Temporal variations of atmospheric aerosol in four European urban areas

Purpose

The concentrations of PM₁₀ mass, PM_2.5 mass and particle number were continuously measured for 18 months in urban background locations across Europe to determine the spatial and temporal variability of particulate matter.

Methods

Daily PM₁₀ and PM_2.5 samples were continuously collected from October 2002 to April 2004 in background areas in Helsinki, Athens, Amsterdam and Birmingham. Particle mass was determined using analytical microbalances with precision of 1 ??g. Pre- and post-reflectance measurements were taken using smoke-stain reflectometers. One-minute measurements of particle number were obtained using condensation particle counters.

Results

The 18-month mean PM₁₀ and PM_2.5 mass concentrations ranged from 15.4 ??g/m³ in Helsinki to 56.7 ??g/m³ in Athens and from 9.0 ??g/m³ in Helsinki to 25.0 ??g/m³ in Athens, respectively. Particle number concentrations ranged from 10,091 part/cm³ in Helsinki to 24,180 part/cm³ in Athens with highest levels being measured in winter. Fine particles accounted for more than 60% of PM₁₀ with the exception of Athens where PM_2.5 comprised 43% of PM₁₀. Higher PM mass and number concentrations were measured in winter as compared to summer in all urban areas at a significance level p?Conclusions Significant quantitative and qualitative differences for particle mass across the four urban areas in Europe were observed. These were due to strong local and regional characteristics of particulate pollution sources which contribute to the heterogeneity of health responses. In addition, these findings also bear on the ability of different countries to comply with existing directives and the effectiveness of mitigation policies.     

Development and Evaluation of an Impactor for a PM2.5 Speciation Sampler

ABSTRACT

A conventional impactor for a particle speciation sampler was developed and validated through laboratory and field tests. The speciation sampler consists of the following components: a PM_2.5 conventional impactor that removes particles larger than 2.5 μm, an all-glass, coated honeycomb diffusion denuder, and a 47-mm filter pack. The speciation sampler can operate at two different sampling rates: 10 and 16.7 L/min. An experimental characterization of the impactor’s performance was conducted. The impactor’s collection efficiency was examined as a function of critical design parameters such as Reynolds number, the distance from the nozzle exit to the impac-tion plate, and the impaction substrate coating method. The bounce of particles larger than the cut point was successfully minimized by using a greased surface as the im-paction substrate. Additionally, a series of field intercomparison experiments were conducted at both 10 and 16.7 L/min airflow. PM_2.5 mass and SO₄ ^2- concentrations were measured and compared with the Federal Reference Method (FRM) and found to be in good agreement. Results of the laboratory chamber tests also indicated that the impactor’s performance was in good agreement with the FRM.     

Chemical characterization of emissions from vegetable oil processing and their contribution to aerosol mass using the organic molecular markers approach

The organic fraction of aerosol emitted from a vegetable oil processing plant was studied to investigate the contribution of emissions to ambient particles in the surrounding area. Solvent-soluble particulate organic compounds emitted from the plant accounted for 10% of total suspended particles. This percentage was lower in the receptor sites (less than 6% of total aerosol mass). Nonpolar, moderate polar, polar, and acidic compounds were detected in both emitted and ambient aerosol samples. The processing and combustion of olive pits yielded a source with strong biogenic characteristics, such as the high values of the carbon preference index (CPI) for all compound classes. Polycyclic aromatic hydrocarbons (PAHs) detected in emissions were associated with both olive pits and diesel combustion. The chromatographic profile of dimethylphenanthrenes (DMPs) was characteristic of olive pit combustion. Organic aerosols collected in two receptor sites provided a different pattern. The significant contribution of vehicular emissions was identified by CPI values (approximately 1) of n-alkanes and the presence of the unresolved complex mixture (UCM). In addition, PAH concentration diagnostic ratios indicated that emissions from catalyst and noncatalyst automobiles and heavy trucks were significant. The strong even-to-odd predominance of n-alkanols, n-alkanoic acids, and their salts indicated the contribution of a source with biogenic characteristics. However, the profile of DMPs at receptor sites was similar to that observed for diesel particulates. These differences indicated that the contribution of vegetable oil processing emissions to the atmosphere was negligible.     

Vitrification of lead-rich solid ashes from incineration of hazardous industrial wastes

Lead-rich solid industrial wastes were vitrified by the addition of glass formers in various concentrations, to produce non-toxic vitreous stabilized products that can be freely disposed or used as construction materials. Toxicity of both the as-received industrial solid waste and the stabilized products was determined using standard leaching test procedures. The chemically stable vitreous products were subjected to thermal annealing in order to investigate the extent of crystal separation that could occur during cooling of large pieces of glass. Leaching tests were repeated to investigate the relation between annealing process and chemical stability. X-ray, scanning and transmission electron microscopy techniques were employed to identify the microstructure of stabilized products before and after thermal treatment. Relation between synthesis and processing, chemical stability and microstructure was investigated.     

Dependence of home outdoor particulate mass and number concentrations on residential and traffic features in urban areas

The associations between residential outdoor and ambient particle mass, fine particle absorbance, particle number (PN) concentrations, and residential and traffic determinants were investigated in four European urban areas (Helsinki, Athens, Amsterdam, and Birmingham). A total of 152 nonsmoking participants with respiratory diseases, not exposed to occupational pollution, were included in the study, which comprised a 7-day intensive exposure monitoring period of both indoor and home outdoor particle mass and number concentrations. The same pollutants were also continuously measured at ambient fixed sites centrally located to the studied areas (fixed ambient sites). Relationships between concentrations measured directly outside the homes (residential outdoor) and at the fixed ambient sites were pollutant-specific, with substantial variations among the urban areas. Differences were more pronounced for coarse particles due to resuspension of road dust and PN, which is strongly related to traffic emissions. Less significant outdoor-to-fixed variation for particle mass was observed for Amsterdam and Birmingham, predominantly due to regional secondary aerosol. On the contrary, a strong spatial variation was observed for Athens and to a lesser extent for Helsinki. This was attributed to the overwhelming and time-varied inputs from traffic and other local sources. The location of the residence and traffic volume and distance to street and traffic light were important determinants of residential outdoor particle concentrations. On average, particle mass levels in suburban areas were less than 30% of those measured for residences located in the city center. Residences located less than 10 m from a street experienced 133% higher PN concentrations than residences located further away. Overall, the findings of this multi-city study, indicated that (1) spatial variation was larger for PN than for fine particulate matter (PM) mass and varied between the cities, (2) vehicular emissions in the residential street and location in the center of the city were significant predictors of spatial variation, and (3) the impact of traffic and location in the city was much larger for PN than for fine particle mass.     

Chemical Characterization of Emissions from Vegetable Oil Processing and Their Contribution to Aerosol Mass Using the Organic Molecular Markers Approach

ABSTRACT

The organic fraction of aerosol emitted from a vegetable oil processing plant was studied to investigate the contribution of emissions to ambient particles in the surrounding area. Solvent-soluble particulate organic compounds emitted from the plant accounted for 10% of total suspended particles. This percentage was lower in the receptor sites (less than 6% of total aerosol mass). Nonpolar, moderate polar, polar, and acidic compounds were detected in both emitted and ambient aerosol samples. The processing and combustion of olive pits yielded a source with strong biogenic characteristics, such as the high values of the carbon preference index (CPI) for all compound classes. Polycyclic aromatic hydrocarbons (PAHs) detected in emissions were associated with both olive pits and diesel combustion. The chromatographic profile of dimethyl-phenanthrenes (DMPs) was characteristic of olive pit combustion. Organic aerosols collected in two receptor sites provided a different pattern.

The significant contribution of vehicular emissions was identified by CPI values (~1) of n-alkanes and the presence of the unresolved complex mixture (UCM). In addition, PAH concentration diagnostic ratios indicated that emissions from catalyst and noncatalyst automobiles and heavy trucks were significant. The strong even-to-odd predominance of n-alkanols, n-alkanoic acids, and their salts indicated the contribution of a source with biogenic characteristics. However, the profile of DMPs at receptor sites was similar to that observed for diesel particulates. These differences indicated that the contribution of vegetable oil processing emissions to the atmosphere was negligible.     

Measurement of particulate aliphatic and polynuclear aromatic hydrocarbons in Santiago de Chile: source reconciliation and evaluation of sampling artifacts

Using a novel sampler, particulate organic compounds were collected in Santiago de Chile from June 9 to August 10, 1997. This sampler consists of a diffusion denuder to remove gas-phase organics prior to particle collection, a Teflon filter, and a PUF cartridge downstream of the filter. PAHs and n-alkanes were measured using gas chromatography/mass spectrometry analysis. Volatilization of particles collected on the Teflon filter varied from 15 to 85% for both n-alkanes and PAHs, with strong dependence on molecular weight. The relative distribution of n-alkanes and the values of molecular diagnostic ratios, such as Carbon preference index, indicated a mixed origin with strong anthropogenic input. Indeed, CPI values ranged from 0.66 to 1.96 (for the whole range of n-alkanes). The percent contribution of leaf “wax” n-alkanes (4.55–20.83%) indicated the low contribution of biogenic sources. In addition, the distribution pattern of PAHs was characteristic of anthropogenic emissions. The dominant contribution of combustion-related PAHs (CPAHs), 74–84%, indicated that vehicular emissions was the major source of PAHs.     

Source apportionment of PM10 and PM2.5 in five Chilean cities using factor analysis

Chile is a fast-growing country with important industrial activities near urban areas. In this study, the mass and elemental concentrations of PM10 and PM2.5 were measured in five major Chilean urban areas. Samples of particles with diameter less than 10 microm (PM10) and 2.5 microm (PM2.5) were collected in 1998 in Iquique (northern Chile), Valparaiso, Vi?a del Mar, Rancagua (central Chile), and Temuco (southern Chile). Both PM10 and PM2.5 annual mean concentrations (PM10: 56.9-77.6 microg/m3; PM2.5: 22.4-42.6 microg/m3) were significantly higher than the corresponding European Union (EU) and U.S. Environmental Protection Agency (EPA) air quality standards. Moreover, the 24-hr PM10 and PM2.5 U.S. standards were exceeded infrequently for some of the cities (Rancagua and Valparaiso). Elements ranging from Mg to Pb were detected in the aerosol samples using X-ray fluorescence (XRF). For each of the five cities, factor analysis (FA) was applied to identify and quantify the sources of PM10 and PM2.5. The agreement between calculated and measured mass and elemental concentrations was excellent in most of the cities. Both natural and anthropogenic sources were resolved for all five cities. Soil and sea were the most important contributors to coarse particles (PM10-PM2.5), whereas their contributions to PM2.5 were negligible. Emissions from Cu smelters and oil refineries (and/or diesel combustion) were identified as important sources of PM2.5, particularly in the industrial cities of Rancagua, Valparaiso, and Vi?a del Mar. Finally, motor vehicles and wood burning were significant sources of both PM2.5 and PM10 in most of the cities (wood burning was not identified in Iquique).     

Development and evaluation of an impactor for a PM2.5 speciation sampler

A conventional impactor for a particle speciation sampler was developed and validated through laboratory and field tests. The speciation sampler consists of the following components: a PM2.5 conventional impactor that removes particles larger than 2.5 microns, an all-glass, coated honeycomb diffusion denuder, and a 47-mm filter pack. The speciation sampler can operate at two different sampling rates: 10 and 16.7 L/min. An experimental characterization of the impactor's performance was conducted. The impactor's collection efficiency was examined as a function of critical design parameters such as Reynolds number, the distance from the nozzle exit to the impaction plate, and the impaction substrate coating method. The bounce of particles larger than the cut point was successfully minimized by using a greased surface as the impaction substrate. Additionally, a series of field intercomparison experiments were conducted at both 10 and 16.7 L/min airflow. PM2.5 mass and SO4(2-) concentrations were measured and compared with the Federal Reference Method (FRM) and found to be in good agreement. Results of the laboratory chamber tests also indicated that the impactor's performance was in good agreement with the FRM.     

Source Apportionment of PM10 and PM25 in Five Chilean Cities Using Factor Analysis

ABSTRACT

Chile is a fast-growing country with important industrial activities near urban areas. In this study, the mass and elemental concentrations of PM₁₀ and PM_2.5 were measured in five major Chilean urban areas. Samples of particles with diameter less than 10 um (PM₁₀) and 2.5 um (PM_2.5) were collected in 1998 in Iquique (northern Chile), Valparaiso, Vina del Mar, Rancagua (central Chile), and Temuco (southern Chile). Both PM₁₀ and PM₂₅ annual mean concentrations (PM₁₀: 56.9-77.6 u,g/m³; PM₂₅: 22.4-42.6 u.g/m³) were significantly higher than the corresponding European Union (EU) and U.S. Environmental Protection Agency (EPA) air quality standards. Moreover, the 24-hr PM₁₀ and PM₂₅ U.S. standards were exceeded infrequently for some of the cities (Rancagua and Valparaiso).