Atmospheric Particulate Matter Concentrations Research Articles

A method for monitoring mass concentration of black carbon particulate matter using photothermal interferometry.

A method for measurements of mass concentration of black carbon particulate matter (PM) is proposed based on photothermal interferometry (PTI). A folded Jamin photothermal interferometer was used with a laser irradiation of particles deposited on a filter paper. The black carbon PM deposited on the filter paper was regarded as a film while the quartz filter paper was regarded as a substrate to establish a mathematical model for measuring the mass concentration of PM using a photothermal method. The photothermal interferometry system was calibrated and used to measure the atmospheric PM concentration corresponding to different dust-treated filter paper. The measurements were compared to those obtained using β ray method and were found consistent. This method can be particularly relevant to polluted atmospheres where PM is dominated by black carbon.

Retrieval of High-Resolution Atmospheric Particulate Matter Concentrations from Satellite-Based Aerosol Optical Thickness over the Pearl River Delta Area, China

Satellite remote sensing offers an effective approach to estimate indicators of air quality on a large scale. It is critically significant for air quality monitoring in areas experiencing rapid urbanization and consequently severe air pollution, like the Pearl River Delta (PRD) in China. This paper starts with examining ground observations of particulate matter (PM) and the relationship between PM10 (particles smaller than 10 μm) and aerosol optical thickness (AOT) by analyzing observations on the sampling sites in the PRD. A linear regression (R2 = 0.51) is carried out using MODIS-derived 500 m-resolution AOT and PM10 concentration from monitoring stations. Data of atmospheric boundary layer (ABL) height and relative humidity are used to make vertical and humidity corrections on AOT. Results after correction show higher correlations (R2 = 0.55) between extinction coefficient and PM10. However, coarse spatial resolution of meteorological data affects the smoothness of retrieved maps, which suggests high-resolution and accurate meteorological data are critical to increase retrieval accuracy of PM. Finally, the model provides the spatial distribution maps of instantaneous and yearly average PM10 over the PRD. It is proved that observed PM10 is more relevant to yearly mean AOT than instantaneous values.

Evaluation of sampling inhalable PM10 particulate matter (≤ 10 μm) using co-located high volume samplers

This paper presents the results of the determination of the concentrations of atmospheric particulate matter ≤ 10 μm (PM10), collected simultaneously by six PM10 high volume samplers from two different manufacturers installed in the same location. Fifteen samples of 24 h were obtained with each equipment at a selected urban area of Rio de Janeiro city. The concentration of PM10 ranged between 10.73 and 54.04 μg m−3. The samplers were considered comparable to each other, as the adopted methodology presented good repeatability.

Impacts of anthropogenic emissions and cold air pools on urban to montane gradients of snowpack ion concentrations in the Wasatch Mountains, Utah

Urban montane valleys are often characterized by periodic wintertime temperature inversions (cold air pools) that increase atmospheric particulate matter concentrations, potentially stimulating the deposition of major ions to these snow-covered ecosystems. We assessed spatial and temporal patterns of ion concentrations in snow across urban to montane gradients in Salt Lake City, Utah, USA, and the adjacent Wasatch Mountains during January 2011, a period of several persistent cold air pools. Ion concentrations in fresh snow samples were greatest in urban sites, and were lower by factors of 4–130 in a remote high-elevation montane site. Adjacent undeveloped canyons experienced significant incursions of particulate-rich urban air during stable atmospheric conditions, where snow ion concentrations were lower but not significantly different from urban sites. Surface snow ion concentrations on elevation transects in and adjacent to Salt Lake City varied with temporal and spatial trends in aerosol concentrations, increasing following exposure to particulate-rich air as cold air pools developed, and peaking at intermediate elevations (1500–1600 m above sea level, or 200–300 m above the valley floor). Elevation trends in ion concentrations, especially NH4+ and NO3−, corresponded with patterns of aerosol exposure inferred from laser ceilometer data, suggesting that high particulate matter concentrations stimulated fog or dry ion deposition to snow-covered surfaces at the top of the cold air pools. Fog/dry deposition inputs were similar to wet deposition at mid-elevation montane sites, but appeared negligible at lower and higher-elevation sites. Overall, snow ion concentrations in our urban and adjacent montane sites exceeded many values reported from urban precipitation in North America, and greatly exceeded those reported for remote snowpacks. Sodium, Cl−, NH4+, and NO3− concentrations in fresh snow were high relative to previously measured urban precipitation, with means of 120, 117, 42, and 39 μeq l−1, respectively. After exposure to atmospheric particulate matter during cold pool events, surface snow concentrations peaked at 2500, 3600, 93, and 90 μeq l−1 for these ions. Median nitrogen (N) deposition in fresh urban snow samples measured 0.8 kg N ha−1 during January 2011, with similar fog/dry deposition inputs at mid-elevation montane sites. Wintertime anthropogenic air pollution represents a significant source of ions to snow-covered ecosystems proximate to urban montane areas, with important implications for ecosystem function.

California's ammonia emissions have been drastically underestimated

In California, Los Angeles and the Central Valley often have atmospheric concentrations of particulate matter that exceed the U.S. Environmental Protection Agency's health guidelines. In the air, chemical reactions between ammonia, nitrogen oxides, and sulfur oxides can create inorganic aerosols like ammonium nitrate and ammonium sulfate. With their small particle sizes, these compounds can be dangerous to breathe, particularly for those with respiratory problems.

Concentrations and source apportionment of particulate matter in different functional areas of Shanghai, China

Concentrations of atmospheric particulate matter with different sizes and 9 metallic elements (Al, Ca, Mg, Fe, Cu, Mn, Ni, Pb and Zn) were measured in two sampling sites of Baoshan District and Putuo District from July 2009 to September 2010, to investigate the size distribution and the possible sources of particulate matter. The results showed that in these two sampling sites, crustal elements mainly distributed in coarse mode and heavy metals all distributed in fine mode. Source apportionment results by enrichment factor and principal component analysis indicated that in Baoshan sampling site, PM0.43–2.1 was mainly from industrial metallurgical processes, while PM2.1–10 was mainly from re-suspended soil dust. Local road traffic source was the dominant contributor to PM0.43–2.1 and PM2.1–10 in Putuo sampling site.

Independent and combined interaction of fine particulate matter in atmospheric air and the frequency of acute myocardial infarction hospitalizations in Varna, Bulgaria

Abstract

Monitoring of Atmospheric Particles in Beijing and Dunhuang Using a Raman Lidar with Enhanced Dynamics

In high urbanized areas, the atmospheric particulate matter concentration (the so called PM) can exceeds the healthy limit values. Human activities, such as the burning of fossil fuels, industrial activities, and ground transport contribute to measured PM exceedance. Natural contribution is originated mainly from dust storms and volcanic eruptions. The Gobi desert, for instance, is the major source of mineral dust in China, that is one of the most interesting regions for aerosol study being surrounded by the main sources of anthropogenic and natural aerosol. On the base of the above considerations, the need of a new advanced scanning lidar system raised in order to better understand the formation, emission and diffusion of particulate from natural and anthropic sources and to evaluate their relative contribution, to characterize the chemical and physical properties of atmospheric aerosols, their spatial and temporal distribution and the main transport mechanisms. To this aim, a new, versatile and portable Raman scanning lidar system has been designed and developed in the frame of the AMPLE (Aerosol Multi-wavelength Polarization Lidar Experiment) project, the first action of the recently founded China-Italy Laser Remote Sensing Joint Research Center between the National Consortium of Italian Universities for the Physical Science of the Matter (CNISM) and the Beijing Research Institute for Telemetry (BRIT). The AMPLE lidar device has been installed at the Beijing Research Institute for Telemetry in the Beijing city area, which is strongly affected from anthropogenic pollution and sand dust from Gobi desert in order to carry out 4-D (space and time) imaging of the atmospheric aerosol distributions, their optical properties, and microphysical characterization. A first demonstrative measurement campaign has been performed on May 2013 in Beijing, while on August 2013 AMPLE has been carried in Dunhuang close to the Gobi desert and far away from the urban area, in order to study sand dust directly at source. Results of those measurements are described in this paper.

Seasonal variations in the concentration and solubility of elements in atmospheric particulate matter: a case study in Northern Italy

Atmospheric particulate matter is characterized by a variety of chemical components, generally produced by different sources. Chemical fractionation of elements, namely the determination of their extractable and residual fractions, may reliably increase the selectivity of some elements as tracers of specific PM sources. Seasonal variations of atmospheric particulate matter concentration in PM10 and PM2.5, of elemental concentration in PM10 and PM2.5, of the extractable and residual fraction of elements in different size fractions in the range 0.18 - 18 ∝m are reported in this paper. The effect of the ageing of the air masses is discussed.

Analysis of mass concentration of atmospheric particulate matter in a sandstorm course and its affecting factors in the Taklimakan Desert

Analysis of mass concentration of atmospheric particulate matter in a sandstorm course and its affecting factors in the Taklimakan Desert

Assessment of occupational and ambient air quality of traffic police personnel of the Kathmandu valley, Nepal; in view of atmospheric particulate matter concentrations (PM10)

This paper presents the analysis and interpretation of occupational and ambient particulate matter concentrations measured as PM10 at a network of ten high density road traffic intersections in Kathmandu valley during the period of February 2008 to January 2009. The purpose was to understand the pollution trends associated with the high density road traffic intersections considering the levels of particulate matter concentrations (PM10), representing the occupational and ambient air quality of the traffic police personnel of the Kathmandu valley, Nepal. The study indicates that the occupational PM10 play a significant dominant role in controlling ambient PM10 loads at the high density road traffic intersections. The occupational and ambient PM10 concentrations in high density traffic area and road intersection of Kathmandu Valley showed a marked monthly and seasonal variation. High density traffic areas and road intersection of the Kathmandu valley were seriously polluted by PM10. Monthly and yearly average occupational and ambient PM10 concentration at the high density traffic areas and road intersection greatly exceeded the 24–h average limit value (120μg m−3) in Nepal.

Distribution and seasonal variability of trace elements in atmospheric particulate in the Venice Lagoon

Size distribution and selected element concentrations of atmospheric particulate matter (PM) were investigated in the Venice Lagoon, at three sites characterised by different anthropogenic influence. The PM 10 samples were collected in six size fractions (10–7.2, 7.2–3.0, 3.0–1.5, 1.5–0.95; 0.95–0.49 and <0.49 μm) with high volume cascade impactors, and the concentration of 17 elements (Al, As, Ca, Cd, Co, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Sr, V, Zn) was determined by inductively coupled plasma quadrupole mass spectroscopy. More than 1 year of sampling activities allowed the examination of seasonal variability in size distribution of atmospheric particulates and element contents for each site. At all the stations, particles with an aerodynamic diameter <3 μm were predominant, thus accounting for more than 78% of the total aerosol mass concentration. The highest PM 10 concentrations for almost all elements were found at the site which is more influenced by industrial and urban emissions. Similarity in size distribution of elements at all sites allowed the identification of three main behavioural types: (a) elements found mainly within coarse particles (Ca, Mg, Na, Sr); (b) elements found mainly within fine particles (As, Cd, Ni, Pb, V) and (c) elements with several modes spread throughout the entire size range (Co, Cu, Fe, K, Zn, Mn). Factor Analysis was performed on aerosol data separately identified as fine and coarse types in order to examine the relationships between the inorganic elements and to identify their origin. Multivariate statistical analysis and assessment of similarity in the size distribution led to similar conclusions on the sources.

Atmospheric dry deposition of trace elements at a site on Asian-continent side of Japan

The sources of dry-deposited trace elements (As, Cd, Cr, Cu, Mn, Ni, Pb, Sb and V) and the factors controlling their dry deposition fluxes were investigated on the basis of two-year observations (April 2004–March 2006) at a site on the Asian-continent side of Japan, which has been strongly affected by air pollutants from the Asian continent. Dry deposition sampling was conducted using a water surface sampler connected to a wet-only precipitation sampler. The dry deposition of As, Cd, Pb and Sb showed a small contribution to atmospheric deposition (0.25–0.44 as ratios of annual dry/wet deposition fluxes). Moreover, the dry deposition fluxes of those elements increased negligibly during the period when their atmospheric particulate matter (PM) concentrations increased owing to transport from the Asian continent. Thus, the dry deposition of As, Cd, Pb and Sb from the Asian continent was not significant, because their overall dry deposition velocities are relatively low (mostly <1 cm s−1). Conversely, the annual dry deposition fluxes of Cr, Cu and Ni exceeded their annual wet deposition fluxes (2.5–12.4 as ratios of annual dry/wet deposition fluxes). Those overall dry deposition velocities were much higher (3.2–9.7 cm s−1), and the crustal enrichment factors (EFs) frequently exceeded ten. These results suggest that the dry deposition of Cr, Cu and Ni is dominated by considerably coarse particles from local anthropogenic sources. For Mn and V, the dry and wet depositions contributed almost equally to the annual deposition fluxes. Their monthly dry deposition fluxes correlated significantly with that of Al (P < 0.001), and the EFs were close to unity, suggesting a large contribution of background soil to their dry deposition. The dry deposition fluxes of all the trace elements were dependent not on their atmospheric PM concentrations but on their overall dry deposition velocities. The particle size distributions of the elements in the atmosphere are likely the most important factor controlling their dry deposition fluxes on the Asian-continent side of Japan and, consequently, the relative contribution of the dry/wet deposition fluxes.

Examination of discrepancies between beta-attenuation and gravimetric methods for the monitoring of particulate matter

Continuous monitoring of the concentration of atmospheric particulate matter was carried out for 7 years by both gravimetric method and β-ray attenuation method (BAM) from a building rooftop in the Tokyo metropolitan area. The two methods showed a different tendency in each season: the data observed by BAM were higher than those by the gravimetric method in summer, and this difference was reversed in winter. The volatilization of ammonium salts accounted for only 30% of the difference between the monitoring methods in summer. Thus, we considered the differences in the water content measured by each method. The concentration difference between methods increased when relative humidity exceeded the deliquescence point of ammonium sulfate in summer, and the water content was estimated to be 30%. However, differences in relative humidity did not explain why the data obtained by the gravimetric method exceeded BAM data by 20–30% in winter. We found that the gravimetric measurements generally exceeded BAM measurements in winter if the ambient absolute humidity during particle collection was higher than the absolute humidity during sample weighing. The water content of atmospheric aerosols greatly influences their mass concentrations. Care must be taken when using mass concentration data for purposes such as evaluating health effects.

A summer time series of particulate carbon in the air and snow at Summit, Greenland

Carbonaceous particulate matter is ubiquitous in the lower atmosphere, produced by natural and anthropogenic sources and transported to distant regions, including the pristine and climate‐sensitive Greenland Ice Sheet. During the summer of 2006, ambient particulate carbonaceous compounds were characterized on the Greenland Ice Sheet, including the measurement of particulate organic (OC) and elemental (EC) carbon, particulate water‐soluble organic carbon (WSOC), particulate absorption coefficient (σap), and particle size‐resolved number concentration (PM0.1–1.0). Additionally, parallel ∼50‐day time series of water‐soluble organic carbon (WSOC), water‐insoluble organic carbon (WIOC), and elemental carbon (EC) were quantified at time increments of 4–24 h in the surface snow. Measurement of atmospheric particulate carbon found WSOC (average of 52 ng m−3) to constitute a major fraction of particulate OC (average of 56 ng m−3), suggesting that atmospheric organic compounds reaching the Greenland Ice Sheet in summer are highly oxidized. Atmospheric EC (average of 7 ng m−3) was well‐correlated with σap (r = 0.95) and the calculated mass‐absorption cross‐section (average of 24 m2 g−1) appears to be similar to that measured using identical techniques in an urban environment in the United States. Comparing surface snow to atmospheric particulate matter concentrations, it appears the snow has a much higher OC (WSOC+WIOC) to EC ratio (205:1) than air (10:1), suggesting that snow is additionally influenced by water‐soluble gas‐phase compounds. Finally, the higher‐frequency (every 4–6 h) sampling of snow‐phase WSOC revealed significant loss (40–54%) of related organic compounds in surface snow within 8 h of wet deposition.

Magnetic properties of atmospheric particulate matter from automatic air sampler stations in Latium (Italy): Toward a definition of magnetic fingerprints for natural and anthropogenic PM10 sources

Environmental problems linked to the concentration of atmospheric particulate matter with dimensions less than 10 μm (PM10) in urban settings have stimulated a variety of scientific researches. This study reports a systematic analysis of the magnetic properties of PM10 samples collected by six automatic stations installed for air quality monitoring through the Latium Region (Italy). We measured the low‐field magnetic susceptibility of daily air filters collected during the period July 2004 to July 2005. For each station, we derived an empirical linear correlation linking magnetic susceptibility to the concentration of PM10 produced by local sources (i.e., in absence of significant inputs of exogenous dust). An experimental approach is suggested for estimating the percentage of nonmagnetic PM10 transported from natural far‐sided sources (i.e., dust from North Africa and marine aerosols). Moreover, we carried out a variety of additional magnetic measurements to investigate the magnetic mineralogy of selected air filters spanning representative periods. The results indicate that the magnetic fraction of PM10 is composed by a mixture of low‐coercivity, magnetite‐like, ferrimagnetic particles with a wide spectrum of grain sizes, related to a variety of natural and anthropogenic sources. The natural component of PM10 has a characteristic magnetic signature that is indistinguishable from that of eolian dust. The anthropogenic PM10 fraction is mostly originated from circulating vehicles and is a mixture of prevailing fine superparamagnetic particles and subordinate large multidomain grains; the former are more directly related to exhaust, whereas the latter may be associated to abrasion of metallic parts.

Attribution of modeled atmospheric sulfate and SO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; in the Northern Hemisphere for June–July 1997

Abstract. Anthropogenic sulfate aerosol is a major contributor to shortwave radiative forcing of climate change by direct light scattering and by perturbing cloud properties and to local concentrations of atmospheric particulate matter. Here we analyze results from previously published calculations with an Eulerian transport model for atmospheric sulfur species in the Northern Hemisphere in June–July, 1997 to quantify the absolute and relative contributions of specific source regions (North America, Europe, and Asia) and SO2-to-sulfate conversion mechanisms (gas-phase, aqueous-phase and primary sulfate) to sulfate and SO2 column burdens as a function of location and time. Although material emitted within a given region dominates the sulfate and SO2 column burden in that region, examination of time series at specific locations shows that material imported from outside can make a substantial and occasionally dominant contribution. Frequently the major fraction of these exogenous contributions to the sulfate column burden was present aloft, thus minimally impacting air quality at the surface, but contributing substantially to the burden and, by implication, to radiative forcing and diminution of surface irradiance. Although the dominant sulfate formation pathway in the domain as a whole is aqueous-phase reaction in clouds (62%), in regions with minimum opportunity for aqueous-phase reaction gas-phase oxidation is dominant, albeit with considerable temporal variability depending on meteorological conditions. These calculations highlight the importance of transoceanic transport of sulfate, especially at the western margins of continents under the influence of predominantly westerly transport winds.

Ambient air quality of Kathmandu valley as reflected by atmospheric particulate matter concentrations (PM10)

This paper presents the analysis and interpretation of ambient particulate matter concentrations measured as PM10 at a network of six air monitoring stations in Kathmandu valley during the years, 2003 through 2005. The purpose was to understand the pollution trends associated with different areas considering levels particulate matter concentrations representing the ambient air quality of Kathmandu valley. The study indicate that particulate concentrations (PM10) measured are persistently higher at air sampling sites representing roadside areas compared to the background sites. The inter-station network variability with respect the particulate pollution suggests optimizing resources. The comparison of annual average PM10 concentration observed at six air-monitoring sites in Kathmandu Valley with standard annual average concentration prescribed by World Health Organization as well as Europe Union indicates serious PM10 pollution in Kathmandu valley.

Particulate size distributions and mass measured at a motorway during the BAB II campaign

Abstract From 1 May to 25 May 2001, the BAB II campaign was carried out at the motorway BAB (656) near Heidelberg. Atmospheric concentrations of particulate matter and gases were measured together with the meteorological conditions. This paper is focused on the particulate matter measured upwind and downwind from the motorway at ground level. In order to determine the source contribution from the motorway traffic, it was necessary to measure upwind and downwind simultaneously due to variations in background concentrations. The particle number contribution from the motorway was found to be 35,000 particles cm−3 for particles with diameters close to 20 nm and 5000 particles cm−3 for particles with diameters close to 70 nm. Bimodal size distributions were observed on the downwind side, whereas the upwind side showed unimodal size distributions. For particulate mass, it can be estimated that the contribution from the motorway to the PM1 concentrations is in a range 0.6–1.3 μg m−3 for the chosen measurement sites approximately 60 m from the road at a height of 6 m. The soot measurements showed diurnal variation; however, the upwind downwind difference was not measured. Correlation factors showed good correlation between total particle number and number of particles with diameters below 80 nm, CO and NO. There was no correlation between particle number and PM10, which is due to the observation that particle number was dominated by the 20 nm particles.

Smoke-haze from the 1997 Indonesian forest fires: effects on pollution levels, local climate, atmospheric CO 2 concentrations, and tree photosynthesis

Atmospheric composition, local climate and sapling gas exchange were monitored to assess the short-term effects of smoke-haze from the 1997 Indonesian forest fires. Atmospheric concentrations of particulate matter, SO 2, CO, CH 4 and CO 2, and relative humidity were elevated, and photosynthetically active radiation and ambient temperature were reduced by the smoke-haze. Despite elevated CO 2 levels, photosynthesis in three tree species was reduced by the smoke-haze, both indirectly through reduced PAR levels, and directly through elevated aerosol and atmospheric pollutant levels.