Comparison of pah levels and sources in pine needles from Portugal, Spain, and GreeceComparison of pah levels and sources in pine needles from Portugal, Spain, and Greece Peer-Reviewed Journal Publication Δημοσίευση σε Περιοδικό με Κριτές 2015-09-252012enThe main objective of this work was to assess and compare the levels, patterns, and sources of contamination of 16 polycyclic aromatic hydrocarbons (PAHs) between Portugal, Spain, and Greece (in the island of Crete). A total of 9 sampling sites were chosen (4 in urban and 5 in non-urban areas) in each country and pine needles from the Pinus pinea L. species were collected. Although the mean total PAH levels was similar in the three countries (279 ± 236 ng g−1 for Portugal, 294 ± 258 ng g−1 for Spain, 301 ± 253 ng g−1 for Greece, all dry weight) and, in general, 3-ring and 4-ring PAHs were predominant (being phenanthrene consistently the most abundant), there were some visible differences in the aromatic ring patterns and possible sources between the three regions. Source apportionment was done using PAH ratios (Phen/Ant and Flt/Pyr crossplots) and reflected mixed petrogenic and pyrogenic sources. Furthermore, Principal Component Analysis (PCA) clearly separated the urban and the non-urban sites and all three countries, which reinforces that the sources of contaminations vary in each case and the suitability of pine needles for trans-boundary biomonitoring of PAHs.http://creativecommons.org/licenses/by/4.0/Analytical Letters455-6508-525 Elefteria Psillaki Arminda Alves Damià Barceló Nuno Ratola José Manuel Amigo Sílvia Lacorte Taylor & Francis Group