A microscopic and Synchrotron-based characterization of urban particulate matter (PM_(10)-PM_(2.5) and PM_(2.5)) from Athens atmosphere, Greece

摘要

Urban particulate matter (PM_(10)-PM_(2.5) and PM_(2.5)) from Athens (Greece) atmosphere, primarily investigated by SEM-EDS, was further studied in the FLUO and SUL-X beamlines of ANKA Synchrotron facility (KIT, Germany). The SR μ.-XRF study showed both geological (e.g. Ca-Ti, Ca-K and Ca-Sr-K-Rb) and anthropogenic particles exhibiting heavy metal combinations such as Fe-Co, Fe-Co-Cu-V and Zn-V. It was also revealed that very hazardous metalloids and heavy metals, namely As and Pb, are concentrated in isolated respirable (PM_(2.5)) microparticles. It was attempted to investigate the oxidation state of As by means of n-XANES. The As K-edge XANES spectrum of the sample shows a main peak at about 11.874 keV which matches adequately with the As(V) reference spectrum but part of the As seems to have a lower oxidation state (most probably As(IU)). This is the first non-bulk study with regard to the partitioning and solid-state speciation of hazardous chemical elements in uiban atmospheric microparticles from greater Athens area, rated as an alpha-world city with a population of ca. 4 million people.