Cellulose in atmospheric particulate matter at rural and urban sites across France and Switzerland

Abstract

The spatiotemporal variations in free-cellulose concentrations in atmospheric particles, as a proxy for plant debris, were investigated using an improved protocol with a high-performance liquid chromatography with pulsed amperometric detection (HPLC-PAD) method. Filter samples were taken from nine sites of varying characteristics across France and Switzerland, with sampling covering all seasons. Concentrations of cellulose, as well as carbonaceous aerosol and other source-specific chemical tracers (e.g. elemental carbon, EC; levoglucosan; polyols; trace metals; and glucose), were quantified. Annual mean free-cellulose concentrations within PM10 (particulate matter) ranged from 29ĝ€¯±ĝ€¯38ĝ€¯ngĝ€¯m-3 at Basel (urban site) to 284ĝ€¯±ĝ€¯225ĝ€¯ngĝ€¯m-3 at Payerne (rural site). Concentrations were considerably higher during episodes, with spikes exceeding 1150 and 2200ĝ€¯ngĝ€¯m-3 at Payerne and ANDRA-OPE (Agence nationale pour la gestion des déchets radioactifs Observatoire Pérenne de l'Environnement; rural site), respectively. A clear seasonality, with highest cellulose concentrations during summer and autumn, was observed at all rural and some urban sites. However, some urban locations exhibited a weakened seasonality. Contributions of cellulose carbon to total organic carbon are moderate on average (0.7ĝ€¯%-5.9ĝ€¯%) but much greater during "episodes", reaching close to 20ĝ€¯% at Payerne. Cellulose concentrations correlated poorly between sites, even at ranges of about 10ĝ€¯km, indicating the localised nature of the sources of atmospheric plant debris. With regards to these sources, correlations between cellulose and typical biogenic chemical tracers (polyols and glucose) were moderate to strong (Rsĝ€¯Combining double low lineĝ€¯0.28-0.78, pĝ€¯