Modelagem de plumas de efluentes entre Praia Grande e Peruíbe, litoral do estado de São Paulo, Brasil / Modeling effluent plumes between Praia Grande and Peruíbe, São Paulo State's shore, Brazil

RESUMO O presente trabalho teve como objetivo monitorar a dispersão de plumas de efluentes provenientes dos emissários submarinos de Praia Grande e do Rio Itanhaém, por meio do processamento do modelo Delft3D (módulos hidrodinâmico e de qualidade da água) e do modelo Visual Plumes (módulo UM3). A modelagem de campo próximo indicou que as correntes geradas pelo vento foram mais eficientes do que as correntes de maré na diluição inicial das plumas dos emissários; e a modelagem de campo distante, validada qualitativamente, demonstrou que as concentrações dos potenciais poluentes de todas as plumas simuladas não ultrapassam os limites máximos estabelecidos pelo Conselho Nacional do Meio Ambiente quando essas plumas atingem as praias da região de estudo.

ABSTRACT This study's goal was to monitor the dispersion of effluent plumes from the Praia Grande's submarine outfalls and from the Itanhaém River by processing the Delft3D model (hydrodynamic and water quality modules) and the Visual Plumes model (UM3 module). The near field modeling indicated that wind-driven currents were more efficient than tidal currents in the initial dilution of the outfalls' plumes; and the far field modeling, qualitatively validated, demonstrated that the potential pollutants' concentrations in all the simulated plumes don't exceed the maximum limits established by the National Environmental Council when these plumes reach the study region's beaches.

Mercúrio e Metilmercúrio em cabelos de crianças e em peixes mais consumidos em Cubatão, Estado de São Paulo, Brasil / Mercury and Methylmercury in the children hair and fish mostly consumed in Cubatão, São Paulo State, Brazil

This study evaluated Hg and MeHg concentrations in fish muscle and children hair from Cubatão, using asstrategies: i) Hg and MeHg determinations in the mostly consumed fish species, ii) Hg and MeHg determinationsin 93 children hair samples (from 04 to 14 years old), and iii) analysis on the children diet consumptionquestionnaire answered by the respective parents. The results obtained in a similar study in Cananeia were usedas references. These two regions show different environmental anthropogenic impacts and distinct eating habits.The quantity and the frequency of fish consumption were the most important factors of Hg bioaccumulation inchildren hair. In both cities, 95 % of mercury contents in hair were >1 mg.kg-1 (US EPA reference) in analyzedchildren, and MeHg were between 67 and 83 % of total Hg. The median for total Hg concentration in fishmuscle (wet basis) ranged from 10 to 179 μg.kg-1 for Cananéia and 10 to 181 μg.kg-1 for Cubatão, values lowerthan the Brazilian limits for Hg in fish. Considering the Hg contents detected in the mostly consumed fish andhair, they indicate that the children are not at risk for Hg and MeHg contamination...

Este estudo avaliou a concentração de Hg e MeHg em amostras de peixes e de cabelos de crianças de Cubatão, usando-se como estratégia: i) Hg total e MeHg em peixes mais consumidos; ii) Hg total e MeHg em cabelos de 93 crianças (04 a 14 anos); iii) análise do inquérito alimentar respondido pelos pais. Os dados obtidos em estudo similar realizado em Cananéia foram usados como referência. Essas duas regiões estuarinas, sob diferentes graus de impacto ambiental, apresentam diferentes hábitos alimentares. A quantidade e a frequência de consumo de peixes foram os fatores mais importantes na bioacumulação de Hg nos cabelos. Em ambas as cidades, 95 % das concentrações de Hg total nos cabelos foram abaixo de 1 mg.kg-1 (limite US EPA) e o percentual de MeHg ocorreu entre 67 e 83 % em relação ao teor de Hg total. As medianas para Hg total nos músculos (base úmida) variaram de 10 a 179 μg.kg-1 para peixes de Cananéia e 10 a 181 μg.kg-1 de Cubatão, inferiores ao limite da legislação brasileira para Hg. A partir dos teores para Hg total e MeHg em peixes mais consumidos e cabelos, as crianças parecem não estar em risco de contaminação...

Mercury and methylmercury content, fatty acids profile, and proximate composition of consumed fish in Cananéia, São Paulo, Brazil

Fifty three individuals of four most commonly consumed fish species by the Cananéia city population, in São Paulo, Brazil, were analyzedto determine total mercury (Total Hg) and methylmercury (MeHg) levels, as well as, proximate composition and fatty acid profile. Themuscle of three carnivorous species Centropomus parallelus (Fat snook), Macrodon ancylodon (King weakfish) and Micropogonias furnieri(Whitemouth croaker), and one planktivorous species Mugil platanus (Mullet) were analyzed. MeHg and Total Hg determinations wereperformed by Cold Vapour Atomic Absorption Spectrometry (CV AAS). Fatty acid profile was determined by gas chromatography (GC) whilst AOAC methods were used for proximate analysis. The total Hg results (interval) in wet weight basis were: Whitemouth croaker(114–442 μg kg-1), Fat snook (15-178 μg kg-1), King weakfi sh (12-100 μg kg-1) and Mullet (<10–25 μg kg-1), and none of the fish species exceeded the Brazilian legislation limits. MeHg values were below FAO/WHO (2007) recommendations. In nutritional terms, the resultsfor proximate composition for all four fish species proved to be an excellent protein source with very low lipid content as was expected. Fatty acids of all fish species were adequate. Total polyunsaturated fatty acid contents varied from 21.9% (Micropogonias furnieri) to26.4% (Mugil platanus). For the n-3 family, Macrodon ancylodon presented the highest value (20.9%) and Micropogonias furnieri thelowest one (15.8%). Mugil platanus (Mullet) species also showed good levels for all parameters analyzed and very low concentrations of contaminants, indicating it as a good nutritional choice in terms of risks and benefits.