Sedimentary record of polycyclic aromatic hydrocarbons in a sediment core from a maar lake, Northeast China: evidence in historical atmospheric deposition

A maar lake is an excellent ecosystem to study the atmospheric deposition of pollutants, as its contaminants are primarily by atmospheric deposition. In this study, a sediment core from Sihailongwan Maar Lake, Northeast China, was collected and the historical atmospherically deposited polycyclic aromatic hydrocarbons (PAHs) were analyzed. The concentrations of TPAHs (the sum of the US EPA proposed 16 priority PAHs, excluding naphthalene and pyrene) ranged from 473.9 to 2289 ng g(-1) with a slow increasing stage in the deeper sediments and a sharp increasing stage in the upper sediments. The input rate of TPAHs, especially that of PAH(9) (the sum of fluoranthene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, indeno(1,2,3-cd)pyrene, dibenzo(ah)anthrathene, and benzo(ghi)perylene), correlated well to the Chinese historical socioeconomic data. This indicates that sediment PAHs were mainly derived from human activities and PAH(9) can be regarded as a better indicator of the local socioeconomic development. Source identification suggested that PAHs were originated primarily from mixed sources (e.g., coal and biomass burning and petroleum combustion), except for perylene which was mostly of diagenetic origin. In addition, the down-core PAHs profile clearly illustrated that PAHs sources in Northeast China experienced a transformation from low- and moderate temperature to high-temperature combustion processes, especially after the late 1980s. Additionally, an ecological risk assessment using two redefined biological thresholds (TEQ(ERL) and TEQ(ERM)) indicated that most of the PAHs measured in the present sediment core would not cause an immediate toxic effect; only FLU and PHEN are a potential source of concern for biological impairment.     

Impact of urbanization on the concentrations and distribution of organic contaminants in boreal lake sediments

The main goal of this study was to evaluate the impacts of a middle-sized Finnish urban area on the quality of sediments in an adjacent boreal lake. We investigated the sources and distribution of organic pollutants (polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs)) in the sediments from urban stormwater traps and from Lake Vesijärvi. Grab surface sediment samples were taken from Lake Vesijärvi at various distances (25–2,000 m) from four major stormwater drainage outlets and at 15 urban stormwater traps in areas with different degrees of urbanization. These samples were analysed for 16 PAHs and 28 PCBs with gas chromatography–mass spectrometry. The concentrations of pollutants in the lake sediments were elevated in the vicinity of the urban shore (∑PAH 3–16, ∑PCB up to 0.02–0.3 mg/kg dw) and decreased as a function of distance (∑PAH 0.1–2.5, ∑PCB 0.01–0.3 mg/kg dw at a distance of more than 500 m from the shore), whereas contamination levels in suburban areas were notably lower (∑PAH 0.1–3, ∑PCB?<?LOQ–0.03 mg/kg dw; did not decline with distance). Possible sources and pathways of contamination were also investigated. The majority of stormwater trap sediments contained predominantly asphalt-derived PAHs due to pulverized pavement. PAHs in lake sediments were of pyrogenic origin, including the combustion of gasoline, diesel and coal. Suggested pathways of lake contamination are urban runoff discharge, boat traffic and atmospheric deposition.     

Toxicity assessment of sediments associated with the wreck of s/s Stuttgart in the Gulf of Gdańsk (Poland)

The paper presents the results of toxicity determinations carried out on sediment samples collected in the vicinity of the wreck of the German s/s Stuttgart (the southern part of the Gulf of Gdańsk, off the Polish coast) in relation to the determination of polycyclic aromatic hydrocarbons (PAHs). The toxicity of surface and core sediment samples was assessed using two biotest organisms-the bioluminescent bacteria Vibrio fischeri and the ostracod Heterocypris incongruens. PAH levels in these samples were determined by GC-MS. The surface sediments collected at W2 (ca. 34 m north of the shipwreck) and W4 (ca. 415 m north-east of the wreck) as well as the core sediments collected at WR3 (ca. 400 m north-east of the wreck) were the most heavily polluted with substances toxic to the biotest organisms. The chronic and acute toxicities in the case of most of the surface sediment samples studied are correlated. This may suggest that not only hydrophobic chemicals (like PAHs from fuel residues) but also more polar chemicals (resulting from the conversion of aromatic hydrocarbons) are responsible for the toxicity levels found. There is a clear dependence between the levels of chronic toxicity and PAH concentrations in the core sediment samples. In addition, a simultaneous decrease in the PAH content and chronic toxicity was noted in all the core sediment samples at depths below 80 cm.     

Spatial and temporal distribution of polycyclic aromatic hydrocarbons (PAHs) in sediments of the Nansi Lake, China

Polycyclic aromatic hydrocarbons (PAHs) were measured in surface sediments and dated core sediments from the Nansi Lake of China to investigate the spatial and temporal distribution characteristics. The concentrations of 16 kinds priority PAH compounds were determined by GC-MS method. And ²¹⁰Pb isotope dating method was used to determine the chronological age of the sediment as well as the deposition rate. The results indicated that the total PAHs concentration ranges in surface and core sediment samples were 160 ~32,600 and 137 ~ 693 ng/g (dry wt.), respectively. The sediment rate and the average mass sedimentation were calculated to be 0.330 cm·year^???1 and 0.237 g·cm^???2·yr^???1 and the sediment time of the collected core sample ranged from 1899 to 2000. The peak of PAH concentrations came at recent years. The source analysis showed PAHs mainly came from the contamination of low temperature pyrogenic processes, such as coal combustion. The PAHs concentrations were lower than ERL and LEL values for most collected samples. However, in several surface sediment samples especially in estuary sites, the PAHs concentrations were not only higher than ERL and LEL values, but also higher than ERM values.     

Occurrence, source apportionment and toxicity assessment of polycyclic aromatic hydrocarbons in surface sediments of Chaohu, one of the most polluted lakes in China

In order to evaluate the effect of local anthropogenic activities on Chaohu Lake, one of the most eutrophicated lakes in China, surface sediments have been collected from the whole lake with 0.05 × 0.05 degree latitude/longitude resolution and in the estuaries of three main inflowing rivers. The concentrations of the 28 polycyclic aromatic hydrocarbons (PAHs) determined were in a range 82.4-13,000 ng g(-1) with an average value of 1670 ng g(-1) dry weight for total 28 PAHs (referred to as Σ(28)PAH). Amongst the 28 PAHs, 16 are listed as high priority PAHs by the USEPA and they were in the range of 60.8-10,200 ng g(-1) with an average value of 1230 ng g(-1) for the total of them (referred to as Σ(16)PAH); 7 are known as carcinogenic PAHs and their levels ranged from 34.2 to 6400 ng g(-1) with an average of 815 ng g(-1) in total (referred to as Σ(7)PAH). Chaohu Lake was considered significantly polluted by PAHs through the comparison with the PAH burdens in fresh-water lakes both in China and worldwide. Toxic units (TUs) evaluation showed some sampling locations possibly were over the median lethal level for benthic invertebrate. The highest PAH concentrations were found in sediments from the Nanfei River estuary, suggesting the major contributor of PAHs contamination to the lake. The PAHs with four and five rings were found to be dominant among the PAHs detected in all of the sediment samples, and perylene was the most abundant. Σ(16)PAH had a good correlation with those PAHs from pyrogenic sources, such as anthracene and phenanthrene, but a poor correlation with perylene. The results demonstrated that the environmental behavior of PAHs from pyrogenic sources is significantly different to that of perylene from diagenetic sources. The PAHs in sediments were mainly from traffic-related emission by qualitatively assessing with the diagnostic ratios of PAH isomers, and the ratios for low molecular weight PAHs were strongly altered during their transport.     

The polycyclic aromatic hydrocarbon and geochemical biomarker composition of sediments from sea lochs on the west coast of Scotland

Sediments from twelve sea lochs on the west coast of Scotland were analysed for parent and branched 2- to 6-ring polycyclic aromatic hydrocarbons (PAHs), n-alkanes and geochemical biomarkers (triterpanes). Where possible at least fourteen sediment samples were collected at random from each sea loch. All sea lochs were remote, most had limited industrial and urban inputs, although all had fish farms. Four lochs had moderate total PAH concentrations and eight lochs had high total PAH concentrations. Total PAH concentration was related to organic carbon content and particle size distribution, with sandier sediments having lower PAH concentrations. The highest total PAH concentrations, normalised for organic carbon, were in Loch Linnhe and Ballachulish Bay (Loch Leven), close to an aluminium smelter. PAH concentration ratios showed that pyrolysis was the main source of PAHs in most lochs. Only sediments from Loch Clash showed evidence of petrogenic input based on their geochemical biomarker (triterpane and sterane) and n-alkane profiles. PAH profiles were similar across lochs apart from Loch Linnhe and Ballachulish Bay, which had a greater proportion of heavy parent PAHs. West coast sediments had a smaller proportion of heavy PAHs than sediments collected from voes in Shetland and a smaller proportion of alkylated PAHs relative to sediments collected from coastal waters around Orkney.     

Environmental assessment of polycyclic aromatic hydrocarbons in the surface sediments of a remote region on the eastern coast,Taiwan

Surface sediment samples were collected in He-Ping Harbor and the nearby He-Ping Estuary from 2005 to 2006 to examine spatial and temporal variability in polycyclic aromatic hydrocarbon (PAH) concentrations. The sum of the 16 USEPA priority pollutant PAHs varied from 8 to 312 ng/g dry weight, which was relatively low compared to values obtained from other studies in the world. Regarding temporal changes in the PAH profile, total PAH concentrations in the wet season were lower than during the dry season in He-Ping Harbor. However, the concentration of PAHs exhibited no significant difference in the four seasons in the He-Ping Estuary. PAH concentrations in He-Ping Harbor were higher than those in the He-Ping Estuary. In comparison with sediment quality guidelines, PAH concentrations of sediments in this study were lower than those outlined in the criteria, which suggests no evident adverse biological effects due to PAHs around the He-Ping coast. Ratios of specific PAH compounds calculated to assess the possible sources of PAHs reflect that PAHs in He-Ping Harbor may mainly be from pyrogenic coal combustion.     

Polycyclic aromatic hydrocarbons and polychlorinated biphenyls in the harbour of Naples (Southern Italy): time and spatial distribution patterns

Seventeen parent polycyclic aromatic hydrocarbons (PAHs) and 38 congeners of polychlorinated biphenyls were measured at five different sediment depths (between the surface and ~300 cm below the seafloor) at 160 sites in Naples harbour. Total PAH (??PAH) and PCB (??PCB) concentrations ranged between 0.012?C21.73^???nd 0.001?C0.222 mg kg^???1, respectively. For PAHs, an evident and progressive decrease in concentration with depth documents the effects of a more intense anthropic impact of this group of pollutants in the recent period. A selected number of PAH isomer pairs (phenanthrene/anthracene, fluoranthene/pyrene and benzo(a)anthracene/crysene) were used to distinguish between contaminants of pyrolitic and petrogenic origin. More than 90% of PAHs present at the different depths of the studied sediments indicate pyrolitic industrial origins. On the other hand, relatively high concentrations of three- and four-ring PAHs suggest a limited contribution of vehicular emissions to the contamination of sediments. An unexpected and systematic increase of ??PCB concentration, exceeding values approved by international regulations, was found in the studied sediments, testifying to the uncontrolled discharge to the studied area from industrial and commercial activity on nearby land. Ecotoxicological risk levels calculated for PAHs suggests a relatively elevated level of toxicity in surface sediments decreasing with depth and very low toxicity values associated to PCB toxicity.     

Polycyclic aromatic hydrocarbons in river sediments from the western and southern catchments of the Bohai Sea, China: toxicity assessment and source identification

The concentration, distribution, and origin of 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs) were investigated in river sediments from the western and southern catchments of the Bohai Sea, China. A toxicity assessment of 28 sediment samples collected from 15 main rivers was conducted by utilizing threshold and probable effect concentrations (TEC and PEC, respectively) derived from consensus-based sediment quality guidelines. The concentrations of total PAHs (∑PAH₁₆) ranged from 0.14 to 10,757 μg/kg dry weight (mean?=?1,368.6 μg/kg). The high concentrations of PAHs found in Binhai New Area of Tianjin and Binzhou City are likely the result of rapid population and heavy industry growth, resulting in elevated point and nonpoint source inputs of PAHs. Of the samples collected, samples 1 and 10 (7.1 % of the total) were categorized as toxic since some of the PAH concentrations exceeded the corresponding PECs. Twenty samples were classified as nontoxic, with both the individual PAH and the∑PAH₁₆ concentrations falling below the corresponding TECs. Analyses of selected PAH isomer ratios aided in the identification of PAH origins, allowing for a discrimination between pyrogenic and petrogenic sources. Spatial variability confirmed source heterogeneity within the study area. The most significant PAH-associated contamination was found in the Beitang River and Ji Canal, which are located in Binhai New Area. The magnitude of contamination and the likelihood of an ongoing influx of PAHs support the need for a better understanding of pollution sources and methods for both control and sediment restoration.     

Concentrations of polycyclic aromatic hydrocarbon in the surface sediments from inter-tidal areas of Kenting coast,Taiwan

The main objective of this study was to investigate the concentrations of polycyclic aromatic hydrocarbons (PAHs) in inter-tidal sediments of the Kenting coast, Taiwan, to assess the levels and origin of PAHs, and to provide useful information on the potential ecological risk of PAHs to benthic organisms. The total concentrations of 38 PAHs ranged from 0.2 to 493 ng/g dry weight. The high variation in total PAH concentrations was caused by the sand content of the sediment in the area. Compared with other coasts and bays in the world, the concentrations of PAHs in the inter-tidal surface sediment of the Kenting coast is low to moderate. Based on the sediment quality guidelines, the total PAH concentrations were below the effects range low value, indicating that the PAH levels in the Kenting area were within minimal effects ranges for benthic organisms. Principal component analysis and isomer ratios were analyzed to identify the contamination source in the inter-tidal surface sediment of the Kenting coast. The results of compounds’ pattern and origin analysis suggest that the source of PAHs in the inter-tidal surface sediment of the Kenting coast is the combustion of petroleum and biomass.     

Long-term fate of polycyclic aromatic hydrocarbons (PAH) in sediments from Loch Leven after closure of an aluminium smelter

An aluminium smelter discharged polycyclic aromatic hydrocarbons (PAHs) into Loch Leven on the west of Scotland from 1907 until it closed in 2000, resulting in elevated PAH concentrations in the sediment. A temporal monitoring programme to investigate any recovery in sediment concentrations began in 2004, with sampling each year until 2008 and again in 2010. Cores were also collected to investigate temporal trends over a longer time scale and to estimate the sedimentation rate in the loch. The loch is divided into two basins, and PAH concentrations were significantly higher in the upper basin, closer to the smelter, than in the lower basin. The PAH distribution and concentration ratios were consistent with a pyrolytic source of PAHs, with a high proportion of heavier parent PAHs. There was no evidence of any recovery in PAH concentrations, perhaps due to the mixing and disturbances of the sediment, and the persistence of PAHs. Concentrations of all PAHs were above the Background Assessment Concentrations (BACs) in both basins. In the lower basin only the 5- and 6-ring PAHs were above the Effects Range Low (ERL) values, but in the upper basin all but naphthalene were above the ERLs. There is therefore still an unacceptable risk of chronic effects in marine species. Concentrations decreased down the cores, falling below BACs in the deepest sections. However, ERLs were exceeded as far down the core as 30 cm for some PAHs.     

The distribution and composition of hydrocarbons in sediments from the Fladen Ground, North Sea, an area of oil production

The distribution and composition of hydrocarbons in sediment from the Fladen Ground oilfield in the northern North Sea have been investigated. The total PAH concentrations (2- to 6-ring parent and alkylated PAHs, including the 16 US EPA PAHs) in sediments were relatively low (<100 microg kg(-1) dry weight). The PAH, the Forties crude and diesel oil equivalent concentrations were generally higher in sediment of fine grain size and higher organic carbon concentration. PAH distributions and concentration ratios indicated a predominantly pyrolytic input, being dominated by the heavier, more persistent, 5- and 6-ring compounds, and with a high proportion of parent PAHs. The n-alkane profiles of a number of the sediments contained small, high boiling point, UCMs, indicative of weathered oil arising from a limited petrogenic input. The geochemical biomarker profiles of the sediments that contained UCMs showed a small bisnorhopane peak and a high proportion of norhopane relative to hopane, indicating that there was contamination from both Middle Eastern and North Sea oils. Therefore contamination was not directly as a result of oil exploration activity in the area. The most likely source of petrogenic contamination was from general shipping activity.     

Multivariate assessment of polycyclic aromatic hydrocarbons in surface sediments of the Beijiang, a tributary of the Pearl River in Southern China

To estimate the severity of polycyclic aromatic hydrocarbon (PAH) contamination in the upper sediment of the Beijiang River, 42 sediment samples were analyzed for the presence of 16 key PAHs using gas chromatography–mass spectrometry. The concentrations of PAH in the sediment ranged from 44 to 8,921 ng g^?1 dry weight. The four- to six-ring PAHs, contributing >50 % to PAHs in 34 of the 42 sites, were the dominant species. Based on a principal component analysis, combined with multivariate linear regression, it became clear that the most important contributors of PAH were fossil fuel combustion (48 %), diesel emissions plus oil spillage (33 %), and coke combustion (19 %). The surface sediments of Beijiang River were grossly contaminated by PAHs mainly derived from combustion.     

Polycyclic aromatic hydrocarbons in surface water and bed sediments of the Hungarian upper section of the Danube River

This study was performed to elucidate the distribution, concentration trend and possible source of polycyclic aromatic hydrocarbons (PAHs) in surface water and bed sediments of the Hungarian upper section of the Danube River and the Moson Danube branch. A total of 217 samples (water and sediments) were collected from four different sampling sites in the period of 2001–2010 and analysed for the 16 priority US Environmental Protection Agency PAHs. Concentrations of total 16 PAHs (∑PAHs) in water samples ranged from 25 to 1,208 ng/L, which were predominated by two- and three-ring PAHs. The ∑PAH concentrations in sediments ranged from 8.3 to 1,202.5 ng/g dry weight. Four-ring PAHs including fluoranthene and pyrene were the dominant species in sediment samples. A selected number of concentration ratios of specific PAH compounds were calculated to evaluate the possible sources of PAH contamination. The ratios reflected a pattern of pyrogenic input as a major source of PAHs. The levels of PAHs determined were compared with other sections of the Danube and other regions of the world.     

Source apportionment of polycyclic aromatic hydrocarbons in the Dahuofang Reservoir, Northeast China

Polycyclic aromatic hydrocarbons (PAHs) in 24 surface sediments from the Dahuofang Reservoir (DHF), the largest man-made lake in Northeast China, were measured. The results showed that the concentrations of 16 US EPA priority PAHs in the sediments ranged from 323 to 912 ng/g dry weight with a mean concentration of 592?±?139 ng/g. The PAH source contributions were estimated based on positive matrix factorization model. The coal combustion contributed to 31 % of the measured PAHs, followed by residential emissions (22 %), biomass burning (21 %), and traffic-related emissions (10 %). Pyrogenic sources contributed ～84 % of anthropogenic PAHs to the sediments, indicating that energy consumption release was a predominant contribution of PAH pollution in DHF. Compared with the results from the urban atmospheric PAHs in the region, there was a low contribution from traffic-related emissions in the sediments possibly due to the low mobility of the traffic-related derived 5+6-ring PAHs and their rapid deposition close to the urban area.     

Evaluation of a fluorometric screening method for predicting total PAH concentrations in contaminated sediments

A fluorometric screening method was used to estimate total polycyclic aromatic hydrocarbon (t-PAH) concentrations in sediments collected from the St. Louis River Area of Concern (AOC) in northeastern Minnesota. Sediments were collected as part of a Regional Environmental Monitoring and Assessment Program (R-EMAP) study to assess sediment quality in the AOC. The screening method was calibrated using a PAH surrogate standard consisting of eight PAHs commonly found in the St. LouisRiver system, at their approximate proportions. Estimated PAHconcentrations were compared to GC/MS measured `true' PAH concentrations to evaluate the overall predictive power of thescreening method. Regression analysis of log transformed estimated versus true PAH concentration yielded an r² of 0.72 (n = 86). In addition, the rates of false positive and false negative predictions associated with the screening methodwere determined relative to different sediment effects concentrations (SECs) for total PAHs. In general, the rate of false positive predictions was shown to increase as the SEC criteria value decreased, while false negative rates remainedconsistently low (below 7%). Methodological recommendations which led to a three-fold reduction in false negatives, and theimproved prediction of both high and low PAH samples, are presented.     

Polycyclic aromatic hydrocarbons (PAHs) in surface sediments from the Bizerte Lagoon,Tunisia: levels,sources, and toxicological significance

To assess the status of polycyclic aromatic hydrocarbon (PAH) contamination in sediments from the Bizerte Lagoon (northern Tunisia), 18 surface sediment samples were collected in March 2011 and analyzed for 14 US Environmental Protection Agency priority PAHs by high-performance liquid chromatography. The total concentrations of the 14 PAHs (ΣPAHs) ranged from 16.9 to 394.1 ng g^?1 dry weight (dw) with a mean concentration of 85.5 ng g^?1 dw. Compared with other lagoons, coasts, and bays in the world, the concentrations of PAHs in surface sediments of the Bizerte Lagoon are low to moderate. The PAHs’ composition pattern was dominated by the presence of four-ring PAHs (45.8 %) followed by five-ring (26.8 %) and three-ring PAHs (12.7 %). The PAH source analysis suggested that the main origin of PAHs in the sediments of the lagoon was mainly from pyrolytic sources. According to the numerical effect-based sediment quality guidelines of the USA, the levels of PAHs in the Bizerte Lagoon should not exert adverse biological effects. The total benzo[a]pyrene toxicity equivalent values calculated for the samples varied from 3.1 to 53.7 ng g^?1 dw with an average of 10.6 ng g^?1 dw.     

Chemical (polycyclic aromatic hydrocarbon and heavy metal) levels in contaminated stormwater and sediments from a motorway dry detention pond drainage system

Chemical (polycyclic aromatic hydrocarbon - PAH and heavy metal) levels in stormwater and sediment samples collected from the London Orbital (M25) motorway drainage dry detention pond at Oxted, Surrey, UK were determined. Such chemicals are derived from vehicular combustion products and the wear and tear materials deposited onto the motorway surface. Gas chromatography-mass spectrometry (GC-MS) was used for the qualitative and quantitative determination of 16 USEPA priority PAHs in motorway drainage sediments. The GC-MS method, incorporating a solid phase extraction step, provides detection limits ranging from 0.17 to 0.41 mg kg(-1)(dry weight). Almost all of the 16 USEPA listed PAHs were detected. Phenanthrene, fluoranthene, pyrene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(a)pyrene and benzo(g,h,i)perylene (PAH numbers 5, 7, 8, 9, 10, 11, 13 and 16) were among the PAHs found at "higher" levels (ranging from 0.3-10.2 mg kg(-1), dry weight) in the sediment samples. PAH levels show little change along the motorway drainage silt trap (facility for reducing the levels of suspended particulate matter in the stormwater). PAH concentrations are considerably higher in the dry detention pond outflow interceptor. Statistical analysis showed that significant correlation coefficients (based on a t-test at the 95% confidence interval) were obtained between those PAHs found at high concentrations over all of the sampling sites. Several PAHs were dispersed beyond the treatment facility and accumulation in the sediment of the deer park resulted in levels ranging from 0.3-1.6 mg kg(-1), dry weight. These PAHs found beyond the treatment facility (in the local farm deer park) may contribute a serious health threat to farm animals or even fish in the aquatic environment. Heavy metal levels (V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Cd, Sb and Pb) of the drainage stormwater and sediments were determined by inductively coupled plasma mass spectrometry (ICP-MS), with quality control evaluation using two certified reference materials. Typical detection limits were found to be below 0.1 [micro sign]g l(-1) for stormwater and 0.005 mg kg(-1) for acid digested sediments. Raised heavy metal levels were found throughout the dry detention pond facility and only decrease when the stormwater is diluted following discharge into the river Eden. Statistical analysis also confirms that some significant correlations exist between various heavy metals and PAHs. However, no overall conclusive trend is found indicating that a particular PAH is deposited in sediment relative to a specific heavy metal/s. These results raise some serious concerns about the dispersion and accumulation of chemicals in the sediments of motorway stormwater drainage systems and the need for maintenance and clean-up of contaminated material from such systems.     

Distribution characteristics of polycyclic aromatic hydrocarbons in sediments and biota from the Zha Long Wetland, China

In this paper, the concentrations of polycyclic aromatic hydrocarbons (PAHs) were measured in biota (reed, grass, mussel, fish, and red-crowned crane) and sediments collected from seven locations in the Zha Long Wetland. PAHs were recovered from the sediments and biota by ultrasonic extraction and then analyzed by means of gas chromatography-mass spectrometry. The total PAH concentrations were 244–713 ng/g dw in sediments, 82.8–415 ng/g dw in plants and 207–4,780 ng/g dw in animals. The total sediment PAH concentrations were categorized as lower to moderate contamination compared with other regions of China and the world. In the plant samples, the accumulation abilities of reed roots and stems for PAHs were higher than those of grass roots. In addition, the concentration of individual PAHs in mussel muscles was the highest in all of the animal samples, followed by fish, feeding crane fetuses, and wild crane fetuses. Compositional analysis suggests that the PAHs in the sediments from the Zha Long Wetland were derived from incomplete biomass combustion. Risk assessment shows that the levels of PAHs in sediments are mostly lower than the effects range mean value (effects range mean), whereas only naphthalene in all sample sites was higher than the effects range low value. It is worthwhile to note that benzo(b)fluoranthene, benzo(k)fluoranthene, indeno(1,2,3-cd)pyrene and benzo(ghi)perylene were detected in crane fetal, which have potential carcinogenicity for organisms from the Zha Long Wetland.     

Aliphatic and polycyclic aromatic hydrocarbons in the surface sediments of the Mediterranean: assessment and source recognition of petroleum hydrocarbons

Coastal marine sediment samples were collected from ten sampling stations along the Egyptian Mediterranean coast in April 2010. All sediment samples were analyzed for aliphatic (C7 to C34) and polycyclic aromatic hydrocarbons (PAHs) as well as total organic carbon (TOC) contents and grain size analysis. Total aliphatic hydrocarbons ranged from 1621.82 to 9069.99 ng/g (dry weight), while aromatic hydrocarbons (16 PAHs) varied between 208.69 and 1020.02 ng/g with an average of 530.68?±?225.86 ng/g?dwt. Good correlations observed between certain PAH concentrations allowed to identify its origin. The average TOC percent was varied from 0.13 to 1.46 %. Principal component analysis was used to determine the sources of hydrocarbon pollutants in sediments of Mediterranean. Additionally, special PAHs compound ratios suggest the petrogenic origins.