title: Model-based evaluation of the use of polycyclic aromatic hydrocarbons molecular diagnostic ratios as a source identification tool.
abstract: Polycyclic Aromatic Hydrocarbons (PAHs) molecular diagnostic ratios (MDRs) are unitless concentration ratios of pair-PAHs with the same molecular weight (MW); MDRs have long been used as a tool for PAHs source identification purposes. In the present paper, the efficiency of the MDR methodology is evaluated through the use of a multimedia fate model, the calculation of characteristic travel distances (CTD) and the estimation of air concentrations for individual PAHs as a function of distance from an initial point source. The results show that PAHs with the same MW are sometimes characterized by substantially different CTDs and therefore their air concentrations and hence MDRs are predicted to change as the distance from the original source increases. From the assessed pair-PAHs, the biggest CTD difference is seen for Fluoranthene (107 km) vs. Pyrene (26 km). This study provides a strong indication that MDRs are of limited use as a source identification tool.
authors.affiliation: Norwegian Institute for Air Research (NILU), FRAM - High North Research Centre for Climate and the Environment, Hjalmar Johanssens gt 14, NO-9296 Tromsø, Norway. Electronic address: aak@nilu.no.
authors.forename: Athanasios
authors.initials: A
authors.lastname: Katsoyiannis
authors.forename: Knut
authors.initials: K
authors.lastname: Breivik
mesh_terms: D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis* / Q000737:chemistry; D008958:Models, Molecular; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis* / Q000737:chemistry
chemical_list: D004785:Environmental Pollutants; D011084:Polycyclic Aromatic Hydrocarbons
keywords: Characteristic travel distance; Fate; Long range transport; Molecular diagnostic ratio; PAHs; Source identification