Seasonal Changes in Urban PM2.5 Hotspots and Sources from Low-Cost Sensors

0558025 - ÚVGZ 2023 RIV CH eng J - Journal Article
Harr, L. - Sinsel, T. - Simon, H. - Esper, Jan
Seasonal Changes in Urban PM2.5 Hotspots and Sources from Low-Cost Sensors.
Atmosphere. Roč. 13, č. 5 (2022), č. článku 694. E-ISSN 2073-4433
R&D Projects: GA MŠMT(CZ) EF16_019/0000797
Research Infrastructure: CzeCOS III - 90123
Institutional support: RVO:86652079
Keywords : particulate matter pm2.5 * ambient air * particle number * pollution * exposure * variability * performance * opc-n2 * pm10 * opc-n3 * particulate matter * personal exposure * mobile measurement * PM2.5/PM10 ratio
OECD category: Meteorology and atmospheric sciences
Impact factor: 2.9, year: 2022
Method of publishing: Open access
https://www.mdpi.com/2073-4433/13/5/694

PM2.5 concentrations in urban areas are highly variable, both spatially and seasonally. To assess these patterns and the underlying sources, we conducted PM 2.5 exposure measurements at the adult breath level (1.6 m) along three5 km routes in urban districts of Mainz (Germany) using portable low-cost Alphasense OPC-N3 sensors. The survey took place on five consecutive days including four runs each day (38 in total) in September 2020 and March 2021. While the betweensensor accuracy was tested to be good (R-2 = 0.98), the recorded PM2.5 values underestimated the official measurement station data by up to 25 mu g/m(3). The collected data showed no consistent PM2.5 hotspots between September and March. Whereas during the fall, the pedestrian and park areas appeared as hotspots in >60% of the runs, construction sites and a bridge with high traffic intensity stuck out in spring. We considered PM2.5/PM10 ratios to assign anthropogenic emission sources with high apportionment of PM2.5 in PM10 (>0.6), except for the parks (0.24) where fine particles likely originated from unpaved surfaces. The spatial PM 2.5 apportionment in PM10 increased from September (0.56) to March (0.76) because of a pronounced cooler thermal inversion accumulating fine particles near ground. Our results showed that highly resolved low-cost measurements can help to identify PM2.5 hotspots and be used to differentiate types of particle sources via PM2.5/PM10 ratios.
Permanent Link: http://hdl.handle.net/11104/0331869