Levels and sources of polycyclic aromatic hydrocarbons in the soluble fraction of the atmospheric deposition in Cantabria (northern Spain)

Abstract

The aim of this work is to assess the levels of polycyclic aromatic hydrocarbons (PAHs) in the soluble fraction of the bulk atmospheric deposition in four sites of a small region located in northern Spain (Cantabria). Samples were collected monthly for two years at an urban site (Santander), and for one year at an industrial (Maliaño), rural (Bárcena Mayor) and traffic (Cabezón de la Sal) sites. Samples were filtered and the filtrate was extracted, concentrated, purified and analysed for 15 PAHs: acenaphthylene (ACY), acenaphthene (ACE), fluorene (FLU), phenanthrene (PHE), anthracene (ANT), fluoranthene (FLA), pyrene (PYR), benzo[a]anthracene (BaA), chrysene (CHR), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a]pyrene (BaP), indeno[1,2,3-cd]pyrene (IcdP), dibenzo[a,h]anthracene (DahA), and benzo[ghi]perylene (BghiP). The highest deposition fluxes of PAHs were found at the industrial site (Maliaño); the total PAH fluxes at the other sites were similar. Box plots of the PAH levels found in the literature in wet and bulk deposition samples were used to compare the values observed in this work. FLA, BaA, PHE and PYR were the most abundant PAHs at the industrial site. At the urban and rural site, the profile found in the deposition samples was similar: PHE>FLA>BaA>PYR. The traffic site showed a different profile: PYR>ANT>FLU>FLA. A preliminary source identification study was made by calculating diagnostic ratios of some PAH isomers (FLA/(FLA+PYR) and BaA/(BaA+CHR)); these ratios were compared with those found for the main PAH industrial and non-industrial sources in the region.