A wintertime study of polycyclic aromatic hydrocarbons (PAHs) in indoor and outdoor air in a big student residence in Algiers,Algeria

The wintertime concentrations and diel cycles of n-alkanes and polycyclic aromatic hydrocarbons (PAHs) associated to atmospheric particulate matter with aerodynamic diameter lesser than 10 μm were determined at the biggest student residence in Algeria located in Bab-Ezzouar, 15 km southeast from Algiers city area. Samplings were carried out from December 2009 to March 2010, and organic compounds were characterized using gas chromatography coupled with mass spectrometric detection. Volatile PAHs were also monitored inside some student residence rooms in order to evaluate the impact of indoor air pollution to student health. For the sake of comparison, aerial concentrations of n-alkanes and PAHs were determined in parallel in the Oued Smar industrial zone and two suburban areas, all located in Algiers. Total concentrations recorded in CUB1 student residence ranged from 101 to 204 ng?m^?3 for n-alkanes and from 8 to 87 ng?m^?3 for PAHs. Diel cycles have shown that, while concentrations of n-alkanes peaked at morning and afternoon–evening and dropped at night, those of PAHs exhibited higher levels at morning and night and lower levels at afternoon–evening, likely due to the reactivity of some PAHs. As expected, the indoor levels of PAHs were larger than in the outdoor of the student residence and were of serious health concern. Overall, the concentrations of n-alkanes and PAHs were as high as those observed in the industrial zone and higher than the two suburban sites.