Petrogenic Polycyclic Aromatic Hydrocarbons Research Articles

PAHs in high Arctic copepods Calanus hyperboreus following exposure of residues from in situ burning of oil spill

In situ burning of marine oil spills reduces the total amount of oil in the environment, but a negative side effect may be the generation of environmentally hazardous polycyclic aromatic hydrocarbons (PAHs) that may pose a risk for bioaccumulation, particularly in organisms having a high lipid content. In this study uptake of PAHs from oil and burn residue were examined in the high arctic copepod Calanus hyperboreus. A major part of the low ring number petrogenic PAHs in the oil was removed during burning and relative higher concentrations of pyrogenic high ring number PAHs was found in the burn residue. This suggests that burning markedly reduces the general PAH exposure load. Furthermore, the pyrogenic PAHs generated during the burn were not bioconcentrated to quantifiable levels in the copepods. We conclude that in situ burning can mitigate the potential risk of PAH uptake for copepods and other pelagic organisms in the marine environment as the pyrogenic PAHs only pose low risk for uptake from the water by the copepods and other pelagic organisms.

Occurrence and Sources of Polycyclic Aromatic Hydrocarbons and Factors Influencing Their Accumulation in Surface Sediment of a Deep-Sea Depression, Namely, the Tatar Trough (Tatar Strait, the Sea of Japan)

The concentrations of 14 polycyclic aromatic hydrocarbons (PAHs) in the sediment of the Tatar Trough were studied. Despite the increase in PAH concentrations over recent decades, which is likely the result of the handling and transportation of fossil fuels, PAH levels and ecological risk were found to be low. The spatial pattern revealed that higher PAH concentrations were mainly in the deeper water sites, suggesting that trough slope failure transported the PAHs to the deeper part of the basin. There was no correlation between the PAHs and grain size or the PAHs and organic carbon that is related to the PAH input from a variety of sources and the heterogeneity of organic matter. The PAH composition, isomer ratio, and PCA identified two areas with different PAH sources. The most northern part of the Tatar Trough received petrogenic PAHs that are probably transported downslope from the northern Tatar Strait where fossil fuels are handled in some ports. Another trough part was polluted by the PAHs from the combustion of coal and biomass and the exhaust of marine vehicles. The minor presence of genes responsible for aerobic PAH destruction can be explained by the anaerobic degradation of PAHs or the spontaneous creation of favorable conditions that promote bacterial PAH oxidation.

Unravelling mixed sources of polycyclic aromatic hydrocarbons (PAH) in urban soils by visual characterization of anthropogenic substrates and coal particles, 71 PAH and alkylated PAH patterns

The identification of polycyclic aromatic hydrocarbon (PAH) sources in heterogeneous urban soils containing pyrogenic and/or petrogenic anthropogenic substrates is a common task for risk assessment. Here, for the first time, the results of source identification using analysis of 71 PAH, alkylated PAH patterns and PAH Alkylation Index were related to visually identified and quantified anthropogenic substrates in 50 soil samples. Only the combination of chemical methods with visual characterization enabled the deeper understanding of varying alkylated PAH patterns used for source apportionment and their superimposition if multiple sources occur. Pyrogenic substrates show homogenic slope-shape PAH patterns despite large visual variety. Petrogenic substrates (bituminous coals), show prevailingly bell-shape patterns but pyrogenic patterns also occur, probably due to residues from industrial processes and/or sorption of other pyrogenic PAH. Superimposition of both PAH patterns within a sample results in intermediate patterns, which are determined by the abundance of substrates and their individual PAH contents. A discrepancy between the share of petrogenic substrates and petrogenic PAH was observed due to low-medium PAH contents from coals/tailings. This may lead to misinterpretations if only chemical source identification methods are applied. With increasing proportion of petrogenic PAH in the mixture, the intermediate V-shape pattern (later bell-shape) appears in lower molecular weight PAH and moves progressively to higher molecular weight PAH. ∑71 PAH contents vary from 1.77 to 326.5 mg/kg (median 26.5 mg/kg). Non-EPA PAH measured include highly toxic ∑4 dibenzopyrene isomers (0.045–6.23 mg/kg, median 0.79 mg/kg) and 7H-benzo[c]fluorene (0.008–1.57 mg/kg, median 0.12 mg/kg). Most common anthropogenic substrates are bottom ashes, slags, bituminous coals/tailings and coke/coke ash. The PAH Alkylation Index identifies reliably samples dominated by either petrogenic (<0.4) or pyrogenic (>0.9) PAH, independently of the PAH content. Mixed or primarily pyrogenic PAH sources (0.4–0.9) need further investigations, like the presented combination of methods, which enables a reliable source apportionment.

Tarballs on the Brazilian coast in late 2022 sustain Lepas anatifera Linnaeus, 1758 (Crustacea: Cirripedia): Occurrence and risk of petroleum hydrocarbon ingestion

Since the 2019 oil spill on the northeastern coast of Brazil, oil materials have washed up on the beaches. A characteristic of the recent oil spill that began in late August was that some of the oiled material, such as tarballs, contained the goose barnacle species Lepas anatifera (Cirripedia, Lepadomorpha), which is well-known for its cosmopolitan distribution and wide occurrence in the oceans. The findings of this study provide information on the occurrence and contamination of petroleum hydrocarbons in animals adhered to the surfaces of tarballs sampled from beaches in the Brazilian states of Ceará and Rio Grande do Norte, between September and November 2022. The size of the barnacles varied from 0.122 to 2.20 cm, suggesting that the tarballs had been floating in the ocean for at least a month. All groups of L. anatifera collected from the tarballs had polycyclic aromatic hydrocarbons (PAHs) present (∑21PAHs from 476.33 to 3816.53 ng g−1). In comparison to high-molecular-weight PAHs, which are primarily from pyrolytic sources, low-molecular-weight PAHs, such as naphthalene and phenanthrene, which are mostly related to petrogenic sources, were shown to be more abundant. In addition, dibenzothiophene, which is exclusive of petrogenic origin, was found in all samples (30.74–537.76 ng g−1). The aliphatic hydrocarbons (AHs): n-alkanes, pristane, and phytane were also found and displayed petroleum characteristics. These results highlight the danger of increasing the absorption of petrogenic PAHs and AHs by organisms that use tarballs as substrates. L. anatifera is a crucial component of the food chain because many animals such as crabs, starfish, and gastropods consume it.

Polycyclic aromatic hydrocarbons in Fildes Peninsula, maritime Antarctica: Effects of human disturbance

This study provides the first data on the distribution, sources, and transport dynamics of polycyclic aromatic hydrocarbons (PAHs) in Fildes Peninsula, Antarctica via summertime analyses of lakes, seawater, snow, and air in 2013. Relatively high PAH levels and similar composition profiles (dominance of two- and three-ring PAHs) in the investigated marine and terrestrial environmental matrices were found, indicating substantial primary emissions of petrogenic PAHs. This result was corroborated by nonequilibrium partitioning of atmospheric PAHs caused by release of anthropically-derived lighter PAHs and air mass movement trajectories mainly originated from the Antarctic marginal seas. Notable geographical disparities of PAH pollution in the various types of samples consistently suggested impacts of station-related activities, rather than long-range atmospheric transport, on PAHs in Fildes Peninsula. The lack for temperature dependence for gas-phase concentrations and various molecular diagnostic ratios of atmospheric PAHs demonstrated that the impact of local anthropogenic inputs on air PAH variability supersedes the re-emission effect. The derived air–water and air–snow exchanges of PAHs in this remote region indicated a disequilibrium state, partially associated with intense local emissions of PAHs. PAH outgassing from, and absorption into, lake and marine waters were both observed, probably due to differences in anthropogenic influences among sites, while the net deposition of gaseous PAHs into snow prevailed. The results of this study shed lights on the major importance of native anthropogenic sources in the footprint and fate of PAHs in the Fildes Peninsula, which merits further monitoring.

A multi-criteria approach to investigate spatial distribution, sources, and the potential toxicological effect of polycyclic aromatic hydrocarbons (PAHs) in sediments of urban retention tanks

Bottom sediments deposited in retention tanks (RTs) located on two urban streams (Oliwski and Strzyza) in the central part of Gdansk (Poland) were analysed for polycyclic aromatic hydrocarbons’ (PAHs) content. PAHs were extracted from samples with methylene chloride, then the extracts were subjected to clean-up applying the solid phase extraction (SPE) method. Quantitative and qualitative determination of 16 PAHs was performed with the use of gas chromatography/mass spectrometry technique. A multi-dimensional approach was applied to analyse PAHs’ spatial distribution, source, and contamination status. Potential sources of PAHs were verified using isomer ratios supported by a statistical approach. The Σ16PAHs (in mg/kg d.w.) ranged from 1.95 ± 0.64 to 20.4 ± 6.8 for RTs located on the Oliwski Stream and from 0.50 ± 0.17 to 8.6 ± 2.9 for RTs located on the Strzyza Stream. PAHs detected in bottom sediments were mainly composed of 4- and 5-ring compounds. PAH isomer ratios such as Phen/Anth, Flth/Pyr, B(a)A/B(a)A + Chry, Inpy/Inpy + B(ghi)P, Flth/Flth + Pyr, Anth/Anth + Phen, and Flth/Flth + Pyr suggested delivery pathways for biomass, coal, and petroleum combustion. Petrogenic PAHs related to fuel leaks from cars were not detected. Statistical analyses confirmed traffic and heating system sources, while factor analysis (FA) pointed out the abrasion of wasting parts of vehicles. Based on threshold levels presented in sediment quality guidelines (SQGs), in most cases, PAHs were at low levels with occasional negative biological effects on organisms. Only sediments deposited in two RTs located on the Oliwski Stream presented harmful features for sediment-dwelling organisms. The risk assessment performed accordingly to the Σ16PAHs presented a moderate and high risk for biota. This study not only reflects the direct threat related to PAH content in bottom sediments, but also highlights the overall pollution of an area, considered to be a recreational part of the city (Oliwski Stream catchment). The findings of this study highlight the need to launch preventative methods to protect the area against pollution from heating system emission and traffic.

Sorption of benzo(a)pyrene and of a complex mixture of petrogenic polycyclic aromatic hydrocarbons onto polystyrene microplastics

Microplastics (MPs) largely occur in aquatic ecosystems due to degradation of larger plastics or release from MP-containing products. Due to the hydrophobic nature and large specific surface of MPs, other contaminants, such as polycyclic aromatic hydrocarbons (PAHs), can potentially sorb onto MPs. Several studies have addressed the potential impact of MPs as vectors of PAHs for aquatic organisms. Therefore the role of MPs as sorbents of these compounds should be carefully investigated. The present study aimed to determine the sorption capacity of benzo(a)pyrene (B(a)P), as a model pyrolytic PAH, to polystyrene (PS) MPs of different sizes (4.5 and 0.5 μm). In addition, the sorption of PAHs present in the water accommodated fraction (WAF) of a naphthenic North Sea crude oil to 4.5 μm MPs was also studied as a model of a complex mixture of petrogenic PAHs that could appear in oil-polluted environments. The results indicated that 0.5 μm MPs showed higher maximum sorption capacity (Qmax) for B(a)P (145–242.89 μg/g) than 4.5 μm MPs (30.50–67.65 μg/g). From the WAF mixture, naphthalene was sorbed at a higher extent than the other PAHs to 4.5 μm MPs but with weak binding interactions (Kf = 69.25 L/g; 1/n = 0.46) according to the analysis of the aqueous phase, whereas phenanthrene showed stronger binding interactions (Kf = 0.24 L/g; 1/n = 0.98) based on the analysis of the solid phase. Sorption of PAHs of the complex WAF mixture to 4.5 μm MPs was relatively limited and driven by the hydrophobicity and initial concentration of each PAH. Overall, the results indicate that sorption estimations based solely on the analysis of the aqueous phase could overestimate the capacity of MPs to carry PAHs. Therefore, controlled laboratory assays assessing the “Trojan Horse effect” of MPs for aquatic organisms should consider these findings in order to design accurate and relevant experimental procedures.

Aromatic hydrocarbon signatures of the late Miocene-early Pliocene in the Yinggehai Basin, South China Sea: Implications for climate variations

Aromatic hydrocarbons in 36 shales from the late Miocene-early Pliocene strata of the Yinggehai Basin in the South China Sea were investigated. Various higher plant-derived aromatic hydrocarbons were identified, including cadalene, retene, 1,2,7-trimethylnaphthalene, 1-methylphenanthrene (MP), 1,7-dimethylphenanthrene (DMP), 6-isopropyl-1-isohexyl-2-methylnaphthalene, and other polycyclic aromatic hydrocarbons (PAHs). Higher plant parameters suggest that the relative abundance of terrigenous organic matter in the early Pliocene was lower than in the angiosperm-dominated late Miocene Huangliu Formation. Various plant parameters including retene/(retene + cadalene), 1-MP/9-MP, 1,7-DMP/(1,3- + 3,9- + 2,10 + 3,10-DMP), and the higher plant index, indicate that gymnosperms made a larger contribution to the organic matter when the lower Yinggehai Formation was deposited during the early Pliocene. Combustion-derived PAHs, including fluoranthene, benzo[a]anthracene, benzofluoranthenes and coronene, predominate over petrogenic PAHs in the lower Yinggehai Formation and the upper Meishan Formation, indicating that there were more wildfires during deposition of these units compared to the Huangliu Formation. In contrast, there is a mixed input of combustion-derived and petrogenic PAHs in the Huangliu Formation. As also supported by higher abundances of Pinus in palynological records, the combustion-derived PAHs and the gymnosperm/angiosperm parameters provide unequivocal evidence for a cooling climate from the late Miocene to the early Pliocene in the South China Sea.

Seasonal distribution pattern and bioaccumulation of Polycyclic aromatic hydrocarbons (PAHs) in four bioindicator coastal fishes of Argentina

Polycyclic aromatic hydrocarbons (PAHs) are pollutants of global concern in coastal environments. They have a wide range of biological toxicity and due to their inherent properties, can easily bioaccumulate in organisms and concentrate in the environment. This work evaluated, in an integrated way, the seasonal PAH distribution patterns in sediments and four bioindicators fish species in a highly impacted estuary of Argentina; besides, their bioaccumulation patterns were assessed for the first time as indicator of ecological risk. The highest PAH levels in fish were found for Ramnogaster arcuata with an average of 64 ng g−1 w.w., followed by Micropogonias furnieri (45 ng g−1 w.w.), Cynoscion guatucupa (28 ng g−1 w.w.), and Mustelus schmitti (16 ng g−1 w.w.). Fish presented the highest PAH levels in fall with a predominance of petrogenic PAHs in colder seasons and pyrolytic PAHs in warmer seasons. Sediments presented an average of 233 ng g−1 d.w. with the same seasonal composition pattern of the fish tissues. Additionally, the data suggested that the main source of PAHs are wastewater discharges. The bioaccumulation factor (BAF) of PAHs in the tested fishes were found to range from 0.3 to 8. The highest values were observed during fall and winter, while bioaccumulation did not occur in moist spring and summer samples, which would suggest a high biotransformation process during these seasons. Results suggested that class III of juvenile C. guatucupa and M. furnieri, and adults R. arcuata are more sensitive bioindicators of chronic PAH contamination and that their bioaccumulation is independent of the compound hydrophobicity; this could have a positively influence on the criteria used for biological monitoring programs along the Atlantic coast. In addition, the presented BAF data on the target species will serve as a useful pollution indicator for South Atlantic coastal fish.

Distribution Trends and Source Diagnosis of Polycyclic Aromatic Hydrocarbons (PAHs) in Sediments of Imiringi River

The environmental menace caused by hydrocarbon releasing activities on water bodies have remained a cause for great concern. Such activities are accompanied by the release of highly toxic and carcinogenic polycyclic aromatic hydrocarbons (PAH), which are easily biomagnified across the food chain, ultimately aggravating adverse health conditions in human. This study was aimed at identifying the most important environmental contributors of PAHs in sediments of the Imiringi river. Owing to the activities of oil facilities among other anthropogenic influences, water bodies are inundated with hydrocarbon pollutants which settle within river bed sediments, thereby, playing an important role in the redistribution of contaminants. The applied diagnostic ratios (Phenanthrene/Anthracene, Fluorene/Fluorene + Pyrene, Fluoranthene/Fluoranthene + Pyrene, pyrogenic index and total index) revealed the presence of mixed source of PAHs (pyrogenic and petrogenic). PAH concentrations ranged from &lt;0.01 to 3,965.4 µg/kg with most detected compounds exceeding regulatory limits. The high molecular mass PAHs (4 - 6 ring HPAHs) represents the primary source showing 94.29% distribution, while the low molecular mass PAHs (2 - 3 ring LPAHs) recorded trace concentrations of about 5.71% of total PAHs. Principal component analysis (PCA) revealed Indeno(1,2,3-cd)pyrene and Dibenz(a,h)anthracene as principal PAH components in the environment. In addition, Pearson correlation showed Benzo(k)fluoranthene and Benzo(b)fluoranthene as the most positively correlating PAH species in sediment. Overall, the midstream section of the river was relatively more polluted than the up and down-river locations. Most notably, HPAHs recorded higher concentrations than the LPAHs. This may be due to intensive agricultural practices such as bush incineration, while waste dumps along the river bank remain tangible pyrogenic PAH contributors. On the other hand, trace amounts of observed petrogenic PAHs in some locations are possibly spill-over’s from oil bunkering activities and infiltrations from nearby oil installations.

Baseline PAHs, N-PAHs and 210Pb in Segment Samples from Bodo Creek: Comparison with Bonny Estuary, Niger Delta

Polycyclic aromatic hydrocarbons (PAHs), the nitrogen-containing analogues (N-PAHs) and lead 210 (210Pb) were measured in 2-cm interval core segments from Bodo Creek to evaluate impact of oil pollution in the waterbody. PAHs and N-PAHs were measured by gas chromatography analysis with mass spectrometry detection, and 210Pb activity concentration was determined by alpha spectrometry measurement. Data shows that ƩPAHs and ƩN-PAHs ranged from 12,774.3–18,470.2 µg/kg and 524.0–672.2 µg/kg, respectively. Concentrations were found to increase with increase in depth (cm). Petrogenic PAHs predominated the surface sediment (with elevated levels of 2,3,6-trimethyl-naphthalene, phenanthrene and 1-methyl-phenanthrene), while pyrogenic-PAHs dominated the deeper segments (with high levels of pyrene, benzo[a]anthracene, chrysene and benzo[k]fluoranthene). For N-PAHs, benzo[h]quinoline, 4,7-phenanthroline and benzo[a]acridine recorded high values. Chemicals comparison with values measured from Bonny Estuary revealed greater PAHs contamination in the estuary, while N-PAHs recorded elevated values in the creek. 210Pb activity concentration in the creek showed relatively low activity compared to the estuary, and similar distribution with the aromatic hydrocarbons. The measured hydrocarbons were high and exceeded the Canadian sediment quality guidelines. However, there are concerns over toxic ratios > 70% and radioactivity (EPR-D-values) > 3 – 4.E ± 01 Bq measured in the polluted creek. This gives insight on the level of radioactivity, PAHs, N-PAHs and PAHs toxic ratios in Bodo creek which would be useful in future remediation studies and/or monitoring the ability of sediments to recover under natural conditions.

Study of the Crude oil Properties of Oily seepages found in South Eastern Nigeria.

ASTM D-270 method was applied in obtaining well-head crude oil samples from Awoba 8T (Rivers State), Odidi 23L, and Odidi 46S (Delta State), Eremor 1L (Bayelsa State) and Oily Seepage samples from Ugwueme (Enugu State) and Anam (Anambra State). The0API gravity value of all the samples were 16.190 and 21.470 for Ugwueme seepage and Eremorcrude respectively, 22.470 for Odidi 46s crudeand 44.700, 43.840 and 34.760 for Anam seepage, Awoba 8t and Odidi 23L crudesrespectively, indicating heavy, medium and light crude oils respectively. All the well-head crudes and oily seepage samples studied in this work are onshore samples except Odidi 46s which is an offshore crude sample. The samples were subjected to liquid-liquid extraction using a mixture of n-hexane and dichloromethane (3:1). The extracted fractions were analyzed using GC-FID. The result of the analyses gave polycyclic aromatic hydrocarbons (PAHs) concentrations (mg/kg) of 7106.43 for Awoba 8T crude, 6767.41 for Odidi 23L crude, 5771.20 for Odidi 46S crude, 5191.21 for Eremor crude, 4908.04 for Ugwueme Seepage and 6983.16 for Anam seepage. The predominance of low molecular weight PAHs (LMWPs) over the high molecular weight PAHs (HMWPs) indicate that both the crude oil samples and the oily seepage samples were of Petrogenic Source. However, various ratios were obtained to identify the possible source of PAHs in the crude oil and seepage samples. Mixed sources of pyrogenic and petrogenic PAHs were also discovered with evidence of „pyrolytic‟ input which may suggest some geothermal-mediated processes.

Determination of sources, spatial variability, and concentration of polycyclic aromatic hydrocarbons in surface water and sediment of Imiringi River

Polycyclic aromatic hydrocarbons (PAHs) are very toxic and persistent environmental micro-contaminants that possess health-impacting tendencies. Environmental levels of PAHs are mainly exacerbated by anthropogenic activities. At elevated concentrations, PAHs become toxic and readily bio-magnify across the food chain. This study was undertaken to determine the concentration and identify possible sources of PAHs in Imiringi River. PAH concentrations depicted the following ranges; Oswan-1 (0.00046 – 0.05010 mg/L and 0.00002 – 0.01812 mg/kg); Olem-1 (0.02428 - 2.86264 mg/L and 0.00151 - 3.96536 mg/kg); Oswan-4 (0.00041 - 0.30012 mg/L and 0.00143 - 0.04530 mg/kg) for water and sediment samples respectively. PAHs mostly exceeded the recommended maximum contaminant levels (MCL) stipulated by United States Environmental Protection Agency (USEPA), while high molecular weight PAHs (4 – 6 ring PAHs) are prevalent in the environment. The applied diagnostic ratio (fluoranthene/pyrene) values for surface waters at Oswan-1 (0.8364) and Olem-1 (0.7337), and sediment at Olem-1 (0.4894) were less than 1, thereby reflecting petrogenic PAHs (from gasoline and diesel). On the other hand, Fluoranthene/Pyrene ratio of sediments from Oswan-1 (2.4558), Oswan-4 (2.3565) and surface water at Oswan-4 (2.0252) depicted values greater than 1, indicating pyrogenic PAHs (from coal combustion). Results further showed Fluoranthene/(Fluoranthene + Pyrene) ratio for all sampling locations at values greater than 0.4 for both surface water and sediment. Hence, revealing pyrogenic source PAHs (from combustion of fossil fuel, coal, grass, wood, etc). Overall, the water body showed reasonable hydrocarbon contamination. As such, it is unsuitable for consumption, as well as recreational and agricultural activities. The application of One-way ANOVA statistics showed spatial variability (p &lt; 0.05) for different PAH species across different sections of river, while principal component analysis (PCA) revealed discrete similarities for most PAHs, excluding anthracene and Dibenz(a,h)anthracene.

Anthropogenic and natural inputs of polycyclic aromatic hydrocarbons in the sediment of three coastal systems of the Brazilian Amazon.

Polycyclic aromatic hydrocarbons (PAHs) were measured in 32 surface sediment samples collected around three cities (Barcarena, Belém, and Santana) located on the coast of the Brazilian Amazon. The concentration of total PAHs ranged from lower than detection limit to 33,101 ng g-1 in a sample from Barcarena and was related to a large aluminum industrial complex and port activities. In Belém, which is the most populated area in the Amazon region, PAHs were probably derived from untreated sewage discharge and inputs from a large municipal landfill. Pyrogenic PAHs were predominant in both cities, with a smaller contribution of petrogenic PAHs. Low alkylated PAH levels may be associated with small boats and ship traffic. Santana had low total PAH concentrations, with a predominance of unusual alkylated PAHs, probably related to diagenetic transformations of organic matter in the sediment. In general, PAH concentrations in the samples were low and may reflect baseline levels for this Amazon estuarine system.

Polycyclic aromatic hydrocarbons (PAHs) cycling and fates in Galveston Bay, Texas, USA.

The cycling and fate of polycyclic aromatic hydrocarbons (PAHs) is not well understood in estuarine systems. It is critical now more than ever given the increased ecosystem pressures on these critical coastal habitats. A budget of PAHs and cycling has been created for Galveston Bay (Texas) in the northwestern Gulf of Mexico, an estuary surrounded by 30–50% of the US capacity of oil refineries and chemical industry. We estimate that approximately 3 to 4 mt per year of pyrogenic PAHs are introduced to Galveston Bay via gaseous exchange from the atmosphere (ca. 2 mt/year) in addition to numerous spills of petrogenic PAHs from oil and gas operations (ca. 1.0 to 1.9 mt/year). PAHs are cycled through and stored in the biota, and ca. 20 to 30% of the total (0.8 to 1.5 mt per year) are estimated to be buried in the sediments. Oysters concentrate PAHs to levels above their surroundings (water and sediments) and contain substantially greater concentrations than other fish catch (shrimp, blue crabs and fin fish). Smaller organisms (infaunal invertebrates, phytoplankton and zooplankton) might also retain a significant fraction of the total, but direct evidence for this is lacking. The amount of PAHs delivered to humans in seafood, based on reported landings, is trivially small compared to the total inputs, sediment accumulation and other possible fates (metabolic remineralization, export in tides, etc.), which remain poorly known. The generally higher concentrations in biota from Galveston Bay compared to other coastal habitats can be attributed to both intermittent spills of gas and oil and the bay's close proximity to high production of pyrogenic PAHs within the urban industrial complex of the city of Houston as well as periodic flood events that transport PAHs from land surfaces to the Bay.

Alkylated phenanthrene distributions in black rockfish (Sebastes schlegelii) and biotransformation into hydroxylated metabolites after intragastric administration

Marine organisms such as fish are at risk of exposure to petrogenic polycyclic aromatic hydrocarbons (PAHs) released in oil spills. PAH toxicities are affected by the rates of PAH biotransformation and elimination in fish tissues, but little information on these rates is available. In this study, the biotransformation and tissue distribution of methylated phenanthrenes—typical petrogenic PAHs found after oil spills—in black rockfish (Sebastes schlegelii) were investigated. Two groups of fish were used. Each fish in one group was given a single intragastric dose of 3-methylphenanthrene, and each fish in the other group was given a single intragastric dose of 3,6-dimethylphenanthrene. The fish were allowed to recover in purified sea water for 196 h. Methylated phenanthrenes were detected in only blood and liver for 24 h after dosing, but the concentrations decreased over time and > 98% had been eliminated by the end of the study. Four mono-hydroxylated metabolites of 3,6-dimethylphenanthrene and six mono-hydroxylated metabolites of 3-methylphenanthrene were tentatively identified for the first time from tandem mass spectrometry analyses of fish bile. The concentrations of these metabolites in bile remained constant for 192 h, suggesting that the metabolites could be used as biomarkers of rockfish exposure to petrogenic PAHs.

Polycyclic Aromatic Hydrocarbons in the Estuaries of Two Rivers of the Sea of Japan.

The seasonal polycyclic aromatic hydrocarbon (PAH) variability was studied in the estuaries of the Partizanskaya River and the Tumen River, the largest transboundary river of the Sea of Japan. The PAH levels were generally low over the year; however, the PAH concentrations increased according to one of two seasonal trends, which were either an increase in PAHs during the cold period, influenced by heating, or a PAH enrichment during the wet period due to higher run-off inputs. The major PAH source was the combustion of fossil fuels and biomass, but a minor input of petrogenic PAHs in some seasons was observed. Higher PAH concentrations were observed in fresh and brackish water compared to the saline waters in the Tumen River estuary, while the PAH concentrations in both types of water were similar in the Partizanskaya River estuary, suggesting different pathways of PAH input into the estuaries. The annual riverine PAH mass flux amounted to 0.028 t/year and 2.5 t/year for the Partizanskaya River and the Tumen River, respectively. The riverine PAH contribution to the coastal water of the Sea of Japan depends on the river discharge rather than the PAH level in the river water.

Dietary intake of polycyclic aromatic hydrocarbons (PAHs) from coral reef fish in the Persian Gulf — Human health risk assessment

The present study investigated accumulation of petrogenic polycyclic aromatic hydrocarbons (∑39PAHs) in the livers and muscles of three coral-reef fish (50 specimens) from the Persian Gulf, Kharg Island (Iran), specifically Lethrinus microdon (n = 18), Lutjanus argentimaculatus (n = 17), and Scomberomorus guttatus (n = 15). For all fish, PAHs originated mostly from petroleum and combustion sources. Concentrations of ∑39PAHs were 1004 ngg−1 freeze-dried weight (fdw) and 1390 ngg−1 fdw for liver and muscle, respectively. The biota-sediment accumulation factor of 20,181 and equivalent concentrations of ∑PAHs (liver) were highest for L. argentimaculatus. Most of the abundant PAHs identified were low molecular weight (LMW-PAH) (liver > muscle) with 2–3 aromatic ring. Results for the human health risk assessment concluded the probability of PAHs intake via fish consumption was considerable in this area (lifetime cancer risk (ILCR) > 1 × 10−5; hazard quotients (HQs) > 1; hazard index (HI) ≈6; the excess cancer risk (ECR) > 1 × 10−6) and, therefore, comprehensive management and long-term monitoring is needed.

Background concentrations of polycyclic aromatic hydrocarbons (PAHs) in deep core sediments from the Norwegian Sea and the Barents Sea: A proposed update of the OSPAR Commission background values for these sea areas

Geochemical studies of 174 sediment cores collected by the MAREANO mapping program in Norwegian waters of the North Atlantic Ocean give new sets of values of background concentrations (BCs) for polycyclic aromatic hydrocarbons (PAHs) for the studied regions. The study is based on deep core sediment samples representing background levels of PAHs. The samples selected were only from the deeper parts of undisturbed sediment cores with low, stable concentrations of petrogenic and pyrogenic PAHs, with low variation for individual PAH compounds between the samples within the same core, and from below the parts of the cores dated with 210Pb to approximately the last 100–150 years. The results show that the main part of the studied area has BCs different from those previously established by OSPAR Commission (OSPAR) for the North-East Atlantic. Another area in central Barents Sea has a separate set of BCs of pyrogenic PAHs, apparently due to the influence from marginal ice zone mechanisms. A third area with its own set of BCs has been established for north-western Barents Sea off the coast of Svalbard, due to high natural contents of PAHs in this area. BCs for several PAHs not included in the present OSPAR list are also provided.

Temporal Variability of Polycyclic Aromatic Hydrocarbons in Deep-Sea Cephalopods of the Northern Gulf of Mexico

As part of the effort to understand the effects of the Deepwater Horizon Oil Spill (DWHOS), we analyzed tissue from five species of midwater oceanic cephalopods in the northern Gulf of Mexico (GoM) during three time periods, including one period sampled fortuitously just before the spill (2010), and two periods sampled after the spill (2011 and 2015-2016). The species, Japetella diaphana, Abralia redfieldi, Histioteuthis corona, Leachia atlantica, and Onychoteuthis banksii were collected in three geographic areas in the GoM (east, south and southeast of the Macondo wellhead). Results indicate a shift in the composition of polycyclic aromatic hydrocarbons (PAHs) in the tissue of all cephalopods after 2010, with a more petrogenic source in 2011 that weathered and mixed with other sources in 2015-2016. Overall, PAH concentrations, as well as lipid content, were lower in 2011 relative to 2010 and 2015-2016, suggesting secondary effects to oil-residues exposure from the DWHOS. Collectively, PAHs in the tissues of deep-sea cephalopods indicate an episodic exposure to petrogenic PAHs that occurred between 2010 (pre-spill) and 2011, and continued through 2015-2016.