Spatiotemporal Gradients of PAH Concentrations in Greek Cities and Associated Exposure Impacts

Irini Tsiodra; Kalliopi Tavernaraki; Georgios Grivas; Constantine Parinos; Kyriaki Papoutsidaki; Despina Paraskevopoulou; Eleni Liakakou; Alexandra Gogou; Aikaterini Bougiatioti; Evangelos Gerasopoulos; Maria Kanakidou; Nikolaos Mihalopoulos

doi:10.3390/toxics12040293

Spatiotemporal Gradients of PAH Concentrations in Greek Cities and Associated Exposure Impacts

Toxics. 2024 Apr 16;12(4):293. doi: 10.3390/toxics12040293.

Authors

Irini Tsiodra¹, Kalliopi Tavernaraki^{1

2}, Georgios Grivas¹, Constantine Parinos³, Kyriaki Papoutsidaki², Despina Paraskevopoulou^{1

2}, Eleni Liakakou¹, Alexandra Gogou³, Aikaterini Bougiatioti¹, Evangelos Gerasopoulos¹, Maria Kanakidou^{2

4

5}, Nikolaos Mihalopoulos^{1

2}

Affiliations

¹ Institute for Environmental Research and Sustainable Development, National Observatory of Athens, 15236 Athens, Greece.
² Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 71003 Heraklion, Greece.
³ Institute of Oceanography, Hellenic Centre for Marine Research, 19013 Anavyssos, Greece.
⁴ Center for Studies of Air Quality and Climate Change, Institute for Chemical Engineering Sciences, Foundation for Research and Technology Hellas, 26504 Patras, Greece.
⁵ Institute of Environmental Physics, University of Bremen, 28359 Bremen, Germany.

Abstract

To study the spatiotemporal variability of particle-bound polycyclic aromatic hydrocarbons (PAHs) and assess their carcinogenic potential in six contrasting urban environments in Greece, a total of 305 filter samples were collected and analyzed. Sampling sites included a variety of urban background, traffic (Athens, Ioannina and Heraklion), rural (Xanthi) and near-port locations (Piraeus and Volos). When considering the sum of 16 U.S. EPA priority PAHs, as well as that of the six EU-proposed members, average concentrations observed across locations during summer varied moderately (0.4-2.2 ng m^-3) and independently of the population of each site, with the highest values observed in the areas of Piraeus and Volos that are affected by port and industrial activities. Winter levels were significantly higher and more spatially variable compared to summer, with the seasonal enhancement ranging from 7 times in Piraeus to 98 times in Ioannina, indicating the large impact of PAH emissions from residential wood burning. Regarding benzo(a)pyrene (BaP), an IARC Group 1 carcinogen and the only EU-regulated PAH, the winter/summer ratios were 24-33 in Athens, Volos, Heraklion and Xanthi; 60 in Piraeus; and 480 in Ioannina, which is afflicted by severe wood-burning pollution events. An excellent correlation was observed between organic carbon (OC) and benzo(a)pyrene (BaP) during the cold period at all urban sites (r² > 0.8) with stable BaP/OC slopes (0.09-0.14 × 10^-3), highlighting the potential use of OC as a proxy for the estimation of BaP in winter conditions. The identified spatiotemporal contrasts, which were explored for the first time for PAHs at such a scale in the Eastern Mediterranean, provide important insights into sources and controlling atmospheric conditions and reveal large deviations in exposure risks among cities that raise the issue of environmental injustice on a national level.

Keywords: Eastern Mediterranean; Greece; benzo(a)pyrene; biomass burning; diagnostic ratio; exposure risk; polycyclic aromatic hydrocarbons.

Grants and funding

3232/Hellenic Foundation for Research and Innovation