Levels and sources of hydrocarbons in the Patos Lagoon estuary and Cassino Beach mud bank (South Atlantic, Brazil): evidence of transference between environments

This study assessed the concentrations and sources of natural and anthropogenic aliphatic (AHs) and polycyclic aromatic hydrocarbons (PAHs) in superficial sediments collected along the Patos Lagoon estuary and in sediment cores obtained from the Cassino Beach mud bank. Levels and distribution of n-alkanes indicate terrestrial sources, overlapping with a low amount of petrogenic hydrocarbons (heavy oils). Unresolved complex mixture (UCM) was observed in all samples. On the other hand, the distribution of PAHs in the sediments showed a predominance of pyrolytic over petrogenic sources. In general, hydrocarbons (HCs) contamination in the Patos Lagoon estuary and its adjacent coastal area can be considered low, except for sites near urban or industrial effluents, where moderate to high levels of contamination were found. Concentrations of hydrocarbons were homogeneous throughout the sediment cores, suggesting that mixing processes may have occurred along the layers or that HCs inputs to the mud banks were uniform during the studied deposition period. In addition, the levels and profile of HCs in the coastal sediments were similar to those observed in the estuary. Moreover, the frequent remobilization of sediments from the mud bank towards Cassino beach does not seem to pose any threats to the local biota or beach users since the levels of contamination were relatively low and below the threshold limits of sediment quality guideline

Co-exposure of the organic nanomaterial fullerene C60 with benzo[a]pyrene in Danio rerio (zebrafish) hepatocytes: Evidence of toxicological interactions

Compounds from the nanotechnology industry, such as carbon-based nanomaterials, are strong candidates to contaminate aquatic environments because their production and disposal have exponentially grown in a few years. Previous evidence shows that fullerene C60, a carbon nanomaterial, can facilitate the intake of metals or PAHs both in vivo and in vitro, potentially amplifying the deleterious effects of these toxicants in organisms. The present work aimed to investigate the effects of fullerene C60 in a Danio rerio (zebrafish) hepatocyte cell lineage exposed to benzo[a]pyrene (BaP) in terms of cell viability, oxidative stress parameters and BaP intracellular accumulation. Additionally, a computational docking was performed to investigate the interaction of the fullerene C60 molecule with the detoxificatory and antioxidant enzyme πGST. Fullerene C60 provoked a significant (p 0.05) alter the enzyme activity when added to GST purified extracts from the zebrafish hepatocyte cells. These results show that fullerene C60 can increase the intake of BaP into the cells, decreasing cell viability and impairing the detoxificatory response by phase II enzymes, such as GST, and this latter effect should be occurring at the transcriptional level.Fil: Ribas Ferreira, Josencler L.. Universidade Federal do Rio Grande do Sul; BrasilFil: Lonné, María Noelia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: França, Thiago A.. Universidade Federal do Rio Grande do Sul; BrasilFil: Maximilla, Naiana R.. Universidade Federal do Rio Grande do Sul; BrasilFil: Lugokenski, Thiago H.. Universidade Federal de Santa Maria. Departamento de Química; BrasilFil: Costa, Patrícia G.. Universidade Federal do Rio Grande do Sul; BrasilFil: Fillmann, Gilberto. Universidade Federal do Rio Grande do Sul; BrasilFil: Soares, Félix A.. Universidade Federal de Santa Maria. Departamento de Química; BrasilFil: de la Torre, Fernando Roman. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Luján. Departamento de Ciencias Básicas; ArgentinaFil: Monserrat, José María. Universidade Federal do Rio Grande do Sul; Brasil. Instituto Nacional de Ciência e Tecnologia de Nanomateriais de Carbono; Brasi

Relative performance of immunochemical (enzyme-linked immunosorbent assay) and gas chromatography-electron-capture detection techniques to quantify polychlorinated biphenyls in mussel tissues

Results from polychlorinated biphenyls (PCB) analyses of mussel tissue extracts by immunoassay (PCB RaPID Assay®) and conventional gas chromatography–electron-capture detection (GC–ECD) are described and compared. Mussels from natural populations with diverse concentrations of PCBs, mussel tissue fortified with technical Aroclor® 1254 and a certified reference material are included.A strong correlation is reported between “total” PCBs quantified by both techniques (r2 = 0.95, n = 27). Immunoassay results, however, exhibited lower values compared to GC–ECD, particularly when GC results are corrected for procedural recovery. A reduced antibody response, due to differences in the congener composition between the mussel extracts and Aroclor® 1254 (used to raise and calibrate the ELISA), provides the most likely explanation for this difference. Non-parametric statistical analyses confirmed that,although differing from Aroclor® 1254, PCB congener compositions in the mussel extracts most closely resemble that of Aroclor® 1254. At very high PCB concentrations (>30 g g−1 dry weight), however, ELISA results are statistically different (P < 0.01) from GC–ECD results, which is likely to be related to the solvation capacity of ELISA diluent. Similarity analysis showed high correlations between the most prominent congeners in Aroclor® 1254 and immunoassay results. This analysis did not, however, identify a specific chlorine substitution pattern to which the immunoassay preferentially responded. Whilst GC–ECD affords the capability to quantify individual congeners of different reactivity and toxicity, the data reported do indicate that immunoassay offers a rapid and inexpensive alternative method for estimation of “total” PCBs at environmental significant levels. It is, however, necessary to remove extraneous lipids to reduce matrix effects in the immunoassay

Assessing the potential toxicity of marine sediments found in petroleum industry areas: A new approach based on responses of postlarval shrimp

In this study we tested the toxicity of bulk sediment from the northeastern area of Todos os Santos Bay, Bahia, Brazil, to evaluate environmental impact induced by 50 years of exposure to the local petroleum industry (Petrobras). Sediment samples were collected during one year, at three-month intervals, from four sites in areas of oil extraction (Ilha das Fontes, station 4), transportation (Ilhas de Madre de Deus and Pati, stations 2 and 3) and refinement (RELAM, station 1). Two reference stations (5 and 6) were located outside the petroleum influence area, to the south of the bay. Static bioassays were conducted for 96 h, using 7–8 day old Litopenaeus vannamei postlarvae (PL). The assays were conducted in 2.5 L plastic jars containing 200 g of surface (1 cm deep) bulk sediment covered by 2 L of dilution water (filtered seawater, 28 ppt salinity, 27 + 2ºC and DO under saturation). Fifteen exposed PL in each jar were fed daily on 60 recently hatched Artemia salina nauplii. Physico-chemical parameters were monitored. Mortality and dry weight gain were taken as end-points. The PL mortality data obtained for sediment from the Petrobras stations in comparison to the data from the reference stations were not significantly different (P > 0.05); however, the dry weight gain showed significant differences among stations. A maximum value was reached at station 5 (reference area) and a minimum at station 1 (RELAM refinery). Stations 2 and 3 in petroleum transportation areas did not show significant differences (P > 0.05). To evaluate the sensitivity of this bulk-sediment test in detecting contaminant effects generated by the petroleum industry, the toxicity data were considered in terms of the hydrocarbon levels analyzed in sediments from the same Petrobras areas and in one of the control areas, located outside the bay. The results support the assumption that the bulksediment bioassay on penaeid PL is a suitable methodology not only to distinguish between impacted and relatively unperturbed environments, but also to separate the different degrees of impact among areas subjected to petroleum industry activities in the coastal environment