Contribution of traffic and tobacco smoke in the distribution of polycyclic aromatic hydrocarbons on outdoor and indoor PM2.5

Traffic emissions and tobacco smoke are considered two main sources of polycyclic aromatic
hydrocarbons (PAHs) in indoor and outdoor air. In this study, the impact of these sources on
the level of fine particulate matter (PM2.5) and on the distribution of 15 PAHs regarded as
priority pollutants by the US-EPA on PM2.5 were evaluated and compared.
Outdoor and indoor PM2.5 samples were collected during winter 2008 in Oporto city in
Portugal, for sampling periods of 12 and 24 hours, respectively. The outdoor PM2.5 were
sampled at one site directly influenced by traffic emissions and the indoor PM2.5 samples were
collected at one home directly influenced by tobacco smoke and another one without smoke.
A methodology based on microwave-assisted extraction and liquid chromatography with
fluorescence detection was applied for the efficient PAHs determination in indoor and outdoor
PM2.5.
PAHs in indoor PM2.5 concentrations were significantly influenced by the presence of traffic
and tobacco smoking emissions. The mean of ΣPAHs in the outdoor traffic PM2.5 was not
significantly different from the value attained in the indoor without smoking site.
The tobacco smoke increased significantly PAHs concentrations on average about 1000
times more, when compared with the outdoor profile samples suggesting that tobacco
smoking may be the most important source of indoor PAHs pollution.