Quantifying the Impact of Residential Heating on the Urban Air Quality in a Typical European Coal Combustion Region

摘要

The present investigation, carried out as a case study in a typical major city situated in a European coal combustion region (Krakow, Poland), aims at quantifying the impact on the urban air quality of residential heating by coal combustion in comparison with other potential pollution sources such as power plants, industry, and traffic. Emissions were measured for 20 major sources, including small stoves and boilers, and thernpaniculate matter (PM) was analyzed for 52 individual compounds together with outdoor and indoor PM_(10) collected during typical winter pollution episodes. The data were analyzed using chemical mass balance modeling (CMB) and constrained positive matrix factorization (CMF) yielding source apportionments for PM_(10), B(a)P, and other regulated air pollutants namely Cd, Ni, As, and Pb. The results are potentially very useful for planning abatement strategies in all areas of the world, where coal combustion in small appliances is significant During the studied pollution episodes in Krakow, European air quality limits were exceeded with up to a factor 8 for PM_(10) and up to a factor 200 for B(a)P. The levels of these air pollutants were accompanied by high concentrations of azaarenes, known markers for inefficient coal combustion. The major culprit for the extreme pollution levels was demonstrated to be residential heating by coal combustion in small stoves and boilers (>50% for PM_(10) and >90% B(a)P), whereas road transport (<10% for PM_(10) and <3% for B(a)P), and industry (4-15% for PM_(10) and <6% for B(a)P) played a lesser role. The indoor PM_(10) and B(a)P concentrations were at high levels similar to those of outdoor concentrations and were found to have the same sources as outdoors. The inorganic secondary aerosol component of PM_(10) amounted to around 30%, which for a large part may be attributed to the industrial emission of the precursors SO_2 and NO_x.