4.4. Contribution to total carcinogenicity
The concentrations obtained in the present study indicate that
the most abundant PAHs in ambient air are fluoranthene, pyrene and
phenanthrene (Table 1). However, health risk assessment of carcinogenic
PAH takes into account not only individual concentrations
of PAH, but also the carcinogenic potential of each compound. Hence,
whilst the previous PAH compounds are the most abundant, these
contribute very little to the total carcinogenicity of the PAH mixture.
Table 3 shows that the compound that most contributes to the total
carcinogenicity of the PAH mixture is BaP (48–57%) followed by DahA
(14–33%) in all locations measured. These results are consistent with
carcinogenic profiles reported in the literature, where BaP is the main
contributor to the overall carcinogenic potency of the PAH mixture
with percentage ranging 37–70%, and DahA is generally the second in
importance with most of the contributions between 16 and 42%, as
evidenced by the studies summarized in Table 3.