J.R.D. Thieringer, J. Szabadi, J. Meyer, A. Dittler

Processes 2022, 10, 545, https://doi.org/10.3390/pr10030545 (open access)

In Germany, the number of small wood-burning combustion plants was around 11 million in 2020. The PM2.5 immissions caused by the operation of these combustion plants are already about as high as those from traffic exhaust gases. Thus, particulate matter immissions occur not only on busy roads but also in residential areas. Since there are few official measuring stations for PM2.5 in residential areas and suburbs, this study determined PM2.5 concentrations from November 2020 to June 2021 at three stations (urban, suburban, and residential) in the Karlsruhe area. Simultaneous measurements of PM2.5 at the three locations have been implemented to determine short-term (peaks), medium-term, and long-term particulate matter levels and to assign them to sources by observation, considering wind direction. Illustratively, PM2.5 immission levels in January and May 2021 were compared in this paper. The comparison of the particulate matter immissions measured in the urban and residential area in January revealed that PM2.5 concentration peaks of up to 60 µg/m3 occurred for short periods in the residential area, especially on Fridays and in the evenings, which could be assigned towood stove operation. In the urban and suburban areas, the number of the immission peaks was lower by 70–80%, and the peak concentrations were also lower by an average of 13–18%. However, the high short-term peaks have no significant impact when calculating the PM2.5 annual average according to the current limit value regulation (39 BlmSchV).