Search

Time series (1996-2000) of levels of PM (PM10 and TSP) and gaseous pollutants recorded in air quality monitoring networks from Northeastern Spain were interpreted using meteorological data and satellite observations of African dust plumes. The main objective of this study was to identify the processes affecting time variations of PM levels on a day-to-day and seasonal basis. From March to October PM levels at rural, urban, and industrial sites vary as a function of the concatenation of Atlantic air mass advections (Atlantic episodes with Iow PM levels) and regional circulations (regional events with high PM levels, very often associated with high ozone levels), which favor the aging of air masses in the Western Mediterranean basin. During these regional episodes, PM is transported from urban/industrial to rural sites by meso-scale circulations. From November to February Iow PM levels are recorded at rural sites, and variations in PM levels at urban/industrial sites are governed by the successive occurrence of Atlantic episodes and local urban/industrial pollution events. The African dust outbreaks take place throughout the year and may induce PM levels to increase simultaneously in large areas of the Iberian peninsula. The difference between PM concentrations measured at urban and rural sites experiences a seasonal trend similar to that of levels of N0[sub x] and CO, which is characterized by a winter maximum due to the higher frequency of intensive local urban pollution events. However, maximum PM levels are recorded in summer at rural sites owing to the frequent occurrence of regional episodes. Furthermore, in three years of the study period (1997, 1998, and 2000), a secondorder PM maximum was also recorded at rural sites in March owing to intensive African dust outbreaks. [ABSTRACT FROM AUTHOR]

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 the particulate matter (PM) was analyzed for 52 individual compounds together with outdoor and indoor PM10 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 PM10 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 PM10 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 PM10 and >90% B(a)P), whereas road transport (<10% for PM10 and <3% for B(a)P), and industry (4-15% for PM10 and <6% for B(a)P) played a lesser role. The indoor PM10 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 PM10 amounted to around 30%, which for a large part may be attributed to the industrial emission of the precursors SO2 and NOx. [ABSTRACT FROM AUTHOR]