Contribution to PM(2.5) from domestic wood burning in a small community in Sweden

Biomass burning for domestic heating has increased in many countries with cold climates in recent years. This paper presents and compares two ways of estimating the contribution of particulate matter (PM2.5) to ambient air from local domestic wood burning, using daily stationary parallel PM2.5 measurements in a wood-burning area and at a reference location. In the first method (based on air mass back trajectories), daily gravimetric PM2.5 mass differences were compared between the two stations for days with low contributions from regional sources. In the second method, 28 filters from each location were chemically analysed, and source contributions were calculated using positive matrix factorisation (PMF). The trajectory method estimated the extra local contribution from domestic wood burning in the wood-burning area to be 0.7-1.1 μg m(-3), while the PMF method gave a contribution of 0.64 μg m(-3). With the PMF method, the total contribution to ambient air from local domestic wood burning was estimated to be 25% of the total PM2.5 mass. The estimated mass contribution using the trajectory method gave a result similar to that of the PMF method, and the method can therefore be a time- and cost-effective first step, especially when no chemical analysis is possible.