Contributions of carbonaceous particles from fossil emissions and biomass burning to PM10 in the Ruhr area, Germany

Concentrations of CMfossil were found to be almost constant during the whole period whereas biomass emissions exhibited significant seasonal variability, leading to heating period/summer ratios of 2.82 and 2.51 at the urban background and traffic site, respectively. During the heating period concentrations of CMbiomass summed up to 2.8 μg/m3 (14.6% of PM10) at the urban background site compared to 2.2 μg/m3 (11.2% of PM10) at the traffic site - being in good agreement with those determined for other European sites. The PM10 share of CMbiomass was almost equal to CMfossil at the traffic site whilst at the urban background site contributions of fossil fuel emissions were even outrun during the colder months. Additionally, data from those two sites observed during the study indicate that emissions from biomass burning processes might be of similar relevance as fossil fuel emissions in terms of exceedances of the daily PM10 limit value.