Inputs and sources of hydrocarbons in sediments from Cienfuegos bay, Cuba

Trends of legacy and emerging organic contaminants in a sediment core from Cienfuegos Bay, Cuba, from 1990 to 2015

Legacy and emerging organic pollutants pose an ever-expanding challenge for the marine environment. This study analysed a dated sediment core from Cienfuegos Bay, Cuba, to assess the occurrence of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), alternative halogenated flame retardants (aHFRs), organophosphate esters (OPEs), and phthalates (PAEs) from 1990 to 2015. The results evidence the continuing presence of historical regulated contaminants (PCBs, OCPs, and PBDEs) in the southern basin of Cienfuegos Bay. PCB contamination declined since 2007, likely in response to the gradual global phasing out of PCB containing materials. There have been relatively consistent low accumulation rates for OCPs and PBDEs at this location (in 2015 approximately 1.9 and 0.26ng/cm²/year, respectively, with 2.8ng/cm²/year for Σ₆PCBs), with indications of recent local DDT use in response to public health emergencies. In contrast, sharp increases are observed between 2012 and 2015 for the contaminants of emerging concern (PAEs, OPEs, and aHFRs), and in the case of two PAEs (DEHP and DnBP) the concentrations were above the established environmental effect limits for sediment dwelling organisms. These increasing trends reflect the growing global usage of both alternative flame retardants and plasticizer additives. Local drivers for these trends include nearby industrial sources such as a plastic recycling plant, multiple urban waste outfalls, and a cement factory. The limited capacity for solid waste management may also contribute to the high concentrations of emerging contaminants, especially plastic additives. For the most recent year (2015), the accumulation rates for Σ₁₇aHFRs, Σ₁₉PAEs, and Σ₁₇OPEs into sediment at this location were estimated to be 10, 46 000, and 750ng/cm²/year, respectively. This data provides an initial survey of emerging organic contaminants within this understudied region of the world. The increasing temporal trends observed for aHFRs, OPEs, and PAEs highlights the need for further research concerning the rapid influx of these emerging contaminants.

Effects of PAHs on meiofauna from three estuaries with different levels of urbanization in the South Atlantic

Estuarine environments are suggested to be the final receivers of human pollution and are impacted by surrounding urbanization and compounds carried by the river waters that flow from the continent. Polycyclic aromatic hydrocarbons (PAHs) are among the contaminants that can reach estuaries and can directly affect marine conservation, being considered highly deleterious to organisms living in these environments. This research investigated the meiofauna of three estuaries exposed to different levels of urbanization and consequently different levels of PAH concentrations, in order to assess how these compounds and environmental factors affect the distribution, structure and diversity of these interstitial invertebrates. A total of 15 major meiofauna groups were identified, with Nematoda being the dominant taxon (74.64%), followed by Copepoda (9.55%) and Polychaeta (8.56%). It was possible to observe significant differences in all diversity indices studied in the estuaries. With the exception of average density, the diversity indices (richness, Shannon index and evenness) were higher in the reference estuary, Goiana estuarine system (GES). On the other hand, the Timbó estuarine system (TES) had the lowest Shannon index value and richness, while the Capibaribe estuarine system (CES) had the lowest evenness value. The latter two estuaries (TES and CES) presented intermediate and high levels of urbanization, respectively. The ecological quality assessment (EcoQ) in the studied estuaries was classified from Poor to Moderate and the estuary with the lowest demographic density in its surroundings, GES, showed a better ecological quality (Moderate EcoQ). A significant distance-based multivariate linear modelling regression (DistLM) was observed between the environmental variables and the density of the meiobenthic community, where PAHs and pH were the main contributors to organism variation. The sediments were characterized by predominance of very fine sand and silt-clay in the most polluted environments, while the control site environment (GES) was dominated by medium grains. The highest concentrations of PAHs were found in the most urbanized estuaries, and directly affected the structure of the interstitial benthic community. The metrics used in the present study proved to be adequate for assessing the environmental quality of the investigated estuaries.

Occurrence and source apportionment of organic pollutants in deep sediment cores of the Venice Lagoon

In this study, recent and aged inputs of five classes of organic contaminants (i.e. PCBs, OCPs, PCDD/Fs, PAHs, and n-Alkanes) were evaluated in eight deep sediment cores of the Venice Lagoon, collected along the path of a new waterway whose excavation is under evaluation by local authorities, to assess the environmental quality status of the area. Diagnostic indices were calculated for identifying pollutant distribution patterns and their major emission sources, whose relative contribution was quantified by a Positive Matrix Factorization source apportionment model. Sedimentary depth profiles highlighted higher contamination in the top layer, mainly related to ship traffic combustion and vehicular/industrial emissions from the mainland. Nevertheless, a significant level of pollution has been detected also in the deeper layers, probably due to the transport of particulate matter through the aquifers underlying the lagoon seabed. The results underlined the threat posed by the possible resuspension of pollutants in the water column during contaminated sediment dredging.

One century of historical deposition and flux of hydrocarbons in a sediment core from a South Atlantic RAMSAR subtropical estuary

Levels and fluxes of Polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons (AHs), including n-alkanes and petroleum biomarkers (PBMs), were measured in a sedimentary core from a nominated RAMSAR (Guaratuba Bay, Brazil) subtropical estuary experiencing relatively low human impacts, to describe the evolution of anthropogenic activities over the last century. TOC contents varied from 0.80 to 1.25%. No significant correlation between hydrocarbons and TOC with grain size (predominantly sand) was observed. Concentration and flux of total AHs ranged from 65.5 to 195 μg g^-1 and 27.6 to 82.0 μg cm^-2 y^-1, respectively, with the highest levels found in 1960-1966, when access routes to Guaratuba city were improved. Diagnostic ratios based on AH components showed an apparent change in the sources over time, with biogenic origins prevailing until 1966-1971, followed by subsequent increases in petroleum sources. Petroleum tricyclic terpanes were detected in the core (0.40 to 3.0 μg g^-1), suggesting the use of lubricating oil in the bay area. Hopanes were mainly attributed to biological sources. Concentration and flux of total PAHs ranged from 8.65 to 35.9 ng g^-1 and 3.64 to 15.1 ng cm^-2 y^-1, respectively, with the highest levels found in the top core section, reflecting recently increased human activity, while a peak PAH concentration at approximately 1977-1983 can be assumed to be a delayed signal of increased human occupation as a consequence of the improvement of access roads to the area, which started in the 1960s. Alkylated were the most abundant group of PAHs throughout the core. Despite relatively low concentrations of hydrocarbon deposition over approximately 90 years, this study highlights the influence of human occupation and slight petroleum contamination in this preserved area, mainly in recent core sections.

Chronic PAH exposures and associated declines in fish health indices observed for ten grouper species in the Gulf of Mexico

Ten grouper species grouper (n = 584) were collected throughout the Gulf of Mexico (GoM) from 2011 through 2017 to provide information on hepatobiliary polycyclic aromatic hydrocarbon (PAH) concentrations in the aftermath of the Deepwater Horizon (DWH) oil spill. Liver and bile samples were analyzed for PAHs and their metabolites using triple quadrupole mass spectrometry (GC/MS/MS) and high-performance liquid chromatography with fluorescence detection (HPLC-F), respectively. Data were compared among species and sub-regions of the GoM to understand spatiotemporal exposure dynamics in these economically and ecologically important species. Significant differences in the composition and concentrations of PAHs were detected spatially, over time and by species. The West Florida Shelf, Cuba coast and the Yucatan Shelf had a greater proportion of the pyrogenic PAHs in their livers than the other regions likely due to non-oil industry related sources (e.g., marine vessel traffic) in the regional composition profiles. Mean liver PAH concentrations were highest in the north central region of the GoM where DWH occurred. Biliary PAH concentrations and health indicator biometrics initially decrease during the first three years following the DWH oil spill but significantly increased thereafter. Increased exposures are likely explained by the resuspension of residual DWH oil as well as continued inputs from natural (e.g., seeps) sources and other anthropogenically derived sources (e.g., riverine runoff, other oil spills, and leaking oil and gas infrastructure). The increasing trend in PAH concentrations in the bile and liver of grouper species in the north central region of the GoM post-DWH suggest continued chronic exposures, however the critical stage at which permanent, irreparable damage may occur is unknown. Long-term monitoring of PAH levels and associated fish health biomarkers is necessary to evaluate impacts of chronic exposures, particularly in regions subject to intensive oil extraction activities.

Depositional input of hydrocarbons recorded in sedimentary cores from Deception and Penguin Islands (South Shetland Archipelago, Antarctica)

Polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons (AHs), including petroleum biomarkers, were studied in four sediment cores collected around Deception and Penguin Islands, Antarctica. Total PAHs in Deception Island (DCP) samples ranged from 2.0 to 26.8 ng g^-1, and in Penguin Island (PGI) varied between 13.2 and 60.3 ng g^-1. Multiple sources of PAHs were verified in DCP, with petrogenic-derived compounds being predominant over the last 10 years. In PGI, PAHs related to natural contributions from the erosion of coal deposits were reported. Total AHs in DCP ranged from 4.5 to 19 μg g^-1 and in PGI varied between 5.3 and 21.9 μg g^-1. In DCP, the n-alkanes distribution pattern showed the presence of petroleum residues in the top sections and both terpanes and hopanes were detected, related to the use of fossil fuels for power generation and in different types of vessels. In PGI, the main source of n-alkanes was marine inputs and only terpanes were detected. The slight increase in hydrocarbon levels observed from 1980 onward in DCP was assumed to be due to the development of tourism in the region and to the scientific station activities. In PGI, anthropogenic-related hydrocarbons were detected in the recent sections and were linked to the development of tourism near the island, scientific activities and the increase in vessel traffic. In general, the concentrations of hydrocarbons found around both islands were comparable to those found in uncontaminated Antarctic regions.

Petroleum biomarkers as tracers of low-level chronic oil contamination of coastal environments: A systematic approach in a subtropical mangrove

Petroleum biomarkers (hopanes, terpanes and steranes) are frequently assessed in estuarine sediments as tracers of oil input. In order to compare distinct patterns of hydrocarbon accumulation in mudflats, salt marsh and mangrove, sediments from two transects (control and impacted areas) were sampled in Paranaguá Bay, SW Atlantic. Concentrations of n-alkanes, polycyclic aromatic hydrocarbons (PAHs) and petroleum biomarkers (hopanes, terpanes and steranes) were determined, as well as bulk parameters (TOC, grain size and δ¹³C). N-alkanes concentrations were similar between control and impacted sites (respectively, 3.03 ± 1.20 μg g^-1 and 4.11 ± 3.02 μg g^-1) and reflected a high biogenic input. Conversely, PAHs and petroleum biomarker concentrations were three to six times higher in impacted site than the control site (respectively, 60.4 ± 23.3 ng g^-1 and 22.0 ± 25.0 ng g^-1 for PAHs and 197.7 ± 51.8 ng g^-1 and 40.2 ± 32. ng g^-1 for hopanes). Despite these differences, concentrations were lower than those reported for highly impacted areas worldwide. Diagnostic ratios and hydrocarbon parameters (e.g. total PAHs and total petroleum biomarkers) helped to distinguish human impact in the ecological zones, suggesting different sources and/or levels of weathering, confirmed by ANOVA tests. TOC played a fundamental role to the concentration of hydrocarbons, showing similar distributions along the transects. Petroleum biomarkers could clearly indicate the preferential sites of deposition and assign different levels of anthropic contamination by hydrocarbons, thus providing clear information about the chronic petroleum pollution in coastal sediments.

Distribution pattern and health risk assessment of polycyclic aromatic hydrocarbons in the water and sediment of Algoa Bay, South Africa

Polycyclic aromatic hydrocarbons are amongst the pollutants of major concern in the terrestrial and aquatic habitats. They are mostly characterised by carcinogenic and non-carcinogenic effects. Distribution and potential health risks of sixteen priority PAHs in the water and sediment samples collected between December 2015 and June 2016 from Algoa Bay, South Africa, were evaluated. Water and sediment samples collected were extracted with liquid-liquid and soxhlet extraction methods, respectively, and then cleaned up using glass column loaded with silica gel. Final concentrations of the target PAHs were determined by gas chromatography interfaced with flame ionization detector. Results indicated that individual PAH concentrations in surface water, bottom water and sediment samples ranged from not detected (ND) to 24.66 µg/L, ND to 22.81 µg/L and ND to 5.23 mg/kg correspondingly. Total PAHs concentrations varied as 12.78-78.94 µg/L, 1.20-90.51 µg/L and 1.17-10.47 mg/kg in the three environmental matrices in that order. The non-carcinogenic risk was generally below 1, whereas risk indices (dermal contact) were above the acceptable limit of 1 × 10^-4 in the water column, suggesting possible carcinogenic effects to humans, with adults being the most vulnerable. Similarly, highest contributions to TEQs and MEQs in the sediments were made by benzo(a)pyrene and dibenzo(a,h)anthracene, the two most toxic congeners, signifying the possibility of carcinogenicity and mutagenicity in humans. Diagnostic ratios of PAHs reflect a prevailing pyrogenic input all through. The pollution was albeit moderate, yet regular check is recommended to ensure safe and healthy environment for human and aquatic lives.

Assessment of the toxicity, origin, biodegradation and weathering extent of petroleum hydrocarbons in surface sediments of Pars Special Economic Energy Zone, Persian Gulf

During the last years, the oil and gas explorations, extractions and refineries have led to severe ecological damages into the sensitive environment of the Persian Gulf. In this study, the level of oil contamination, the source of hydrocarbons and the degree of weathering or degradation extent were investigated in the Surface Sediments of Pars Special Zone, Persian Gulf. Fifteen sediment samples were collected. The Gas Chromatography-Mass Spectrometry used to analyze Aliphatic Hydrocarbons (AHC) and EPA's sixteen compounds of Polycyclic Aromatic Hydrocarbons (PAHs). The total concentration of Aliphatic Hydrocarbons found to be in the range of 693 to 3752 μg/g and the 16 EPA PAHs compounds varied between 46.6 and 84.7 ng/g dry weight in the region. The concentration of hydrocarbons found to be lower than the level of threshold effects. The source of compounds was also identified by developing the multiple indices.

Hydrocarbon and sewage contamination near fringing reefs along the west coast of Havana, Cuba: A multiple sedimentary molecular marker approach

Organic contamination is a major environmental concern in coastal regions, and it can be evaluated by the determination of aliphatic hydrocarbons (AHs), polycyclic aromatic hydrocarbons (PAHs), faecal sterols and linear alkylbenzenes (LABs). The concentrations of these organic markers were obtained from nine surface sediment samples to evaluate a possible contamination near a fringing reef on the west coast of Havana, Cuba. The AH levels ranged from 1.24 to 135.6 μg g^-1, the PAH levels were up to 2133 ng g^-1, the faecal sterol levels ranged from 0.03 to 1.54 μg g^-1, and the total LAB levels were up to 22.7 ng g^-1. The highest concentrations were obtained at sites close to Havana Bay and at the sources of untreated sewage input. A decreasing concentration gradient was observed from Havana Bay to the outer sites. Although only two sites presented high levels of contamination, untreated sewage discharged close to the fringing reef may affect its environment.

The distribution of and biodegradation impact on spilled oil in sediments from Dalian Bay, NE China

Three cores collected in the area of 16th July 2010 oil spill by box crab in May 2013 and July 2014 at the Dalian Bay have been geochemically characterized to investigate the fate of chemical components in sediments. The total organic carbon, extractable organic matter contents and biomarker compositions have been applied for the differentiation of alien organic matters from in situ ones and evaluation of the biodegradation impact. Multivariate statistical analysis suggests four groups of sediments. Except a few samples at deepest part of BQ050, majority samples have certain affinity with the spilled oil. The most contaminated sediments occur at site BQ050 and the spilled oil has migrated to 8-12 cm depth. The degree of contamination can be ranked by the similarity of molecular compositions with spilled oil. Variable biomarker components in sediment extracts were also altered by ongoing biodegradation.

Ecological risk assessment of sedimentary hydrocarbons in a subtropical estuary as tools to select priority areas for environmental management

The concentration, distribution, and ecological risk of hydrocarbons, as well as bulk parameters, were determined in surface sediments of the Babitonga Bay, a subtropical human-impacted estuary in South Atlantic. Total aliphatic and polycyclic aromatic hydrocarbons (PAHs) ranged between 0.8 and 201.2 μg g^-1 and from 8.7 to 5489 ng g^-1, respectively. Saguaçú Lagoon, the region near the ferry boat and the vicinity of São Francisco harbour (SFH), presented high hydrocarbon concentrations. Despite the low accumulation trend in this region, the SFH and city may act as a punctual hydrocarbon source. The inner portion of the estuary had the finest sediment grains and the highest concentrations of carbon, nitrogen, and sulphur, indicating its importance as a depositional and cumulative area. The occurrence of unresolved complex mixture suggested chronic oil contamination. Petrogenic (based on the high percentage of alkylated PAHs) and pyrolytic (according to the diagnostic ratios of PAH isomer pairs) sources were confirmed. Ecological risk assessment was evaluated by the risk quotient (RQ). All samples had at least one priority PAH present at above the negligible concentration, including naphthalene, which was observed in all samples. Only the sites near the ferry boat and at the Saguaçú Lagoon contained compounds with concentrations above their maximum permissible concentrations, while all other sampling sites are classified as "Low-risk." The spatial distribution of RQs coincides with PAHs distribution, indicating that the regions near SFH, ferry-boat, and the Saguaçú Lagoon should be considered to be priority areas when making environmental monitoring policies.

Vertical distribution, composition profiles, sources and toxicity assessment of PAH residues in the reclaimed mudflat sediments from the adjacent Thane Creek of Mumbai

A study on vertical distribution of magnetic susceptibility, carcinogenic and endocrine disrupting PAHs was performed in the reclaimed mudflat sediments adjacent to the Thane Creek of Mumbai. The 5-rings PAHs and ΣC-PAHs were more dominant at 120cm depth contributing 52.23% and 60.19% respectively to ∑PAHs. The average ratio values of LMW/HMW PAHs (0.58); Fla/(Fla+Pyr) (0.50); Ant/(Ant+Phe) (0.50); BaA/(Chry+BaA) (0.48); BaP/BghiP (2.06), Phe/Ant (1.03) and BaA/Chr (0.93) indicate that the PAH contamination might have raised due to inefficient combustion and pyrogenic emissions during the open burning of solid waste in the vicinity. This was further supported by the anthropogenic ferri(o)magnetic loading over the last 100years influencing the Creek sediments. The PAHs toxicity estimation was performed by calculating the toxic equivalent quantity (TEQ) value of 8.62ng TEQ/g which was below the safe level (600ng TEQ/g) suggested by the Canadian risk-based soil criterion for protection of human health.

Studies on polycyclic aromatic hydrocarbons in surface sediments of Mithi River near Mumbai, India: Assessment of sources, toxicity risk and biological impact

This study investigated the levels, sources and potential risks of 17 polycyclic aromatic hydrocarbons in surface sediment samples collected along the Mithi River of Mumbai. The concentration level of ΣPAHs found in the present study was in the range of 1206-4735 ng/g dw. The composition patterns of PAHs by ring size in sediment were surveyed which indicate the dominance of four rings followed by five and three ring PAHs. In the study it was observed that the high molecular weight PAHs (HMW PAHs) made greater contributions of 90.83% as compared to that of low molecular PAHs (LMW PAHs) contributing to 9.17% to the total PAH concentrations. Toxicity and biological risk were assessed using toxic equivalent quantity and sediment quality guideline quotient. It is feared that the pollution level of PAHs in the sediments might increase in coming times resulting in an unconspicuous risks for the environment and humans through food chains.

Distribution, Sources, and Potential Ecotoxicological Risk of Polycyclic Aromatic Hydrocarbons in Surface Sediments from Bahía Blanca Estuary, Argentina

Thirty-four surface sediment samples were collected from Bahía Blanca Estuary, Argentina, to evaluate polycyclic aromatic hydrocarbon (PAH) contamination and ecotoxicity risk by applying sediment-quality guidelines (SQGs) and toxic equivalent factors (TEQ). Total concentrations of 17 parent PAHs, including the 16 United States Environmental Protection Agency priority PAHs, were measured using gas chromatography-mass spectrometry, and their levels ranged from 19.7 to 30,054.5 ng/g dry weight. The greatest values were found near the urban/industrial core and decreasing as the distance from that site increased. Molecular ratios determined mixed sources of PAHs with a slight imposition of pyrolitic over the petrogenic inputs. The ecotoxicological evaluation, based on the SQG model, showed that some of the individual PAHs were in excess of the effects range low (ERL) and the effects range median's threshold; then, predicted occasional (ERL) and frequent adverse effects over the surrounding biota at the area of study were determined. Total PAH levels were expressed as benzo-a-pyrene TEQ and compared with literature data.

Occurrence and Source Appraisal of Polycyclic Aromatic Hydrocarbons (PAHs) in Surface Waters of the Almendares River, Cuba

In this work, 14 polycyclic aromatic hydrocarbons (PAHs) included in the United States Environmental Protection Agency pollutant priority list were analyzed in the surface water of the upper urbanized part of Almendares River, the most important water course in Havana, Cuba. Surface water from five sampling sites was collected at the end of dry season and analyzed by high-performance liquid chromatography-fluorescence detection method after solid phase extraction procedure. Total PAHs concentrations varied from 836 to 15 811 ng L(-1) with a geometric mean value of 2512 ng L(-1). PAH typology was dominated by low molecular-weight PAHs (2- to 3-ring components). Pollutant source appraisal was determined by diagnostic ratios method in five sampling sites. Factor analysis of normalized samples was used to concentration identified two factors as the main significant pollutant sources and to cluster similar sampling sites corresponding to petrogenic and combustion inputs, respectively. Ecological risks were considered. For animal aquatic life, acute toxicity values exceed the permissible values in the more-polluted sampling sites.

Sedimentary hydrocarbons and sterols in a South Atlantic estuarine/shallow continental shelf transitional environment under oil terminal and grain port influences

Sterols and hydrocarbons were determined in the surface sediments from the transitional environment between Paranaguá Bay and the shallow continental shelf in the South Atlantic to assess the sources of organic matter (OM) and the contamination status of an area exposed to multiple anthropogenic inputs. Total aliphatic hydrocarbon concentrations were less than 10μgg(-1), which is typical of unpolluted sediments, and related to recent inputs from higher terrestrial plants. Total polycyclic aromatic hydrocarbon ranged from<DL to 14.41ngg(-1) (dry weight), which was predominantly derived from combustion with non-detectable levels occurring in 65% of the samples. Sterols typically related to marine sources predominated in the analysed sediments. Hence, the study area was protected from human activity. The relative absence of anthropogenic input and OM preservation clearly indicate that the organic markers analysed can be used to investigate the biogenic input of sedimentary OM in the study area.

Polycyclic aromatic hydrocarbons in sediments from the Old Yellow River Estuary, China: occurrence, sources, characterization and correlation with the relocation history of the Yellow River

The levels of 16 USEPA priority PAHs were determined in surface sediments and one dated sediment core from the abandoned Old Yellow River Estuary, China. Total PAH concentrations in the surface sediments ranged from 100.4 to 197.3 ng g(-1) dry weight and the total toxic equivalent quantity (TEQ(carc)) values of the carcinogenic PAHs were very low. An evaluation of PAH sources based on diagnostic ratios and principal component analysis suggested that PAHs in the surface sediments mainly derived from combustion sources. The total PAH concentrations altered significantly with year of deposition and showed quite different patterns of change compared with other studies: it is hypothesized that the principal cause of these changes is the relocation of the course of the Yellow River to the sea in 1976 and 1996.

Steroid markers to assess sewage and other sources of organic contaminants in surface sediments of Cienfuegos Bay, Cuba

Analyses of faecal steroids in coastal sediments from Cienfuegos Bay Cuba indicate chronic sewage contamination at the main outfalls from the city, where concentrations of coprostanol up to 5400ngg(-)(1) (dry wt) were measured. In contrast, steroid concentrations and compositions from sites from the south part of the Bay are characteristic of uncontaminated sewage environments. The levels of coprostanol in the Cienfuegos sediments compares to the lower to mid-range of concentrations reported for coastal sediments on a world-wide basis, with sedimentary levels markedly below those previously reported for heavily impacted sites. This study delivers baseline data for further investigation of the effectiveness of the proposed sewerage plan promoted by the GEF project in Cienfuegos. Investigations on the correlations between faecal steroids and other organic contaminants confirmed that the major source of petroleum hydrocarbons within the bay was associated with the sewage effluents from the Cienfuegos city.

Naturally occurring radioactive materials (NORM) in ashes from a fuel-oil power plant in Cienfuegos, Cuba, and the associated radiation hazards

The radioactivity of NORM was measured in ashes collected from a fuel-oil power plant in Cienfuegos, Cuba, using an HPGe gamma-ray spectrometer. The (226)Ra, (210)Pb, (40)K, (232)Th and (238)U activity concentrations reached 240, 77, 59, 70 and 15 Bq kg(-1), respectively. The potential radiological hazard of these residuals was assessed. The radium equivalent activities of the samples varied from 54 to 345 Bq kg(-1). The gamma index was calculated to be lower than that of the reference values, and the gamma absorbed dose rate was higher than the average reported for the earth's crust; however, the assessed annual effective dose was slightly lower than the annual effective dose limit for public, i.e. 1 mSv. Therefore, these bottom ashes were not dramatically enriched with radionuclides and may be used as an additive for building materials without restrictions from a radiological protection point of view.

Spatial variations in polycyclic aromatic hydrocarbons concentrations at surface sediments from the Cyprus (Eastern Mediterranean): relation to ecological risk assessment

The objective of the present study was to evaluate the distribution, sources, origins, and environmental risk assessment of polycyclic aromatic hydrocarbons (16 US EPA priority pollutants) pollution in 23 surface sediments from Cyprus coast. The mean total polycyclic aromatic hydrocarbons (PAHs) concentrations in the sediments from Gemi Konagi, Girne and Gazi Magusa areas were found 47, 52 and 50 ng/g, respectively. Molecular ratios and principle component analysis indicated that PAH pollution originated mainly from fossil sources, with higher pyrolytic contributions. The 2-3 ring PAHs were dominant in Cyprus sediments. Concentrations of PAHs observed in this study were compared with available soil quality guidelines and the concentrations were lower than the guideline values. The guideline values suggested that the Cyprus sediments were likely to be not contaminated by toxic PAH compounds.

Sources and preservation of organic matter in soils of the wetlands in the Liaohe (Liao River) Delta, North China

Total organic carbon, total nitrogen, δ(13)Corg, δ(15)N, and aliphatic and polyaromatic hydrocarbons of fifty-five soil samples collected from the coastal wetlands of the Liaohe Delta were measured, in order to determine the sources and possible preservation of organic matter (OM). The δ(15)N and δ(13)Corg values in the samples ranged from 3.0‰ to 9.4‰ and from -30.4‰ to -20.3‰, respectively, implying that the OM in the soils is predominantly derived from C3 plant. The long-chain n-alkanes had a strong odd-over-even carbon number predominance, suggesting a significant contribution from waxes of higher plants. The ubiquitous presence of unresolved complex mixture, alkylated polycylic aromatic hydrocarbons and typical biomarkers of petroleum hydrocarbons (pristane, phytane, hopanes and steranes) indicates that there is a contribution of petroleum hydrocarbons to the organic carbon pool in the wetland soils. P. australis-vegetated wetlands have strong potentials for the preservation of organic carbon in the wetlands.

Aliphatic and polycyclic aromatic hydrocarbons in sediments of the Slovenian coastal area (Gulf of Trieste, northern Adriatic)

The distribution and sources of aliphatic and polycyclic aromatic hydrocarbons (PAH) were determined in sediments at seven sites around the Slovenian coastal area. The potential toxicological significance was also assessed using biological thresholds. The results of the analyses showed higher concentrations of hydrocarbons in the Port of Koper and in the Marina of Portoroz. The influence of pollution was also evident in rather higher concentrations of hydrocarbons in the surrounding area in the Bays of Koper and Piran. Concentrations of hydrocarbons decrease toward the central part of the Gulf of Trieste. The major component of the aliphatic fraction was the unresolved complex mixture. Concentrations of the total resolved aliphatic hydrocarbons were in a range from 689 to 3,164 ng g(-1). Concentrations of the total PAHs were between 330 and 1,173 ng g(-1). Polycyclic aromatic hydrocarbons are primarily of pyrolytic origin with some smaller contributions of the petrogenic, while the aliphatic are mostly of petrogenic origin with significant amounts of biogenic derived compounds of terrestrial and marine origin. Strong evidence of the diagenetic origin of perylene in the investigated area was also found. Quite a good linear relationship between PAH concentration and TOC and between aliphatic hydrocarbon concentrations and TOC was observed. The principal component analysis showed differences between the nearshore and offshore sites. In general, the investigated area is moderately contaminated by hydrocarbons. Concentrations of PAHs, hydrocarbons of high concern, are below the levels (effects range low and the effects range median) associated with adverse biological effects.

Occurrence and Distribution of Polycyclic Aromatic Hydrocarbons in Water and Sediment Collected along the Harbour Line, Mumbai, India

This study investigated the occurrence of polycyclic aromatic hydrocarbons (PAHs) in water and sediment samples collected along the harbour line, Mumbai, India. The ∑PAHs quantified in water and sediment samples were ranged from 8.66 ng/L to 46.74 ng/L and from 2608 ng/g to 134134 ng/g dry wt., respectively. Significantly high concentration of ∑PAHs was found in water samples of Sewri and sediment samples of Mahul (P<0.05). PAH concentrations detected in the present study were several folds higher than the existing sediment quality criteria suggested by various statutory agencies. The PAH composition patterns in water and sediments suggest the dominance of high molecular weight compounds and indicate important pyrolytic and petrogenic sources. The occurrence of PAHs in the marine environment has attracted the attention of the scientific community as these compounds are frequently detected in seawater and sediments at increasing levels and can have adverse health effects on marine organisms and humans. PAH concentrations detected at Sewri-Mahul site were sufficiently high to pose a risk to marine organisms if they are exposed continuously to this concentration. Hence, continuous monitoring of the ecosystem is highly warranted.

Vertical distribution and inventories of (239+240)Pu and mercury in Sagua la Grande estuary, Cuba

The vertical activity distribution and inventories of (239+240)Pu profile and Hg were determined in Sagua la Grande estuary, Cuba. The shape of the (239+240)Pu profile in the core column resembled very closely the history of atmospheric nuclear weapons' testing, and the maximum deposition in 1963 was recorded in the sediment core history. The (239+240)Pu activity concentrations in the surface layer sediments varied from 0.163 to 0.611 mBq g(-1). The inventory of (239+240)Pu was 42 ± 5.6 Bq m(-2), a value close to that expected from direct global fallout. Using the (239+240)Pu as a chronomarker the mass sedimentation rate in the area for the last 60 years was calculated, reaching values of 0.173 g cm(-2) y(-1). The mercury profile reflects the history of anthropogenic pollution in the estuary and perfectly describes the operation of the mercury-cell chlor-alkali plant, for production of NaOH, which began operations in 1980. The inventory of Hg was 2.42 ± 0.19 μg cm(-2). These results contribute to the scarce regional database for pollutants and anthropogenic radionuclides in the Caribbean marine environment, particularly in relation to (239+240)Pu.

Sources and distribution of aliphatic and polyaromatic hydrocarbons in coastal sediments from the Ushuaia Bay (Tierra del Fuego, Patagonia, Argentina)

The environmental quality of Ushuaia Bay, located at the southernmost tip of South America, is affected by the anthropogenic pressure of Ushuaia city. In this study, levels and sources of hydrocarbons in coastal sediments were assessed. Aliphatic hydrocarbon fractions ranged between 5.5 and 1185.3 μg/g dry weight and PAHs from not detected to 360 ng/g. Aliphatic diagnostic indices, the nalkanes homologous series occurrence, Aliphatic Unresolved Complex Mixtures (AliUCMs), and pristane and phytane isoprenoids indicated a petrogenic input. Some sites showed biogenic features masked by the anthropogenic signature. Particularly in port areas biodegradation processes were evident. PAH ratios showed a mixture of petrogenic and pyrogenic sources. Aliphatic and aromatic UCMs were strongly correlated, reflecting chronic pollution. Three areas were distinguished inside the bay: (1) east, with low hydrocarbons impact; (2) central, where hydrocarbons accumulation was related to source proximity and sediment characteristics; (3) south-west, where sediment characteristics and current circulation favour hydrocarbons accumulation.

Aliphatic and polycyclic aromatic hydrocarbons in the surface sediments from the Eastern Aegean: assessment and source recognition of petroleum hydrocarbons

MATERIALS AND METHODS

Aliphatic and polycyclic aromatic hydrocarbons (PAHs) were determined in surficial sediments from the Aegean Sea in the Eastern Mediterranean in 2008.

RESULTS

Total aliphatic hydrocarbons (n-C12 to n-C35) ranged from 330 to 2,660 ng g(-1) dry weight (dwt), while aromatics (19 PAHs) varied between 73.5 and 2,170 ng g(-1) dwt. Total concentrations of both aliphatic hydrocarbons and PAHs ranged from a relatively low to a moderate PAHs pollution compared to other urbanized coastal areas worldwide. PAH consisted mainly of pyrolytic four- to five-ring compounds. Both pyrolytic and petrogenic PAHs are present in most samples, although petroleum-derived PAH are dominant at Izmir Inner Bay (IIB) and Dardanelles Strait, and pyrolytic sources are prevalent in other sampling sites. A high contribution of perylene, a diagenetic originated PAH, to the total penta PAHs was found greater than 70% in Meric River Estuary, Dikili Bay, Candarli Bay, and Gokova Bay sites.

CONCLUSION

The spatial distributions of aliphatic hydrocarbons and PAHs indicated that urban runoff and transport from the continental shelf is the major input pathway of anthropogenic and biogenic hydrocarbons from terrestrial sources in the near-shore area. PAH levels at all sites were below the effects range-low (ERL) and effects range-median (ERM) values except fluorene. The average and maximum fluorene concentrations exceeded ERL, but below ERM, in the IIB. Meanwhile, the concentration levels of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, benzo[a]anthracene, and chrysene were higher than threshold effect level values at the same site, but all these compounds were significantly lower than the probable effect level values. The results indicated that the sediments should have potential biological impact.

Polycyclic aromatic hydrocarbons (PAHs) in a large South American industrial coastal area (Santos Estuary, Southeastern Brazil): sources and depositional history

Located in southeastern Brazil, the Santos Estuary has the most important industrial and urban population area of South America. Since the 1950's, increased urbanization and industrialization near the estuary margins has caused the degradation of mangroves and has increased the discharge of sewage and industrial effluents. The main objectives of this work were to determine the concentrations and sources of polycyclic aromatic hydrocarbons (PAHs) in sediment cores in order to investigate the input of these substances in the last 50 years. The PAHs analyses indicated multiple sources of these compounds (oil and pyrolitic origin), basically anthropogenic contributions from biomass, coal and fossil fuels combustion. The distribution of PAHs in the cores was associated with the formation and development of Cubatão industrial complex and the Santos harbour, waste disposal, world oil crisis and the pollution control program, which results in the decrease of organic pollutants input in this area.

Anthropogenic organic contaminants in water, sediments and benthic organisms of the mangrove-fringed Segara Anakan Lagoon, Java, Indonesia

Segara Anakan, a mangrove-fringed coastal lagoon in Indonesia, has a high diversity of macrobenthic invertebrates and is increasingly affected by human activities. We found > 50 organic contaminants in water, sediment and macrobenthic invertebrates from the lagoon most of which were polycyclic aromatic compounds (PACs). Composition of PACs pointed to petrogenic contamination in the eastern lagoon. PACs mainly consisted of alkylated PAHs, which are more abundant in crude oil than parent PAHs. Highest total PAC concentration in sediment was above reported toxicity thresholds for aquatic invertebrates. Other identified compounds derived from municipal sewage and also included novel contaminants like triphenylphosphine oxide. Numbers of stored contaminants varied between species which is probably related to differences in microhabitat and feeding mode. Most contaminants were detected in Telescopium telescopium and Polymesoda erosa. Our findings suggest that more attention should be paid to the risk potential of alkylated PAHs, which has hardly been addressed previously.

Effects of organic enrichment on nematode assemblages in a microcosm experiment

Marine nematodes from subtidal tropical sediments of Cienfuegos Bay were subjected to organic enrichment in a microcosm experiment for 32 days. Nematode abundance and diversity decreased, and the taxonomic and trophic structure was altered. The results suggested that the nematodes were not food limited in the microcosms or in their natural environment. Chemical stressors such as ammonia and hydrogen sulfide derived from reduced conditions in sediments may be important factors affecting the assemblages. Hypoxic conditions occurred in all experimental units, as well as in the field, suggesting a nematode assemblage adapted to naturally enriched sediments. However, tolerant species showed a grade of sensitivity to reduced conditions. In agreement with the model by Pearson and Rosenberg (1978), we predict that further organic enrichment in sediments from Cienfuegos Bay may cause a phase shift into a strongly depleted benthic fauna and reduced conditions in water and sediments.

Organochlorine contamination (PCBs, DDTs, HCB, HCHs) in sediments from Cienfuegos bay, Cuba

The spatial distribution of various organochlorinated compounds, e.g. PCBs, DDTs, HCB and HCHs, were investigated in sediments from Cienfuegos bay, Cuba. Their concentrations appeared to be relatively low by global standards and only sediments receiving the impact from the residual waters of the city and thermoelectrical power approached the sediment quality guidelines for PCBs and DDTs. Relatively higher SigmaDDT concentrations and high DDT/DDE+DDD ratios in two sites near the outfalls of the city indicated a current DDT usage, probably linked to public health emergencies. These results contribute to the sparse regional database for organochlorinated compounds in the Caribbean marine environment.