Concentration, variation, and correlation with traffic vehicle volume of the pollutants - polycyclic aromatic hydrocarbons (PAHs) in street dust in Hanoi

Abstract

The average concentration of 16 PAHs in street dust in Hanoi (n=27) was 1,226 ng/g, ranging from 532 to 2,276 ng/g. The total toxic equivalent amount of 16 PAHs, in comparison with BaP, TEQ_BaP was 121.58 ng/g on average and varried in a range of 35.36 and 322.22 ng/g. Amongst 16 analysed PAHs, the most abundant compounds were Pyr (16.4%)>BbF (14.0%)~Fluth (14.0%)>BghiP (12.3%)>Phe (7.9%). However, BaP occupied up to 52.6% of the toxic equivalent amount, followed by DahA (15.9%) and BkF (14.2%). In Hanoi street dust, the ratios of some special PAHs such as Fluth/Fluth+Pyr (0.46±0.04); BaA/Chr in a range of 0.27-0.49 (occupied 60% of the dust sample amount), and IcdP/BghiP (0.40±0.11), showed that the main emission source of PAHs in Hanoi road dust was from traffic vehicles using gasoline. The PAHs concentrations in street dust in Hanoi tended to be reduced up to approximately 10% in the observation for a few recent years despite the increasing traffic vehicle volume of the city. That means the better traffic vehicles and road management in Hanoi, the lesser emission of toxic organic pollutants, especially PAHs, to the ambient air.