The mangrove's sediments from the coastal areas under human activities may contain significant contaminations by hydrocarbons, even when there are no visual evidences of it. The microorganisms are essential to these ecosystems, especially in the control of their chemical environment. Sediment samples were collected in two regions under different environment conditions (pristine and contaminated) of the Paranaguá Estuarine Complex (Paranaguá Bay and Laranjeiras Bay), Brazil. Aliphatic hydrocarbons were determined by the GC-FID to assess the status of contamination of the studied areas. The total DNA was extracted from these samples. The 16S rRNA gene was amplified by the PCR reactions with the pair of primers 21F and 958R for the archaeal domain, and 27F and 1492R for the bacterial domain. Comparisons of communities were made by the ARDRA technique, using the HinfI restriction enzyme. The phosphate concentration showed significant differences between the two regions. The aliphatic hydrocarbons analysis showed the presence of unresolved complex mixture (UCM), an indicator of oil contamination, in the samples from the Paranaguá Bay, which was corroborated by the concentration of total aliphatic hydrocarbons. The ARDRA profile indicated that the structure of archaeal and bacterial communities of the sampled areas was very similar. Therefore, the anthropogenic influences in the Paranaguá Bay showed to be not sufficient to produce disturbances in the prokaryotic dominant groups.

Organic markers, such as sterols and ketones, were used to assess sewage contamination in sediments from the Santos Bay, SP, and its continental shelf. These compounds were analyzed by GC/FID after soxhlet extraction, clean up and derivatization. The concentration of coprostanol and ratios between selected sterols were used to evaluate fecal contamination. The stations located in the mid-western part of the Santos Bay presented organic matter from sewage due to the input of fecal material from the city of Santos by submarine sewage outfall. Stations located at the continental shelf did not present fecal contamination. Coprostanol levels in sewage outfall stations were higher in comparison to other Brazilian coastal areas, except Guanabara Bay/RJ, and could be related to the fraction of the population without sewage treatment.

A Lagoa dos Patos (RS), considerada a maior lagoa costeira do mundo, tem sido afetada por diversas atividades antrópicas. Um risco de contaminação por esgoto ocorre devido ao estabelecimento de mais de 2 milhões de habitantes ao longo da bacia de drenagem desta região. Amostras de sedimentos foram coletadas e analisadas por CG-EM. Dez diferentes esteróis, incluindo coprostanol e epicoprostanol (fecais), e cetonas foram identificados e quantificados. A maior concentração de coprostanol foi encontrada próximo à cidade de Porto Alegre (1.423 ng g-1). Nos demais pontos, a concentração variou desde o limite de detecção até 91,78 ng g-1. As maiores concentrações foram encontradas próximo à descarga de esgotos e os níveis diminuíram com o aumento da distância desde as fontes. As razões isoméricas 5beta / (5beta+5alfa) indicaram sedimentos contaminados próximo a Porto Alegre. A razão epicoprostanol/coprostanol mostrou valores característicos do aporte de esgoto sem tratamento ao longo da Lagoa dos Patos.

The Patos Lagoon, the largest coastal lagoon in the world, has long been receiving considerable anthropogenic input resulting from urban, rural and industrial activities. Thus, sewage contamination possibly originating from the more than 2 million inhabitants living within its drainage basin is examined in this study. Sediment samples collected from various points along the Lagoon were extracted, purified and analysed by GC-MS. Ten different sterols and ketones, including coprostanol and epicoprostanol, were identified and quantified. The highest coprostanol concentration was found near Porto Alegre City (1,423 ng g-1 dry wt.), whilst most sediment levels ranged between < DOL and 91.78 ng g-1. The highest concentrations were found at those three sites located closest to domestic outfalls though levels tended to decrease with distance from the sources. The 5beta/(5beta+5alpha) isomeric ratios indicated sewage-contaminated sediments near Porto Alegre City, while the epicoprostanol/coprostanol ratio showed values characteristic of untreated sewage input.

Amostras de sedimento, coletadas nas proximidades da saída de esgoto da Estação Antártica Comandante Ferraz (Brasil), Antártica, foram medidos durante o verão de 1999/2000. As concentrações de esteróis totais e coprostanol variaram entre 0,09 e 19,6 ¼g.g-1 e < 0,01 e 14,0 ¼g.g-1 de sedimento seco. Nossas análises mostraram que apenas os pontos localizados até 400 m desde a saída de esgotos apresentaram contribuições provenientes do esgoto da estação brasileira. Baixos níveis de coprostanol e alta concentração de colesterol em pontos distantes puderam ser atribuídos a fontes naturais, como os mamíferos marinhos e organismos planctônicos. Indicadores microbiológicos (E. coli, streptococci fecais e Clostridium perfringens) não foram detectados até 50 m desde a saída de esgotos. Ambos indicadores de poluição fecal produziram dados consistentes, embora os esteróis fecais tenham sido mais apropriados para avaliar quantidades traço de material fecal. Este estudo concluiu que a contaminação por esgotos está limitada apenas aos pontos mais próximos da saída de esgoto. Em geral, as concentrações de esteróis fecais e indicadores microbiológicos foram menores do que em outras regiões antárticas e centros urbanos.

Sediments from the proximity of Ferraz station outfall, located in Admiralty Bay, Antarctica, were analyzed for fecal indicator microorganisms and sterols during the austral summer of 1999/2000 in order to assess human sewage input. Concentrations of total sterols and coprostanol ranged from 0.09 to 19.6 ¼g.g-1 and < 0.01 and 14.0 ¼g.g-1 dry weight (dw), respectively. Our analyses indicated that only sites within to 400m of the sewage outfall exhibited a sterol signal characteristic of human sewage input. Low levels of coprostanol and high levels of cholesterol in distant sites could be attributed to natural sources such as marine mammals and planktonic organisms. Fecal indicator microorganisms (E. coli, fecal streptococci and Clostridium perfringens) were non-detectable beyond 50m from outfall. Both indicators (sterols and fecal indicator microorganisms) produced consistent data and fecal sterol parameters have sho wn themselves to be efficient in the evaluation of trace amounts of fecal material. This study concluded that sewage contamination is limited to the immediate vicinity of the sewage outfall. In general, the concentration of fecal sterols and microbiological indicators were lower than in other Antarctic areas.