Umweltmedizinische Bewertung von Feinstäuben : Schadstoffmonitoring, physikochemische Einflussgrößen und in vitro Toxizität

According to recent model calculations, each year 3.3 million people die worldwide due to the toxicological effects of air pollution, whereby a large part can be attributed to the long-term exposure to particulate air pollutants. The main reasons for this are lung diseases and disorders of the cardiovascular system. However, it is still unclear which toxicological mechanisms form the basis of epidemiological detected effects, and how particle properties such as composition, size, concentration or meteorological and geographical parameters affect the toxicological potential of particulate matter. To solve these questions, combined investigations of standardized sampling methods, comprehensive chemical analyzes and cell-based in vitro screening procedures of specific toxicological endpoints were applied. This approach design enables a more detailed and cause-specific environmental health assessment, which will make a significant contribution by the optimization of particulate matter minimization strategies within an adapted air quality management. The city and region of Aachen were chosen as study area due to its size, geographical and topographical situation, which represents a suitable model region for central Europe pollution levels. The air pollution monitoring identifies a clear mass concentration dependent urban-rural gap, whereby changes of the particle mass and composition are based on variable source contributions (local vs. national) or meteorological fluctuations. Primary emission sources are constituted by the transport sector and domestic heating in all investigated sampling sites, therefore the mass-related air quality studies focus on inorganic indicator parameters such as carbon black or (transition) metals. The in vitro screening analyzes illustrate the complexity and variability of particulate matter induced toxicological effects with regard to the chemical composition and external variables. Cellular time- and concentration-dependent exposure experiments with different in vitro cell systems of the lung, skin and liver lead to variations in the effect characteristics and intensities depending on tissue or cell type, particle size, sampling site or period, under the same test conditions. Especially anthropogenic particulate matter with a high carbon black, PAH or metal content induce oxidative cell damage (cytotoxicity, oxidative stress), whereas biogenic particles mainly trigger pro-inflammatory effects. Overall, in the present study an influence of physicochemical particle properties on the toxicological potential of particulate matter could be clearly proven, so that a combination of geographical, meteorological and particle-specific variables and indicator parameters should always be taken into account in future effect-related air quality regulations or PM-minimization strategies