Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental
contaminants that are either man-made or occur naturally. A
number of them are carcinogenic and/or mutagenic, which may have
a significant contribution to human cancer (Liu et al., 2008). They are
usually released as a result of automobile exhaust, industrial emissions
and tobacco smoke (Rodgman et al., 2000; Chang et al., 2006).