Chemical Composition Of PM2 Research Articles

Morphology and Chemical Composition of PM10 by SEM-EDS

Morphology and Chemical Composition of PM10 by SEM-EDS

Clues for a standardised thermal-optical protocol for the assessment of organic and elemental carbon within ambient air particulate matter

Abstract. Along with some research networking programmes, the European Directive 2008/50/CE requires chemical speciation of fine aerosol (PM2.5), including elemental (EC) and organic carbon (OC), at a few rural sites in European countries. Meanwhile, the thermal-optical technique is considered by the European and US networking agencies and normalisation bodies as a reference method to quantify EC–OC collected on filters. Although commonly used for many years, this technique still suffers from a lack of information on the comparability of the different analytical protocols (temperature protocols, type of optical correction) currently applied in the laboratories. To better evaluate the EC–OC data set quality and related uncertainties, the French National Reference Laboratory for Ambient Air Quality Monitoring (LCSQA) organised an EC–OC comparison exercise for French laboratories using different thermal-optical methods (five laboratories only). While there is good agreement on total carbon (TC) measurements among all participants, some differences can be observed on the EC / TC ratio, even among laboratories using the same thermal protocol. These results led to further tests on the influence of the optical correction: results obtained from different European laboratories confirmed that there were higher differences between OCTOT and OCTOR measured with NIOSH 5040 in comparison to EUSAAR-2. Also, striking differences between ECTOT / ECTOR ratios can be observed when comparing results obtained for rural and urban samples, with ECTOT being 50% lower than ECTOR at rural sites whereas it is only 20% lower at urban sites. The PM chemical composition could explain these differences but the way it influences the EC–OC measurement is not clear and needs further investigation. Meanwhile, some additional tests seem to indicate an influence of oven soiling on the EC–OC measurement data quality. This highlights the necessity to follow the laser signal decrease with time and its impact on measurements. Nevertheless, this should be confirmed by further experiments, involving more samples and various instruments, to enable statistical processing. All these results provide insights to determine the quality of EC–OC analytical methods and may contribute to the work toward establishing method standardisation.

Mutagenicity and clastogenicity of native airborne particulate matter samples collected under industrial, urban or rural influence

Airborne particulate matter has recently been classified by the IARC as carcinogenic to humans (group 1). However, the link between PM chemical composition and its carcinogenicity is still unclear. The aim of the present study was to evaluate and to compare genotoxic potencies of 6 native PM samples collected in spring–summer or autumn–winter, either in industrial, urban or rural area. We evaluated their mutagenicity through Ames test on YG1041, TA98, and TA102 tester strains, and their clastogenicity on human bronchial epithelial BEAS-2B cells using comet assay, γ-H2AX quantification, and micronucleus assay. Ames test results showed a strong positive response, presumably associated with nitro-aromatics content. In addition, at least 2 positive responses were observed out of the 3 genotoxicity assays for each of the 6 samples, demonstrating their clastogenicity. Our data suggest that PM samples collected in autumn–winter season are more genotoxic than those collected in spring–summer, potentially because of higher concentrations of adsorbed organic compounds. Taken together, our results showed the mutagenicity and clastogenicity of native PM2.5 samples from different origins, and bring additional elements to explain the newly recognized carcinogenicity of outdoor air pollution.

Chemistry and mineralogy studies of PM<SUB align="right">10 atmospheric aerosols in the Gulf of Gabès, South Tunisia

This study provides a comprehensive report on mass concentrations, chemical composition and mineralogy characterisations of PM10 atmospheric aerosols in the Gulf of Gabes, in South Tunisia. Data were collected at 18 locations (sample points in urban zones with industrial influence). Principally, they were located near the industrial complex. At each sample point, PM10 was measured, with a mobile monitoring unit equipped with real-time analysers, which generated a mean value of each pollutant for an interval of 15 min. The duration of this measurement campaign was 20 days successive in 2007. In this study, statistical and geostatistical techniques were used to estimate PM10. After analysing data and obtaining a good variogram, multivariate data analysis, cartography via ordinary kriging was used to estimate PM10 concentration at unsampled locations. The mineral phase identified by X-ray powder diffraction technique and SEM-EDX provides information about morphology and chemical composition of PM10. The result shows that PM10 samples were enriched with metal elements specially Fe and Cd, and it shows also that the minerals phases identified in the samples were calcite, gypsum and dolmite.

Source Apportionment of PM2.5 Using a CMB Model for a Centrally Located Indian City

Samples of PM2.5 were collected sequentially for 24 hours during the last week of September to mid February 2009–10 at three locations representing residential (R), commercial (C) and industrial (I) sites in Nagpur city to determine their chemical composition and estimations of the sources contributing to them. Two receptor models were used for the source apportionment viz. enrichment factors (EF) to differentiate crustal and non-crustal sources, whereas chemical mass balance (CMB 8.2) was used to identify and quantify the major sources contributing to PM2.5. The ambient mass concentrations and chemical compositions of PM2.5 with respect to ionic species (Na+, NH4+, K+, Ca2+, F–, Cl–, NO3– and SO42–); carbonaceous species (organic and elemental carbon) and trace metals (Al, Ba, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Si and Zn) were determined. The most abundant chemical species were OC, EC, SO42–, NO3–, NH4+, K+ and trace metals (Al, Fe, Si, Mg, and Cu) at all the sites. Findings of EF showed the anthropogenic origin of Cd, Ni, Pb, Cu, Fe and Zn, whereas Ba, Cr, Mg, Mn, and Si were contributed from crustal sources. On the other hand, results of CMB using source profiles developed in India for non-vehicular and vehicular sources revealed that vehicular emissions were major contributing sources 57, 62 and 65%; followed by secondary inorganic aerosol 16, 12, 16%; biomass burning 15, 11, 9% and then by re-suspended dust 6,10, 7% at R, C and I sites, respectively. This study showed that while the sources at all three sites were mostly consistent, the percent contributions of these varied among the sites as per the intensity of ongoing activities at the receptor sites.

Optical properties and chemical composition of PM2.5 in Shanghai in the spring of 2012

The semi-diurnal mean aerosol mass concentration, chemical composition, and optical properties of PM2.5 were investigated in Shanghai during the spring of 2012. Slight pollution was observed during the study period. The average PM2.5 concentration was 64.11±22.83μg/m3. The mean coefficients of extinction, scattering, and absorption at 532nm were 125.9±78.5, 91.1±56.3, and 34.9±23.6Mm−1, respectively. A relatively low mean single scattering albedo at 532nm (0.73±0.04) and low level of elemental carbon (EC, 2.67±1.96μg/m3) suggested that the light absorption was enhanced due to the internal mixing of the EC. Sulfate contributed the most to aerosol light scattering in Shanghai. The chemical composition of PM2.5 was dominated by particulate organic matter, sulfate, nitrate, ammonium, and EC. Anthropogenic sources made a significant contribution to the emission and loading of the particulate pollutants. A relatively good correlation between the aerosol chemical composition and the cloud condensation nuclei (CCN) activation indicated that aerosol chemistry is an important factor that influences the saturated hygroscopicity and growth of the aerosol.

Lidar Measurements of the Vertical Distribution of Aerosol Optical and Physical Properties over Central Asia

The vertical structure of aerosol optical and physical properties was measured by Lidar in Eastern Kyrgyzstan, Central Asia, from June 2008 to May 2009. Lidar measurements were supplemented with surface-based measurements of PM2.5 and PM10 mass and chemical composition in both size fractions. Dust transported into the region is common, being detected 33% of the time. The maximum frequency occurred in the spring of 2009. Dust transported to Central Asia comes from regional sources, for example, Taklimakan desert and Aral Sea basin, and from long-range transport, for example, deserts of Arabia, Northeast Africa, Iran, and Pakistan. Regional sources are characterized by pollution transport with maximum values of coarse particles within the planetary boundary layer, aerosol optical thickness, extinction coefficient, integral coefficient of aerosol backscatter, and minimum values of the Ångström exponent. Pollution associated with air masses transported over long distances has different characteristics during autumn, winter, and spring. During winter, dust emissions were low resulting in high values of the Ångström exponent (about 0.51) and the fine particle mass fraction (64%). Dust storms were more frequent during spring with an increase in coarse dust particles in comparison to winter. The aerosol vertical profiles can be used to lower uncertainty in estimating radiative forcing.

Fine Particle and Gaseous Emissions from a Small-Scale Boiler Fueled by Pellets of Various Raw Materials

The market of pellet fuels has undergone drastic changes in Europe in recent years. Traditional raw materials have become inaccessible due to unavailability or dramatic increases in prices. It is possible to use other feasible raw materials for pellet production. However, novel raw materials can have disadvantages with respect to usability and emissions, and these issues need to be considered before such raw materials are taken into wide-scale production. Such factors are especially important in small-scale pellet combustion. Fine particle and gaseous emissions from 21 pellet fuels of various raw materials were studied in a residential pellet boiler. These fuels represented a wide range of stem wood, bark, and forest residues from different tree species, as well as peat, agricultural biomass, and different mixtures of these. Fuel characteristics, fine particle mass (PM1) emissions, number emissions, number size distribution, PM1 chemical composition, and the main gaseous emissions were measured. The small...

Chemical characteristics of PM10 during the summer in the mega-city Guangzhou, China

With rapid economic development and the acceleration of urbanization, air pollution has become a serious problem in the mega-city Guangzhou, China. A field campaign to sample and analyze particulate matter (PM) chemical components was performed from July 6, 2006 to July 26, 2006, in Guangzhou. During the campaign, the average mass concentration of PM10 was 89.0±46.6μgm−3 (the error represents one standard deviation). The PM10, sulfate, nitrate, ammonium, organic carbon (OC), and elemental carbon (EC) mass frequency distributions were analyzed. The [NO3−]/[SO42−] mass ratio varied from 0.1 to 0.3, with an average of 0.2. A Pearson correlation analysis between [SO42−] and [NH4+] and between [NO3−] and [Na+] showed that SO42− existed as (NH4)2SO4 and NO3− existed as NH4NO3 and NaNO3. Sulfate, nitrate, ammonium, EC and POM (particulate organic matter) accounted for 24.4%, 4.9%, 5.7%, 5.7% and 21.0%, respectively, of the PM10 mass concentration during clean days and 25.7%, 3.9%, 7.9%, 5.4% and 20.8%, respectively, on hazy days. Among these species, SNA (sulfate, nitrate, and ammonium) were the most abundant, accounting for 35.0% and 37.5% of the PM10 during clean and hazy days, respectively. The sum of POM and EC accounted for 26.7% and 26.2% of PM10 in Guangzhou during clean and hazy days, respectively. There was no apparent difference in the chemical composition of PM10 between clean and haze days.

Sensitivity analysis of source regions to PM2.5 concentration at Fukue Island, Japan

The authors analyze the sensitivities of source regions in East Asia to PM2.5 (particulate matter with an aerodynamic diameter of ≤2.5 µm) concentration at Fukue Island located in the western part of Japan by using a regional chemical transport model with emission sensitivity simulations for the year 2010. The temporal variations in PM2.5 concentration are generally reproduced, but the absolute concentration is underestimated by the model. Chemical composition of PM2.5 in the model is compared with filter sampling data in spring; simulated sulfate, ammonium, and elemental carbon are consistent with observations, but mass concentration of particulate organic matters is underestimated. The relative contribution from each source region shows the seasonal variation, especially in summer. The contribution from central north China (105°E–124°E, 34°N–42°N) accounts for 50–60% of PM2.5 at Fukue Island except in summer; it significantly decreases in summer (18%). Central south China (105°E–123°E, 26°N–34°N) has the relative contribution of 15–30%. The contribution from the Korean Peninsula is estimated at about 10% except in summer. The domestic contribution accounts for about 7% in spring and autumn and increases to 19% in summer. We also estimate the relative contribution to daily average concentration in high PM2.5 days (>35 μg m−3). Central north China has a significant contribution of 60–70% except in summer. The relative contribution from central south China is estimated at 46% in summer and about 30% in the other seasons. The contributions from central north and south China on high PM2.5 days are generally larger than those of their seasonal mean contributions. The domestic contribution is smaller than the seasonal mean value in every season; it is less than 10% even in summer. These model results suggest that foreign anthropogenic sources have a substantial impact on attainment of the atmospheric environmental standard of Japan at Fukue Island.Implications: The contribution from several source regions in East Asia to PM2.5 concentration at Fukue Island, a remote island located in the western part of Japan and close to the Asian continent, is estimated using a three-dimensional chemical transport model. The model results suggest that PM2.5 that is attributed to foreign anthropogenic sources have a larger contribution than that of domestic pollution and have a substantial impact on attainment of the atmospheric environmental standard of Japan at Fukue Island.

Emergency hospital admissions for cardiorespiratory diseases and PM10 chemical composition in Hong Kong

Background: Research on how individual chemical components of PM affect human health has been focusing on fine particles (i.e., PM2.5). PM composition differs by size, with more crustal materials i...

Mineral Characteristics Analysis of PM<sub>2.5</sub> in Northern China

PM2.5 (sandstorm-related) was sampled at four sites near dust source areas in Northern China in spring 2012. Every site was away from obvious pollution source. After drying 24 hours in a dry dish, X-ray diffraction (XRD), x-ray fluorescence (XRF) and scanning electron microscope (SEM) of all the samples were examined. The main phases were quartz, albite, calcite and mica. SEM observations showed that the particles were mainly irregular shaped, but different sample the particle morphology is slightly different. And the surface was rough because of erosion mark or pores on them. The chemical composition of PM2.5 is characteristic of high SiO2 and CaO, while low K2O, Na2O. Main elements of the samples were Si, Al, Fe, Ca, which were familiar with crust elements and dust fall components [, but some samples also contained low-level heavy metals like As and Pb.

Chemical composition of PM2.5 at an urban site of Chengdu in southwestern China

PM2.5 aerosols were sampled in urban Chengdu from April 2009 to January 2010, and their chemical compositions were characterized in detail for elements, water soluble inorganic ions, and carbonaceous matter. The annual average of PM2.5 was 165 µ gm −3 , which is generally higher than measurements in other Chinese cities, suggesting serious particulate pollution issues in the city. Water soluble ions contributed 43.5% to the annual total PM2.5 mass, carbonaceous aerosols including elemental carbon and organic carbon contributed 32.0%, and trace elements contributed 13.8%. Distinct daily and seasonal variations were observed in the mass concentrations of PM2.5 and its components, reflecting the seasonal variations of different anthropogenic and natural sources. Weakly acidic to neutral particles were found for PM2.5 .M ajor sources of PM2.5 identified from source apportionment analysis included coal combustion, traffic exhaust, biomass burning, soil dust, and construction dust emissions. The low nitrate: sulfate ratio suggested that stationary emissions were more important than vehicle emissions. The reconstructed masses of ammonium sulfate, ammonium nitrate, particulate carbonaceous matter, and fine soil accounted for 79% of the total measured PM2.5 mass; they also accounted for 92% of the total measured particle scattering.

Extraction method for manipulation of water- and organic-soluble extracts of PM2.5 in Korean winter season and its chemical composition

Particulate matter (PM) air pollution is a significant environmental issue. PM is divided into three main fractions based on its size: coarse (2.5–10 μm), fine (0.1–2.5 μm), and ultrafine fractions (<0.1 μm). Fine particles and ultrafine fractions which are designated as particulate matter 2.5 (PM2.5) is small enough to reach alveoli in the lungs. Although the correlation between the chemical composition of PM2.5 and its toxic mechanisms has not been elucidated, several studies of PM2.5 have found evidence that ambient air PM2.5 is associated with adverse health effects. In the present study, the chemical compositions of water- and organic-soluble extracts of PM2.5 from 50 sample filters collected in the winter in the middle part of Seoul were measured. The water-soluble extract was analyzed to determine its contents of inorganic ions and metals using ion chromatography, atomic absorption spectrometry, and inductively coupled plasma-atomic emission spectrometry. The main inorganic ions were Cl−, NO3−, SO42−, and NH4+, with a total quantity in the range of 20.02 to 40.22 μg/m3 in ambient air. In a sample of all five groups, Na, K, Ca, Mg, Cd, Cr, Cu, Fe, Mn, Ni, V, and Zn together accounted for 902.14 to 1631.25 ng/m3 in ambient air. The concentrations of thirteen polycyclic aromatic hydrocarbons (PAHs) in the organic-soluble extract were analyzed using gas chromatography/time of flight-mass spectrometry. The thirteen PAHs combined constituted 6.24–76.05 ng/m3 in ambient air. In this study, we report the chemical composition of PM2.5 during the winter season in Seoul and suggest using a high-volume air sampler to create water- and organic-soluble extracts from large amounts of PM2.5, which could be used to conduct in vitro and in vivo experiments, including studying genomic changes following PM exposure.

Source contributions to PM2.5 and PM10 at an urban background and a street location

The contribution of regional, urban and traffic sources to PM2.5 and PM10 in an urban area was investigated in this study. The chemical composition of PM2.5 and PM10 was measured over a year at a street location and up- and down-wind of the city of Rotterdam, the Netherlands. The 14C content in EC and OC concentrations was also determined, to distinguish the contribution from “modern” carbon (e.g., biogenic emissions, biomass burning and wildfires) and fossil fuel combustion. It was concluded that the urban background of PM2.5 and PM10 is dominated by the regional background, and that primary and secondary PM emission by urban sources contribute less than 15%. The 14C analysis revealed that 70% of OC originates from modern carbon and 30% from fossil fuel combustion. The corresponding percentages for EC are, respectively 17% and 83%. It is concluded that in particular the urban population living in street canyons with intense road traffic has potential health risks. This is due to exposure to elevated concentrations of a factor two for EC from exhaust emissions in PM2.5 and a factor 2–3 for heavy metals from brake and tyre wear, and re-suspended road dust in PM10. It follows that local air quality management may focus on local measures to street canyons with intense road traffic.

Source apportionment of ambient fine particulate matter in Dearborn, Michigan, using hourly resolved PM chemical composition data

High time-resolution aerosol sampling was conducted for one month during July–August 2007 in Dearborn, MI, a non-attainment area for fine particulate matter (PM2.5) National Ambient Air Quality Standards (NAAQS). Measurements of more than 30 PM2.5 species were made using a suite of semi-continuous sampling and monitoring instruments. Dynamic variations in the sub-hourly concentrations of source ‘marker’ elements were observed when discrete plumes from local sources impacted the sampling site. Hourly averaged PM2.5 composition data for 639 samples were used to identify and apportion PM2.5 emission sources using the multivariate receptor modeling techniques EPA Positive Matrix Factorization (PMF) v4.2 and EPA Unmix v6.0. Source contribution estimates from PMF and Unmix were then evaluated using the Sustained Wind Instance Method (SWIM), which identified plausible source origins. Ten sources were identified by both PMF and Unmix: (1) secondary sulfate, (2) secondary nitrate characterized by a significant diurnal trend, (3) iron and steel production, (4) a potassium-rich factor attributable to iron/steel slag waste processing, (5) a cadmium-rich factor attributable to incineration, (6) an oil refinery characterized by La/Ce>1 specific to south wind, (7) oil combustion, (8) coal combustion, (9) motor vehicles, and (10) road dust enriched with organic carbon. While both models apportioned secondary sulfate, oil refinery, and oil combustion PM2.5 masses closely, the mobile and industrial source apportionments differed. Analyses were also carried out to help infer time-of-day variations in the contributions of local sources.

How a Steel Plant Affects Air Quality of a Nearby Urban Area: A Study on Metals and PAH Concentrations

Taranto (in the Apulia Region of southern Italy) has been included in a list of the most polluted sites of national interest because of its large industrial area that is situated near the urban centre. The impact of this on urban air quality has been evaluated by monitoring PM2.5 and PM10 at the industrial site of ‘via Orsini’ and the urban station of ‘via Dante’. At both sites, the temporal distribution and chemical composition of PM, in terms of PAHs and element concentrations, were used to characterize the air quality in the urban area and to deduce the possible and theoretical carcinogenic indices, and thus the impact on human health. High PM concentrations were found to be caused by wind coming from the north (industrial area), and during days when the wind was from this direction the PAH and elemental concentrations (such as iron, manganese and zinc) were the highest of the sampling period. These data confirm the impact of this industrial area, in particular its steel plant activities, on urban air quality in Taranto. In order to determine the source contributions to PM levels at the two investigated sites, Principal Component Analysis was applied to the collected data. Statistical investigations also included PAH and elemental concentrations determined at two other sites in Apulia Region, characterized by traffic and biomass burning sources. These investigations made it possible to distinguish the samples collected in via Dante and via Orsini from those collected at the two other sites, confirming the effects of industrial activities on urban air quality in Taranto.

Comparing the Performance of Teflon and Quartz Membrane Filters Collecting Atmospheric PM: Influence of Atmospheric Water

Mass concentration and chemical composition of PM10 and PM2.5 was measured during eight one-month winter and summer field studies carried out in the Po Valley (Northern Italy). PM was daily collected on Teflon (T) and on quartz (Q) filters set side-by-side. During the summer periods the differences between the mass concentrations measured on the two filters (T-Q) were within the range of experimental error, while statistically significant positive differences were detected during the winter periods. The sum of the chemical analyses (elements, ions, elemental and organic carbon) allowed the achievement of satisfactory mass closure during the summer periods, while unaccounted masses of the order of 10–20% of the PM mass measured on Teflon were detected during the winter periods. Unaccounted mass and T-Q differences increased during periods of high atmospheric stability, when the ammonium nitrate concentration also increased rapidly. Unaccounted masses and T-Q differences can be attributed to PM-bound and PM-adsorbed water.

Chemical composition of PM2.5 in an urban environment in Chengdu, China: Importance of springtime dust storms and biomass burning

Daily PM2.5 samples were collected in Chengdu, a megacity in southwest China, for a period of one month in every season during 2009–2010. Mass concentrations of water-soluble inorganic ions, organic carbon (OC), elemental carbon (EC), levoglucosan (LG), water soluble organic carbon (WSOC), and elements were determined to identify the chemical characteristics and potential sources of PM2.5. The data obtained in spring were discussed in detail to explore the impacts of dust storms and biomass burning on the chemical aerosol properties. The daily PM2.5 mass concentrations ranged from 49.2 to 425.0μgm−3 with an annual average of 165.1±85.1μgm−3. The highest seasonal average of PM2.5 concentrations was observed in the winter (225.5±73.2μgm−3) and the lowest in the summer (113.5±39.3μgm−3). Dust storm influence was observed only during the spring, while biomass burning activities occurred frequently in late spring and early summer. In the spring season, water-soluble ions, total carbonaceous aerosols, and the sum of the dominant elements (Al, Si, Ca, Ti, Fe, Mn, Zn, Pb, and Cu) accounted for 30.0±9.3%, 38.6±11.4%, and 6.2±5.3%, respectively, of the total PM2.5 mass. Crustal element levels evidently increased during the dust storm episode and LG, OC, WSOC, Cl− and K+ concentrations increased by a factor of 2-7 during biomass burning episodes. Using the Positive Matrix Factorization (PMF) receptor model, four sources for spring aerosols were identified, including secondary sulfate and nitrate, motor vehicle emissions, soil dust, and biomass burning. The four sources were estimated to contribute 24.6%, 18.8%, 23.6% and 33.0%, respectively, to the total PM2.5 mass.

Determining the influence of different atmospheric circulation patterns on PM10 chemical composition in a source apportionment study

This study combines a set of chemometric analyses with a source apportionment model for discriminating the weather conditions, local processes and remote contributions having an impact on particulate matter levels and chemical composition. The proposed approach was tested on PM10 data collected in a semi-rural coastal site near Venice (Italy). The PM10 mass, elemental composition and the water soluble inorganic ions were quantified and seven sources were identified and apportioned using the positive matrix factorization: sea spray, aged sea salt, mineral dust, mixed combustions, road traffic, secondary sulfate and secondary nitrate. The influence of weather conditions on PM10 composition and its sources was investigated and the importance of air temperature and relative humidity on secondary components was evaluated. Samples collected in days with similar atmospheric circulation patterns were clustered on the basis of wind speed and direction. Significant differences in PM10 levels and chemical composition pointed out that the production of sea salt is strongly depending on the intensity of local winds. Differently, typical primary pollutants (i.e. from combustion and road traffic) increased during slow wind regimes. External contributions were also investigated by clustering the backward trajectories of air masses. The increase of combustion and traffic-related pollutants was observed when air masses originated from Central and Northwestern Europe and secondary sulfate was observed to rise when air masses had passed over the Po Valley. Conversely, anthropogenic contributions dropped when the origin was in the Mediterranean area and Northern Europe. The chemometric approach adopted can discriminate the role local and external sources play in determining the level and composition of airborne particulate matter and points out the weather circumstances favoring the worst pollution conditions. It may be of significant help in designing local and national air pollution control strategies.