Seasonal contribution of assessed sources to submicron and fine particulate matter in a Central European urban area.

This study presents the air pollution findings of the submicron (PM1) and fine (PM2.5) particulate matter. The submicron particles are entirely absorbed by the human body and they cause the greatest health risk. For the PM2.5 concentration, there are yearly and/or daily limit values regulations by the European Union (EU) and World Health Organization (WHO). There are no such regulations for PM1 but for health risk reason the knowledge of its concentration is important. This paper presents the seasonal concentration contribution of PM1 and PM2.5, their chemical composition and assessed three basic sources. Daily samples of both fractions were collected from 2nd July 2016 to 27th February 2017 in Krakow, Poland. Apart from PM1 and PM2.5 the concentration of 16 elements, 8 ions and BC for each samples were measured. Based on these chemical species the positive matrix factorization (PMF) receptor modeling was used for the determination of three main sources contribution to the PM1 and PM2.5 concentrations. Daily average concentrations of PM2.5 were 12 μg/m3 in summer and 60 μg/m3 in winter. For PM1 it was 6.9 μg/m3 in summer and 17.3 μg/m3 in winter. These data show a significant difference in percentage contribution of PM1 in PM2.5 in summer (58%) and in winter (29%). For the combustion source, the concentrations calculated from PMF modeling in winter were 4.8 μg/m3 for PM1 and 31 μg/m3 for PM2.5. In summer, the concentrations were smaller than 1 μg/m3 for both fractions. Secondary aerosols' concentration for PM1 was 3.4 μg/m3 in summer and 11 μg/m3 in winter - for PM2.5 these were 7.1 μg/m3 and 17 μg/m3 respectively. The third source - soil, industry and traffic together, had small seasonal variation: for PM1 it was from 1.4 to 1.8 μg/m3 and for PM2.5 from 4.7 to 7.9 μg/m3.