Seasonal arsenic in catfish (Siluriformes, Ariidae) and the hydrochemical conditions of two areas in a Ramsar site on the Brazilian coast.

The construction of a data bank concerning metal and metalloid content of bioindicator fish from coastal areas is very important as it can help environmental managers in decision making. In natural conditions, the concentration of elements can be influenced by abiotic parameters such as water salinity. In this study, catfish Cathorops spixii were evaluated concerning the total arsenic (As) concentration in the muscle tissues of individuals subjected to different abiotic conditions in the Cananéia-Iguape Estuarine-Lagoon Complex (CIELC), which was recently included on the Ramsar list of wetlands of international importance. Seventy-four catfish were seasonally caught in the northern and southern regions of the CIELC and their hydrochemical parameters were obtained. C. spixii from the southern, best preserved, area showed arsenic concentrations around ten times higher than the maximum limit established for fish intended for human consumption. However, these high concentrations of arsenic could be associated with the abiotic parameters of the water, such as salinity variations, in this area.

Bioaccumulation of Total Mercury (THg) in Catfish (Siluriformes, Ariidae) with Different Sexual Maturity from Cananéia-Iguape Estuary, SP, Brazil.

In order to improve the knowledge of total mercury (THg) bioaccumulation in bioindicator species of sea catfish (Siluriformes, Ariidae) and taking into account the relatively recent approach with respect to estuarine fish on the Brazilian coast, 65 individuals were caught in the northern and southern regions of the Cananeia estuary to determine the concentration of the THg in muscles, gills, gonads and kidney of the Cathorops spixii and Genidens genidens specimens. The difference in the THg accumulation associated to the maturity of the catfish reflects a differential metabolism regarding THg bioaccumulation in adults (males and females) and juveniles. These observations reinforce the importance of considering the maturity of the individual in order to understand the bioaccumulation and metabolism of fish under different environmental stress and conditions. Furthermore, abiotic conditions such as salinity should be evaluated in association with metabolic/biological conditions of the fish's bioindicators, especially in environments with large natural or anthropogenic transition gradients.

Correction to: Bioaccumulation of Total Mercury (THg) in Catfish (Siluriformes, Ariidae) with Different Sexual Maturity from Cananéia-Iguape Estuary, SP, Brazil.

The original version of the article contained a mistake in the unit values. In the fourth paragraph of "Materials and Methods" section, the fourth sentence should read as: The obtained detection and quantification limits were 0.408 ng g-1 and 3.619 ng g-1, respectively, with circa 90% recovery compared with DORM-4, showing high precision and accuracy of the THg determination.

Impact of harbour, industry and sewage on the phosphorus geochemistry of a subtropical estuary in Brazil.

The distribution of different forms of phosphorus in surface sediment from 17 sites were investigated by SEDEX method. The sites were divided into three sectors: Santos Channel (SC - influenced by harbour, fertilizers plants and phosphogypsum mountains), São Vicente Channel (SVC- domestic waste) and Santos Bay (SB - sewage outfall). The average percentage of each P fraction of the surface sediments in this region followed the sequence P-Fe (38%)>P org (27%)>P exch (13%)>Detrital - P (12%)>Auth - P (10%). P total varied from 3.57 to 74.11 µmol g(-)(1) in both seasons. In SVC, P exch ranged from 13% to 27% and P org varied from 12% to 56%. These high percentages of P exch/P total (greater than 20%) may be related to low oxygen resulting from oxygen consumed by intensive organic matter decomposition as well as the salty water that leads to cation and anion flocculation. Also, the possibility of an influence related to the industrial source of P exch is not ruled out. No significant seasonal differences were found among sites, except for sewage outfall, with changing in the grain size and hence, the P geochemistry. During the summer in the sewage outfall station, Porg represented 37% of P total, which decreased to 13% in the winter. These results suggest that high percentages of organic phosphorus cannot be attributed only to autochthonous and allochthonous organic matter, but also to detergents and/or domestic waste. In contrast, spatial differences among sectors were observed, with the highest values of each fraction associated with sites near industrial and domestic waste activities.

Total mercury in sediments and in Brazilian Ariidae catfish from two estuaries under different anthropogenic influence.

Santos-São Vicente estuary, located in São Paulo State, Brazil, has a history of contamination by inorganic chemicals such as mercury (Hg). In the 1980s the Cubatão was considered one of the most polluted sites in the world as a consequence of the intense industrial activities located in the city close to the estuary. To provide data and evaluate the local biota, total mercury (THg) contents were determined in sediments and in fish, Cathorops spixii, from different areas of the Santos-São Vicente estuary. For comparison, samples were also collected in a non-polluted system with similar hydrochemistry characteristics, the Cananeia estuary. The water characteristics and THg levels in sediment and fish samples confirmed a high human influence in the Santos-São Vicente estuary. The lowest THg values, observed in Cananeia, were evidence of low anthropogenic influence. High values observed in Santos-São Vicente show the necessity for a monitoring program.

[Total hair mercury in children from a coastal population in Cananéia, São Paulo State, Brazil]. / Mercúrio total em cabelo de crianças de uma população costeira, Cananéia, São Paulo, Brasil.

Mercury (Hg) levels in hair are directly related to eating habits, especially fish consumption by coastal populations with a large contingent of traditional fishing families. This study assessed total Hg levels in children's hair. The study group was selected from three public elementary schools in Cananéia, São Paulo State, Brazil (ages 4 to 12 years). The results (median and range) for total Hg levels in children's hair were: 0.04 mg.kg-1 (0.01-0.77 mg.kg-1), 0.39 mg.kg-1 (< 0.01-3.33 mg.kg-1), and 0.39 mg.kg-1 (< 0.01-2.81 mg.kg-1) for schools ES1, ES2, and ES3, respectively. The values were well below the level set by World Health Organization for an adult population unexposed to Hg (2.0 mg.kg-1). However, since there are no existing reference values for total Hg in children's hair, these results can be used as a contribution to establishing reference values for total hair Hg in Brazilian children living in coastal areas.

Mercúrio total em cabelo de crianças de uma população costeira, Cananéia, São Paulo, Brasil / Total hair mercury in children from a coastal population in Cananéia, São Paulo State, Brazil

Os níveis de mercúrio (Hg) total em cabelos estão diretamente relacionados à alimentação, particularmente ao consumo de peixes por populações costeiras com grande representação caiçara. No presente estudo foram avaliados os níveis de mercúrio total em cabelos de crianças com idade entre 4 e 12 anos, pertencente a três escolas públicas da cidade de Cananéia, São Paulo, Brasil. Os resultados obtidos (mediana e intervalo) para mercúrio total foram de: 0,04mg.kg-1 (0,01-0,77mg.kg-1), 0,39mg.kg-1 (< 0,01-3,33mg.kg-1) e 0,39mg.kg-1 (< 0,01-2,81mg.kg-1) considerando as escolas ES1, ES2 e ES3, respectivamente. Em geral, os valores encontrados estiveram bem abaixo do valor preconizado pela Organização Mundial da Saúde para uma população adulta não exposta ao mercúrio (2,0mg.kg-1). Os baixos valores observados e a inexistência de valores de referência para mercúrio total em cabelos de crianças brasileiras possibilitam a consideração desses valores como possível referência nacional em cabelos de populações costeiras, uma vez que foram obtidos em região de baixo impacto ambiental.

Mercury (Hg) levels in hair are directly related to eating habits, especially fish consumption by coastal populations with a large contingent of traditional fishing families. This study assessed total Hg levels in children's hair. The study group was selected from three public elementary schools in Cananéia, São Paulo State, Brazil (ages 4 to 12 years). The results (median and range) for total Hg levels in children's hair were: 0.04mg.kg-1 (0.01-0.77mg.kg-1), 0.39mg.kg-1 (< 0.01-3.33mg.kg-1), and 0.39mg.kg-1 (< 0.01-2.81mg.kg-1) for schools ES1, ES2, and ES3, respectively. The values were well below the level set by World Health Organization for an adult population unexposed to Hg (2.0mg.kg-1). However, since there are no existing reference values for total Hg in children's hair, these results can be used as a contribution to establishing reference values for total hair Hg in Brazilian children living in coastal areas.

Phosphorus dynamics in water and sediments in urbanized and non-urbanized rivers in Southern Brazil.

Phosphorus flux models show that the removal tends to be a common feature in polluted estuarine systems whereas the release of P to the adjacent coastal area occurs in pristine environments. This study analyzes the distribution of P in water and sediments along six rivers in the south coast of Brazil. Three rivers located inside protected areas were considered non-polluted and used as a control of urbanization. The other three, situated within urbanized areas, were considered as having highly elevated concentrations of P. Results showed a different behavior of P in water and sediments located in urbanized and non-urbanized areas. The concentrations of dissolved organic (P-org) and inorganic (P-inorg) phosphorus in water, and the total phosphorus (P-tot) and polyphosphate (P-poly) in sediments where higher in the urbanized rivers compared to the non-urbanized ones. Both P of punctual origin and of diffuse origin contributed to the maintenance of elevated concentrations and disturbed the natural fluxes along the polluted rivers. The minimum and maximum concentrations in urbanized areas varied from 0.39 to 12.45 (microM) for P-org and 0.00 to 5.92 (microM) for P-inorg in water, and in sediments from 89.90 to 808.16 (microM g(-1)) for P-tot and 0.00 to 76.51 (microM g(-1)) for P-poly. In non-urbanized areas concentrations in water varied from 0.22 to 1.20 (microM) for P-inorg and 4.43 to 5.56 (microM) for P-org, and in sediments from 45.91 to 652.26 (microM g(-1)) for P-tot and 0.00 to 8.61 (microM g(-1)) for P-poly. Using a hierarchical sampling design and a simple model of variation of P (K(d) model) it was possible to demonstrate that urbanized and non-urbanized estuaries may act as sinks or sources of P. The variation of P analysis in different points along each of the six rivers showed that release and removal areas may occur within a same river independently of its urbanization.