The rapid rising anthropogenic emissions driven by economic growth over China documented by satellite observations and bottom-up inventories have led to severely degraded air quality, and also have been suggested to be linked to the recent upward trends of tropospheric O₃ over the regions downwind of China. Multi-scale modeling analyses facilitated by ground-level, aircraft and satellite observations have been conducted to understand the atmospheric chemistry over China. Analyses using a 1-D photochemical model constrained by measurements at Beijing in August of 2007 suggest that reactive aromatic VOCs are the major source (~75%) of peroxy acetyl nitrate (PAN). Detailed radical budget analyses reveal the very fast ROₓ (OH + HO₂ + RO₂) production, recycling and destruction driven by VOC oxidation and heterogeneous processes. Photoenhanced aerosol surface uptake of NO₂ is found to be the predominant source of nitrous acid (HONO) during daytime (~70%). 3-D regional modeling analyses of tropospheric vertical column densities of glyoxal (CHOCHO) from SCIAMACHY show that anthropogenic emissions of aromatic VOCs are substantially underestimated (by a factor of 5 - 6, regionally varied) over China. Such an underestimation is the main cause of a large missing source of CHOCHO over the region in current global models, and could also partly explain the underestimation of organic aerosols in previous modeling studies.

Reproduction de : Thèse de doctorat : Structure et dynamique des systèmes réactifs : Lille 1 : 2005. / N° d'ordre (Lille 1) : 3618. Titre provenant de la page de titre du document numérisé. Bibliogr. à la suite de chaque chapitre.

During the last 10 years, air pollution has become one of the major public health problems in Ulaanbaatar city of Mongolia, and concentrations of pollutants were measured 3 to 50 times higher than WHO recommendation. This devastating air pollution is produced mostly by thousands of families who migrated from countryside and live in gers (traditional dwellings) in the suburban area which is not connected to the central heating system, and nearly all of them burn coal to keep them warm. Due to air pollution, residents living in Ulaanbaatar city suffer health problems that equal to the smoking of 4-5 packs of cigarettes. During the winter time, PM10 hourly average concentrations increased to 2,300 μg/m3, and daily average became over than 1,000 μg/m3 in the most polluted parts of the city. At present, Mongolian government has accepted that the health of Mongolian residents has deteriorated at an alarming level. In January of 2011, Mongolian Parliament approved the Law on Reduction of Air Pollution in the Capital City to control air pollution and eliminate the gaps in practice. One main provision of this law was to improve ger district electricity transmission and distribution network and reduce the night-time price of electricity by 50 percent. Therefore, this study aimed to estimate direct health benefits of Government Provision on cutting electricity payment by 50 percent during the night time and analyze the efficiency of this program on reducing air pollution and its related health impact. The study result showed when this new regulation is fully implemented in the ger districts, the annual consumption of coal and wood would be decreased by about 550,000 tons and 415,000 tons, accompanied by massive reduction of the emission. These changes would lead into noteworthy health benefits such as 15.7 and 17.4 percent of reduction of total and infant mortality rates and 4.3 and 4.7 percent decrease of cardiovascular and respiratory disease morbidity cases, annually.

Heidelberg, Univ., Diss., 2008.

China's smog air pollution has become an increasingly urgent environmental crisis in China. Using framing as theoretical framework, this research examined how much media attention is focused on smog air pollution and how print media frame smog air pollution. An empirical content analysis of 339 articles in the People’s Daily newspaper was conducted from 2000 to 2016, and the results showed that “non-voluntary solutions” and “problem” frames were the two frames that had been most utilized to construct stories about air pollution. Smog air pollution crisis also discussed in terms of Downs issue-attention cycle, a five-stage model explaining the rise and down of social attention to a social issue. The smog air pollution crisis in China been found that exhibiting three cycles that relate to media attention. Also, the research found that the prominence of the frames varied at different cycles. It is worth noting that the prominence of the frames moved away from the “problem “and “effects on social economic” frames to the “government responsibility,” “individual responsibility,” and the “voluntary” frames. The finding suggests that media attention and media concerns and journalists’ narrative considerations change across the different phases of development, that natural instincts, political influence, and media norms can all affect it.

Outdoor advertising constitutes a part of the public space and as such it affects all inhabitants. Outdoor advertising causes several negative effects, such as traffic hazard or visual pollution. Therefore, it raises a requirement for its effective regulation. The thesis analyzes the current state of regulation of outdoor advertising in the Czech Republic and focuses primarily on advertising alongside the roads and on advertising in Prague. It deals with advertising from a marketing point of view, its role in society and the economic theories and approaches to advertising. Next, the thesis presents the specifics and forms of outdoor advertising, and also negative effects which are associated with it. Last, it analyzes legislative and institutional framework of regulation of outdoor advertising and describes its problematic areas. To evaluate the current state of regulation, an own empirical research was conducted using the method of questionnaires and personal interviews.

Bibliography: leaves 124-131. / Photochemical smog is the name given to a complex sequence of chemical reactions that occurs in the presence of sunlight. These reactions comprise a mix of organic and inorganic compounds, including a number of toxic secondary pollutants such as ozone (O3) and peroxyacetyl nitrate. These substances are commonly referred to as oxidants and are the result of numerous reactions of primary pollutants or precursors (including nitrogen oxides (NOx) and non- methane hydrocarbons (NHHC)) emitted from vehicle exhausts and to some extent industry, O3 is the major constituent of the photochemical oxidants, and its concentration is often used to determine the severity of photochemical smog. Limited research on photochemical smog in Cape Town has been undertaken, and this study has concentrated on providing a more detailed understanding of photochemical precursor and oxidant levels in the urban atmosphere of Greater Cape Town. This was approached by the investigation and assessment of the spatial and temporal behaviour of photochemical pollutants, making use of automatic monitor data collected from 1984 to 1986, and supplemented by data collected during a spatial survey in April and Hay of 1987. Precursor levels were found to be strongly influenced by the seasonal cycle of the weather and were highest in winter when stable atmospheric conditions prevailed, particularly during morning rush hours, O3 behaviour was complex and lacked any definite relationship to season or to selected meteorological variables, although the limited data indicated high levels during the early spring months. Peak levels were generally experienced on fair weather days during the early afternoon hours at the time of maximum ultraviolet radiation, O3 levels did not exceed the USEPA 1-hour standard of 0.12ppm during 1985 and 1986. The spatial distribution of precursor and oxidant concentrations showed the NOx levels to be spatially dependent, following the major arterial roads. NHHC levels were spatially less well defined than NOx, and O3 levels were spatially relatively uniform, exhibiting depletion due to scavenging by nitric oxide (NO) in areas close to main traffic routes. High NOx levels were experienced predominantly in the city centre, while the suburbs tended to experience the higher O3 levels. Cape Town was not considered to have a photochemical smog problem of the same magnitude as Los Angeles or Sydney, ( due to a number of factors which contributed to the complex situation (such as high NO levels, relatively low NMHC levels and strong winds in summer). However in the Northern Suburbs, the absence of high NO levels together with additional NMHC emissions from nearby industry led to the recognition of this area as one of potential photochemical smog formation.

Agricultural emissions are an important contributor to atmospheric aerosol. These emissions include nitrogen containing organic compounds, primarily as amines, which have not been well investigated to date. Although there have been several studies that have looked at the emission of gas phase amines, there are only a few studies that have focused on ambient amine-based aerosol. There have also only been a handful of smog chamber studies that have investigated amine aerosol chemistry. Kinetic studies have looked at the reactions of amines with OH and ozone. However, amine reactions with nitrate radical (NO3) are not well understood. Several years of measuring atmospheric particulate matter in Cache Valley, Utah, using an aerosol mass spectrometer (AMS), has shown the presence of amine aerosol in significant concentrations (0.5-6 μg/m3). Furthermore, the concentration of amine aerosol peaks at night when NO3 is the dominant oxidant. This thesis details experiments aimed at obtaining a better understanding of the underlying reactions that lead to aerosol formation in Cache Valley and is focused on amine reactivity studies, employing both field and laboratory experiments. There were two field studies performed near agricultural facilities in California. These studies provide a good comparison to the ambient chemistry observed in Utah. The detection of a small amount of amine aerosol was important in showing that amine aerosol is not unique to Utah. The results of these studies add to the previous knowledge base of ambient chemistry in California. This should help future researchers performing similar field studies in California and other locations. Smog chamber-based laboratory experiments included amine reactions with common oxidants, such as ozone and NO3. While small amounts of aerosol formation occurred with ozone (~10 μg/m3), reaction with NO3 produced the most aerosol (up to 135 μg/m3). The smog chamber studies show the importance of amine/NO3 chemistry in the formation of ambient aerosol. Researchers can use this work to aid in further understanding the ambient atmospheric chemistry occurring at various locations. The smog chamber studies also provide a knowledge base that should help guide future work into this area of research.

The research in this dissertation explored the sources and chemistry of organic nitrogen aerosols in the atmosphere. Two approaches were employed: field measurements and laboratory experiments. In order to characterize atmospheric aerosol, two ambient studies were conducted in Cache Valley in Northern Utah during strong winter inversions of 2004 and 2005. The economy of this region is heavily dependent on agriculture. There is also a fast growing urban population. Urban and agricultural emissions, aided by the valley geography and meteorology, led to high concentrations of fine particles that often exceeded the national ambient air quality standards. Aerosol composition was dominated by ammonium nitrate and organic species. Mass spectra from an aerosol mass spectrometer revealed that the organic ion peaks were consistent with reduced organic nitrogen compounds, typically associated with animal husbandry practices. Although no direct source characterization studies have been undertaken in Cache Valley with an aerosol mass spectrometer, spectra from a study at a swine facility in Ames, Iowa, did not show any evidence of reduced organic nitrogen species. This, combined with temporal and diurnal characteristics of organic aerosol peaks, was a pointer that the organic nitrogen species in Cache Valley likely formed from secondary chemistry. Application of multivariate statistical analyses to the organic aerosol spectra further supported this hypothesis. To quantify organic nitrogen signals observed in ambient studies as well as understand formation chemistry, three categories of laboratory experiments were performed. These were calibration experiments, smog chamber studies, and an analytical method development. Laboratory calibration experiments using standard calibrants indicated that quantifying the signals from organic nitrogen species was dependent on whether they formed through acid-base chemistry or via secondary organic aerosol pathway. Results from smog chamber reactions of amines with ozone, nitrogen oxides, nitrate radical, and nitric acid showed that the secondary organic aerosol pathway was more plausible than acid-base chemistry, thus making the contribution of the organic nitrogen species to the total aerosol mass in Cache Valley significant. Gas phase and aerosol products formed from the smog chamber reactions were identified and used to devise reaction mechanisms. Finally, an ion chromatographic method for detecting and quantifying some key organic nitrogen species in aerosol was developed and tested.

This thesis aims to create a complex urban analysis of the Obchodna street in the Bratislava city centre. It aims to identify the key problems and provide a conceptual solution for them as well. It focuses on general background analysis and planning documentation, as well as an analysis of the public space. A combination of distant and field research was used to gather the necessary data. All gathered data was subsequently processed and evaluated. Key problems and their solutions were defined on the basis of SWOT analysis. These solutions consist mostly of minor and easy changes, which can help to improve the public space in Obchodna and fulfil its potential.