Assessment of Human Health Risk Indices Due to Metal Contamination in the Surface Water of the Negro River Sub-Basin, Áncash.

The accelerated loss of glacial cover in the Cordillera Blanca in Áncash, Peru, exposes the underlying rocks with high concentrations of sulfides from the Chicama Formation to oxidation and leaching processes, generating acid rock drainage (ARD) in glacial and periglacial areas. These are transported by surface runoff, contaminating the surface water with high concentrations of metals and sulfates, as well as increasing the acidity, which poses a risk to human health and the ecosystem. Therefore, the risk indices for human health due to metal contamination were evaluated at 19 surface water sampling points distributed in the Río Negro sub-basin. Hydrochemical analyses revealed average metal concentrations in the following order: Fe (28.597 mg/L), Al (3.832 mg/L), Mn (1.085 mg/L), Zn (0.234 mg/L), Ni (0.085 mg/L), Co (0.053 mg/L), Li (0.036 mg/L), Cu (0.005 mg/L), and Pb (0.002 mg/L). The risk was determined by calculating the Heavy Metal Pollution Index (HPI) and the Hazard Index (HI). The average HPI value was 360.959, indicating a high level of contamination (HPI ≥ 150). The human health risk assessment indicated that adverse effects caused by iron, lithium, and cobalt in children and adults should be considered. Through the use of Pearson correlation analysis, principal component analysis, and cluster analysis, it was identified that SO42-, Fe, S, Al, Co, Mn, Ni, Zn, and Li originate from natural sources, associated with the generation of ARD in glacial and periglacial areas.

Anurans of a threatened savanna area in western Brazil

The Upper Paraguay River Basin is located in the center of South America and harbors one of the largest wetland in the world, known as Pantanal. This floodplain is surrounded by uplands, which presently have most of their area converted into pastures or monocultures, besides being poorly known scientifically. Also, most of these upland areas are considered conservation priorities. Here we present a list of anuran species from a savanna-like area (municipality of Camapuã, state of Mato Grosso do Sul, Brazil) inserted in the uplands surrounding the Pantanal floodplain, in the Upper Taquari River sub-basin, and evaluate the effectiveness of the sampling effort. Data were obtained through active searches in 22 plots in aquatic habitats, during the rainy season (from December 2009 to April 2010). We found 26 species, in four families. Although sampling effort was found to sufficiently represent the local anuran assemblage, future inventories in this region should ideally include samplings during the dry and early rainy seasons, and include both active and passive capturing methods.

A bacia do Alto Paraguai, localizada no centro da América do Sul, abriga uma das maiores áreas inundáveis do mundo, conhecida como Pantanal. Essa planície alagável é rodeada por planaltos, os quais possuem grande parte de sua área convertida em pastagens ou monoculturas, além de serem pouco conhecidos cientificamente. Além disso, a maioria das áreas de planalto são consideradas prioritárias para a conservação. Apresentamos uma lista de espécies de anuros de uma área semelhante a savanas (município de Camapuã, estado de Mato Grosso do Sul, Brasil) inserida nos planaltos de entorno do Pantanal, na sub-bacia do Alto Taquari, e avaliamos a efetividade do esforço amostral. Os dados foram obtidos através de busca ativa em 22 parcelas em ambientes aquáticos, durante a estação chuvosa (de Dezembro de 2009 a Abril de 2010). Encontramos 26 espécies, em quatro famílias. Apesar de considerarmos o esforço amostral suficiente para representar da comunidade de anuros local, sugerimos que futuros inventários nessa região contemplem a estação seca e início da chuvosa, bem como o uso adicional de métodos passivos de captura.

Biologia populacional de Cyphocarax modestus (Osteichthyes, Curimatidae) no córrego Ribeirão Claro, município de Rio Claro (SP) / Population biology of Cyphocarax modestus (Osteichthyes, Curimatidae) in the Ribeirão Claro stream, Rio Claro (SP)

Neste trabalho buscou-se um melhor entendimento do ciclo anual de Cyphocarax modestus na área do reservatório de captação de água do córrego Ribeirão Claro. Os parâmetros de crescimento foram estimados através da análise de distribuição de freqüência de comprimento e as relações entre época de menor crescimento, atividade alimentar, acúmulo de gordura e período reprodutivo foram consideradas. Além disso, a taxa instantânea de mortalidade natural foi calculada. Amostragens mensais foram realizadas no córrego Ribeirão Claro, no reservatório de captação de água do município de Rio Claro. Para isso, 50 m de rede de espera foram utilizados, com malhas de 1,5; 2,0; 2,5; 3,0 e 3,5 cm entre nós adjacentes. O método utilizado para a estimativa dos parâmetros de crescimento foi o ELEFAN I e sua aplicação foi feita utilizando-se o programa FISAT, sendo utilizada a versão sazonal da curva de crescimento de von Bertalanffy. Considerou-se que a reprodução de C. modestus é anual e concentrada de dezembro a fevereiro, permitindo assim a identificação de diferentes modas nas distribuições, condição essencial para que esse tipo de análise seja conduzida. Os parâmetros estimados foram: K = 0,34/ano, L¥ = 15,40 cm, C = 0,2, Wp = 0,6 e M = 0,949/ano, com a identificação de quatro coortes. Analisando-se conjuntamente os dados de gordura acumulada na cavidade visceral, índice de repleção estomacal, época reprodutiva e de menor crescimento uma seqüência fisiológica no ciclo anual da espécie pôde ser notada: com o início da maturação das gônadas, os recursos energéticos deixaram de ser investidos no crescimento e passaram a ser utilizados na reprodução.

This work aimed a better understanding of the annual cycle of Cyphocarax modestus in the reservoir of water captation of Ribeirão Claro stream. The growth parameters were estimated through the analysis of length distribution and the relationships among time of smaller growth, alimentary activity, fat accumulation and reproductive period were considered. Besides, the instantaneous rate of natural mortality was calculated. Monthly samplings were accomplished in the Ribeirão Claro stream, in the reservoir of water captation of Rio Claro city. For that, 50 m of wait net was used, with meshes of 1.5, 2.0, 2.5, 3.0 and 3.5 cm measured between adjacent knots. The ELEFAN I program was used to estimate the growth parameters, and its application was done using the FISAT program. It was also used the seasonal version of von Bertalanffy's growth curve. It was considered that the reproduction of C. modestus is annual and concentrated from December to February, allowing the identification of different modas in the distributions, an essential condition for the conduction of that analysis type. The estimated parameters were: K = 0.34/year, L ¥ = 15.40 cm, C = 0.2, Wp = 0.6 and M = 0.949/year, with the identification of four cohorts. The physiologic sequence in the annual cycle of the specie could be noted when data of accumulated fat in the visceral cavity, alimentary activity, reproduction time and time of smaller growth were analyzed together. It was noted that with the beginning of the maturation of gonads, the energy resources stopped being invested in the growth and passed to be used for reproduction.