Polycyclic aromatic hydrocarbons (PAHs)

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Environ Sci Pollut Res DOI 10.1007/s11356-015-5573-5

RESEARCH ARTICLE

Polycyclic aromatic hydrocarbons (PAHs) at traffic and urban background sites of northern Greece: source apportionment of ambient PAH levels and PAH-induced lung cancer risk Evangelia Manoli 1 & Athanasios Kouras 1 & Olga Karagkiozidou 1 & Georgios Argyropoulos 1 & Dimitra Voutsa 1 & Constantini Samara 1

Received: 29 June 2015 / Accepted: 7 October 2015 # Springer-Verlag Berlin Heidelberg 2015

Abstract Thirteen particle-phase PAHs, including nine >4ring congeners [Benz[a]anthracene (BaAn), Chrysene (Chry), Benzo[b]fluoranthene (BbF), Benzo[k]fluoranthene (BkF), Benzo[e]pyrene (BeP), Benzo[a]pyrene (BaP), Dibenzo[a, h]anthracene (dBaAn), Benzo[g,h,i]perylene (BghiPe), Indeno(1,2,3-c,d)pyrene (IP)], listed by IARC (International Agency for Research on Cancer) as class 1, class 2A, and 2B carcinogens, plus four ≤4-ring congeners [Phenanthrene (Ph), Anthracene (An), Fluoranthene (Fl), Pyrene (Py)], were concurrently measured in inhalable and respirable particle fractions (PM10 and PM2.5) at a heavy-traffic and an urban background site in Thessaloniki, northern Greece, during the warm and the cold period of the year. Carcinogenic and mutagenic potencies of the PAH-bearing particles were calculated, and the inhalation cancer risk (ICR) for local population was estimated. Finally, Chemical Mass Balance (CMB) modeling was employed for the source apportionment of ambient PAH levels and the estimated lung cancer risk. Resulted inhalation cancer risk during winter was found to be equivalent in the city center and the urban background area suggesting that residential wood burning may offset the benefits from minor traffic emissions.

Keywords BaP . Chemical Mass Balance . Inhalation cancer risk . PM10 . PM2.5 . Wood burning

Responsible editor: Philippe Garrigues * Constantini Samara [email protected] 1

Environmental Pollution Control Laboratory, Department of Chemistry, Aristotle University, GR-54124 Thessaloniki, Greece

Introduction Polycyclic aromatic hydrocarbons (PAHs) are mainly produced by incomplete combustion and pyrolysis of organic material, and their occurrence in urban atmospheres is largely the result of anthropogenic emissions, such as mobile emissions (vehicular, shipping, and flying), domestic heating, oil refining, waste incineration, industrial activities, asphalt production, agricultural burning of biomass, etc. (Marchand et al. 2004; Ravindra et al. 2008a). Generally, PAHs occur in the atmosphere as complex mixtures of congeners with different molecular weights: lighter PAHs (2–3 aromatic rings) are present almost exclusively in the vapor phase, whereas PAHs with higher molecular weights (≥4 rings) are almost totally adsorbed on the particulate matter, especially its fine size range (Chrysikou and Samara 2009; Terzi and Samara 2004). These particles deposit slowly from the atmosphere and, depending on atmospheric conditions, may be airborne for days being transported over long distances. Although PAHs have been identified in remote areas, local sources rather than long-distance transport are mainly responsible for urban concentrations (Ravindra et al. 2008b). In urban areas, motor vehicles and residential wood combustion have been identified as the most significant sources of airborne PAHs (Belis et al. 2011; Gianelle et al. 2013; Manoli et al. 2002 and 2004; Masiol et al. 2012; Perrone et al. 2012; Samara et al. 2003). As many of the heaviest PAHs are carcinogenic (IARC 2010) and were, in particular, categorized by the International Agency for Research on Cancer as human carcinogens (class 1), probable (class 2A), or possible human carcinogens (class 2B) (IARC 2012), quantification of particle-phase PAHs is a key tool to assess health risks for humans exposed to airborne pollutants. The levels and distribution of PAHs in the Greek atmospheric environment during the last three decades have been

Environ Sci Pollut Res

outlined in Manoli et al. (2011). During the years 1984–2001, concentrations of total suspended particles (TSP)-bounded PAHs in various Greek cities ranged between 0.5 and 90 ng m−3 with the maximum observed in 1993–1994 in the industrial area of Thessaloniki, in northern Greece. The highest concentrations of PM10- and PM2.5-bound PAHs were also found in the city of Thessaloniki during 1994–1995, where the target value of Directive 2004/107/EC for the PM10-bound BaP (1 ng m−3 as annual average) was exceeded until the late 90s. The Chemical Mass Balance (CMB) source apportionment of PM 10 at three urban traffic sites in Thessaloniki in 1997 indicated vehicular emissions as the major source of PAHs in the commercial city center and the eastern (residential) sector, with a significant contribution from oil burning in the western sector located close to the industrial area (Samara et al. 2003). After 2000, a declining trend of PAH concentrations was observed in most Greek cities attributable to the pollution abatement measures implemented for air quality improvement (replacement of non-catalyst equipped cars by catalytic ones, fuel quality improvement, occasional use of smoke traps in diesel-fueled buses, increased industrial and domestic use of natural gas, etc.). Nevertheless, the significant increase of the price of fuel oil popularly used for residential heating in 2010, in association with the economic crisis started by the end of 2009, deteriorated air quality in large urban agglomerations. For instance, while ambient PM10 and PM2.5 levels in Thessaloniki during the years of economic crisis (2010–2012) decreased by around 20 % in comparison to the before-crisis years (2007–2009), probably as a result of reduced vehicular traffic, wintertime PM10 and PM2.5 levels increased by 13 and 25 %, respectively, and the hourly peak shifted to the late evening hours, when people could smell a distinct wood smoke odor in the air (Petrakakis et al. 2013). A sampling campaign conducted at an urban background site in Thessaloniki during winter 2013 indicated a 30 % increase in PM2.5 levels in comparison to winter 2012, associated with a twofold to fivefold increase in the concentration of wood burning tracers (water-soluble potassium, levoglucosan, mannosan, galactosan) and a fivefold increase in the concentration of BaP (Saffari et al. 2013). The aim of this study was to comparatively investigate the levels of particle-bound PAHs at an urban background and a heavy-traffic site in Thessaloniki during the warm and the cold period of the year, to assess the associated inhalation cancer risks and to identify/apportion the major PAH sources. Analyzed PAHs were chosen to be consistent with the European Directive and include the higher molecular weight congeners of the USEPA priority pollutant list, i.e., those mainly partitioned in the particulate phase. The spatial variations and seasonal trends of PAHs, their size distribution, the relationships with other air pollutants, and micrometeorological parameters were investigated. Chemical Mass Balance

modeling was employed for source apportionment of ambient PAHs. Carcinogenic and mutagenic potencies of PAH-bearing particles were calculated. Finally, the inhalation cancer risk was assessed and apportioned to specific PAH sources. Results were discussed to identify the critical features of the PAH pollution in Greek cities due to residential wood combustion and help outlining some measures to protect human health.

Materials and methods Site description Built at the innermost point of Thermaikos Gulf, Thessaloniki (40° 62′ E, 22° 95′ N), is the second largest Greek city and the second largest of Greece’s major commercial ports. The city is surrounded by hills to the north and the mountain Hortiatis (1200 m height) to the east. Several industrial activities (oil refining and petrochemical facilities, metal scrap incineration, iron and steel manufacturing, electrolytic MnO2 production, lubricating oil recovery, cement and lime production, quarry works) are located at variable distances to the W, NW and N. Prevailing winds are weak (1–3 m s−1) with a prominent influence of the local circulation system of sea/land breeze, while frequently occurring calms (

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