Source, profile, and carcinogenic risk assessment for cohorts occupationally exposed to dust-bound PAHs in Lahore and Rawalpindi cities (Punjab province, Pakistan)

In this study, the occurrence and concentrations of PAHs in dust samples, which were collected from the traffic police cabins/working spots, located on the main busy roads of Lahore (TP-L) and Rawalpindi (TP-R) cities (Punjab province, Pakistan) and from the public transport vehicles in the same cities (named as AM-L and AM-R, respectively) were determined. The mean and median concentrations of ΣPAHs were observed in the following descending order: AM-L (1340 and 774 ng g−1 d.w., respectively), TP-L (866 and 854 ng g−1 d.w.), TP-R (504 and 379 ng g−1 d.w.), and AMR (393 and 290 ng g−1 d.w. Source apportionment of the soil/dust-bound PAHs was also performed. In all the sampling areas, the diagnostic ratios, principal component analysis (PCA) followed by multiple linear regression (MLR) analysis indicated signatures of mixed sources of PAHs (including vehicular exhaust emission, gasoline/diesel, and coal/wood combustion). Estimated results of incremental lifetime cancer risk (ILCR) indicated that the traffic policemen and drivers, especially those in the urban area of Lahore, were at high risk of cancer via routes of dust ingestion and dermal contact. The results of this research could be very useful for the local Government in order to control the exposure and promote actions to alleviate PAH contamination and to manage health both at work places in the big cities of Pakistan.