Abstrakt
Elevated concentrations of particle-bond PAHs are frequent urban air quality problem in the Czech Republic. EU limit exceedance for B[a]P is everyday reality during cold period of winter when, as an extreme, we recorded peak value of 300 ng.m^-3 of B[a]P in 2012 in the Ostrava city during comprehensive characterization of urban aerosol study.
The study comprises determination of 24 hours averages of 16 US-EPA PAHs in four size aerosol fractions and hourly values for 17 elements in three size aerosol fractions. Therefore, we may analyze relationship between highly time resolved peaks in elemental composition and PAHs enrichment in size-segregated aerosol.
The study consisted of sampling campaigns conducted for 14 or 30 days in four cities in the Czech Republic. First, we analyzed database recorded during 30 days campaign conducted in Ostrava city in winter 2012.
Due to very low air temperatures and low wind-speeds heavy smog was formed and persisted for first 20 days of the campaign. According to analysis, no simple relationship between PAHs and aerosol elemental composition was observed probably because of main PAHs-containing emissions were well mixed during the smog episode.
In contrast, during the last 10 days of the campaign, when temperature and wind speed have risen and smog was dispersed, we observed enrichment of both heavy metal and B[a]P in fine aerosol fraction. Analysis of wind speed/direction points to plume from heavy industry complex nearby the station.
Data analysis from other cities is currently under progress. This work was supported by the project CENATOX under grant GACR P503/12/G147.