The decreasing trend of concentrations can be due to a decline in domestic consumption of fossil fuels for space heating and improvement in domestic and
industrial combustion devices. The highest PAHs concentrations were
observed during the cold months, with the average concentrations of sum of PAH around 5 times higher in winter than summer throughout
the years. Thus, a clear seasonality of the PAH concentrations was
proved. PAH profile analysis and comparison of ratios of some PAHs species
with published literature data were used for source diagnosis. The
potential sources emissions that contribute the most for PAH levels in
the ambient air of the studied area seems to be originated from traffic
emissions, and also coal and wood combustion.