC), plays an important role in aerosol–climate interaction owing to its light-absorbing feature. The radiative forcing of carbonaceous aerosol is largely determined by its mass absorption efficiency (MAE). To depict the MAE of carbonaceous aerosol and its variations with aerosol size and chemical composition, light absorption coefficients and the main chemical composition of PM1 and PM2.5 were comparably measured in a winter field campaign in urban Beijing. On average, aerosol absorption by PM1 at 880 nm wavelength contributes to approximately half of aerosol absorption by PM2.5, mainly because aerosol absorption at this wavelength was dominated by EC and nearly half of the total EC mass in PM2.5 existed in PM1. The average MAE of EC at 880 nm (MAEEC,880nm) was 3.9 ± 0.7 m2 g−1 for PM2.5, lower than that for PM1 (4.4 ± 0.8 m2 g−1) likely because of the larger EC cores and lower coating degrees of EC particles in PM1–2.5. Variation in MAEEC,880nm was related to the bulk mass fractions of nitrate in PM1 and PM2.5, implying the important impact of secondary nitrate formation on the modification of EC mixing states and enhancing EC absorption efficiency in Beijing. Absorption by OC took up about 40% of the absorption coefficients for PM1 and PM2.5 at 370 nm. The mean MAE of OC at 370 nm (MAEOC,370nm) was 2.4 ± 0.9 m2 g−1 for PM1, higher than that of for PM2.5 (1.9 ± 0.6 m2 g−1). The high value of MAEOC,370nm might be associated with regionally transported aerosols during clean and polluted periods. Enlarged particle sizes might have considerably weakened MAEOC,370nm for PM2.5 while exerting negligible impact on MAEOC,370nm for PM1.

Elemental analysis of aircraft engine smoke number filter samples with micro-PIXE

To extract information on elemental components and PM characteristics from smoke number (SN) filter paper, we were performed elemental analysis by micro-PIXE. As a result of elemental analysis of the SN filter, information on the elemental composition of jet engine exhaust PM was obtained. Regarding the SN filter, jet engine exhaust PM have been collected for each difference in engine thrust of various aircraft engines at aircraft turbine engines test cells around the world. By periodically analyzing the elemental composition of such the SN filter, it is possible to grasp the characteristics of the emission PM of each aircraft engine and the transformation of the elemental composition of the emission PM with the passage of time of the jet engine. This was thought to lead to the evaluation of jet engine.

Triggering of ST-elevation myocardial infarction by ultrafine particles in New York: Changes following Tier 3 vehicle introduction

BackgroundPreviously, we found increased rates of ST-elevation myocardial infarction (STEMI) associated with increased ultrafine particle (UFP; <100 nm) concentrations in the previous few hours in Rochester, New York. Relative rates were higher after air quality policies and a recession reduced pollutant concentrations (2014–2016 versus 2005–2013), suggesting PM composition had changed and the same PM mass concentration had become more toxic. Tier 3 light duty vehicles, which should produce less primary organic aerosols and oxidizable gaseous compounds, likely making PM less toxic, were introduced in 2017. Thus, we hypothesized we would observe a lower relative STEMI rate in 2017–2019 than 2014–2016. MethodsUsing STEMI events treated at the University of Rochester Medical Center (2014–2019), UFP and other pollutants measured in Rochester, a case-crossover design, and conditional logistic regression models, we estimated the rate of STEMI associated with increased UFP and other pollutants in the previous hours and days in the 2014–2016 and 2017–2019 periods. ResultsAn increased rate of STEMI was associated with each 3111 particles/cm3 increase in UFP concentration in the previous hour in 2014–2016 (lag hour 0: OR = 1.22; 95% CI = 1.06, 1.39), but not in 2017–2019 (OR = 0.94; 95% CI = 0.80, 1.10). There were similar patterns for black carbon, UFP11–50nm, and UFP51–100nm. In contrast, increased rates of STEMI were associated with each 0.6 ppb increase in SO2 concentration in the previous 120 h in both periods (2014–2016: OR = 1.26, 95% CI = 1.03, 1.55; 2017–2019: OR = 1.21, 95% CI = 0.87, 1.68). ConclusionsGreater rates of STEMI were associated with short term increases in concentrations of UFP and other motor vehicle related pollutants before Tier 3 introduction (2014–2016), but not afterwards (2017–2019). This change may be due to changes in PM composition after Tier 3 introduction, as well as to increased exposure misclassification and greater underestimation of effects from 2017 to 2019.

Triggering of ST-elevation myocardial infarction by ultrafine particles in New York: changes following Tier 3 vehicle introduction

BACKGROUND AND AIM: Previously, we found increased rates of ST-elevation myocardial infarction (STEMI) associated with increased ultrafine particle (UFP; &amp;#x3c;100nm) concentrations in the previous few hours in Rochester, New York. Rates were higher after air quality policies and a recession reduced pollutant concentrations (2014-2016 versus 2005-2013), suggesting PM composition had become more toxic. Tier 3 light duty vehicles, which should produce less primary organic aerosols and oxidizable gaseous compounds, likely making PM less toxic, were introduced in 2017. Because of this, we hypothesized we would observe a lower relative STEMI rate in 2017-2019 than 2014-2016. METHODS: Using STEMI events treated at the University of Rochester Medical Center (2014-2019), local UFP and other pollutant concentrations, a case-crossover design, and conditional logistic regression models, we separately estimated the rate of STEMI associated with increased UFP and other pollutants in the previous hours and days in the 2014-2016 and 2017-2019 periods. RESULTS: An increased rate of STEMI was associated with each 3121 particles/cm3 increase in UFP concentration in 2014-2016 (lag hour 0: OR=1.23; 95% CI = 1.08, 1.41), but not in 2017-2019 (OR=0.93; 95% CI = 0.79, 1.09). There were similar patterns for black carbon, UFP11-50nm, and UFP51-100nm. In contrast, increased rates of STEMI were associated with 0.6ppb increases in SO2 concentrations in the previous 120 hours in both periods (2014-2016: OR=1.25, 95% CI = 1.00, 1.36; 2017-2019: OR=1.22, 95% CI = 0.88, 1.68). CONCLUSIONS: Greater rates of STEMI were associated with short term increases in concentrations of UFP and other motor vehicle related pollutants before Tier 3 introduction (2014-2016), but not afterwards (2017-2019). This change may be due to changes in PM composition, to increased exposure misclassification and greater underestimation of effects from 2017-2019, and/or changes in therapeutic approaches such as preventive aspirin use. KEYWORDS: myocardial infarction, air pollution, ultrafine particles, case-crossover

Oxidative Stress, Cytotoxic and Inflammatory Effects of Urban Ultrafine Road-Deposited Dust from the UK and Mexico in Human Epithelial Lung (Calu-3) Cells.

Road-deposited dust (RD) is a pervasive form of particulate pollution identified (typically via epidemiological or mathematical modelling) as hazardous to human health. Finer RD particle sizes, the most abundant (by number, not mass), may pose greater risk as they can access all major organs. Here, the first in vitro exposure of human lung epithelial (Calu-3) cells to 0–300 µg/mL of the ultrafine (<220 nm) fraction of road dust (UF-RDPs) from three contrasting cities (Lancaster and Birmingham, UK, and Mexico City, Mexico) resulted in differential oxidative, cytotoxic, and inflammatory responses. Except for Cd, Na, and Pb, analysed metals were most abundant in Mexico City UF-RDPs, which were most cytotoxic. Birmingham UF-RDPs provoked greatest ROS release (only at 300 µg/mL) and greatest increase in pro-inflammatory cytokine release. Lancaster UF-RDPs increased cell viability. All three UF-RDP samples stimulated ROS production and pro-inflammatory cytokine release. Mass-based PM limits seem inappropriate given the location-specific PM compositions and health impacts evidenced here. A combination of new, biologically relevant metrics and localised regulations appears critical to mitigating the global pandemic of health impacts of particulate air pollution and road-deposited dust.

Sub-toxic events induced by truck speed-facilitated PM2.5 and its counteraction by epigallocatechin-3-gallate in A549 human lung cells

To distinguish the influences of fuel type and truck speed on chemical composition and sub-toxic effects of particulates (PM2.5) from engine emissions, biomarkers—interleukin-6 (IL-6), cytochrome P450 (CYP) 1A1, heme oxygenase (HO)-1, and NADPH-quinone oxidoreductase (NQO)-1—were studied in A549 human lung cells. Fuel type and truck speed preferentially affected the quantity and ion/polycyclic aromatic hydrocarbon (PAH) composition of PM2.5, respectively. Under idling operation, phenanthrene was the most abundant PAH. At high speed, more than 50% of the PAHs had high molecular weight (HMW), of which benzo[a]pyrene (B[a]P), benzo[ghi]perylene (B[ghi]P), and indeno[1,2,3-cd]pyrene (I[cd]P) were the main PAHs. B[a]P, B[ghi]P, and I[cd]P caused potent induction of IL-6, CYP1A1, and NQO-1, whereas phenanthrene mildly induced CYP1A1. Based on the PAH-mediated induction, the predicted increases in biomarkers were positively correlated with the measured increases. HMW-PAHs contribute to the biomarker induction by PM2.5, at high speed, which was reduced by co-exposure to epigallocatechin-3-gallate.

Seasonal variation of atmospheric Pb sources in Singapore - Elemental and lead isotopic compositions of PM10 as source tracer

Southeast Asia has become a hotspot of anthropogenic particulate matter (PM) emissions due to increased coal combustion, high-temperature industrial operations, vehicular traffic, and agricultural biomass burning. Lead (Pb), a criteria pollutant, bound to such PM can be hazardous when inhaled, even at extremely low concentrations. Precise and accurate source apportionment of atmospheric Pb is thus, critical in order to minimize its exposure. This study investigates the sources of atmospheric Pb in Singapore aerosol samples (PM10) using Pb isotopes and elemental composition as tracers of contamination sources. PM10 aerosol sampling was conducted over a period of 1 year from June 2017 to May 2018 to capture the seasonal variations in sources of atmospheric Pb. Elemental concentrations reveal particularly high enrichment factors for Pb, Cu, V, Ni and Zn, especially when under the influence of southwest (SW) and inter monsoon (IM) winds. Pb isotopic ratios across the three seasons (206/207Pb = 1.147˗1.150 and 208/207Pb = 2.420˗2.428) are not significantly different. The Pb isotopic signatures and V/Ni ratios for all three seasons overlap with those of gasoline, diesel and ship emissions. Moreover, V/Pb values of more than unity for SW and IM winds suggest influence of transboundary coal combustion emissions particularly from Indonesia. Consequently, using Pb isotopic fingerprints and elemental ratios, we find that the primary sources of atmospheric Pb are vehicular & ship emissions, heavy oil combustion, transboundary coal combustion emissions, waste incineration and recirculation of historic leaded gasoline.

Experimental study on PM10 formation characteristics of co-combustion with pulverized coal and sludge

At present, the output of municipal sludge in China is increasing year by year, and co-combustion of sludge and pulverized coal for power generation is a means to treat sludge in large quantities. However, the co-combustion of sludge and pulverized coal will generate a lot of particulate matter (PM). In this paper, the formation characteristics of particulate matter (PM10) produced by the co-combustion of sludge and pulverized coal were studied. The effect of the furnace temperature and the sludge mixing ratio on the mass-based particle size distribution and elemental composition of PM10 in sludge, coal combustion and co-combustion was discussed. The experiment results show that the mass-based particle size distribution of PM10 produced by pulverized coal and sludge combustion are both bimodal, while the elemental composition and particle size distribution of PM10 are different. Whether burning alone or co-firing, increasing the furnace temperature will increase the mass yield of PM10. Increasing the temperature promotes particle fragmentation more than the melting aggregation of particulate minerals, increasing PM0.4–10 yield. The mass yield of PM10 produced by coal combustion is higher than that of sludge. In the sludge addition ratio range ≤ 30%, increasing the sludge addition ratio will reduce the mass yield of PM10. The synergistic effect exists between sludge and pulverized coal co-combustion. Compared to the weighted calculation results, the content of main elements Si, Ca, Fe and S in PM0.4 decreases, while in PM0.4–10 the content of Si decreases and the content of Ca, Fe, Al, and P increases. At a low sludge addition ratio of 10%, the elemental composition of PM10 with the particle size distribution trend is consistent with that of pulverized coal, and sludge co-firing takes negligible effect on PM10 formation.

Chemical Composition and Toxicity of PM10 and PM0.1 Samples near Open-Pit Mines and Coal Power Stations.

Particulate matter (PM) <10 μm in size represents an extremely heterogeneous and variable group of objects that can penetrate the human respiratory tract. The present study aimed to isolate samples of coarse and ultrafine PM at some distance from polluting industries (1–1.5 km from the border of open-cast mines). PM was collected from snow samples which allowed the accumulation of a relatively large amount of ultrafine particles (UFPs) (50–60 mg) from five objects: three open-cast mines, coal power plants, and control territories. The chemical composition of PM was examined using absorption spectroscopy, luminescence spectroscopy, high-performance liquid chromatography, X-ray diffraction (XRD), and X-ray fluorescence (XRF) analyses of solid particle material samples. Toxicity was assessed in human MRC-5 lung fibroblasts after 6 h of in vitro exposure to PM samples. The absorption spectra of all the samples contained a wide non-elementary absorption band with a maximum of 270 nm. This band is usually associated with the absorption of dissolved organic matter (DOM). The X-ray fluorescence spectra of all the studied samples showed intense lines of calcium and potassium and less intense lines of silicon, sulfur, chlorine, and titanium. The proliferation of MRC-5 cells that were exposed to PM0.1 samples was significantly (p < 0.01) lower than that of MRC-5 cells exposed to PM10 at the same concentration, except for PM samples obtained from the control point. PM0.1 samples—even those that were collected from control territories—showed increased genotoxicity (micronucleus, ‰) compared to PM10. The study findings suggest that UFPs deserve special attention as a biological agent, distinct from larger PMs.

New insights into submicron particles impact on visibility.

The aim of the study was to analyze the impact of very fine atmospheric particles (submicron particulate matter; PM1) on visibility deterioration. Taking into consideration not only their entirely different physio-chemical properties in comparison to a well-recognized PM10 but also the origin and a growing environmental awareness of PM1, the main research problem has been solved in few steps. At first, the chemical composition of PM1 was determined in two selected urban areas in Poland. Measurements of meteorological parameters, i.e., air temperature and humidity, precipitation, atmospheric pressure, wind speed, and visibility, were also conducted. The next step of the work was the analysis of (1) seasonal changes of the concentration of PM1 and its main components, (2) the influence of chemical components of PM1 on light extinction, and (3) the influence of PM1 and humidity on visibility. Hierarchical cluster analysis, correlation matrixes and a heat map, and classification and regression tree analysis were used. The light extinction coefficient is influenced mainly by coarse mass of PM, and PM1-bound ammonium nitrate, organic matter, and by Rayleigh scattering. The less important in the light extinction coefficient shaping has PM1-bound ammonium sulfate, elemental carbon, and soil. In this way, the secondary origin PM1 components were proved to most significantly influence the visibility. The obtained results confirmed the possibility of the use of statistical agglomeration techniques to identify ranges of variation of visibility, including independent variables adopted to analyses (meteorological conditions, chemical composition of PM1, etc.).

Mass, composition, and sources of particulate matter in residential and traffic sites of an urban environment.

Present study aims to assess the mass, composition, and sources of PM10 and PM2.5 (particulate matter having aerodynamic diameter less than or equal to 10 and 2.5µm aerodynamic diameter, respectively) in Vellore city. Seasonal samples collected in traffic and residential sites were analyzed for ions, elements, organic carbon (OC), and elemental carbon (EC). Source apportionment of PM10 and PM2.5 is carried out using Chemical Mass Balance, Unmix, Positive Matrix Factorization and Principal Component Analysis receptor models. Results showed that traffic site had higher annual concentration (PM2.5 = 62 ± 32 and PM10 = 112 ± 23µgm-3) when compared to residential site (PM2.5 = 54 ± 22 and PM10 = 98 ± 20µgm-3). Al, Ca, Fe, K, and Mg known to have crustal origin dominated the element composition irrespective of PM size and sampling site. Among ions, SO42- accounted highest in both sites with an average of 70 and 60% to PM2.5 and PM10 ionic mass. Elemental carbon contribution to PM mass was found highest in traffic site (PM2.5 = 17 to 23% and PM10 = 8 to 10%) than residential site (PM2.5 = 9 to 17% and PM10 = 4 to 8%). Elements, ions, OC, and EC accounted 12, 28, 34, and 16% of PM2.5 mass and 12, 21, 20, and 8% of PM10 mass, respectively. Different sources identified by the receptor models are resuspended road dust, crustal material, secondary aerosol, traffic, non-exhaust vehicular emissions, secondary nitrate, construction, cooking, and biomass burning. Since Vellore is aspiring to be a smart city, this study can help the policymakers in effectively curbing PM.

Comparative Study of PM10 Concentrations and Their Elemental Composition Using Two Different Techniques during Winter–Spring Field Observation in Polish Village

The aims of this study were to determine the concentrations and elemental composition of PM10 in the village of Kotórz Mały (Poland), to analyse their seasonal variability, to determine the sources of pollutant emissions and to compare the consistency of the results obtained using different methods. Sampling and weather condition measurements were carried out in the winter (January–February) and spring (April) of 2019. Two combinations of different techniques were used to examine PM10 concentrations and their chemical composition: gravimetric method + atomic absorption spectrometry (GM+AAS) and continuous particle monitor + energy dispersive X-ray fluorescence (CPM+EDXRF). In winter, the average concentrations of PM10 measured by the GM and CPM were similar (GM 44.3 µg/m3; CPM 34.0 µg/m3), while in spring they were clearly different (GM 49.5 µg/m3; CPM 29.8 µg/m3). Both AAS and EDXRF proved that in both seasons, Ca, K and Fe had the highest shares in the PM10 mass. In the case of the lowest shares, the indications of the two methods were slightly different. Factor analysis indicated that air quality in the receptor was determined by soil erosion, coal and burning biomass, and the combustion of fuels in car engines; in the spring, air quality was also affected by gardening activities.

A 3-Dimensional analysis of long-range transported particulate matter to the Eastern Mediterranean: Implication for the chemical components of PM1 and PM10

This study aims to better characterize the location of the strong regional emitters of aerosols affecting the Eastern Mediterranean basin, through the use of a recently developed three-dimensional (3D) version of a Concentration Weighted Trajectory (CWT) model which can identify the prevalent transport pattern of polluted air masses as a function of their altitude (0 m ≤ Layer 1 < 1000 m (near ground layer), 1000 m ≤ Layer 2 < 2000m (intermediate layer), 2000m ≤ Layer 3 (upper layer)). Daily PM10 and PM1 chemical composition measurements from a regional background station on the island of Cyprus were incorporated in the model. Intrusions of PM1 constituents of an anthropogenic origin (Secondary Inorganic Aerosols (SIA) (SO42− and NH4+), K+, EC and OC), were mainly associated with Eastern continental airflows (Middle East regions) in Layers 1 and 2 during the cold periods (16 October to 15 April). During the warm periods (16 April to 15 October) the prevalence of Northern airflows in all layers mainly through Turkey enhanced the levels of SIA and K+ in PM1. Sea salt constituents in PM10 were particularly carried by West – Northwest Mediterranean airflows in all layers during both cold and warm periods. Dust intrusions from Northeast Africa and the Middle East were highlighted by episodes of PM10 crustal species and were most evident in Layer 1 during cold seasons. Therefore, this study reveals the spatial and vertical distribution of air masses transporting the main aerosol components at the Eastern Mediterranean.

Evidence of haze-driven secondary production of supermicrometer aerosol nitrate and sulfate in size distribution data in South Korea

Abstract. This study reports measurements of size-resolved aerosol composition at a site in Incheon along with other aerosol characteristics for contrast between Incheon (coastal) and Seoul (inland), South Korea, during a transboundary pollution event during the early part of an intensive sampling period between 4 and 11 March 2019. Anthropogenic emissions were dominant in the boundary layer over the study region between 4 and 6 March, with much smaller contributions from dust, smoke, and sea salt. The meteorology of this period (shallow boundary layer, enhanced humidity, and low temperature) promoted local heterogeneous formation of secondary inorganic and organic species, including high nitrate (NO3-) relative to sulfate (SO42-). Seoul exhibited higher PM2.5 levels than Incheon, likely due to local emissions. The following findings point to secondary aerosol formation and growth sensitivity to water vapor during this pollution event: (i) significant concentrations of individual inorganic and organic acids in the supermicrometer range relative to their full size range (∼40 %) at higher humidity; (ii) high correlation (r=0.95) between oxalate and SO42-, a marker of secondary aqueous production of oxalate; (iii) increased sulfur and nitrogen oxidation ratios as a function of humidity; and (iv) matching composition apportionment (for soluble ions) between the PM1 and PM2.5−1 size fractions. The last finding confirms that PM1 aerosol composition measurements fully capture PM2.5 composition apportionment (for soluble ions) during haze events and may therefore be reliably applied in modeling studies of such events over the full PM2.5 size range. However, the differences evident in the periods following the haze event imply that under other atmospheric conditions PM1 composition measurements will not fully reflect the apportionment of PM2.5 aerosols. The study period was marked by relatively low temperatures that made NO3- the most abundant species detected, pointing to the sensitivity of PM2.5 levels and composition as a function of season during such transboundary events. For instance, other such events in previous studies exhibited more comparable levels between SO42- and NO3- coincident with higher temperatures than the current study. This dataset can contribute to future evaluation of model PM2.5 composition to better support regulatory efforts to control PM2.5 precursors.