Evaluation of the emissions and uncertainties of PM2.5 originated from vehicular traffic and domestic wood combustion in Finland

Primary fine particulate matter (PM 2.5 ) emissions from low-altitude sources, such as traffic and domestic combustion, may cause immediate exposure near the source. In this paper we present emission estimate and uncertainty analysis of PM 25 emissions from the vehicular traffic and domestic wood combustion sectors. Our estimate of national PM 2.5 emissions in 2000 from domestic wood combustion was 7.6 Gg a -1 and that from vehicular traffic, including non-exhaust emissions, 5.8 Gg a -1 . These values correspond to 25% and 19% of the national total PM 25 emissions, respectively. The uncertainties were high for non-exhaust traffic and domestic wood combustion emissions, 37% down, 53% up and 36% down, 50% up of the mean value (95% confidence interval limits), respectively. For traffic exhaust emissions, the uncertainties were lower, 11% down, 13% up. Uncertainties in the domestic combustion emission factors were the most important individual parameters accounting for total uncertainty.