Effects of ultrafine and fine particles in urban air on peak expiratory flow among children with asthmatic symptoms.
ABSTRACT It has been suggested that ultrafine particles in urban air may cause the health effects associated with thoracic particles (PM10). We therefore compared the effects of daily variations in particles of different sizes on peak expiratory flow (PEF) during a 57-day follow-up of 39 asthmatic children aged 7-12 years. The main source of particulate air pollution in the area was traffic. In addition to the measurements of PM10 and black smoke (BS) concentrations, an electric aerosol spectrometer was used to measure particle number concentrations in six size classes ranging from 0.01 to 10.0 microns. Daily variations in BS and particle number concentrations in size ranges between 0.032 and 0.32 micron and between 1.0 and 10.0 microns were highly intercorrelated (correlation coefficients about 0.9). Correlations with PM10 were somewhat lower (below 0.7). All these pollutants tended also to be associated with declines in morning PEF. However, the only statistically significant associations were observed with PM10 and BS. Different time lags of PM10 were also most consistently associated with declines in PEF. Therefore, in the present study on asthmatic children, the concentration of ultrafine particles was no more strongly associated with variations in PEF than PM10 or BS, as has earlier been suggested.
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ABSTRACT: The effect of silicon dioxide nanoparticles on the expression of key genes of the brain serotonergic (5-HT) system has been studied in specific pathogen-free mice chronically exposed to Tarkosil nanoaerosol (25-nm particles). Males of the Balb/c and C57Bl/6 strains are used to reveal genetic differences in the response to the nanomaterial. The animals are exposed to aerosol with a mean particle size of 107 nm for 10 days. After exposure, their midbrains, hippocampi, and frontal cortices are examined. The expression rates of genes for 5-HT1A and 5-HT2A receptors; tryptophan hydroxylase (TPH2), the key enzyme in 5-HT production; serotonin transporter (5-HTT); and interleukin 6 (IL6) as a marker of inflammation in the brain are assayed by quantitative reverse transcription PCR. The expression of 5-HT1A is notably elevated in the hippocampus of Balb/c mice, but it tends to decrease in C57Bl/6. No changes in the expression of the genes for 5-HT2A, TPH2, 5-HTT, or IL6 are noted in any brain divisions. Thus, the chronic inhalation of silicon dioxide nanoparticles does not activate nonspecific immunity in the brain, but it exerts contrasting genotype-specific effects on the expression of the 5-HT1A receptor in the hippocampus.Nanotechnologies in Russia 03/2014; 9(3-4):213-218. DOI:10.1134/S1995078014020177
International Journal of Environmental Research and Public Health 04/2015; 12(4-4):3756-3773. DOI:10.3390/ijerph120403756 · 1.99 Impact Factor
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ABSTRACT: Data on polycyclic aromatic hydrocarbons (PAHs) in ambient air accessed at selected locations in the vicinity of the industrial zone of the city of Novi Sad, Serbia, have been presented and analyzed in order to determine seasonal and spatial variations and to identify emission sources of particle-bound PAHs. Previous studies have demonstrated that the major contributors of PAHs in urban areas are emissions from vehicle exhaust and from industrial processes like aluminium production, creosote and wood preservation, waste incineration, cement manufacture, petrochemical and related industries, commercial heat/power production, etc. The sampling campaigns were conducted at three sampling sites, during two 14-day Periods. The first site was situated near an industrial area, with a refinery, power plant and heavy-traffic road in the vicinity. The second site was located nearby a heavy traffic area, especially busy during the rush hour. The third site was a residential district. The summer sampling period lasted from June 26th to July 10th 2008, while sampling of ambient air during the winter was undertaken from January 22nd to February 5th 2009. Eighty-four (84) air samples were collected using a high volume air sampler TCR Tecora H0649010/ECHO. 16 US EPA polycyclic aromatic hydrocarbons were determined in all samples using a gas chromatographer with a mass spectrometer as a detector (Shimatzu MDGC//GCMS-2010). The total average concentrations of PAHs ranged from 1.21 to 1.77 ng/m(3) during the summer period and from 6.31 to 7.25 ng/m(3) in the winter. Various techniques, including diagnostic ratio (DR) and principal component analysis (PCA), have been used to define and evaluate potential emission sources of PAHs. Diagnostic ratio analysis indicated that vehicles, diesel or/and gasoline, industrial and combustion emissions were sources of PAHs in the vicinity of the industrial zone. Additionally, principal component analysis was used to constrain the potential sources. The results showed that the predominant source of particle-bound PAHs during the whole year are vehicles, and during the winter period, stationary sources (thermal power and heating plant, oil refinery, individual furnaces) were predominant.Hemijska industrija 03/2013; 67(2):337-348. DOI:10.2298/HEMIND120113062J · 0.56 Impact Factor