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

Abstract

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 29 ± 38 ng m−3 at Basel (urban site) to 284 ± 225 ng m−3 at Payerne (rural site). Concentrations were considerably higher during episodes, with spikes exceeding 1150 and 2200 ng 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 (0.7 %–5.9 %) but much greater during “episodes”, reaching close to 20 % at Payerne. Cellulose concentrations correlated poorly between sites, even at ranges of about 10 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 (Rs = 0.28–0.78, p < 0.0001) across the nine sites. Seasonality was strongest at sites with stronger biogenic correlations, suggesting the main source of cellulose arises from biogenic origins. A second input to ambient plant debris concentrations was suggested via resuspension of plant matter at several urban sites, due to moderate cellulose correlations with mineral dust tracers, Ca2+, and Ti metal (Rs = 0.28–0.45, p < 0.007). No correlation was obtained with the biomass burning tracer (levoglucosan), an indication that this is not a source of atmospheric cellulose. Finally, an investigation into the interannual variability in atmospheric cellulose across the Grenoble metropole was completed. It was shown that concentrations and sources of ambient cellulose can vary considerably between years. All together, these results deeply improve our knowledge on the phenomenology of plant debris within ambient air.

Nine-year trends of PM10 sources and oxidative potential in a rural background site in France

“…Briefly, meteorological conditions, such as high temperature and relative humidity, could facilitate the increase in their formation. This factor can also include some fraction of plant debris, identified by cellulose measurements, as discussed in Samaké et al (2019), Borlaza et al (2021a), and Brighty et al (2022).…”

Composition and sources of carbonaceous aerosol in the European Arctic at Zeppelin Observatory, Svalbard

“…Cellulose was the most abundant organic tracer analyzed (annual mean concentration of 2.2 ± 0.6 ng m -3 ), but levels were much lower than in rural areas of continental Europe (annual mean: 16.3 -284 ng m -3 ) (Sánchez-Ochoa et al, 2007;Brighty et al, 2022), likely due to sparse vegetation at Svalbard. The highest monthly means were seen for June followed by October, but there was no pronounced seasonality for cellulose as seen for the other PBAP tracers (Sect.…”

“…Size distribution measurement of cellulose is limited and inconclusive, with highest concentrations reported both for the fine (Puxbaum and Tenze-Kunit, 2003) and the coarse mode (Yttri et al, 2011a;Brighty et al, 2022). Lack of comparable seasonality between nearby sites indicates that local sources prevail (Brighty et al, 2022), but with a certain fraction associated with fine aerosol, LRT is a possibility. Cellulose did not correlate with other PBAP tracers or levoglucosan, corresponding to the findings by Brighty et al (2022), but this does not exclude co-emission (see Sect.…”

“…Lack of comparable seasonality between nearby sites indicates that local sources prevail (Brighty et al, 2022), but with a certain fraction associated with fine aerosol, LRT is a possibility. Cellulose did not correlate with other PBAP tracers or levoglucosan, corresponding to the findings by Brighty et al (2022), but this does not exclude co-emission (see Sect. 3.4.1).…”

Evaluation of the Sources, Precursors, and Processing of Aerosols at a High-Altitude Tropical Site

“…Primary organic aerosols (POAs) arise from direct emissions whose sources are well identified in the literature, being derived from either anthropogenic or biogenic sources. POAs can include organic aerosols originating from natural sources such as spores, fungi, bacteria, viruses, and plant debris − but are more often associated with anthropogenic sources such as combustion of fossil fuels or biofuels and open biomass burning. , Secondary organic aerosols (SOAs) can be formed from the atmospheric oxidation of volatile organic compounds (VOCs) , or originate from various processes such as heterogeneous reactions, photochemistry, and aqueous-phase oxidation. − On the other hand, SOA formation processes are not as well understood, even though the global SOA contribution to organic aerosol (OA) emissions tends toward approximately 50% to 90% . Their complex chemical composition has been the subject of numerous studies over the two past decades.…”