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J Ruuskanen, Th Tuch,
H Ten Brink,
A Peters,
A Khlystov,
A Mirme,
G P A Kos,
B Brunekreef,
H E Wichmann,
G Buzorius,
M Vallius,
W G Kreyling,
J Pekkanen
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ABSTRACT: Total number concentrations, number concentrations of ultra"ne (0.01}0.1 m) and accumulation (0.1}0.5 m) particles, as well as mass concentration of PM particles and blackness of PM "lters, which is related to Black Smoke were simultaneously monitored in three European cities during the winter period for three and a half months. The purpose of the study was to describe the di!erences in concentration levels and daily and diurnal variations in particle number and mass concentrations between European cities. The results show statistically signi"cant di!erences in the concentrations of PM and the blackness of the PM "lters between the cities, but not in the concentrations of ultra"ne particles. Daily PM levels were found to be poorly correlated with the daily total and ultra"ne number concentrations but better correlated with the number concentration of accumulation particles. According to the principal component analysis airborne particulate pollutants seem to be divided into two major source categories, one identi"ed with particle number concentrations and the other related to mass-based information. The present results underline the importance of using both particle number and mass concentrations to evaluate urban air quality. The study was done within the framework of thèExposure and risk assessment for "ne and ultra"ne particles in ambient aira (ULTRA)-project. The project was funded by the EU EN-VIRONMENT Programme Contract ENV4-CT95-0205. The project was co-ordinated by the Unit of Environmental Epi-demiology, National Public Health Institute, PO BOX 95, 70701 Kuopio, Finland.." (J. Ruuskanen).
Atmospheric Environment 07/2001; · 3.46 Impact Factor
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J Ruuskanen, Th Tuch,
H Ten Brink,
A Peters,
A Khlystov,
A Mirme,
G.P.A Kos,
B Brunekreef,
H.E Wichmann,
G Buzorius,
M Vallius,
W.G Kreyling,
J Pekkanen
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ABSTRACT: Total number concentrations, number concentrations of ultrafine (0.01–0.1 μm) and accumulation (0.1–0.5 μm) particles, as well as mass concentration of PM2.5 particles and blackness of PM2.5 filters, which is related to Black Smoke were simultaneously monitored in three European cities during the winter period for three and a half months. The purpose of the study was to describe the differences in concentration levels and daily and diurnal variations in particle number and mass concentrations between European cities. The results show statistically significant differences in the concentrations of PM2.5 and the blackness of the PM2.5 filters between the cities, but not in the concentrations of ultrafine particles. Daily PM2.5 levels were found to be poorly correlated with the daily total and ultrafine number concentrations but better correlated with the number concentration of accumulation particles. According to the principal component analysis airborne particulate pollutants seem to be divided into two major source categories, one identified with particle number concentrations and the other related to mass-based information. The present results underline the importance of using both particle number and mass concentrations to evaluate urban air quality.
Atmospheric Environment 07/2001; · 3.46 Impact Factor
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ABSTRACT: The comparability was tested of three aerosoìspectrometersa, used in a program for monitoring the spectra of "ne and ultra"ne particles in three European cities. Droplets of sebacate, solid ammonium sulfate and agglomerates of elemental carbon were used in the tests, representing the major chemical and structural types of particles encountered in urban aerosol. Particles in the ultra"ne range (10}100 nm) are sized by electrical mobility (SMPS, DMPS and EAS) and thèspectrometersa gave very similar size distributions for these aerosols. The integrated number concentrations were on average within 20% of the directly measured total number concentrations. Particles with a size between 0.1 and 2.5 m, in which most of the volume/mass is concentrated, are being di!erently classi"ed in the threèspectrometersa, respectively, with a low-and a high-#ow LAS-X, and "eld charging in the EAS. The agreement between the three instruments in this size range was less good, which was partly caused by signal overload in the high-#ow optical sizer, which was solved using a larger threshold. A complication occurred with the elemental carbon, which was composed of highly agglom-erated entities. Particles, sized by the mobility instrumentation as being in the range of 100}400 nm, were not detected by the optical sizers. Volume (spectra) for ammonium sulfate deduced from the number spectra were compared with the mass (spectra) obtained with cascade impactors. The comparison was good for the LAS-Xs; the EAS overestimated volume/mass.
Atmospheric Environment 04/2001; · 3.46 Impact Factor
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ABSTRACT: Eight Beagle dogs were exposed to a sodium bisulphite aerosol at a concentration of 1 mg m−3 for a period of 290 days. This paper summarizes the design, the facilities and the exposure conditions of the exposure experiment.
Journal of Aerosol Science 01/1990; 21, Supplement 1:S471-S474. · 2.45 Impact Factor
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Journal of Aerosol Science 01/1989; 20(8):1277-1280. · 2.45 Impact Factor
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Journal of Aerosol Science 01/1988; 19(7):971-973. · 2.45 Impact Factor
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ABSTRACT: There is an ongoing debate on the question which size fraction of particles in ambient air may be responsible for human health effects observed in epidemiological studies. Since there is no single instrument available for the measurement of the particle-size distribution over the full range of the fine fraction (diameter <2.5 μm) of the atmospheric aerosol, two instruments, the mobile aerosol spectrometer (MAS) and the electrical aerosol spectrometer (EAS), have been tested in a side-by-side comparison measuring ambient aerosol for a time period of six weeks in spring 1996 in the city of Erfurt, Germany. Furthermore, total particle number concentration measured by a condensation particle counter (CPC) and mass concentrations PM10 and PM2.5 were determined. Both spectrometers, MAS and EAS, are based on electrical mobility measurements for particles <0.1 μm and <0.5 μm, respectively, while MAS applies optical particle spectrometry and EAS applies again electrical mobility analysis for particles up to 2.5 and 10 μm, respectively. Both instruments proved to be reliable during this comparison providing data availability of >94%. To compare the spectral data, particle numbers were integrated within three size ranges: 0.01 – 0.1, 0.1 – 0.5, 0.5 – 2.5 μm. Hourly mean number concentrations of each size range observed during the six week comparison was: 2.6×104±19500 (2.48×104±1.79×104), 3.1×103±1.5×103 (4.1×103±2.0×103), 50±45 (1.9×102±1.2×102) cm−3 for MAS (EAS), respectively. Both aerosol spectrometers followed the variations of the ambient aerosol in a similar manner and yielded almost identical results for particle number concentrations of particles with diameters smaller than 0.5 μm. Furthermore, the total particle number concentration derived from MAS and EAS measurements (29000±20000; 29000±19000 cm−3) is well comparable with the number concentration derived from an integral counting CPC (31100±22000 cm−3). The results of this side-by-side comparison suggest that MAS and EAS together with PM2.5 measurements are suitable to reliably characterize size-distribution parameters of number and mass concentration of ambient aerosols.
Atmospheric Environment.
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ABSTRACT: There is an ongoing debate on the question which size fraction of particles in ambient air may be responsible for short-term responses of the respiratory system as observed in several epidemiological studies. However, the available data on ambient particle concentrations in various size ranges are not sufficient to answer this question.Therefore, on 180 days during the winter 1991/92 daily mean size distributions of ambient particles were determined in. Erfurt, a city in Eastern Germany. In the range 0.01–0.3 μm particles were classified by an electrical mobility analyzer and in the range 0.1–2.5 μm by an optical particle counter. From the derived size distributions, number and mass concentrations were calculated.The mean number concentration over this period of time was governed by particles smaller than 0.1 μm (72%), whereas the mean mass concentration was governed by particles in the size range 0.1–0.5 pm (83%). The contribution of particles larger than 0.5 μm to the overall number concentration was negligible and so was the contribution of particles smaller than 0.1 μm to the overall mass concentration. Furthermore, total number and mass concentrations in the range 0.01–2.5 μm were poorly correlated.The results suggest that particles larger than 2.5 μm (or even larger than 0.5 μm) are rare in the European urban environment so that the inhalation of these particles is probably not relevant for human health. Since particle number and mass concentrations can be considered poorly correlated variables, more insight into health-related aspects of particulate air pollution will be obtained by correlating respiratory responses with mass and number concentrations of ambient particles below 0.5 μm.
Atmospheric Environment.
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ABSTRACT: Four large whole-body exposure chambers, 19 m3 in volume, are available at this research centre for studies on the effect on lungs following long-term exposure to particulate air pollutants. Each chamber is designed to house up to five beagle dogs according to the floor space requirements for dogs, thus up to 20 dogs are available for one exposure experiment. Clean air is supplied by an air conditioning system with particle, charcoal and adsorbent filters. A horizontal air flow design provides uniform distribution of aerosol, temperature and relative humidity in the chambers with long-term stability. Data acquisition is fully automated. Alarms are available to warn of deviations from airflow settings and aerosol mass concentration. The design of the chambers and their performance during a 290 day exposure are described in this paper.
Journal of Aerosol Science.
