Tracking changes in atmospheric particulate matter at a semi-urban site in Central France over the past decade

Nearly 10-year (2013-2022) data on atmospheric particulate matters (PMs) were collected to investigate the air quality in a suburban site of Orléans city (France). The PM₁₀ concentration decreased slightly between 2013 and 2022. PMs concentrations showed a monthly variation with higher concentration in cold periods. PM₁₀ presented a clear bimodal diurnal variation peaking at morning rush hour and midnight, whereas the fine PMs such as PM_2.5 and PM_1.0 only had significant peaks during nighttime. Further, PM₁₀ had more pronounced week-end effect than other fine PMs. COVID-19 lockdown impact on PMs levels was further investigated, showing that the lockdown during cold season could result in an increase of PMs concentrations because of the enhanced household heating. We concluded that PM₁₀ could originate from biomass burning and fossil fuel related activities, air parcels from the western Europe through Paris were also important source of PM₁₀ in the investigated area. Fine PMs, such as PM_2.5 and PM_1.0, originated mainly from biomass burning in addition to secondary formation at the local scale. This study provides a long-term PMs measurement database to explore the sources and characterization of PMs in central France, which could support future regulation and formulation of air quality standards.