Monitoring of Polycyclic Aromatic Hydrocarbons (Pahs) in Surface Water of the Hungarian Upper Section of the Danube River

The aim of this paper is to investigate the concentrations of polycyclic aromatic hydrocarbons (PAHs) in surface water of the Hungarian upper section of the Danube River in the period of 2007-2010. A total of 77 water samples were collected from the sampling sites located at Rajka, Medve and Komárom (1848, 1806 and 1766 river km) under the authority of the Inspectorate for Environment, Nature and Water of the North Transdanubian Region designated by the Hungarian National Monitoring Programme. Sixteen PAHs identified by the US Environmental Protection Agency (USEPA) as priority pollutants were monitored. Concentrations of total 16 PAHs (ΣPAHs) ranged from 25 to 357 ng·L-1 with the mean value of 98.27 ± 58.48 ng·L-1. The low and medium molecular weight PAHs (2-3 and 4 ring) ranged from below method detection limit (<1) to 136 ng·L-1 while high molecular weight PAHs (5-6 ring) were present at much lower concentrations (<1-25 ng·L-1). The 2-3-ring PAHs contributed to about 64% while 4-6-ring PAHs accounted for 36% of the ΣPAHs. The dominant species are naphthalene and phenanthrene in the surface water. Concentration ratios of specific PAH compounds including anthracene/(anthracene+phenanthrene) and fluoranthene/(fluoranthene+pyrene) were calculated to evaluate the possible sources of PAH contamination. The levels of ΣPAHs determined in our study were compared with other sections of the Danube and other regions of the world.