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Study of bioaccessibility and oxidative potential of elements using simulated lung fluids
Šidla, Jiří ; Doležalová Weissmannová, Helena (referee) ; Cigánková,, Hana (advisor)
This master thesis deals with the determination of the bioaccessible concentration and oxidative potential of an urban aerosol using 3 simulated lung fluids. Submicron fraction (PM1; urban aerosol particles with aerodynamic diameter less than 1 m) was collected in two campaigns (summer, winter). The mass concentration of PM1 was determined gravimetrically and total concentrations of selected metals were determined by ICP-MS. Next, extraction of the sampled filters into 3 simulated lung fluids (Gamble's solution – GS, Simulated alveoli fluid – SAF, and Curosurf) was performed. The extracts were used to determine the bioaccessibility of each metal by ICP-MS and to determine the oxidative potential. Oxidative potential of standard solutions of selected metals and real aerosol samples was also studied using 3 simulated lung fluids. The highest total concentration in PM1 was measured for Fe. The bioaccessibility of most of the studied metals was higher in Curosurf than in GS and SAF. Although the bioaccessibility of most metals was higher in the summer campaign than in the winter campaign, higher values of OP were measured in the winter campaign. OP was higher for extracted PM in Curosurf than in SAF. A study of relationships between measured variables was also conducted using correlations. This work provides a closer look at the effects of inhaled metals contained in urban atmospheric aerosol on human health. The inclusion of Curosurf among the SLFs analysed is also beneficial, as it is a substance used in hospitals for the treatment of respiratory distress syndrome in children.
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Spatio-temporal distribution of atmospheric aerosol in urban and rural environment
Bendl, Jan
Air quality in Europe remains a significant environmental concern, affecting the health and quality of life of its population. While stationary network ambient air quality monitoring allows for the observation of main trends, it is not fully representative of personal exposure of citizens due to high spatio-temporal variability of atmospheric aerosol. Therefore, highly time-and- space resolved measurements with state-of-the-art instruments and methods are needed to observe the aerosol variability, dynamics, identify hot-spots, and pollution sources, which are necessary for successful targeted mitigation measures. This thesis addresses this gap focusing on the characterization of spatio-temporal distribution of atmospheric aerosol in inhabited environments. Novel mobile measurement systems were developed and employed to investigate diverse environments, including rural, urban and suburban area. Aerosol source-apportionment were conducted, and the toxicological effects associated with these environments were also investigated. A novel mobile measurement system was developed for personal exposure measurements and pollution mapping in urban and rural environments. The system was used to measure air quality in the Munich subway, revealing high aerosol dynamics with significantly higher concentrations of...
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Application of a novel continuous sampler for the determination of compounds in ultrafine aerosol
Hlaváčková, Hana ; Řezáčová, Veronika (referee) ; Alexa,, Lukáš (advisor)
The diploma thesis is focused on the use of new type of continuous sampler for the determination of compounds in ultra-fine aerosol. The aim of the study was to optimize parameters of the aerosol sampler CGU-ACTJU (Condensation-Growth Unit – Aerosol Counterflow Two-Jets Unit) and its application for the real aerosol samples. The ACTJU sampler connected to upstreamed CGU enables sampling of ultra-fine fraction of particulate matter to the diameter about few nanometers. The measured results from CGU-ACTJU were compared with commercial sampler (cascade impactor) with subsequent offline analysis. The atmospheric aerosol was sampled in two campaigns (July–August 2021 and February 2022) on the terrace of Institute of Analytical Chemistry of CAS in Brno. Theoretical part of the study contains information about analytical methods for the characterization of aerosol, the experimental part describes used methods in detail and the results of experiments are discussed.
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Spatio-temporal distribution of atmospheric aerosol in urban and rural environment
Bendl, Jan ; Hovorka, Jan (advisor) ; Mikuška, Pavel (referee) ; Vojtíšek, Michal (referee)
Air quality in Europe remains a significant environmental concern, affecting the health and quality of life of its population. While stationary network ambient air quality monitoring allows for the observation of main trends, it is not fully representative of personal exposure of citizens due to high spatio-temporal variability of atmospheric aerosol. Therefore, highly time-and- space resolved measurements with state-of-the-art instruments and methods are needed to observe the aerosol variability, dynamics, identify hot-spots, and pollution sources, which are necessary for successful targeted mitigation measures. This thesis addresses this gap focusing on the characterization of spatio-temporal distribution of atmospheric aerosol in inhabited environments. Novel mobile measurement systems were developed and employed to investigate diverse environments, including rural, urban and suburban area. Aerosol source-apportionment were conducted, and the toxicological effects associated with these environments were also investigated. A novel mobile measurement system was developed for personal exposure measurements and pollution mapping in urban and rural environments. The system was used to measure air quality in the Munich subway, revealing high aerosol dynamics with significantly higher concentrations of...
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Formation and transformation of atmospheric aerosol in boundary layer
Holubová Šmejkalová, Adéla
Title: Formation and transformation of atmospheric aerosol in boundary layer Author: Mgr. Adéla Holubová Šmejkalová Institute: Institute for Environmental Studies Supervisor: Ing. Vladimír Ždímal, Dr., Institute of Chemical Process Fundamen- tals of the CAS Training workplace: Institute of Chemical Process Fundamentals of the CAS Abstract: The experimental measurement of aerosol clusters from 1.17 nm in size was carried out from August 2016 till December 2018 at the National Atmospheric Observatory Košetice. Atmospheric conditions leading to aerosol clusters stabili- zation, fresh particles formation and particle growth were analyzed. Data of days with no new particle formation confrmed the connection between mixing layer height development and decrease of total aerosol number concentration together with lower gaseous pollutant concentrations. On the contrary, new particle for- mation process overcomes dilution of the atmosphere by increasing the number of freshly nucleated particles. Only decreasing gaseous pollutant concentrations were observed during these events. The atmospheric boundary layer was high du- ring new particle formation events that can mean enrichment of the atmosphere by other components transported by long-range transport or some transfer from the free troposphere. The measurement in...
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Atmospheric aerosol and hydrometeors
Jüthner, Ludvík ; Zíková, Naděžda (advisor) ; Hůnová, Iva (referee)
This thesis examines the interactions between ultrafine and fine modes of atmospheric aerosol and precipitation episodes of rain, snow and drizzle. For the research were used data from the period 1.11.2018 to 30.4.2020 at the rural background station Milešovka. It was chosen a combination of a disdrometer together with a Scanning mobility particle sizer spectrometer (SMPS) for the data collection. Ten-minute averages were then used to determine the change in aerosol particle concentration during individual precipitation episodes and to calculate the scavenging coefficient. Then was calculated a Pearson correlation to determine the effect of raindrop size, rainfall intensity, temperature, relative humidity and wind speed on the decrease in aerosol concentration by individual hydrometeors. Finally, a cluster analysis of the air mass history was performed. An assessment of the change in aerosol particle concentration during each event showed that although all three selected hydrometeors contributed to the decrease in particle concentrations, only rain caused a decrease in all size classes (-5,7%). The result of the scavenging coefficient estimation further confirmed the higher success of rain, with a median coefficient of 6,62 x 10-4 s-1 . The atmospheric cleaning by rain then proceeded best between...
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Simultaneous determination of ultratrace concentration of nitric acid and nitrates in air using chemiluminescent online analysers
Čmelíková, Dorota ; Řezáčová, Veronika (referee) ; Alexa,, Lukáš (advisor)
The diploma thesis is focused on the development, optimization and real use of a continuous flow analyser for online determination of nitric acid and nitrates in air. The principle of analysis is photolytic conversion of nitrate in solution to peroxynitrite with subsequent detection by chemiluminescence reaction with luminol. The main aim of this thesis was to optimize parameters of analyser followed by practical use for analysis of urban air. The detection limit of gaseous nitric acid was 0,13 g·m3, resp. 0,10 g·m3 for nitrates in aerosol. The measured online concentrations were compared with reference offline analysis. The analysis of urban air was realized in two campaigns (September 2022 and February 2023) at Institute of Analytical Chemistry of CAS in Brno. The apparatus was placed in laboratory on the second floor and samples were collected from the window at Veveří street.
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PM2.5 field in the air of Družec village during heating season
Šmok, Dominik ; Hovorka, Jan (advisor) ; Kozáková, Jana (referee)
Residential heating by solid fuel combustion in small settlements has great potential to degrade air quality, especially PM2.5 emissions, during the winter heating season, to such an extent, that WHO and US-EPA limits for PM2.5 are frequently exceeded. There were found significant temporal variability and spatial heterogeneity of the PM2.5 concentration field. 24h limit for PM2.5 (US-EPA, 35 μg∙m-3) using a stationary network of 6 monitors measuring minute concentration of PM2.5, In the village Družec, Kladno district, during the 14-day measuring campaign. Campaign average exceeded the limit at the primary school garden. In the other sites, the limit was usually exceeded occasionally except one day, when the limit exceedance was recorded in all the sites as well at the whole area of the Czech Republic. The analysis of time course of minute values of PM2.5 shows that the residential heating increased PM2.5 concentrations on average by 61-72% (16-25 g∙m-3) or 40-49% (6-10 g∙m-3) at exposed or background sites respectively; PM2.5 values decreased exponentially with wind speed up to 2 m∙s-1, when they stabilized at 8-16 g∙m-3. At the microscale of the village, there were also found spatial and temporal heterogeneity of PM2.5 and aerosol particle concentrations PNC using by mobile measurement of PNC...
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Application of a novel continuous sampler for the determination of compounds in ultrafine aerosol
Hlaváčková, Hana ; Řezáčová, Veronika (referee) ; Alexa,, Lukáš (advisor)
The diploma thesis is focused on the use of new type of continuous sampler for the determination of compounds in ultra-fine aerosol. The aim of the study was to optimize parameters of the aerosol sampler CGU-ACTJU (Condensation-Growth Unit – Aerosol Counterflow Two-Jets Unit) and its application for the real aerosol samples. The ACTJU sampler connected to upstreamed CGU enables sampling of ultra-fine fraction of particulate matter to the diameter about few nanometers. The measured results from CGU-ACTJU were compared with commercial sampler (cascade impactor) with subsequent offline analysis. The atmospheric aerosol was sampled in two campaigns (July–August 2021 and February 2022) on the terrace of Institute of Analytical Chemistry of CAS in Brno. Theoretical part of the study contains information about analytical methods for the characterization of aerosol, the experimental part describes used methods in detail and the results of experiments are discussed.
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Role of aerosol in climate change
Švátora, Milan ; Hůnová, Iva (advisor) ; Hovorka, Jan (referee)
Atmospheric aerosol is a suspension of liquid or solid particles or their mixture in the atmosphere. Tropospheric aerosols can get into the air from its natural sources or from anthropogenic sources. Release of carbon dioxide from burning fossil fuels and organic and elemental carbon from biomass burning are the major anthropogenic sources of aerosols. Primary aerosols have a direct source of emissions (dust from quarries or from land, sea salt particles in the waves, volcanic ash during volcanic eruptions). Secondary aerosols are formed by chemical reactions of substances in the atmosphere, which converts the gas particles - so- called conversion of gases to particles (formation of nitrates by oxidation of nitrogen oxides and sulfates from sulfur dioxide). Atmospheric aerosol is an important component of the atmosphere and contributes to significant atmospheric events, such as precipitation formation and precipation fall, radiation balance of Earth. Aerosols can affect the radiation balance of the Earth in two ways. First, through absorption and scattering of shortwave and long wave radiation - so-called direct effect. Or serve as condensation nuclei on which water is condenses. Aerosols can affect formation, quantity, length of existence and radiation properties of clouds - so-called indirect effect. In...
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