Marine Pollution Bulletin xxx (2014) xxx–xxx
Contents lists available at ScienceDirect
Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul
Baseline
Distribution and sources of polycyclic aromatic hydrocarbons in the surface sediments of Gorgan Bay, Caspian Sea Peyman Eghtesadi Araghi ⇑, Kazem Darvish Bastami, Shirin Rahmanpoor Iranian National Institute for Oceanography and Atmospheric Science (INIOAS), No. 3, Etemadzadeh St., Fatemi Ave., Tehran 1411813389, Islamic Republic of Iran
a r t i c l e
i n f o
Keywords: Polycyclic aromatic hydrocarbons (PAHs) Sediment Gorgan Bay Caspian Sea
a b s t r a c t The level and source of 16 polycyclic aromatic hydrocarbons (PAHs) were investigated in the surface sediments from the Gorgan Bay, Caspian Sea. The sum of 16 PAHs (RPAH16) concentrations varied from 107.87 to 516.18 ng g1 dry weight, with average value of 270.96 ± 150.47 ng g1 dry weight. Ecological risk assessment of PAHs, indicated that adverse biological effects caused by acenaphthene, naphthalene, fluoranthene and Pyrene occasionally and frequently may take place in the sediments of Gorgan Bay. PAHs source identification demonstrated that the PAHs come from mixed and pyrogenic origin. Crown Copyright Ó 2013 Published by Elsevier Ltd. All rights reserved.
Polycyclic aromatic hydrocarbons (PAHs) are among the most important contaminants in the marine environment which are produced from different resources. PAHs are a large group of organic compounds with two or more fused aromatic rings. They have mutagenic and carcinogenic activity that are usually present in the air, water and aquatic system, soils and sediments (Neff, 1979). These compounds are generally generated by natural and anthropogenic processes and can be introduced into the environments through various routes. Anthropogenic input from incomplete combustion, oil spills, urban runoff, domestic and industrial wastewater discharges, as well as atmospheric fallout of vehicle exhaust and industrial stack emission have caused significant accumulation of these compounds in the environments (Nadal et al. 2004; Durand et al. 2004). The Gorgan Bay located at the southeastern section of the Caspian Sea with 60 km length and 12 km width, is a semi-enclosed basin, as it receives no wave’s energy from the Caspian Sea. The Bay is mostly affected by the currents originating from inside the basin. This area is best known for its high economical and ecological importance as a fishing and recreational ground because of appropriate biological conditions for aquatic animals. The Gorgan Bay is the ultimate sink for water flows from Gharehso River. The Gorgan River faces the Caspian Sea at the vicinity of the Bay mouth at the northeast part (Bastami et al., 2012). Little information is available on PAH in the sediment of Gorgan Bay, therefore; the objective of this study was to determine the concentration and possible sources of PAHs in the sediment of Gorgan Bay. ⇑ Corresponding author. Tel.: +98 9124755635. E-mail address: [email protected] (P.E. Araghi).
Fifteen stations were selected for this study and sediments of sites were collected by using van veen grab in August, 2010 (Fig. 1). The samples are collected in aluminium container and kept it in the freezer (20 °C). Sediment samples obtained from one location was mixed and a composite sample was prepared. Then, these sediment samples (200 g of sediment) were freeze dried (freeze-drier Model: OPR-FDB-5503, Korea) at 40 °C for 24 h to a constant weight. 10 g of each sample were mixed with 250 ml of n-hexane and dichloromethane mixture (1:1 ratio). The mixture was placed for 8 h in Soxhlet. The combined extracts were evaporated on a rotary vacuum evaporator until 15 ml was left. To eliminate sulphur and their compounds, 3 g of active copper was added to the mixture and allowed to pass through a folded filter paper (Whatman GF/ C, 24micron) for 24 h. The mixture was concentrated in a rotary (Buchi B-490) to a volume of 5 ml. Samples were allowed to pass through a column containing 10 g silica gel in n-hexane, 1–2 g anhydrous sodium sulphate and 10 g alumina. Then, 30 ml of n-hexane and dichloromethane mixture (9:1 ratio) were added to the column. Samples were concentrated again in a rotary evaporator to a volume of 5 ml. The concentrated extract was dried under nitrogen steam (N-E VAP 112, USA). The residue was dissolved in 1 ml of acetonitrile (MOOPAM, 1999). The PAHs were detected with a Hewlett–Packard 1100 HPLC equipped with an Agilent-1100 fluorescence and UV detector. Injection volume was 20 ll. The initial mobile phase was 60% acetonitrile and 40% HPLC water for 8 min, which was then gradiently changed to 100% acetonitrile in 5 min, held at 100% for 22 min, then decreased to initial phase. In this analysis the column type was RESTEK, Pinacle II PAH (150 3.2 mm, 5 lm) and temperature was 25 °C.
http://dx.doi.org/10.1016/j.marpolbul.2013.12.001 0025-326X/Crown Copyright Ó 2013 Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Araghi, P.E., et al. Distribution and sources of polycyclic aromatic hydrocarbons in the surface sediments of Gorgan Bay, Caspian Sea. Mar. Pollut. Bull. (2014), http://dx.doi.org/10.1016/j.marpolbul.2013.12.001
2
P.E. Araghi et al. / Marine Pollution Bulletin xxx (2014) xxx–xxx
Fig. 1. The locations of the sampling sites at the Gorgan Bay.
The sixteen most toxic PAHs listed by the USEPA (Bashe and Baker, 1990) were assessed in three sample media. The abbreviations used for the identified PAHs are: naphthalene, N; acenaphthylene, AC; acenaphthene, ACE; fluorene, F; phenanthrene, Ph; anthracene, A; fluoranthene, Fl; pyrene, Py; benzo (a) anthracene, B(a)A; chrysene, Ch; benzo (b) fluoranthene, B(b)Fl; benzo (k) fluoranthene, B(k)Fl; benzo (a) pyrene, B(a)Py; indeno (1, 2, 3-c, d) pyrene, IPy; dibenz (a, h) anthracene, DB(ah)A; benzo (ghi) perylene, B(ghi)Pe. Replicate samples, certified reference materials IAEA-417 and procedural blanks were used as quality control procedures. All the obtained values for PAHs in CRM were in the reported range. Reproducibility and recovery were high (85–110%) with relative standard deviation (RSD) 4–11%. To measure the quality control, the procedural blanks were periodically analysed for each batch of 10 samples. Quantitative analysis was conducted on a three-point linear calibration of PAH solution, obtained by dilution of the certified standard mixture of 16-PAH (kit 610-N-Supelco4-7351). The method detection limits (MDLs) of PAHs were determined with a signal-to-noise ratio (S/N) of 3. The MDLs were between 0.1 and 1 ng/g. Satisfactory linearity was obtained with values of the correlation coefficient R above 0.99. For determination of organic matter, sediment samples were dried at 70 °C for 24 h and then combusted in an oven at 550 °C for 4 h. Total organic matter, as described by Abrantes et al. (1999), was measured by the following equation:
Total organic matter ðTOM; %Þ ¼ ðB C=BÞ 100 where B and C are the weights of dried sediment before and after combusting in the oven, respectively. Sediment grain size analysis was made from sediment samples collected in separate polythene bags. For that, samples were air dried and sieved through a mechanical sieve to remove shells, debris, etc. Dried sediment samples were
subjected to size fraction analysis following the procedure of Wentworth (1992). Hundred grams of sample was taken and sieved through a 62 lm mesh-sized screen for 10 min in a mechanical sieve shaker. The sample that remained in the sieve was weighed and treated as sand. The sediment samples which passed through the sieve were the silt and clay. The silt and clay fractions were then separated by means of pipette method, described by Lindholm (1987). Regression Correlation was employed for a better understanding of the relationship between the concentration of PAHs, Clay and TOM by using statistical package of SPSS 19. The sand, silt and clay contents averaged 23.38 ± 27.56%, 36.61 ± 18.3%, and 39.76 ± 14.40%, respectively (Table 1). Gorgan Bay depth ranges from 0.62 to 4.12 m with an average value of 1.84 ± 1.14 m. The highest and the lowest depths were observed at stations 6 and 10, respectively. Regarding to the analysis, TOM content in sediment of the Gorgan Bay was 1.75–9% (averaged 4.45 ± 1.72%) which exhibited the highest and the lowest amounts at stations 15 and 14, respectively. As proposed by Marin et al. (2008), ecological quality status is classified into three levels according to organic matter content: high-good (less than 5%), moderate (between 5% and 10%) and poor-bad (greater than 10%). As illustrated in Table 1, TOM content of all stations was less than the presented above range (1.75–9%) in the current study. According to their proposal, stations 1, 2, 3, 4, 7, 8, 9, 10, 12, 13, and 14 showed a high-good quality while the remaining stations (5, 6, 11 and 15) should be classified as moderate. Ten PAHs were measured at detectable levels in the sediment from Gorgan Bay. The highest concentration of individual PAH was Fluoranthene, while B (a) anthracen showed the lowest concentration in the sediment of Gorgan Bay (Fig. 2). The concenP tration of PAHs ranges 107.87–516.18 ng g1 dry weight with an average value of 274.31 ± 152.29 ng g1 dry weight (Table 2).
Please cite this article in press as: Araghi, P.E., et al. Distribution and sources of polycyclic aromatic hydrocarbons in the surface sediments of Gorgan Bay, Caspian Sea. Mar. Pollut. Bull. (2014), http://dx.doi.org/10.1016/j.marpolbul.2013.12.001
3
P.E. Araghi et al. / Marine Pollution Bulletin xxx (2014) xxx–xxx Table 1 General characteristics of sediments sampled at the Gorgan Bay. Location
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Average ± SD
N36.92678 N36.90136 N36.85419 N36.81467 N36.87553 N36.83781 N36.79842 N36.86936 N36.83289 N36.79514 N36.80301 N36.89981 N36.85264 N36.82233 N36.80717 –
E54.02814 E54.03072 E54.03125 E54.03192 E53.90889 E53.90906 E53.91261 E53.78997 E53.79058 E53.79281 E53.79083 E53.95894 E53.57528 E53.61694 E53.57667
Depth (m)
TOM (%)
Clay (%)
Sand (%)
Silt (%)
3.65 3.07 2.24 1.46 2.87 4.12 2.35 1.54 1.05 0.62 0.76 1.5 0.77 0.65 1.03 1.84 ± 1.14
3.5 3.75 3.5 4 5.75 6 4 3.5 3.75 3 6.25 4.75 4.25 1.75 9 4.45 ± 1.72
37.56 35.35 34.72 32.68 50.76 59.04 41.51 44.74 53.66 36.76 50.62 27.75 23.62 6.5 61.05 39.75 ± 14.40
20.42 11.85 0.79 0.66 0.86 0.43 34.43 26.9 4 58.71 17.39 18.22 65.1 89.62 1.37 23.38 ± 27.56
42.02 52.18 64.49 66.66 48.18 40.52 24.07 28.36 39.46 13.54 45.85 31.16 11.27 3.88 37.58 36.61 ± 18.31
en e ph t hy A len ce na ph th en e Fl uo re Ph ne en an th en A e nt hr ac en Fl uo e ra nt he ne Py B( re a) ne an th ra Be ce n nz o[ Cr b] y Be se flu n nz or an o[ k] th en flu e or an th e ne B Di (a be )p nz In y o re de A n ne nt [1 hr ,2 a ce ,3 -c n Be d] nz py o[ r e gh i]p ne er yl en e
300 250 200 150 100 50 0
na
Ac e
Na p
ht ha l
ng/g dw
Sampling site
Fig. 2. Average (±SD) individual PAH in sediment (ng g1 dry weight) of the Gorgan Bay.
The processes controlling the level of PAHs in the sediments are complex. It has been demonstrated that the nature of the sediments influences the distribution and concentration of PAHs. The distributions of PAHs in the sediments are affected by chemical composition of the sediments such as organic matter and clay content. The sediments with high levels of organic matter have a strong affinity to hydrophobic compounds, such as PAHs, in comparison with sediments with low levels of organic matter (MacRae and Hall, 1998, Xia and Wang, 2008). Furthermore, the PAHs are mainly adsorbed in the small particles (clay), which have a greater capacity for adsorption because of their greater specific surface area (Xia and Wang, 2008). In the present study the regression analysis was completed to P investigate the relationship between the concentration of PAHs and the percentage of organic matter and clay. The linear regresP sions show no significant correlation between PAHs with total organic matter (P > 0.05), while a significant correlation was found P between clay and PAHs (P < 0.05) (Fig. 3).This study, suggest that the distribution and concentration of PAHs in sediments of Gorgan Bay is determined by the type of the sediment found locally. P Data in Table 3 shows concentration of PAHs in sediment of P other locations. Concentrations of the total PAHs in this study were lower than those found in some aquatic environments but were higher than those in other locations (Table 3). Although a quantitative comparison across reported PAH data is difficult because of variances in the number and type of individual species determined in each study, the sediment fraction analysed, and the analytical methods used. According to Baumard et al. (1998), PAH pollution levels can be characterized as low, moderate, high, and very high when the total PAHs concentrations are 0–100 ng g1 dry weight, 100–1000 ng g1 dry weight, 1000–5000 ng g1 dry weight, and >5000 ng g1 dry
weight, respectively. Based on this classification, sediments from Gorgan Bay (107.87 to 516.18 ng g1 dry weight) could be considered as moderately polluted with PAHs. Sediment quality guidelines (SQGs) are an important tool for the assessment of contamination in marine and estuarine sediments (Long et al., 1995). In this study, two sets of SQGs, including: (a) the ERL/ERM and (b) the TEL/PEL values were applied to assess the ecological toxicity of individual PAH concentrations in sediments. According to SQGs adverse biological effects are expected rarely (0.5 implies grass, wood, or coal combustion. To distinguish samples containing petrogenic or pyrogenic PAH, the ratios of Anthracene/(anthracene + phenanthrene), Benzo[a] anthracene/(Benzo[a] anthracene + chrysen) and fluoranthene/ (fluoranthene + pyrene) were used and the results for all sites appear in Table 4.
Please cite this article in press as: Araghi, P.E., et al. Distribution and sources of polycyclic aromatic hydrocarbons in the surface sediments of Gorgan Bay, Caspian Sea. Mar. Pollut. Bull. (2014), http://dx.doi.org/10.1016/j.marpolbul.2013.12.001
P.E. Araghi et al. / Marine Pollution Bulletin xxx (2014) xxx–xxx Table 4 Characteristic PAH molecular diagnostic ratios.
a b c
Sampling sites
An/An + pha
Flt/Flt + Pyb
BaA/BaA + Chc
Petrogenic Pyrogenic 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
0.1 0.84 – – – –
0.4 0.94 – – 0.84 – 0.91 – 0.73 0.58 – – – – – 0.97
0.35 0.35 – 0.35 – 0.33 0.33 – 0.42 0.35 0.37 – – 0.33 – –
– 0.96 0.33 – 0.31 – – –
Anthracene/(anthracene + phenanthrene). Fluoranthene/(fluoranthene + pyrene). Benzo[a] anthracene/(Benzo[a] anthracene + chrysen).
In this study, BaA/BaA + CHR ratio in surface sediment at sites 1, 3, 5, 6 and 13 were between 0.2 and 0.35, indicating mixed sources of PAH. Ratio of ANT/ANT + PHE was higher than 0.1 in all sampling sites, suggesting pyrolitic sources of PAHs. Range of Flu/Flu + Pyr ratio was 0.58 and 0.97 in all sampling sites, demonstrating grass, wood, or coal combustion sources of PAHs. These findings suggest that the sources of PAHs in the surface sediments of Gorgan Bay could arise from mixed sources, with pyrogenic -related contamination as the dominant source. The diagnostic ratios used in this study defined different origin of PAHs at sampling sites. This might be due to the complexity of the parameters determining PAHs distributions in the environment. This study provides important information on PAH concentrations in surface sediments of the Gorgan Bay (Caspian Sea). Contamination levels of PAHs in the Gorgan Bay were lower than those found in some aquatic environments but were higher than those in other locations. Acenaphthene, naphthalene, fluoranthene and pyrene concentrations were high in sediment from the Gorgan Bay. This may cause toxicity to certain exposed organisms.
References Abrantes, A., Pinto, F., Moreira, M., 1999. Ecology of polychaete Nereis diversicolor, in the Cannal de Mira (Ria de averio, Portugal). Population dynamics, production and oogenic cycle. Acta Oceanol. 20 (4), 267–283. Anderson, J.W., Newton, F.C., Hardin, J., Tukey, R.H., Richter, K.E., 1996. Chemistry and toxicity of sediments from San Diego Bay including a biomarker (P450 RGS) response. In: Bengtson, D.A., Henshel, D.S. (Eds.), Environmental Toxicology and Risk Assessment. Biomarkers and Risk Assessment, ASTM STP 1306, vol. 5. American Society for Testing and Materials, Philadelphia, pp. 53–78. Badawy, M.I., Al-Mujainy, I.S., Hernandez, M.D., 1993. Petroleum derived hydrocarbons in water, sediment and biota from the Mina al Fahal coastal waters. Mar. Pollut. Bull. 26, 457–460. Bashe, W.J., Baker, T.V., 1990. Determination of Polycyclic Aromatic Hydrocarbons in Drinking Water by Liquid–Solid Extraction and HPLC with Coupled
5
Ultraviolet and Fluorescence Detection. In: USEPA Method 550.1: 143-167. Environmental Monitoring Systems Laboratory, Ohio, USA. Bastami, K.D., Bagheri, H., Haghparast, S., Soltani, F., Hamzehpoor, A., Bastami, M.D., 2012. Geochemical and geo-statistical assessment of selected heavy metals in the surface sediments of the Gorgan Bay, Iran. Mar. Pollut. Bull. 64, 2877–2884. Bastami, K.D., Afkhami, M., Ehsanpour, M., Kazaali, A., Mohammadizadeh, M., Haghparast, S., Soltani, F., Zanjani, S.A., Ghorghani, N,F., Pourzare, R., 2013. Polycyclic aromatic hydrocarbons in the coastal water, surface sediment and mullet Liza klunzingeri from northern part of Hormuz strait (Persian Gulf). Mar. Pollut. Bull. . Baumard, P., Budzinski, H., Garrigues, P., Sorbe, J.C., Burgeot, T., Belloca, J., 1998. Concentration of PAH in various marine organisms in relation to those in sediments to trophic level. Mar. Pollut. Bull. 36, 951–960. Durand, C., Ruban, V., et al., 2004. Characterization of the organic matter of sludge: determination of lipids, hydrocarbons and PAHs from road retention/infiltration ponds in France. Environ. Pollut. 132, 375–384. Eghtesadi, P., Riazi, G., Taghikhani, M., Ranaei Siadat, S.O., 2002. Distribution and sources of polycyclic aromatic hydrocarbons in the northern Persian Gulf as indicated by kinetic and thermodynamic criteria. Bull. Environ. Contam. Toxicol. 69 (5), 704–711. Hu, N.J., Shi, X.F., Liu, J.H., Huang, P., Liu, Y.G., Liu, Y., 2010. Concentrations and possible sources of PAHs in sediments from Bohai Bay and adjacent shelf. Environ. Earth Sci. 60, 1771–1782. Kim, G.B., Maruya, K.A., Lee, R.F., Lee, J.H., Koh, C.H., Tanabe, S., 1999. Distribution and sources of polycyclic aromatic hydrocarbons in sediments from Kyeonggi Bay, Korea. Mar. Pollut. Bull. 38, 7–15. Lindholm, R., 1987. A Practical Approach to Sedimentology. Allen and Unwin, London, pp. 1–278. Liu, Y., Ling, C.N., Zhao, J.F., Huang, Q.H., Zhu, Z.L., Gao, H.W., 2008. Distribution and sources of polycyclic aromatic hydrocarbons in surface sediments of rivers and an estuary in Shanghai, China. Environ. Pollut. 154, 298–305. Long, E.R., MacDonald, D.D., Smith, S.L., Calder, F.D., 1995. Incidence of adverse biological effects within ranges of chemical concentrations in marine and estuarine sediments. J. Environ. Manage. 19, 18–97. Lubecki, L., Kowalewska, G., 2012. Indices of PAH origin – a case study of the Gulf of Gdansk (SE Baltic) sediments. Polycyclic Aromat. Compd. 32, 335–363. MacDonald, D.D., Carr, R.S., Calder, F.D., Long, E.R., Ingersoll, C.G., 1996. Development and evaluation of sediment quality guidelines for Florida coastal waters. Ecotoxicology 5, 253–278. MacRae, J.D., Hall, K.J., 1998. Biodegradation of polycyclic aromatic hydrocarbons (PAHs) in marine sediment under denitrifying conditions Water Science. Technology 38, 177–185. Marin, V., Moreno, M., Vassallo, P., Vezzulli, L., Fabiano, M., 2008. Development of a multistep indicator-based approach (MIBA) for the assessment of environmental quality of harbours. ICES J. Mar. Sci. 65, 1436–1441. MOOPAM (Manual of oceanographic observations and pollutant analyses methods), 1999. third ed., Section 6, Regional Organization for the Protection of the Marine Environment (ROPME), Kuwait. Nadal, M., Schuhmacher, M., Domingo, J.L., 2004. Levels of PAHs in soil and vegetation samples from Tarragona County’’, Spain. Environ. Pollut. 132, 1–11. Neff, J.M., 1979. Polycyclic Aromatic Hydrocarbons in the Aquatic Environment. Sources, Fates and Biological Effects. Applied Science, Barking, Essex, UK, p. 262. Ningjing, Hu, Xuefa, Shi, Huang, Peng, Mao, Jian, Liu, Jihua, Liu, Ying, Ma, Deyi, 2010. Polycyclic aromatic hydrocarbons (PAHs) in surface sediments of Liaodong Bay, Bohai Sea, China. Environ. Sci. Pollut. Res. 18, 163–172. Tobiszewski, M., Namiesnik, J., 2012. PAH diagnostic ratios for the identification ofpollution emission sources. Environ. Pollut. 162, 110–119. Tolosa, I., de Mora, S., Sheikholeslami, M.R., Villeneuve, J.P., Bartocci, J., Cattini, C., 2004. Aliphatic and aromatic hydrocarbons in coastal Caspian Sea sediments. Mar. Pollut. Bull. 48, 44–60. Wagener, A., Hamacher, C., Farias, C., Godoy, J.M., Scofield, A., 2010. Evaluation of tools to identify hydrocarbon sources in recent and historical sediments of a tropical bay. Mar. Chem. 121, 67–79. Wentworth, C.K., 1992. A scale of grade and class terms for clastic sediments. J. Geol. 30, 377–392. Xia, X., Wang, R., 2008. Effect of sediment particle size on polycyclic aromatic hydrocarbon biodegradation: importance of the sediment–water interface. Environ. Toxicol. Chem. 27, 119–125. Yan, W., Chi, J.S., Wang, Z.Y., Huang, W.X., Zhang, G., 2009. Spatial and temporal distribution of polycyclic aromatic hydrocarbons(PAHs) in sediments from Daya Bay, South China. Environ. Pollut. 30, 1–8. Yunker, M.B., MacDonald, R.W., Vingarzan, R., Mitchell, R.H., Goyette, D., Sylvestre, S., 2002. PAHs in the Fraser River basin: a critical appraisal of PAH ratios as indicators of PAH source and composition. Org. Geochem. 33, 489–515.
Please cite this article in press as: Araghi, P.E., et al. Distribution and sources of polycyclic aromatic hydrocarbons in the surface sediments of Gorgan Bay, Caspian Sea. Mar. Pollut. Bull. (2014), http://dx.doi.org/10.1016/j.marpolbul.2013.12.001
Contents lists available at ScienceDirect
Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul
Baseline
Distribution and sources of polycyclic aromatic hydrocarbons in the surface sediments of Gorgan Bay, Caspian Sea Peyman Eghtesadi Araghi ⇑, Kazem Darvish Bastami, Shirin Rahmanpoor Iranian National Institute for Oceanography and Atmospheric Science (INIOAS), No. 3, Etemadzadeh St., Fatemi Ave., Tehran 1411813389, Islamic Republic of Iran
a r t i c l e
i n f o
Keywords: Polycyclic aromatic hydrocarbons (PAHs) Sediment Gorgan Bay Caspian Sea
a b s t r a c t The level and source of 16 polycyclic aromatic hydrocarbons (PAHs) were investigated in the surface sediments from the Gorgan Bay, Caspian Sea. The sum of 16 PAHs (RPAH16) concentrations varied from 107.87 to 516.18 ng g1 dry weight, with average value of 270.96 ± 150.47 ng g1 dry weight. Ecological risk assessment of PAHs, indicated that adverse biological effects caused by acenaphthene, naphthalene, fluoranthene and Pyrene occasionally and frequently may take place in the sediments of Gorgan Bay. PAHs source identification demonstrated that the PAHs come from mixed and pyrogenic origin. Crown Copyright Ó 2013 Published by Elsevier Ltd. All rights reserved.
Polycyclic aromatic hydrocarbons (PAHs) are among the most important contaminants in the marine environment which are produced from different resources. PAHs are a large group of organic compounds with two or more fused aromatic rings. They have mutagenic and carcinogenic activity that are usually present in the air, water and aquatic system, soils and sediments (Neff, 1979). These compounds are generally generated by natural and anthropogenic processes and can be introduced into the environments through various routes. Anthropogenic input from incomplete combustion, oil spills, urban runoff, domestic and industrial wastewater discharges, as well as atmospheric fallout of vehicle exhaust and industrial stack emission have caused significant accumulation of these compounds in the environments (Nadal et al. 2004; Durand et al. 2004). The Gorgan Bay located at the southeastern section of the Caspian Sea with 60 km length and 12 km width, is a semi-enclosed basin, as it receives no wave’s energy from the Caspian Sea. The Bay is mostly affected by the currents originating from inside the basin. This area is best known for its high economical and ecological importance as a fishing and recreational ground because of appropriate biological conditions for aquatic animals. The Gorgan Bay is the ultimate sink for water flows from Gharehso River. The Gorgan River faces the Caspian Sea at the vicinity of the Bay mouth at the northeast part (Bastami et al., 2012). Little information is available on PAH in the sediment of Gorgan Bay, therefore; the objective of this study was to determine the concentration and possible sources of PAHs in the sediment of Gorgan Bay. ⇑ Corresponding author. Tel.: +98 9124755635. E-mail address: [email protected] (P.E. Araghi).
Fifteen stations were selected for this study and sediments of sites were collected by using van veen grab in August, 2010 (Fig. 1). The samples are collected in aluminium container and kept it in the freezer (20 °C). Sediment samples obtained from one location was mixed and a composite sample was prepared. Then, these sediment samples (200 g of sediment) were freeze dried (freeze-drier Model: OPR-FDB-5503, Korea) at 40 °C for 24 h to a constant weight. 10 g of each sample were mixed with 250 ml of n-hexane and dichloromethane mixture (1:1 ratio). The mixture was placed for 8 h in Soxhlet. The combined extracts were evaporated on a rotary vacuum evaporator until 15 ml was left. To eliminate sulphur and their compounds, 3 g of active copper was added to the mixture and allowed to pass through a folded filter paper (Whatman GF/ C, 24micron) for 24 h. The mixture was concentrated in a rotary (Buchi B-490) to a volume of 5 ml. Samples were allowed to pass through a column containing 10 g silica gel in n-hexane, 1–2 g anhydrous sodium sulphate and 10 g alumina. Then, 30 ml of n-hexane and dichloromethane mixture (9:1 ratio) were added to the column. Samples were concentrated again in a rotary evaporator to a volume of 5 ml. The concentrated extract was dried under nitrogen steam (N-E VAP 112, USA). The residue was dissolved in 1 ml of acetonitrile (MOOPAM, 1999). The PAHs were detected with a Hewlett–Packard 1100 HPLC equipped with an Agilent-1100 fluorescence and UV detector. Injection volume was 20 ll. The initial mobile phase was 60% acetonitrile and 40% HPLC water for 8 min, which was then gradiently changed to 100% acetonitrile in 5 min, held at 100% for 22 min, then decreased to initial phase. In this analysis the column type was RESTEK, Pinacle II PAH (150 3.2 mm, 5 lm) and temperature was 25 °C.
http://dx.doi.org/10.1016/j.marpolbul.2013.12.001 0025-326X/Crown Copyright Ó 2013 Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Araghi, P.E., et al. Distribution and sources of polycyclic aromatic hydrocarbons in the surface sediments of Gorgan Bay, Caspian Sea. Mar. Pollut. Bull. (2014), http://dx.doi.org/10.1016/j.marpolbul.2013.12.001
2
P.E. Araghi et al. / Marine Pollution Bulletin xxx (2014) xxx–xxx
Fig. 1. The locations of the sampling sites at the Gorgan Bay.
The sixteen most toxic PAHs listed by the USEPA (Bashe and Baker, 1990) were assessed in three sample media. The abbreviations used for the identified PAHs are: naphthalene, N; acenaphthylene, AC; acenaphthene, ACE; fluorene, F; phenanthrene, Ph; anthracene, A; fluoranthene, Fl; pyrene, Py; benzo (a) anthracene, B(a)A; chrysene, Ch; benzo (b) fluoranthene, B(b)Fl; benzo (k) fluoranthene, B(k)Fl; benzo (a) pyrene, B(a)Py; indeno (1, 2, 3-c, d) pyrene, IPy; dibenz (a, h) anthracene, DB(ah)A; benzo (ghi) perylene, B(ghi)Pe. Replicate samples, certified reference materials IAEA-417 and procedural blanks were used as quality control procedures. All the obtained values for PAHs in CRM were in the reported range. Reproducibility and recovery were high (85–110%) with relative standard deviation (RSD) 4–11%. To measure the quality control, the procedural blanks were periodically analysed for each batch of 10 samples. Quantitative analysis was conducted on a three-point linear calibration of PAH solution, obtained by dilution of the certified standard mixture of 16-PAH (kit 610-N-Supelco4-7351). The method detection limits (MDLs) of PAHs were determined with a signal-to-noise ratio (S/N) of 3. The MDLs were between 0.1 and 1 ng/g. Satisfactory linearity was obtained with values of the correlation coefficient R above 0.99. For determination of organic matter, sediment samples were dried at 70 °C for 24 h and then combusted in an oven at 550 °C for 4 h. Total organic matter, as described by Abrantes et al. (1999), was measured by the following equation:
Total organic matter ðTOM; %Þ ¼ ðB C=BÞ 100 where B and C are the weights of dried sediment before and after combusting in the oven, respectively. Sediment grain size analysis was made from sediment samples collected in separate polythene bags. For that, samples were air dried and sieved through a mechanical sieve to remove shells, debris, etc. Dried sediment samples were
subjected to size fraction analysis following the procedure of Wentworth (1992). Hundred grams of sample was taken and sieved through a 62 lm mesh-sized screen for 10 min in a mechanical sieve shaker. The sample that remained in the sieve was weighed and treated as sand. The sediment samples which passed through the sieve were the silt and clay. The silt and clay fractions were then separated by means of pipette method, described by Lindholm (1987). Regression Correlation was employed for a better understanding of the relationship between the concentration of PAHs, Clay and TOM by using statistical package of SPSS 19. The sand, silt and clay contents averaged 23.38 ± 27.56%, 36.61 ± 18.3%, and 39.76 ± 14.40%, respectively (Table 1). Gorgan Bay depth ranges from 0.62 to 4.12 m with an average value of 1.84 ± 1.14 m. The highest and the lowest depths were observed at stations 6 and 10, respectively. Regarding to the analysis, TOM content in sediment of the Gorgan Bay was 1.75–9% (averaged 4.45 ± 1.72%) which exhibited the highest and the lowest amounts at stations 15 and 14, respectively. As proposed by Marin et al. (2008), ecological quality status is classified into three levels according to organic matter content: high-good (less than 5%), moderate (between 5% and 10%) and poor-bad (greater than 10%). As illustrated in Table 1, TOM content of all stations was less than the presented above range (1.75–9%) in the current study. According to their proposal, stations 1, 2, 3, 4, 7, 8, 9, 10, 12, 13, and 14 showed a high-good quality while the remaining stations (5, 6, 11 and 15) should be classified as moderate. Ten PAHs were measured at detectable levels in the sediment from Gorgan Bay. The highest concentration of individual PAH was Fluoranthene, while B (a) anthracen showed the lowest concentration in the sediment of Gorgan Bay (Fig. 2). The concenP tration of PAHs ranges 107.87–516.18 ng g1 dry weight with an average value of 274.31 ± 152.29 ng g1 dry weight (Table 2).
Please cite this article in press as: Araghi, P.E., et al. Distribution and sources of polycyclic aromatic hydrocarbons in the surface sediments of Gorgan Bay, Caspian Sea. Mar. Pollut. Bull. (2014), http://dx.doi.org/10.1016/j.marpolbul.2013.12.001
3
P.E. Araghi et al. / Marine Pollution Bulletin xxx (2014) xxx–xxx Table 1 General characteristics of sediments sampled at the Gorgan Bay. Location
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Average ± SD
N36.92678 N36.90136 N36.85419 N36.81467 N36.87553 N36.83781 N36.79842 N36.86936 N36.83289 N36.79514 N36.80301 N36.89981 N36.85264 N36.82233 N36.80717 –
E54.02814 E54.03072 E54.03125 E54.03192 E53.90889 E53.90906 E53.91261 E53.78997 E53.79058 E53.79281 E53.79083 E53.95894 E53.57528 E53.61694 E53.57667
Depth (m)
TOM (%)
Clay (%)
Sand (%)
Silt (%)
3.65 3.07 2.24 1.46 2.87 4.12 2.35 1.54 1.05 0.62 0.76 1.5 0.77 0.65 1.03 1.84 ± 1.14
3.5 3.75 3.5 4 5.75 6 4 3.5 3.75 3 6.25 4.75 4.25 1.75 9 4.45 ± 1.72
37.56 35.35 34.72 32.68 50.76 59.04 41.51 44.74 53.66 36.76 50.62 27.75 23.62 6.5 61.05 39.75 ± 14.40
20.42 11.85 0.79 0.66 0.86 0.43 34.43 26.9 4 58.71 17.39 18.22 65.1 89.62 1.37 23.38 ± 27.56
42.02 52.18 64.49 66.66 48.18 40.52 24.07 28.36 39.46 13.54 45.85 31.16 11.27 3.88 37.58 36.61 ± 18.31
en e ph t hy A len ce na ph th en e Fl uo re Ph ne en an th en A e nt hr ac en Fl uo e ra nt he ne Py B( re a) ne an th ra Be ce n nz o[ Cr b] y Be se flu n nz or an o[ k] th en flu e or an th e ne B Di (a be )p nz In y o re de A n ne nt [1 hr ,2 a ce ,3 -c n Be d] nz py o[ r e gh i]p ne er yl en e
300 250 200 150 100 50 0
na
Ac e
Na p
ht ha l
ng/g dw
Sampling site
Fig. 2. Average (±SD) individual PAH in sediment (ng g1 dry weight) of the Gorgan Bay.
The processes controlling the level of PAHs in the sediments are complex. It has been demonstrated that the nature of the sediments influences the distribution and concentration of PAHs. The distributions of PAHs in the sediments are affected by chemical composition of the sediments such as organic matter and clay content. The sediments with high levels of organic matter have a strong affinity to hydrophobic compounds, such as PAHs, in comparison with sediments with low levels of organic matter (MacRae and Hall, 1998, Xia and Wang, 2008). Furthermore, the PAHs are mainly adsorbed in the small particles (clay), which have a greater capacity for adsorption because of their greater specific surface area (Xia and Wang, 2008). In the present study the regression analysis was completed to P investigate the relationship between the concentration of PAHs and the percentage of organic matter and clay. The linear regresP sions show no significant correlation between PAHs with total organic matter (P > 0.05), while a significant correlation was found P between clay and PAHs (P < 0.05) (Fig. 3).This study, suggest that the distribution and concentration of PAHs in sediments of Gorgan Bay is determined by the type of the sediment found locally. P Data in Table 3 shows concentration of PAHs in sediment of P other locations. Concentrations of the total PAHs in this study were lower than those found in some aquatic environments but were higher than those in other locations (Table 3). Although a quantitative comparison across reported PAH data is difficult because of variances in the number and type of individual species determined in each study, the sediment fraction analysed, and the analytical methods used. According to Baumard et al. (1998), PAH pollution levels can be characterized as low, moderate, high, and very high when the total PAHs concentrations are 0–100 ng g1 dry weight, 100–1000 ng g1 dry weight, 1000–5000 ng g1 dry weight, and >5000 ng g1 dry
weight, respectively. Based on this classification, sediments from Gorgan Bay (107.87 to 516.18 ng g1 dry weight) could be considered as moderately polluted with PAHs. Sediment quality guidelines (SQGs) are an important tool for the assessment of contamination in marine and estuarine sediments (Long et al., 1995). In this study, two sets of SQGs, including: (a) the ERL/ERM and (b) the TEL/PEL values were applied to assess the ecological toxicity of individual PAH concentrations in sediments. According to SQGs adverse biological effects are expected rarely (0.5 implies grass, wood, or coal combustion. To distinguish samples containing petrogenic or pyrogenic PAH, the ratios of Anthracene/(anthracene + phenanthrene), Benzo[a] anthracene/(Benzo[a] anthracene + chrysen) and fluoranthene/ (fluoranthene + pyrene) were used and the results for all sites appear in Table 4.
Please cite this article in press as: Araghi, P.E., et al. Distribution and sources of polycyclic aromatic hydrocarbons in the surface sediments of Gorgan Bay, Caspian Sea. Mar. Pollut. Bull. (2014), http://dx.doi.org/10.1016/j.marpolbul.2013.12.001
P.E. Araghi et al. / Marine Pollution Bulletin xxx (2014) xxx–xxx Table 4 Characteristic PAH molecular diagnostic ratios.
a b c
Sampling sites
An/An + pha
Flt/Flt + Pyb
BaA/BaA + Chc
Petrogenic Pyrogenic 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
0.1 0.84 – – – –
0.4 0.94 – – 0.84 – 0.91 – 0.73 0.58 – – – – – 0.97
0.35 0.35 – 0.35 – 0.33 0.33 – 0.42 0.35 0.37 – – 0.33 – –
– 0.96 0.33 – 0.31 – – –
Anthracene/(anthracene + phenanthrene). Fluoranthene/(fluoranthene + pyrene). Benzo[a] anthracene/(Benzo[a] anthracene + chrysen).
In this study, BaA/BaA + CHR ratio in surface sediment at sites 1, 3, 5, 6 and 13 were between 0.2 and 0.35, indicating mixed sources of PAH. Ratio of ANT/ANT + PHE was higher than 0.1 in all sampling sites, suggesting pyrolitic sources of PAHs. Range of Flu/Flu + Pyr ratio was 0.58 and 0.97 in all sampling sites, demonstrating grass, wood, or coal combustion sources of PAHs. These findings suggest that the sources of PAHs in the surface sediments of Gorgan Bay could arise from mixed sources, with pyrogenic -related contamination as the dominant source. The diagnostic ratios used in this study defined different origin of PAHs at sampling sites. This might be due to the complexity of the parameters determining PAHs distributions in the environment. This study provides important information on PAH concentrations in surface sediments of the Gorgan Bay (Caspian Sea). Contamination levels of PAHs in the Gorgan Bay were lower than those found in some aquatic environments but were higher than those in other locations. Acenaphthene, naphthalene, fluoranthene and pyrene concentrations were high in sediment from the Gorgan Bay. This may cause toxicity to certain exposed organisms.
References Abrantes, A., Pinto, F., Moreira, M., 1999. Ecology of polychaete Nereis diversicolor, in the Cannal de Mira (Ria de averio, Portugal). Population dynamics, production and oogenic cycle. Acta Oceanol. 20 (4), 267–283. Anderson, J.W., Newton, F.C., Hardin, J., Tukey, R.H., Richter, K.E., 1996. Chemistry and toxicity of sediments from San Diego Bay including a biomarker (P450 RGS) response. In: Bengtson, D.A., Henshel, D.S. (Eds.), Environmental Toxicology and Risk Assessment. Biomarkers and Risk Assessment, ASTM STP 1306, vol. 5. American Society for Testing and Materials, Philadelphia, pp. 53–78. Badawy, M.I., Al-Mujainy, I.S., Hernandez, M.D., 1993. Petroleum derived hydrocarbons in water, sediment and biota from the Mina al Fahal coastal waters. Mar. Pollut. Bull. 26, 457–460. Bashe, W.J., Baker, T.V., 1990. Determination of Polycyclic Aromatic Hydrocarbons in Drinking Water by Liquid–Solid Extraction and HPLC with Coupled
5
Ultraviolet and Fluorescence Detection. In: USEPA Method 550.1: 143-167. Environmental Monitoring Systems Laboratory, Ohio, USA. Bastami, K.D., Bagheri, H., Haghparast, S., Soltani, F., Hamzehpoor, A., Bastami, M.D., 2012. Geochemical and geo-statistical assessment of selected heavy metals in the surface sediments of the Gorgan Bay, Iran. Mar. Pollut. Bull. 64, 2877–2884. Bastami, K.D., Afkhami, M., Ehsanpour, M., Kazaali, A., Mohammadizadeh, M., Haghparast, S., Soltani, F., Zanjani, S.A., Ghorghani, N,F., Pourzare, R., 2013. Polycyclic aromatic hydrocarbons in the coastal water, surface sediment and mullet Liza klunzingeri from northern part of Hormuz strait (Persian Gulf). Mar. Pollut. Bull. . Baumard, P., Budzinski, H., Garrigues, P., Sorbe, J.C., Burgeot, T., Belloca, J., 1998. Concentration of PAH in various marine organisms in relation to those in sediments to trophic level. Mar. Pollut. Bull. 36, 951–960. Durand, C., Ruban, V., et al., 2004. Characterization of the organic matter of sludge: determination of lipids, hydrocarbons and PAHs from road retention/infiltration ponds in France. Environ. Pollut. 132, 375–384. Eghtesadi, P., Riazi, G., Taghikhani, M., Ranaei Siadat, S.O., 2002. Distribution and sources of polycyclic aromatic hydrocarbons in the northern Persian Gulf as indicated by kinetic and thermodynamic criteria. Bull. Environ. Contam. Toxicol. 69 (5), 704–711. Hu, N.J., Shi, X.F., Liu, J.H., Huang, P., Liu, Y.G., Liu, Y., 2010. Concentrations and possible sources of PAHs in sediments from Bohai Bay and adjacent shelf. Environ. Earth Sci. 60, 1771–1782. Kim, G.B., Maruya, K.A., Lee, R.F., Lee, J.H., Koh, C.H., Tanabe, S., 1999. Distribution and sources of polycyclic aromatic hydrocarbons in sediments from Kyeonggi Bay, Korea. Mar. Pollut. Bull. 38, 7–15. Lindholm, R., 1987. A Practical Approach to Sedimentology. Allen and Unwin, London, pp. 1–278. Liu, Y., Ling, C.N., Zhao, J.F., Huang, Q.H., Zhu, Z.L., Gao, H.W., 2008. Distribution and sources of polycyclic aromatic hydrocarbons in surface sediments of rivers and an estuary in Shanghai, China. Environ. Pollut. 154, 298–305. Long, E.R., MacDonald, D.D., Smith, S.L., Calder, F.D., 1995. Incidence of adverse biological effects within ranges of chemical concentrations in marine and estuarine sediments. J. Environ. Manage. 19, 18–97. Lubecki, L., Kowalewska, G., 2012. Indices of PAH origin – a case study of the Gulf of Gdansk (SE Baltic) sediments. Polycyclic Aromat. Compd. 32, 335–363. MacDonald, D.D., Carr, R.S., Calder, F.D., Long, E.R., Ingersoll, C.G., 1996. Development and evaluation of sediment quality guidelines for Florida coastal waters. Ecotoxicology 5, 253–278. MacRae, J.D., Hall, K.J., 1998. Biodegradation of polycyclic aromatic hydrocarbons (PAHs) in marine sediment under denitrifying conditions Water Science. Technology 38, 177–185. Marin, V., Moreno, M., Vassallo, P., Vezzulli, L., Fabiano, M., 2008. Development of a multistep indicator-based approach (MIBA) for the assessment of environmental quality of harbours. ICES J. Mar. Sci. 65, 1436–1441. MOOPAM (Manual of oceanographic observations and pollutant analyses methods), 1999. third ed., Section 6, Regional Organization for the Protection of the Marine Environment (ROPME), Kuwait. Nadal, M., Schuhmacher, M., Domingo, J.L., 2004. Levels of PAHs in soil and vegetation samples from Tarragona County’’, Spain. Environ. Pollut. 132, 1–11. Neff, J.M., 1979. Polycyclic Aromatic Hydrocarbons in the Aquatic Environment. Sources, Fates and Biological Effects. Applied Science, Barking, Essex, UK, p. 262. Ningjing, Hu, Xuefa, Shi, Huang, Peng, Mao, Jian, Liu, Jihua, Liu, Ying, Ma, Deyi, 2010. Polycyclic aromatic hydrocarbons (PAHs) in surface sediments of Liaodong Bay, Bohai Sea, China. Environ. Sci. Pollut. Res. 18, 163–172. Tobiszewski, M., Namiesnik, J., 2012. PAH diagnostic ratios for the identification ofpollution emission sources. Environ. Pollut. 162, 110–119. Tolosa, I., de Mora, S., Sheikholeslami, M.R., Villeneuve, J.P., Bartocci, J., Cattini, C., 2004. Aliphatic and aromatic hydrocarbons in coastal Caspian Sea sediments. Mar. Pollut. Bull. 48, 44–60. Wagener, A., Hamacher, C., Farias, C., Godoy, J.M., Scofield, A., 2010. Evaluation of tools to identify hydrocarbon sources in recent and historical sediments of a tropical bay. Mar. Chem. 121, 67–79. Wentworth, C.K., 1992. A scale of grade and class terms for clastic sediments. J. Geol. 30, 377–392. Xia, X., Wang, R., 2008. Effect of sediment particle size on polycyclic aromatic hydrocarbon biodegradation: importance of the sediment–water interface. Environ. Toxicol. Chem. 27, 119–125. Yan, W., Chi, J.S., Wang, Z.Y., Huang, W.X., Zhang, G., 2009. Spatial and temporal distribution of polycyclic aromatic hydrocarbons(PAHs) in sediments from Daya Bay, South China. Environ. Pollut. 30, 1–8. Yunker, M.B., MacDonald, R.W., Vingarzan, R., Mitchell, R.H., Goyette, D., Sylvestre, S., 2002. PAHs in the Fraser River basin: a critical appraisal of PAH ratios as indicators of PAH source and composition. Org. Geochem. 33, 489–515.
Please cite this article in press as: Araghi, P.E., et al. Distribution and sources of polycyclic aromatic hydrocarbons in the surface sediments of Gorgan Bay, Caspian Sea. Mar. Pollut. Bull. (2014), http://dx.doi.org/10.1016/j.marpolbul.2013.12.001
