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Commercial bulk powder of SiC and SHS-synthesized SiC nanowires were studied. Gold nanoparticles were deposited onto a surface of both samples. Basic properties, such as crystalline structure, phase composition, morphology and photocatalytic activity with the chromatographic analysis of the reaction products, were determined. Obtained silicon carbides are crystalline materials of hexagonal (commercial SiC) and cubic (synthesized SiC nanowires) structures. The presence of gold nanoparticles was proven through Raman spectroscopy, inductively coupled plasma mass spectrometry and transmission electron microscopy. No gold phase was detected as a separate crystalline component in both Au-modified samples. The neat nanowires were indicated as a catalyst rather accumulating intermediate organic substances than commercial SiC which enables shifting equilibrium to the generation of gaseous products (CO and CH4). The gold-containing SiC nanowires demonstrated an essential enhancement of photocatalytic activity keeping Au nanoparticles on the surface after the reaction.

Investigation were carried out targeting distribution and source apportioning of hydrocarbons in surface sediments from shallow to deep waters in the Campos Basin, one of the most important oil-producing provinces in Brazil. The observed levels of aliphatic (≤ 124 μg g−1) and polycyclic aromatic hydrocarbons (PAHs ≤ 599 ng g−1) are lower than those considered relevant for environmental risk to the benthic habitats. Higher median concentrations of aliphatic hydrocarbons (8.49 μg g−1) and PAHs (84.8 ng g−1) in the middle slope sediments (700–1000-m water depths) showed the influence of hydrodynamics upon hydrocarbon accumulation in the sediments. Diagnostic ratios and conventional statistical analysis applied to hydrocarbon data produced insufficient information on the contribution of different sources. These traditional approaches do not consider the potential changes affecting source assignment and therefore cannot deal with the uncertainties. The fuzzy logic applied as an alternative method for data treatment successfully incorporated the uncertainties in the differentiation between petrogenic and pyrolytic sources, including those due to degradation. Moreover, by using fuzzy logic, it was possible to identify that water circulation patterns, mass transport, deposition, and degradation processes are more relevant factors in determining hydrocarbon composition than source proximity.

Summary Here we present baseline data of δ¹³C of n-alkanes (δ¹³Cn-alkanes) from leaf waxes of mangrove trees – Avicennia schaueriana, Rhizophora mangle and Laguncularia racemosa – distributed along a latitudinal gradient in Brazil. The objective was to evaluate the influence of trees physiology, local hydrology and climatic factors upon the molecular and isotopic signature of the leaf wax n-alkanes. Higher weighted average δ¹³Cn-alkanes (δ¹³CWA), average chain lenght (ACL25-35) and carbon preference index (CPI24-36) for R. mangle and A. schaueriana contrasting with lower values for L. racemosa seem to be linked to physiological characteristics of each species regarding intrinsic water use efficiency under the specific tidal flooding regime of mangrove forests. About the plant’s response to local environment influence, inverse correlations between all δ¹³Cn-alkanes values (δ¹³C₂₇, δ¹³C₂₉, δ¹³C₃₁, δ¹³C₃₃ and δ¹³CWA) and mean annual precipitation were found for the A. schaueriana samples. For the R. mangle species, a relationship between ACL25-35 and mean annual potential evapotranspiration and between CPI24-36 and mean annual temperature were observed. The different molecular and isotopic footprints of the three mangrove species presented here have potential to be used in future interpretations of n-alkanes as biomarkers in biogeochemical and paleoclimate studies near mangrove-dominated coastal regions.

Investigation were carried out targeting distribution and source apportioning of hydrocarbons in surface sediments from shallow to deep waters in the Campos Basin, one of the most important oil-producing provinces in Brazil. The observed levels of aliphatic (≤ 124 μg g

Different clean-up methods to determine isotopic composition of n-alkanes were tested. Sources of organic matter in Guanabara Bay were re-examined through the δ13C of individual n-alkanes in surface sediment samples. The n-alkanes were efficiently isolated without significant losses of the compounds of interest. The δ13C of n-alkanes (n-C17 to n-C35) ranged between -34.0 and -26.4‰. More depleted δ13C values associated to higher carbon preference index (CPI > 4) suggest prevalence of biogenic n-alkanes from terrestrial origin in the inner stations influenced by inputs from mangrove areas. Small isotopic differences between odd and even-numbered chains and 13C-enrichment in long-chain homologues indicate a petrogenic hydrocarbons contribution. Higher concentrations of short-chain compounds associated to a more 13C-enriched total organic carbon (TOC) were found near the most intense sewage discharges. Results show that δ13C of n-alkanes can be applied to a highly degraded system as the Guanabara Bay and help improve the characterization of the organic matter.

RESUMO Lipidios biomarcadores [acidos graxos (FA), esterois e alcoois], isotopos estaveis (δ13C e δ15N), aminoacidos totais hidrolisaveis (THAA) e carbono orgânico total (COT) foram quantificados em 215 amostras de sedimentos superficiais coletadas em dois periodos (seco e chuvoso de 2008/2009) entre 25 e 3.000 m de profundidade ao longo de nove transectos transversais a margem continental. Tambem foram analisadas amostras de sedimento superficial em dois cânions (Grussai e Almirante Câmara) para os mesmos indicadores, com excecao de isotopos. O objetivo foi investigar os processos relacionados com a origem, transporte e acumulo de materia orgânica (MO) na regiao de estudo. Nas amostras dos transectos, a composicao de lipidios biomarcadores sugeriu a predominância de materia orgânica derivada de produtores primarios e secundarios na coluna d’agua, mas foram observados gradientes espaciais significativos da qualidade e quantidade da materia orgânica sedimentar. As menores concentracoes de lipidios, com predominância de compostos labeis, foram medidas na plataforma continental (< 150 m), exceto nas areas influenciadas por ressurgencia costeira e/ou por intrusao subsuperficial de aguas mais ricas em nutrientes, onde maiores concentracoes de carbono orgânico total e lipidios foram obtidas. O talude superior e medio (400 a 1.300 m) tambem exibiram elevadas concentracoes de carbono orgânico total e lipidios, mas com uma maior influencia de lipidios ja alterados pela atividade bacteriana. Isto sugeriu que ha exportacao de materiais de areas rasas para o talude, possivelmente devido a acao de vortices e meandros da Corrente do Brasil e por correntes de fundo. No talude inferior (1.900 a 3.000 m), apenas os compostos mais recalcitrantes foram medidos acima dos limites de deteccao. Em relacao aos cânions, a distribuicao dos lipidios biomarcadores sugeriram que eles sao locais efetivos de acumulo e transporte de materia orgânica labil para porcoes mais profundas da margem continental. No geral, os isotopos e os aminoacidos totais hidrolisaveis proveram informacoes que foram consistentes e corroboraram as observacoes feitas com base nos lipidios biomarcadores.

RESUMO O objetivo do presente estudo constituiu-se da avaliacao e caracterizacao dos hidrocarbonetos e de carbono negro (BC) presentes em sedimentos da Bacia de Campos. Para tal foram coletadas amostras superficiais em 108 estacoes distribuidas de Cabo Frio ao Cabo de Sao Tome, entre as isobatas de 25 e 3.000 m, em duas estacoes do ano. Foram estudados, tambem, sedimentos dos cânions Grussai e Almirante Câmara. Encontraram-se, em geral, baixas concentracoes de hidrocarbonetos policiclicos aromaticos (HPAs), para os quais as razoes diagnosticas indicaram origem pirogenica ou mista (pirogenica e petrogenica). No entanto, em todas as amostras determinou-se a serie de hopanos e esteranos maturados, que e indicativa da presenca de oleo, e apenas em algumas amostras, na fracao alifatica, ha mistura complexa nao resolvida e serie homologa completa de n-alcanos. A contribuicao de carbono negro para o conjunto de carbono orgânico (Corg) foi muito elevada, demonstrando o dominio de carbono orgânico recalcitrante nos sedimentos e o significativo aporte de material originado de queima incompleta de materia orgânica. Houve correlacoes estatisticas entre carbono negro e os hidrocarbonetos policiclicos aromaticos de 5-6 aneis principalmente provenientes de processos de combustao incompleta. Identificou-se o talude como regiao de deposicao, onde ocorrem as concentracoes mais elevadas de todos os compostos estudados.

RESUMO Hidrocarbonetos policiclicos e alifaticos foram determinados em amostras de agua do mar superficial coletadas na area da Bacia de Campos compreendida entre o Cabo de Sao Tome e Cabo Frio e as isobatas de 25 e 3.000 m (oito isobatas e nove perfis perpendiculares a costa), totalizando 72 estacoes de coleta visitadas em dois periodos aqui denominados chuvoso e seco. As amostras para determinacao de hidrocarbonetos foram extraidas segundo o metodo EPA 3510. Os hidrocarbonetos alifaticos, hidrocarbonetos totais de petroleo (HTP), hidrocarbonetos policiclicos aromaticos (HPAs), fenois e benzeno, tolueno, etilbenzeno e xilenos (BTEX) foram determinados segundo os metodos EPA 8015B, EPA 8270C e EPA 502.2, respectivamente. As concentracoes de todos os compostos mostraram-se baixas nas duas campanhas de amostragem. Fenois e BTEX mostraram-se abaixo do limite de quantificacao do metodo. Porem, no periodo seco, foi observada a presenca de n-alcanos e de mistura complexa nao resolvida (MCNR) com caracteristicas de origem petrogenica degradada ou nao.

In this study, the development of the technique APCI+ LC/MS/MS allowed the detection of phenanthrene, pyrene and metabolites of alkyl homologs in fish bile (in situ) and in urine of crabs. Laboratory experiments were carried out exposing crabs from an unpolluted mangrove (Barra de Guaratiba) to phenanthrene, and to the alkylated homologs 1-methyl phenanthrene and 2,6,9-trimethyl phenanthrene. Urine samples were collected at 0, 24, 48, 72, and 96 h. Fishes were captured from strategic sites from Guanabara Bay. Hydroxylated metabolites of phenanthrene, epoxides, orthoquinone and glucoside conjugates were identified in both samples. The method APCI+ LC/MS/MS showed to be effective in a preliminary assessment of phenanthrene metabolite formation, although the low concentrations of 1-methyl phenanthene and 2,6,9-trimethyl phenanthrene did not allow a systematic evaluation of data. The method, however, proved to be excellent tool for studies of PAHs metabolites due to the high selectivity, sensitivity and separation attained.

Waters and sediments from the Potiguar Basin (NE Brazilian coast) were investigated for the presence and nature of polycyclic aromatic hydrocarbons (PAH) and aliphatic hydrocarbons. The region receives treated produced waters through a submarine outfall system serving the industrial district. The total dispersed/dissolved concentrations in the water column ranged from 10-50 ng L(-1) for ∑16PAH and 5-10 μg L(-1) for total aliphatic hydrocarbons. In the sediments, hydrocarbon concentrations were low (0.5-10 ng g(-1)for ∑16PAH and 0.01-5.0 μg g(-1) for total aliphatic hydrocarbons) and were consistent with the low organic carbon content of the local sandy sediments. These data indicate little and/or absence of anthropogenic influence on hydrocarbon distribution in water and sediment. Therefore, the measured values may be taken as background values for the region and can be used as future reference following new developments of the petroleum industry in the Potiguar Basin.

The presence of black carbon (BC) and its interaction with polycyclic aromatic hydrocarbons (PAHs) in mangrove sediments were studied for the first time. The study included an oil contaminated mangrove and two other sites of different character. BC content ranged from 0.03% to 0.47% (dry weight sediment), reaching a maximum of 9% of the total organic carbon. Cluster analysis indicated strong BC and high molecular weight (HMW) PAH association but no relationship was found between BC and alkylated PAHs. The ratio C4Ph/BaP was used to verify differences in the mobility of alkylated and HMW PAHs along a core from the oil contaminated site. Results for the solid–water coefficient of distribution (Kd in l kg−1) for pyrene were similar using untreated sediment samples (log Kd 4.66 ± 0.03) and chemo-thermal oxidation (CTO) residues (log Kd 4.39 ± 0.03), confirming the importance of BC in the partitioning of PAHs. However, the resulting BC-normalized distribution coefficients (log KBC 7.1–7.4 μg kg BC - 1 ) were greater than published values, probably because of the presence of other hydrophobic phases in the refractory organic matter pool. In addition, BC normalization of pyrene concentration in mangrove crabs reduced the variability in calculated bioaccumulation factors vs. organic carbon-normalized concentrations for the sites. The evidence agrees with the general view of BC particles controlling the fate of PAHs in sediments, but also points out the necessity for studying the process in further detail when considering organic matter-rich mangrove sediments.

A number of diagnostic ratios have been applied as tools to distinguish provenance of hydrocarbons in sediments. In the present work the effectiveness of such ratios as source indicators under tropical conditions is evaluated using aliphatic and aromatic hydrocarbons determined in recent and historical sediments from the Todos os Santos Bay (TSB), Brazil. It turned out that substantive alteration of the original hydrocarbon composition often produced misleading results and that source evaluation in sediments required more complex approaches. In surface sediments sampled in summer and winter Total PAH (sum of parental and alkylated PAH) ranged from 42 µg kg − 1 to 3335 µg kg − 1 and from 64 µg kg − 1 to 4187 µg kg − 1 , respectively. In most cases diagnostic ratios pointed out incomplete combustion as the single or major PAH source while detailed data examination revealed ubiquitous presence of oil residues. The same observation holds for some of the examined cores. The mean ( n = 8) Total PAH flux in recent times is of 608 ± 741 ng cm − 2 year − 1 . There are indications in some cores that the relative contribution from combustion sources were more pronounced in the past, as for instance, the continuous decrease of B(a)Py fluxes from 92 ng cm − 2 year − 1 in the 1900s to 23 ng cm − 2 year − 1 in the 2000s.

Compositional alterations of oil (MF380) spilled in mangrove sediments was studied over 4 years with an emphasis on weathering of PAH. Sediment cores were sampled yearly in three mangrove forests in Guanabara Bay, Rio de Janeiro, two of which were contaminated by the spill in January 2000 and one was used as a reference area. Hopanes and steranes (46 compounds) were successfully applied to identify the presence of the oil in the most contaminated mangrove (Surui). However extensive alterations under these tropical climate conditions hampered, in some cases, relating high concentrations of petrogenic PAH to the spill. Accentuated weathering of C34-17α,21β(H)-tetrakishomohopane 22S, C34-17α,21β(H)-tetrakishomohopane 22R, C35-17α,21β(H)-pentakishomohopane 22S and C35-17α,21β(H)-pentakishomohopane 22R was observed while the ratio 17α,21β(H)-30-norhopane/C30-17α,21β(H)-hopane in the samples varied from 0.42 in 2000 to 0.32 in 2004 (compared to 0.43 in the original oil) demonstrating the intensity of biodegradation processes. Fluoranthene/pyrene and ∑3–6 rings PAH/Σ5-alkylated PAH series were identified as the most robust PAH diagnostic ratios to distinguish samples with petrogenic contamination. Vertical migration of the oil in the sediment column and a decrease by 70% in total PAH were observed during the study period. Relative decay constants were obtained for total and individual PAH after normalization to the C30-17α,21β(H)-hopane and by adjusting the data to first order kinetics. PAH decay rates decreased with increasing degree of alkylation. The highly eutrophic conditions in the bay and the sandy character of sediments contributed to the observed degradation in surface sediments as well as in deeper sediment layers.

Stramonita haemastoma was investigated as a suitable bioindicator of TBT and TPhT contamination in the tropical Atlantic Ocean by: 1. Imposex induction in healthy females after inoculation with TBT and TPhT in the laboratory; and 2. Determining incidence of imposex in S. haemastoma collected from areas with various levels of tributyltin (TBT) and triphenyltin (TPhT) and determining the concentrations of these chemical in its tissues and that of its prey, the mussell Perna pernas. Imposex intensities and organotin concentrations in tissues showed good correlation, indicating S. haemastoma as a reliable bioindicator of TBT and TPhT contamination in coastal waters. Body burden threshold of TBT and TPhT for imposex induction was estimated to be 10-20 ng g(-1).

The mussel Perna perna was used to monitor and assess areas suspected of oil contamination by transplanting animals from unimpacted to impacted sites and vice versa . The deployment lasted for three months during which total PAH were measured in seawater samples collected every 15 days. PAH concentrations were determined in mussel tissue monthly. The lysosomal neutral red assay and the condition index were used as biomarkers of the adverse biological effects. The PAH concentration in mussels at unimpacted sites, prior to deployment was ca. 100 μg kg −1 but increased to 300 μg kg −1 after three months at the contaminated site. Mussels transplanted to the uncontaminated site showed a decrease from 380 to 80 μg kg −1 . Significant changes in lysosomal stability occurred within one month of the beginning of the transposition; in contrast condition indexes were not correlated with the observed changes in PAH concentration.

The Marine and Environmental Studies Laboratory at PUC-Rio, in partnership with the PETROBRAS R&D Center (Brazil), conducted an interlaboratory comparison of aliphatic and aromatic hydrocarbons and trace element determinations. The goal of this study was to produce a homogeneous and stable material and obtain consensus concentration values for its use as a reference material (RM) for sediments from tropical regions. The prepared material is adequate for use as a reference material because it has remained stable (Test F, ANOVA, p < 0.05) since its preparation in 2007. In this study, several alkylated polycyclic aromatic hydrocarbon (PAH) compounds were included, and the resulting dispersion was the same order of magnitude as the parental PAH (16 PAH USEPA).

Ethanol is a biofuel produced in Brazil through fermentation of sugarcane, requiring vast plantation areas and water availability. The present work aimed at testing isotopic markers as tools for ethanol source appointment or certification of origin. For this, oxygen and hydrogen isotopic patterns were determined in plant-water, soil-water, rainwater, and water from reservoirs and some rivers in four sugarcane crop areas. The isotopic fingerprint of carbon and hydrogen in ethanol produced in the respective mills was also determined. Samples were collected in 2011 and 2012 in crop areas of the state of Amazonas (North), Mato Grosso (Center-West), Sao Paulo (Southeast) and Rio Grande do Sul (South). The substantial and complex influence of the hydrological cycle on the ethanol δD and the small δ13C variations constrain the use of isotopes for the intended objectives.

The goal of the present work was to test the response of Perna perna to oil contamination in the marine environment. Mussels Perna perna were collected on several occasions from the pillars of Rio-Niteroi Bridge, Guanabara Bay, Rio de Janeiro, including after a major spill of MFO380 in January 2000. Condition index evaluation and neutral red assay were carried out in these mussels, which were also tested for polycyclic aromatic hydrocarbons (PAHs) concentration by using GC/MS. The PAH burden in mussels, analyzed before and after the oil spill, increased between 2 and 5 fold. This change was dominated by measurable increases in naphthalene, phenanthrene, dibenzothiophene, and their respective alkylated homologs. Although indicative ratios revealed petrogenic contamination after the spill, source indicative ratios for PAHs in the mussels differ from that for the oil. In agreement to what is reported in the literature for other bivalves, Perna perna responds reliably to variations in oil derived PAHs in the ...

The water-soluble fraction (WSF) of crude oil is a complex highly volatile and toxic mixture of hydrocarbon chains (polyaromatics, heterocyclics), phenols, and heterocyclic compounds containing nitrogen and sulfur. To evaluate the toxic effects of WSF in tropical freshwater teleosts and to develop methodologies that could investigate the toxic mechanisms of WSF in tropical organisms, an acute toxicity experiment was conducted with Astyanax sp. Three dilutions (15%, 33%, and 50%) of WSF obtained from Campos Bay's crude oil (Brazil) were used to study morphological and biochemical responses of the fish. Prior to exposure, the distribution and rate of volatilization of the WSF into each aquarium for the same exposure period was quantified by spectrofluorimetry. Five individuals of Astyvanax sp. were exposed to duplicate WSF of 0, 15, 33, and 50% for each of 12-, 24-, and 96-h exposures for a total of 120 individuals. Liver and gills were sampled from five fish from each treatment and were analyzed by histology, scanning and transmission electron microscopy. A fragment of muscle was also collected from each fish to measure acetylcholinesterase activity. Water analysis showed that only 4 h after dilution, an important loss of hydrocarbons in 33% and 50% of WSF was observed. In addition, 50% of hydrocarbon mass was lost in all tested dilutions after 24 h with significant difference for the 50% WSF at all measured times, demonstrating the high volatility of WSF in freshwater. Damage in the liver and the gills included the presence of necrosis, loss of hepatocytes limit, inflammation areas, cellular proliferation, aneurysms, and disorganization of the second lamellae. The 33% WSF significantly reduced acetylcholinesterase activity in fish. Our study demonstrated that the WSF of crude oil caused damage in organs and tissues of tropical freshwater Astyanax sp. and provided also the basis for a better understanding of the toxic mechanisms of WSF in freshwater fishes.

In January 2000, approximately 1,300 m3 (340,000 gallons) of marine fuel oil were released during a pipeline transference accident in the Guanabara Bay, Rio de Janeiro, Brazil, reaching island and land shorelines situated at the north and northeast part of the bay. An Emergency Action Plan for oil recovery and cleanup was performed, and the effort of this strategy resulted in the recovery of approximately 40% of the spilled oil. Although there was no official fishery closure, several areas were, in practice, closed to marine traffic, and fishermen were not fishing in the oil-affected area; thus, there was a de facto fishery closure. Chemical and toxicological analyses were performed on water and sediment samples to evaluate the degree of the contamination of the affected area 10 days after the spill. The results of these analyses showed background levels for polycyclic aromatic hydrocarbons (PAHs) in finfish habitat in Guanabara Bay. A study was then conducted as a cooperative effort among the governmental environmental agency (IBAMA), universities, and PETROBRAS to assess the degree of contamination of finfish from the area for hydrocarbons and microorganisms. Microbial essays and chemical analyses for PAHs were conducted on six composite samples of edible tissue of two species (Mugil lisa and Micropogonias furnieri) collected in nets and fish traps in the most affected area. The species were chosen based on their abundance, marketability, and feeding habits. Two samples collected in the bay 1 year before the oil spill were used as reference to PAHs. The microbial analyses were conducted according to the rules from the Health Ministry and also were done for other species collected by net fishing. All samples were found free of microbial contamination and were approved to be consumed in accordance with the MERCOSUL criteria. The concentration of PAHs in the samples collected after the oil spill were at the same level of the reference samples, confirming the expectation from the literature. These results were compared to three international concentration-based and risk-based criteria since there were no legal limits for PAHs in fishes. No sample analyzed contained PAH contamination exceeding the criteria used as reference in this study. No carcinogenic compounds were detected in the samples. The net results of this work were the rapid resumption of the finfisheries and the acquisition of a preliminary database of PAH concentration and microbial conditions on finfish tissue for the Guanabara Bay.

The present study evaluates the potential of Hymeniacidon heliophila as bioindicator of PAH contamination. For this, concentration of 33 PAH was determined in organisms from sites with different contamination level including the heavily polluted Guanabara Bay, Rio de Janeiro, and less impacted coastal areas. PAH concentration and typology were determined in sponges collected from different depths and in two different seasons. The brown mussel broadly studied as bioindicator was also sampled from the same sites for comparison. Both species provided similar information on total PAH concentration which is related to site contamination level. Sponges, however, revealed slight tendency to accumulation of combustion-derived PAH in relation to petrogenic compounds. Differences in PAH typology between species may derive from the interspecific variation in particle size ingestion. Different hydrocarbon typologies were observed in sponges from dry and wet season and PAH concentration varied with depth. H. heliophila may be used as an alternative approach to investigate the presence and sources of PAH in estuarine areas.

The accumulation history of combustion products from the metropolitan area around Guanabara Bay was evaluated using black carbon and polycyclic aromatic hydrocarbons as indicators. BC concentration varied between 0.23 and 0.51%, with an increasing mass accumulation tendency over the last 118 years, whereas a decrease in the values of the ratio BC/organic carbon was observed in the upper sediment layers, probably reflecting the enhancement of bay's eutrophication process in the last 30 years. Higher concentrations of pyrolytic PAH were observed between 1925 and 1976, being consistent with the subsequent deforestation, urbanization, and industrialization that occurred in the Guanabara basin in the period. These PAHs were best characterized by the BFl/(BFl+BePy) diagnostic ratio. The data obtained allowed the characterization of the main events that influenced the combustion patterns in the region: burning of biomass and fossil fuel, economic crisis of 1970 and 1990 and the introduction of ethanol in the Brazilian energetic matrix., Journal of the Brazilian Chemical Society, 24 (11), ISSN:0103-5053

Cultured and native brown mussels ( Perna perna Linnaeus 1758) were used to evaluate the contamination by PAHs in the SE Brazilian coastal zone. Mean concentrations of total PAH (38 parental and alkylated compounds) and cluster analysis revealed that: (i) mussel farms (32.7–70.1 ng g −1 ) are located in uncontaminated areas; (ii) coastal rockyshore areas (89.7 ± 25.8 ng g −1 ) have low level of contamination; and (iii) the Guanabara Bay (760.9 ± 456.3 ng g −1 ) is chronically contaminated by hydrocarbons, which is consistent with previous results. PAH profiles and diagnostic ratios suggested mixed petrogenic and pyrolitic sources for group (ii) and petrogenic sources for group (iii). The levels of PAH in the cultured and native mussels are below threshold values for safe food, even in Guanabara Bay, and thus in such cases other contaminants and pathogens should be considered in order to evaluate the quality of shellfish for human consumption.

Aliphatic hydrocarbons and 39 PAH (parental and alkylated homologs) determined in ca. 100 sediment samples from the Guanabara Bay, Rio de Janeiro, were evaluated for source discrimination using new approaches. Concentrations of total PAH were in the range of 96–135,000 μg kg −1 similar to other coastal urbanized embayment. Traditional diagnostic ratios were not as efficient PAH source indicators, e.g. biomass combustion was assigned as the major source of the pyrolytic PAH although the hydrographic basin is highly industrialized and urbanized. It is proved petrogenic imprint cannot be detected if only the 16 USEPA PAH are determined. The high production in the eutrophic system is not apparent in the aliphatic fraction dominated by land derived n -alkanes due to the effectiveness of microbial degradation. The present work demonstrates the complexity of hydrocarbon forensics when applied to chronically contaminated environments.

A novel multivariate method based on principal component analysis of pre-processed sections of chromatograms is used to characterize the complex PAH pollution patterns in sediments from Guanabara Bay, Brazil. Five distinct sources of 3- to 6-ring PAHs could be revealed. The harbour is the most contaminated site in the bay, its plume stretches in a South West to North East direction and the chemical profile indicates mainly pyrogenic sources mixed with a fraction of high-molecular-weight petrogenic PAHs. Rio Sao Joao de Meriti is the second largest source of PAHs, and introduces mainly a fraction of low-molecular-weight petrogenic PAHs from the western region of Rio de Janeiro. The sites close to the ruptured pipeline at the Duque de Caxias Refinery show a distinctive pollution pattern indicating a heavy petroleum fraction. The method also led to the identification of new potential indicator ratios also involving coeluting peaks (e.g., triphenylene and chrysene).

Pyrene metabolites in urine and micronucleus in haemocytes of crabs (Ucides cordatus) were tested as biomarkers of exposure to oil derived PAHs in mangrove sediments. The goal was to verify how well pyrene metabolites in urine represent levels of oil contamination in mangroves and whether the micronuclei assay indicates exposure. For this, bioassays were performed using crabs from clean and contaminated areas, and field studies were conducted in four mangroves. Results of the bioassay show that U. cordatus assimilates, metabolises, and excretes pyrene in urine as pyrene-1-glucoside, pyrene-sulphate and pyrene-conjugate. OH-pyrene-sulphate was the major metabolite produced/excreted over 120 h of observation by crabs from the clean mangrove. The production/excretion of pyrene-1-glucoside in this case increased linearly with time at a rate of 2.3 x 10(-10)mol L(-1)day(-1). The number of micronuclei in haemocytes also increased with the time after pyrene inoculation, indicating that exposure to pyrene triggers genotoxic and mutagenic response. In crabs from a heavily oil-contaminated mangrove pyrene-1-glucoside was the major metabolite, an indication that production/excretion of a certain metabolite varies depending on adaptation of the animal to the environment. A highly significant correlation was found between the concentration of pyrene metabolites in urine of field crabs expressed as OH-pyrene equivalents and the sum of 38 PAHs determined in hepatopancreas/sediments (r=0.825, n=23, p

This study is aimed at verifying the relevance of Ucides cordatus as a bioindicator of oil contamination and PAH bioavailability in mangrove sediments. For this, crabs and sediment cores were sampled from five mangroves, including an area suspected of contamination derived from an MF380 oil spillage, and analyzed for the 16 PAH in the USEPA priority list as well as for the five series of alkylated homologues. Concentrations in sediments varied from 35 μg kg−1 in the lower core layer of the control area to 33,000 μg kg−1 in the upper layer of the most contaminated area. Total PAH contents in crabs varied from 206 to 62,000 μg kg−1 and were closely correlated to that in sediments. In general, individual PAH profiles in both matrices were in good agreement. Phenanthrenes, however, were more predominant in crabs making up to 30–46% of the Total PAH. Accumulation factors found in the range of 0.7 to 35 were highly variable even after normalizing concentrations for organic carbon and lipid content. Survival in highly contaminated environment and reliable record of environmental contamination in the tissue provide evidence that U. cordatus is an excellent bioindicator for oil in mangroves. Keywords: Ucides cordatus, Crabs, PAH, Oil contamination, Sediments, Monitoring

Pontifica Universidade Catolica do Rio de Janeiro - PUC-Rio Departamento de Quimica (Rua Marques de Sao Vicente, 225, 22453-900, Gavea, RJ, Brasil) *Corresponding author: hallfz@uerj.br The toxic effects of tributyltin (TBT) and triphenyltin (TPT), used as biocides in antifouling paints, as defensives fungicides or present in industrial effluents, on aquatic organisms are well known (Fent, 1996) and has led many countries to control their application as antifoulants since the eighties (Champ, 2000; Hoch, 2001). A global ban on the application of these compounds as biocides was scheduled by IMO to begin in January, 2003. The convention has, however, not yet been enforced and the use of the compounds continues in several countries. The biological effects of organotin compounds have been described for many places on the Brazilian coast, always related to centers of maritime activity such as harbors, shipyards and marinas, and relatively high concentrations of organotins have been detected in sediments and organisms in the two most important areas of maritime activity in Brazil (Fernandez

An integrated biological-chemical survey of organotin compounds was carried out in Guanabara Bay, the second most important Brazilian harbor complex. The biological survey revealed high levels of imposex in Stramonita haemastoma populations. Inside the bay values of relative penis length index from 42.7 to 107.6 and vas deferens sequence index from III to VI were found, while organisms collected outside the bay had values ranging from