Total carbon and benzo(a)pyrene in particulate matter over a Polish urban site - A combined effect of major anthropogenic sources and air mass transport

Anthropogenic sources have a significant impact on air quality in urbanized areas and can contribute to large variability of atmospheric particle sizes, its matrix composition and potential for toxicological effects on environment and public health. This paper presents data from one-year measurements of total carbon (TC) and particulate phase benzo(a)pyrene (BaP) in aerosol samples collected at the urban site in central Poland, in 2014. The role of meteorological conditions and different local/regional sources in the intraannual variability of TC and BaP in total suspended particles was examined. Atmospheric concentrations of TC and BaP were higher during the cold sampling period (winter and fall) than in summer, suggesting significant contribution of local combustion processes (mostly related to industrial activities, coal/wood burning for residential heating, traffic emission) to wintertime aerosol loading. Also, high TC and BaP concentrations in particulate matter during wintertime observations were forced by specific meteorological conditions, i.e. below zero ambient air temperature, lower solar radiation, lower height of urban mixing boundary layer, stable atmospheric conditions. In contrast to the winter study period, in summer the particulate phase BaP showed small variation and lower concentrations, probably as an effect of considerable reduction in emission related to residential sector, photochemical reaction with oxidizing agents, higher partitioning towards the gas phase and higher precipitation height.