Characterization of iron and manganese species in atmospheric aerosols from anthropogenic sources

Electron paramagnetic resonance (EPR) was used to study the chemical form of iron, manganese and other paramagnetic species in airborne particles collected on southern coastal part of the North Sea, located in France. In parallel, chemical analysis was performed to obtain the metal concentrations in samples whereas an individual analysis of particles was provided by scanning electron microscopy coupled to an energy-dispersive X-ray spectrometer (SEM-EDX). EPR spectra have evidenced Fe 3+ and Mn 2+ ions in the form of isolated or agglomerated species, as well as carbonaceous products with variable signal intensities according to the wind direction. The monitoring of a signal of isolated Mn 2+ ions on a distance close to 90 km was proposed as tracer of particles from a Mn local emission source. Fe 3+ signals are relative to agglomerated species and differences in the type of interaction between these species were evidenced following the wind direction. Fe 3+ EPR signals parameters revealing antiferromagnetic contribution in Fe-rich particles were found for an industrial origin at Dunkerque.