Water Air Soil Pollut (2011) 215:189–203 DOI 10.1007/s11270-010-0469-y
Biomonitoring of Polycyclic Aromatic Hydrocarbons Contamination in the Island of Crete Using Pine Needles Nuno Ratola & Arminda Alves & Elefteria Psillakis
Received: 12 January 2010 / Accepted: 4 May 2010 / Published online: 26 May 2010 # Springer Science+Business Media B.V. 2010
Abstract Pine needles were selected as cost-effective and easy collectable matrices suitable for long-term monitoring of the lower troposphere pollution with polycyclic aromatic hydrocarbons (PAHs). Overall, 27 sampling sites around the island of Crete were selected, and upon availability, second- and third-year needles from two pine species (Pinus brutia Ten. and Pinus pinea L.) were collected. In general, the results for both pine species showed that sites belonging in the urban group yielded the highest contamination levels when compared to the rural and the remote ones and that third-year needles had higher PAH contamination than the second-year ones. Phenanthrene was the prevailing PAH, representing 39% and 46% of the total contamination for second- and thirdyear needles, respectively. Fluoranthene, pyrene, chrysene and fluorene followed, with individual concentrations between 6% and 12%. The dominance of three-ringed PAHs was evidenced for the vast majority of the sites. An urban, rural and remote N. Ratola : A. Alves LEPAE, Department of Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal E. Psillakis (*) Department of Environmental Engineering, Technical University of Crete, Polytechneioupolis, 73100 Chania, Greece e-mail:
[email protected]
fingerprint was determined over a more general uniform contamination pattern, and the diagnostic PAH ratios pointed towards mixed petrogenic and pyrogenic sources. Overall, the present findings showed that the presence of PAHs is not negligible throughout the Cretan atmosphere and can be even considered quite high in some areas, especially when comparing the results to the ones found for more densely populated or industry-related areas. Keywords PAHs . Passive vegetation samplers . Ultrasonic extraction . GC-MS
1 Introduction Over the past years, biomonitoring methods using passive vegetation samplers proved to be a practicable low-cost alternative, especially in terms of high spatial resolution and time-averaged data series. In this context, pine needles represent typical natural passive air samplers. The lipid-rich cuticle and pore structure of pine needles surfaces give them a high affinity for vapour phase semi-volatile organic compounds and can intercept particles. The occurrence of polycyclic aromatic hydrocarbons (PAHs), a ubiquitous class of pollutants with established carcinogenic and mutagenic properties (IARC 1991), in needles of some pine species was studied from remote to densely populated and industrialised sites of several countries such as the UK (Tremolada et al. 1996), the USA
190
(Hwang et al. 2003; Hwang and Wade 2008), China (Liu et al. 2006), Germany (Lehndorff and Schwark 2004; Wenzel et al. 1997), Italy (Librando et al. 2002; Piccardo et al. 2005), Portugal and Spain (Ratola et al. 2006, 2009), Poland (Malawska et al. 2002), Mexico and Korea (Hwang et al. 2003), Argentina (Wenzel et al. 1997), Czech Republic (Holoubek et al. 2000) or Russia (Gorshkov 2008). Being the southernmost part of Europe and in a rather isolated position, the island of Crete is the fifth biggest island in the Mediterranean Sea, with an area of 8,336 km2 and population over 600,000. Previous work revealed that the atmosphere of Crete suffers from long-range transport from the neighbouring regions (Mihalopoulos et al. 1997), and it was reported that PAH release from the heavy forest fires in mainland Greece may also account for the levels in the island (Stephanou 1991). Indeed, Greece is considered as one of the most affected member states in Europe, and in 2006, Greece had a 12,661.4-ha total burned area of which 176.9 ha was reported in the region of Crete and 2,373.1 ha in the neighbouring mainland region of Peloponisou (EUR 22931 EN 2007). The assessment of PAH levels in the Eastern Mediterranean area in general and in Crete in particular has been reported in the atmosphere (Mastral et al. 2003), sediments (Gogou et al. 2000; Tsapakis et al. 2003), soil and sand (Martens et al. 1998) and waters (Tsapakis et al. 2006; Terzakis et al. 2008). Besides the frequent forest fires taking place in the summer months, other possible local PAH sources include traffic (both land and maritime), due to increased tourism-related activities, as shown in Table 1. In terms of motor vehicles, there is a predominance of passenger cars in the island (51% of the total vehicles), but with a considerable incidence of trucks (25%) and motorcycles (23%; ΕΣΥΕ—National Statistical Service of Greece 2010). In this context, fuel consumption is divided into diesel oil (41%) and crude oil (59%; Syllignakis and Papazoglu 2006). Maritime traffic is observed mostly in the large ports of Souda (near Chania) and Heraklion, although other minor ports, such as in Hora Sfakion, are typically busy during the summer months. As to the energy production, 87% is covered by three major conventional oil-fired power plants situated in Atherinolakkos (Lasithi) and in the suburban of Chania and Heraklion. It should be mentioned here that industrial activities are rather
Water Air Soil Pollut (2011) 215:189–203
scarce in the island, and this sector only accounts for 8.8% of the total energy consumption. The purpose of this study was to quantify for the first time in Crete PAH contamination using pine needles, a cost-effective and easy collectable environmental matrix. Despite the sparse forest coverage of the island (5% of the total vegetation; Sarris et al. 2005), pine trees could be found in urban, rural and remote areas. Twenty-seven sampling sites throughout Crete were selected, allowing a thorough assessment and characterisation of the presence of PAHs. Upon availability in each site, two pine species were used, namely Pinus brutia Ten. (native to the Eastern Mediterranean area) and Pinus pinea L. (widespread in the Mediterranean region). Pine trees can generally maintain the needles of each shoot for several years, and as such, needles from the second- and third-year shoots were collected to discuss results in terms of needle age, as well as site type (urban, rural or remote) and pine species. Possible sources of contamination were assigned based on the most abundant compounds and diagnostic PAH ratios. Fingerprint techniques enabled differences in the PAH composition among the different type areas to be highlighted. Finally, the results of the present investigation were discussed and compared with others found in the literature.
2 Methods and Materials 2.1 Chemicals and Reagents The 16 priority PAHs investigated here (naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a] anthracene, chrysene, benzo[b]fluoranthene, benzo[k] fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene, dibenzo[a,h]anthracene and benzo[ghi]perylene) were obtained from Supelco (Bellefonte, PA, USA) at 2,000 mg L−1 (in hexane). A mixture of deuterated PAHs containing naphthalene-d8, acenaphthene-d10, phenanthrene-d10, chrysene-d12 and perylene-d12 (2,000 mg L−1 in hexane) was used as the internal standard solution (Supelco, Bellefonte, PA, USA). Anthracene-d10 (200 mg L−1 in hexane) also from Supelco was added just before chromatographic analysis in order to detect possible instrumental errors. International Sorbent Technology (Mid Gla-
Hora Sfakion Sougia Elafonisi Samaria
13
6
8
19
a
Kato Zakros
16
Moni Preveli
Moni Toplou
20
Spili
Analipsi
2
5
Lasithi Plateau
23
7
Sitia
9
Rethymno Anogia
Agios Nikolaos
1
17 12
Ierapetra
15
Pyrgos Knossos Festos
27 24 10
6
642
27,868 2,454
24
47
502
3,152
8,238
10,080
11,678
1,098 360 0
3,722
8,018
12,542
130,914
0
0
109
278
2,213
3,757
3,821
55,838 6,384
186
421
115 805
5
165
7
820
34
12
10
281 106 94
19
40
34
37
1,220
4
5
10
11
158
10
19 6
Traffic
Intense farming
Traffic
Oil refinery, power station
Airport
Port
Port, naval base
Population Altitude Possible point (m) sources (
