Distribution and Sources of Polycyclic Aromatic Hydrocarbons (PAHs) in Surface Sediments from the Northern Part of the Persian Gulf (Hormuzgan Province)

Sediments from the intertidal areas of Hormuzgan province in northern part of Persian Gulf (Iran) were investigated for the levels and possible sources of 15 polycyclic aromatic hydrocarbons (PAHs). Samples of sediments were collected from twelve sampling sites and analyzed for PAHs by gas chromatography–mass spectrometry (GC-MS). The results showed that the total concentrations of PAHs ranged from 765 to 1898 ng/g dry weight. Composition pattern in the sediment samples from 12 sampling sites was dominated by 4-ring PAH compounds. Molecular indices based on ratios of PAH concentrations were used to differentiate PAHs from pyrolitic, petrogenic and mixed origins. The results of study suggested that the main sources of PAHs in the sediment were mixed with pyrolitic and petrogenic inputs. According to the US sediments quality guidelines (SQGs) (ERL/ERM) sediments of the mentioned region did not show any ecotoxicological risk for benthic organisms.     

THE FATE AND BEHAVIOR OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) THROUGH FEEDING AND EXCRETION OF ANNELIDS

The concentration of polycyclic aromatic hydrocarbons (PAHs) in sediment and excrements of annelids was measured by gas chromatography-mass spectrometry (GC/MS) and the movement of PAHs in the tidal flat was investigated. The PAH concentrations ranged 4.4–80.4 and 61.2–286.9 μg/kg-dry for the excrement of Arenicola basiliensis and of Marphysa sanguinea, respectively; the former contained about 10 times as much PAHs as the sediment and the latter about 100 times. The difference in the PAH concentration between the two organisms was attributed to their feeding behavior; M. sanguinea intakes much more detritus containing PAHs than A. basiliensis. Moreover, after the excrement of M. sanguinea had stood on the sediment for 2 hours, the PAH concentrations decreased to half. The reduction of the PAHs may arise from chemical changes owing to microorganisms and/or enzymes in the excrement of M. sanguinea.     

Priority Polycyclic Aromatic Hydrocarbons (PAHs): Distribution,Possible Sources and Toxicity Equivalency in Urban Drains

Wastewater from urban areas constitutes one of the major sources of pollutants contributed to aquatic ecosystem. This study was carried out to elucidate the occurrence and possible source of US Environmental Protection Agency identified 16 priority polycyclic aromatic hydrocarbons (PAHs) in water and sediments from the urban wastewater drains in Delhi, India. A total 60 samples (water and sediment) collected during year 2011–2012, and analyzed the following USEPA methods. Water and sediment samples were extracted using liquid-liquid and ultrasonication techniques, respectively. Glass column chromatography with activated silica was used for sample extracts clean-up, followed by quantification on HPLC equipped with diode array detector at 254 nm wavelength using mixture of acetonitrule and water as mobile phase. Concentrations of total 16 PAHs (∑16PAHs) in all drain water samples ranged from 0.29–35.22 μg/L (mean ± SD, 10.83 ± 10.66 μg/L), predominated by two- and three -ring PAHs. The ∑16PAHs concentrations in all collected sediments ranged between 220–19321 μg/kg (mean±SD, 5574 ± 6820 μg/kg) dry weights. High molecular weight PAHs (≥4-ring PAHs) were dominant in sediment samples. Benzo(a)pyrene equivalent (BaPeq), a relative carcinogenic potential to the corresponding PAHs to BaP was estimated and presented. A selected number of concentration ratios of specific PAHs compounds were calculated and used to diagnose the possible sources of PAHs contamination. The diagnostic ratios reflected pyrogenic input from gasoline or diesel powered vehicular emissions as the major source of PAHs. The levels of PAHs observed in water and sediments were compared with similar studies undertaken in other regions of the world.     

Polycyclic Aromatic Hydrocarbons in Sediments of Marine Coastal Lagoons in Messina,Italy: Extraction and GC/MS Analysis,Distribution and Sources

The content of 21 polycyclic aromatic hydrocarbons (PAHs) were determined in 16 samples of sediments collected from Ganzirri and Faro marine coastal lagoons in Messina, Italy. Analysis was performed by gas chromatography/mass spectrometry (GC/MS) in selected ion monitoring (SIM) mode. The total concentration of polycyclic aromatic hydrocarbons (ΣPAHs) ranged from 74 to 5755 μg/kg of dry matrix. The resulting distributions and molecular ratios of specific compounds are discussed in terms of sampling location and origin of organic matter. The results obtained show that levels of contamination are not homogeneous throughout the stations, while the relative distributions of PAHs are homogeneous in most of the sampling stations. The organic matter content and PAH concentration were found to be correlated (r = 0.90). It is also shown that the pyrolytic origin is the main source of these compounds in Ganzirri and Faro Lakes sediments.     

DETERMINATION OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHs) IN SEDIMENTS AND BENTHOS COLLECTED ON THE COAST OF CHIBA

Eight polycyclic aromatic hydrocarbons (PAHs) including benzo[a]pyrene were analyzed in sediment and benthos collected on the coast of Chiba Prefecture in Japan by gas chromatography-mass spectrometry (GC/MS). The total concentration of the PAHs ranged from 8 to 18 μ g/kg-dry in the sediments and from 36 to 59 μ g/kg-wet in the benthos, Mactra quadrangularis, Scoletoma nipponica, and Arenicola basiliensis. The PAH composition in the sediments and the benthos was similar at four sampling points and dominated by phenanthrene (Phe), fluoranthene (Flu), and pyrene (Pyr). The ratios of abundance of Flu to that of Pyr, Flu/Pyr, and of Phe/anthracene suggest that the PAHs in the benthos are derived from the combustion of fossil fuels. The ratio, R, of the PAH concentration in the benthos to that in the sediment is 2.0 for Scoletoma nipponica and 1.8 for Arenicola basiliensis in average, indicating that the bioaccumulation is not significant in the benthos. However, the R value for perylene in Scoletoma nipponica was 3.7 times as large as the average.     

THE LOADS OF PAHS IN WASTEWATER AND SEWAGE SLUDGE OF MUNICIPAL TREATMENT PLANT

Abstract

Sewage and sewage sludge from a municipal wastewater treatment plant were analyzed for 16 EPA-PAHs. This plant is a classic mechanical-biological treatment plant, consisting of activated sludge technology with additional chemical treatment for the removal of phosphorus compounds. The process of sewage sludge treatment is carried out in closed as well as open sludge digesters. Primary and mechanically thickened sludge are passed through the fermentation process. Digested sludge is dewatered on filter-press through addition of flocculent. The measurements were obtained to investigate the effect of different treatment stages on PAH content in wastewater and sewage sludge. The following wastewater samples were collected: crude ones and those after sand trap, primary sedimentation, biological treatment and secondary sedimentation. Sewage sludge samples were collected from: primary sludge, digested sludge and dewatered sludge. PAH load in influent, mechanically and biologically treated sewage, as well as in raw digested and dewatered sludge, were calculated. PAHs were extracted from wastewater and sludge samples, with cyclohexane, dichloromethane using an ultrasonic method. Gas chromatograph equipped with mass spectrometry was used for qualitative and quantitative determination of PAHs. Mechanical and biological treatment proved the removal of 83–85% of PAHs from the influent. Despite this its daily PAH load introduced into the environment was high and reached 27–37% of PAH load in influent. In sewage sludge it was 46–70 g/d of PAHs (carcinogenic PAHs content 4–12%). In waste sludge (filter pressed sludge and sand from detrirer) PAH total load reached 42–68 g/d with (10–17% of carcinogenic PAHs).     

Levels of Polycyclic Aromatic Hydrocarbons in Perna viridis,in Cienfuegos Bay,Cuba

Green mussel, Perna viridis, was used to measure bioaccumulated levels of polycyclic aromatic hydrocarbons (PAHs) in Cienfuegos Bay. Mussels were collected from four sites between November 2009 and November 2010. Sixteen individual PAHs compound controlled by Environmental Protection Agency (EPA) were quantified using gas chromatography—mass spectrometry (GC—MS). Concentration for phenanthrene ranged from 22.14 to 43.04 μg/kg (wet weight), for fluorene 5.19—9.33 μg/kg (wet weight), and 3.47—15.97μg/kg (wet weight) for fluoranthene. The overall concentration levels of PAH in this study are comparable to sites with low pollution levels around the world and its composition suggests a contribution from petrogenic sources. According to European Regulation No. 835/2011, the concentration levels of PAHs found are safe for human consumption of mussels in Cienfuegos Bay. These results contribute to the database of the Caribbean region because the information about the contamination for PAHs is scarce in bivalves, in Cuba.     

Levels and Origin of PAHs in Some Big Lakes

This study was designed to assess the contamination of a very special lake, Lake Baikal in Siberia, and two big lakes, Ladoga and Onega in the European part of Russia, by polycyclic aromatic hydrocarbons (PAHs). PAH compounds were analyzed by HPLC and the target PAH, benzo[ a ]pyrene (B a P), by using the spectral-luminescence (Shpol'skii) method. Elevated levels (to 96 w g kg m 1 ) of B a P in sediments of Lake Baikal reflected proximity to potential sources of emission, situated either on shore (a paper and pulp mill in Baikalsk) or upstream river systems. The concentration of B a P in sediments decreased with the distance from outlet and the depth. The sediment samples contained several representatives of PAHs. The total content of identified compounds reached 873 w g kg m 1 (less than four nuclear representatives not included). Dominating heavy PAHs were dibenz[ a,j ]anthracene, dibenz[ a,h ]anthracene, dibenzo[ a,e ]pyrene, and dibenzo[ a,l ]pyrene. The concentration of B a P in sediments of northeastern Baikal was more than two times less than that for the southern part of the lake and corresponds to the background level. The B a P levels estimated for sediments close to paper and pulp mills of the Lake Ladoga exceeded 160 w g kg m 1 , being two orders of magnitude higher than that for other areas of these lakes. The contamination of sediments of Lake Onega by PAHs is affected by pulp and paper mills as well as other sources. Our results clearly demonstrate the contribution of specific industrial sources like paper and pulp mills to the content of PAHs in the Baikal, Ladoga, and Onega water ecosystem.     

LONG TERM MONITORING OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) IN BLUE MUSSELS (Mytilus edulis) FROM A REMOTE SCOTTISH LOCATION

Farmed mussels have been collected on a monthly basis since 1999 from a remote site on the west coast of Scotland for polycyclic aromatic hydrocarbon (PAHs) analysis with the aim of establishing background concentrations as a benchmark against which to assess any environmental incident. Total PAH (2- to 6-ring parent and alkylated) concentrations ranged from 12.5 to 151.2 μg kg^?1 wet weight. Seasonal trends were evident with concentrations being significantly higher for samples collected between November and March compared to those collected between April and October. By taking the median of medians for each of these time periods two background concentrations are suggested for the total PAH concentrations (2- to 6-ring PAHs parent and alkylated); for April to October: 31.2 μg kg^?1 wet weight and for November to March: 62.9 μg kg^?1 wet weight. Individual PAH concentrations were mainly below the OSPAR Background Assessment Concentrations (BACs), where they are specified, and were only exceeded for the heavier 4- and 5-ring PAHs (fluoranthene, pyrene, benz[a]anthracene and benzo[a]pyrene) in samples collected between November and March. Differences were also seen in the PAH profiles with season. Mussels collected between November and March had a higher proportion of the heavier PAHs compared to mussels collected in the summer and autumn.     

Polychlorinated Biphenyls in Sediments from Sicilian Coastal Area (Scoglitti) using Automated Soxhlet,GC-MS,and Principal Component Analysis

A methodology for the PAHs and PCBs congener determination in sediment samples has been revised. We determined the distributions of PAHs and PCBs in the superficial sediments of the Scoglitti (Italy) coastal area to provide data for comparison with other marine systems and to hypothesize the sources. Extraction yield, for PCB, was never less than 60% in most cases, while for PAHs, utilizing perdeuterated surrogate standard (benz[a]anthracene-d₁₂ and anthracene-d₁₀) was never less than 72%. The total concentration of the 16 PAHs investigated, expressed as the sum of concentrations, ∑PAHs, varied from 1–5087 μg/kg of dry matrix, while the ∑ PCBs ranged from detection limit to 36 μg/kg of dry matrix. Linear relationships were found between PAHs concentration and organic matter percentages (R² = 0.60) and water content and organic matter percentages (R² = 0.87). Isomeric ratios were used for discriminating between pyrolitic and petroleum origin. The principal component analysis (PCA) has been conduced to discriminate the different sampling sites in internal or external harbor area.     

Distribution,Sources, and Risk of Polycyclic Aromatic Hydrocarbons in the Core Sediments from Baiyangdian Lake,China

The burial characteristics and risks of 16 polycyclic aromatic hydrocarbons (PAHs) in core sediments from Baiyangdian Lake were investigated through gas-chromato graphy/mass spectrometry. The total concentrations of the 16 PAHs ranged from 39.48–1877.75 ng g^?1. The low-molecular-weight PAHs (two- to three-ring PAHs) were the dominant species, contributing 40.10–92.18% to the total PAHs, with a mean of 71.01%. Based on the observed molecular indices and on principal component analysis, the PAHs inputs were initially dominated by biomass and coal combustion, and atmospheric deposition and surface runoff could be the major transport pathways. The contaminated source characteristics, hydrodynamic condition, and sediment textural composition are the key factors affecting the distribution and source of PAHs. By conducting a risk quotient analysis between specific PAH concentrations and their corresponding sediment quality values, the top layer sediments were found to have a potential biological impact and relatively high toxicity. However, such impact should have no impairment. The toxic potency of PAHs in Baiyangdian Lake could be described by using the toxic equivalent of benzo[a]pyrene.     

BIOAVAILABILITY AND BIOACCUMULATION OF PAH IN AMPHIPODS EXPOSED TO REFERENCE AND HARBOR SEDIMENTS

The amphipods Corophium volutator collected from inter-tidal mud flats away from urbanization display the presence of phenanthrene, while larger molecular weight PAHs were only detected in sediments. The latter compounds were abundant in sieved surface sediments collected from Halifax Harbor receiving combined road runoff and sewage effluents and a smaller fraction of the contaminants were bioavailable to amphipods. In laboratory exposures, the kinetics of contaminants uptake by amphipods displayed the steepest increase in concentration the first day of exposure, continued to increase and then decreased, reaching a steady state within a week. The depuration of PAH was more than ten times slower than observed for maximum uptake. Our study indicated the important role played by feeding in the bioavailability and toxicity of sediments. The PAH fingerprint associated with the grain size of particles needs pursuing to better delineate the exposure pathway of PAH to sediment dwelling organisms.     

Microprobe laser mass spectrometry studies of polycyclic aromatic hydrocarbon distributions on harbor sediments and coals

Microprobe two-step laser mass spectrometry (μL²MS) was used to assess the distribution and origin of polycyclic aromatic hydrocarbons (PAHs) on sediment particles dredged from the harbor of Milwaukee, Wisconsin. PAH concentrations are largely associated with coal-derived particles and other carbonaceous environments. PAH distributions on these coal-derived particles and carbonaceous environments, which are thought to have separate origins, were found to be quite similar. μL²MS data of coal and thermally-processed coal showed profound differences from μL²MS data obtained from the coal-derived particles in the sediment. The results of these experiments indicate that the coal-derived particles are not the source of PAHs in the sediment but are scavengers of PAH contaminants in the Milwaukee Harbor sediments.     

Urban Runoff Contribution to Surface Sediment Accumulation for Polycyclic Aromatic Hydrocarbons in the Cotonou Lagoon,Benin

The carcinogenic and mutagenic properties of some polycyclic aromatic hydrocarbons (PAHs) and their widespread presence in the environment have led to many scientific investigations during the past three decades. In this study, surface sediments from six sampling sites in the Cotonou lagoon (three sites in the channel and three in Lake Nokoue) during the highest stormy season (May, June, and July) were used to assess the urban runoff contribution of PAH accumulation in this ecosystem. This assessment showed relatively high PAH loads (140-625 ng/g) during the rainy season and high inputs of organic materials (total organic carbon contents between 2.5 and 9.5% dry weight). Generally known as originating from different processes, PAHs detected in most of the Cotonou lagoon sampling sites were characterized by the predominance of the high-molecular-weight PAH over the low-molecular-weight PAH, which is an indicator of pyrolytic origin PAH inputs. PAH contamination in the Cotonou lagoon surface sediments was mainly from heavy urban traffic linked to the use of diesel vehicles and to the motorbike taxis proliferating across and around the city. Regression analysis carried out between total PAH concentration and total organic carbon contents showed, excluding the rural sampling site, a positive linear relationship for most samples ( R 2 = 0.9996), and confirmed the pyrogenic input of PAHs in the Cotonou lagoon. Mitigation measures were suggested to ameliorate the PAH pollution in the lagoon.     

POLYCYCLIC AROMATIC HYDROCARBONS IN BALTIC SEA BIVALVES

Concentrations of parent polycyclic aromatic hydrocarbons (PAHs) in the bivalves Macoma balthica and Astarte borealis were studied as an indication of the state of the Baltic Sea. Samples were collected between 1999 and 2001 from the Gulf of Finland, the Eastern Gotland Basin, and the Southern Baltic Proper. PAHs were quantified by liquid chromatography with fluorescence detection. The sum of 12 PAHs varied between 44 and 298 ng/g (ww), with the most contaminated bivalves found in Hanö Bight (the Bornholm basin). High-molecular-weight PAHs predominated among the PAHs. The PAH profiles of M. balthica differed from those determined in sediment from the same area. Both pyrolytic and petrogenic origins were indicated. Toxic equivalency factors evaluated as benzo[a]pyrene equivalents (BaPEs) were used to assess the PAH contamination. BaPEs were higher than values for M. balthica found in the southern part of the Gulf of Finland in 1995 and much lower than values measured in 1987 after the most serious oil spill in the Gulf of Finland in the past 25 years.     

Source characterization and the environmental impact of urban street dusts from Egypt based on hydrocarbon distributions

The aliphatic and aromatic fractions of the extracts of ten street dust (SD) samples collected from eight cities covering a wide geographic area of Egypt were analyzed using gas chromatography with flame ionization detector (GC-FID) and GC-MS to compare their hydrocarbon distributions. To identify their sources, the extracts of the possible source materials were also analyzed. The impact of SDs on the marine environment was investigated in a marine sediment collected from the Western Harbor of Alexandria. The GC-FID profiles of the aliphatic fractions showed considerable differences in the n-alkane distribution that permits the classification of the SDs into five groups. This grouping reflects the environments of the cities in which they are collected. The carbon preference index and the unresolved complex mixture relative to the total resolved peaks values revealed that automobile exhaust is the main source of the hydrocarbons in these SDs with a significant contribution from terrestrial higher plant waxes to group 1 (Nile Delta cities). The sterane and hopane profiles supported this conclusion. The total polycyclic aromatic hydrocarbon (PAH) concentrations ranged from 27 to 379 ng/g (dry wt.) and showed clear differences between the SDs. The lowest and highest concentrations were found in samples from Shebeen and Port Said, respectively. The PAH distribution patterns and the ratio of the sum of combustion specific PAHs to total PAHs in samples from Alexandria, Port Said and Cairo were similar, implying similar sources. PAH ratios indicated a mixture of pyrogenic and petrogenic sources of PAHs in all samples where asphalt and automobile fuel exhaust were the major contributors of PAHs in Alexandria, Port Said, Cairo and Sharm El Sheikh cities. These ratios also indicated the predominance of diesel-operated vehicles to the PAHs signatures of Alexandria, Port Said and Cairo while gasoline emissions influence more strongly the PAH distributions in the SDs from Shebeen, Kafr El Sheikh and Sharkea. The PAH fingerprints excluded fresh oil and tire particles as major contributors. Both SDs and petrogenic sources significantly contributed to the hydrocarbon signature of the marine sediment from the Western Harbor of Alexandria.     

POLYCYCLIC AROMATIC HYDROCARBONS IN BALTIC SEA SEDIMENTS

Present concentrations of parent polycyclic aromatic hydrocarbons (PAHs) were studied in bottom sediments of the Baltic Sea. Sediments were collected in 2001 and 2002 from the Gulf of Finland, the Northern Baltic Proper, the Eastern Gotland Basin, the Southern Baltic Proper, and Kattegat. Parent PAHs were quantified by liquid chromatography with fluorescence detection. The sum of 13 PAHs in 1 cm slices in the first 5 cm varied between 64 and 5161 ng/g (dw) depending on the bottom type. The most contaminated area was in the Eastern Gotland Basin, and the most abundant PAH components found in sediments were fluoranthene, benzo[b]fluoranthene, benzo[ghi]perylene, and indeno[1,2,3-cd]pyrene. The studied PAHs were both pyrolytic and petrogenic in origin. In addition, the concentrations of indeno[1,2,3-cd]pyrene and benzo[ghi]perylene indicated a contribution from diesel engines, which may indicate pollution caused by the steadily increased shipping in the Baltic Sea.     

Levels of Some Persistent Organic Pollutants (PCBs and PAHs) in Jordanian Oil Shale Ash after Direct Heating at Different Temperature Ranges

The levels of 13 polycyclic aromatic hydrocarbons (PAHs) and 12 polychlorinated biphenyls (PCBs) were studied in oil shale ash samples gathered after heating oil shale samples collected from major deposit sites in Jordan. All analyses were carried out using GC/MS instrument. The results showed that the total concentration of the studied polycyclic aromatic hydrocarbon (PAHs) was the highest (75.99–317.53 μg /kg) at the lowest temperature range (200–400°C) and it decreased as the temperature increased. For the heating temperature range 400–600°C the concentrations were all decreased to below the limit of quantification while none of the samples contained any of the studied PAHs at the highest temperature range 600–800°C. While all the analyzed samples did not contain any of the studied 13 compounds of PCBs at different temperature ranges.

Recoveries of PAHs and PCBs were found between 82–106% and 91–114%, respectively. Precision of the analytical method for both PAHs and PCBs, calculated as relative standard deviation (RSD), ranged from 0.95–7.08% and 0.78–9.03%, respectively. The limit of detection values for PAHs and PCBs were between 0.006–0.070 μg/kg and 0.149–0.330 μg/kg, respectively.

The total estimated cancer risks of exposure to PAHs in the soil samples were ranged from 9.13 × 10^?7 to 2.15 × 10^?6. By multiplying these numbers of cancer risks of exposure to oil shale ash sample-PAHs by 10⁶, it is possible to determine the maximum theoretical number of cancer cases per million of people. The maximum estimated cancer risks cases determined in this study (2 out of 1 million) are well within the acceptable range of excess cancer risk specified by the US Environmental Protection Agency.     

Distribution of Polycyclic Aromatic Hydrocarbons in Surficial Sediments of the Vigo Estuary,Spain, Central Axis and Adjacent Shelf

For the first time, 13 polycyclic aromatic hydrocarbons (PAHs) have been identified in samples of surface sediments at 17 stations on the Vigo estuary (northwest Spain) and its adjacent shelf. The separation and quantification of the analyzed compounds were performed using high-performance liquid chromatography, and a fluorescence detector with wavelength programming. The values found, for the sum of the 13 PAHs, varied between 28 and 2,150 w g/kg dry weight. These concentrations may be considered to be between very low and medium when compared with other estuaries. A concentration gradient with lower values on the continental shelf, that increase as the distance to the city of Vigo decreases, may be appreciated. Variations also can be noted in the participation of each PAH in the total sum, as a consequence of the differing degradability levels of each compound.     

Occurrence of Polycyclic Aromatic Hydrocarbons in Smoke Flavourings

The presence of Polycyclic Aromatic Hydrocarbons (PAHs) in four liquid smoke flavourings of different origins has been studied, in order to test whether a relation between their PAH content and their composition could be established, and to evaluate whether the use of these flavourings could involve a risk to human health. The samples were subjected to an alkaline treatment, extracted with cyclohexane, cleaned up, and the PAHs determined by gas chromatography-mass spectrometry. The results reveal a wide range of PAHs, especially in the commercial flavourings studied, which present higher concentrations of both total and carcinogenic PAHs than those obtained in the laboratory. Benzo(a)pyrene has been detected in three of the samples studied, but its levels do not exceed, in any of the cases, the 10 μg/kg value fixed by the FAO/WHO.