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

Abstract. Long-term monitoring at sites with relatively low particulate pollution could provide an opportunity to identify changes in pollutant concentration and potential effects of current air quality policies. In this study, 9-year sampling PM10 (particles aerodynamic diameter below 10 µm) was performed a rural background site France (Observatoire Pérenne de l'Environnement or OPE) from 28 February 2012 22 December 2020. The positive matrix factorization (PMF) method used apportion sources based on quantified chemical constituents specific tracers analysed collected filters. Oxidative (OP), emerging health metric that measures PM capability potentially cause anti-oxidant imbalance the lung, also measured using two acellular assays: dithiothreitol (DTT) ascorbic acid (AA). OP were estimated multiple linear regression (MLR) analysis. terms mass contribution, dominant are secondary aerosols (nitrate- sulfate-rich) associated long-range transport (LRT). However, contributions, main drivers traffic, mineral dust, biomass burning factors. There is some contribution apportioned sulfate- nitrate-rich influenced by processes ageing during LRT have encouraged mixing other anthropogenic sources. study indicates much lower values than urban areas. A substantial decrease (58 % reduction year 2020) contributions traffic factor found, even though not clearly reflected its contribution. Nevertheless, findings long-term OPE indicate effectiveness implemented emission control policies, as seen studies conducted Europe, mainly for