Biomonitor-Reflection of Large-Distance Air Mass Transported Trace Elements

The present thesis’ topic is the biomonitoring of atmospheric trace elements with attention focused on the long-range transported trace elements. The aim was to provide improved understanding of aerosol characteristics under the atmospheric transport dynamics of Central North Atlantic at different altitudes, and also evaluate the usability of lichen transplants to monitor those long-range transported elements. The study was carried out at Pico mountain in Azores, Portugal. The high altitude of this mountain reaching the Low Free Troposphere and its position in the central North Atlantic were the decisive factors for the selection of this sample site, because it was possible to analyze aerosol deposition from surrounding continents (Africa, Europe and Central-North America) at the layer of the atmosphere where the aerosol transportation occurs, both with sample collectors (active sampling) and with biomonitors (passive sampling). Since the number of samples was several hundreds, the thesis also includes a study on analytical aspects: a comparison of Nuclear Activation Analysis methods, in terms of accuracy, sensitivity and flexibility in routine application. The thesis comprises three main parts, divided in 8 chapters, including the general introduction and the general discussion and outlook: the first part is about a comparison of several NAA approaches under different experimental conditions; the second part is about aerosol characterization and source apportionment; and the third part focused on vitality of transplanted lichens and their usability, the latter in the case study implying several altitudes transects at Pico mountain, aiming at the possible recognition of elemental deposition from long-range pollution sources.