Avaliação da contaminação por organofosforados em águas superficiais no município de Rondinha - Rio Grande do Sul

Water pollution is a serious environmental problem. In Rondinha, Rio Grande do Sul, on a small area planted with tobacco, it has been using organophosphates pesticides. The purpose of this study was to evaluate the organophosphates pesticides contamination of the superficial water in this municipality. The samples collected in fifteen places were evaluated by the method of organophosphates acethylcolinestherase inhibition. In five samples the organophosphates levels were above the limit established by CONAMA, indicating the necessity of arrangements that allow reducing the risk of the population and the environment contamination.

Efeitos antrópicos sobre concentrações de metais alcalinos na região da microbacia do Arroio Araçá, Canoas - Rio Grande do Sul

This work presents alterations in the concentrations of alkaline metals sodium, lithium and potassium, in abiotic compartments, at Araçá stream micro-basin, located in Canoas, RS. Its spring is located in a low populational density region and crosses an elevated environmental impacted urban area. Its final course crosses an agricultural area. Samples of atmospheric particulates, macrophites, water and sediments were analyzed. High concentrations of alkaline metals, related with draining of rice fields or with the ground type, as well as correlations among its concentrations with regional activities were verified. Tripogandra diurética has shown bioaccumulation compatible with their concentrations on waters.

Produção científica e formação de recursos humanos na área de bioquímica em instituições federais do Rio Grande do Sul: fomento estadual

Brazilian scientific production in Biochemistry is growing impressively fast, and Rio Grande do Sul is outstanding in that context. This study aims to outline the state's scientific research profile, given its prominent position in the national scenario. Hence, researchers, laboratories, development of human resources and investments by Foundation for the Support to Research in the State of Rio Grande do Sul (FAPERGS) were identified and mapped. We observed that amount of financial support by FAPERGS decreases in last years. Therefore, there is the necessity to reestablish some of FAPERGS's programs, as well as to increase financial support to Biochemistry departments.

Variabilidade espacial e temporal de parâmetros físico-químicos nos rios Turvo, Preto e Grande no estado de São Paulo, Brasil

This work aims to study spatial and seasonal variability of some chemical-physical parameters in the Turvo/Grande watershed, São Paulo State, Brazil. Water samples were taken monthly, 2007/07-2008/11, from fourteen sampling stations sited along the Turvo, Preto and Grande Rivers and its main tributaries. The Principal Component Analysis and hierarchical cluster analysis showed two distinct groups in this watershed, the first one associated for the places more impacted by domestic effluent (lower levels of dissolved oxygen in the studied region). The sampling places located to downstream (Turvo and Grande rivers) were discriminate by diffuse source of pollutants from flooding and agriculture runoffs in a second group.

Fluxos de nutrientes associados às descargas de água subterrânea para a Lagoa Mangueira (Rio Grande do Sul, Brasil)

This study assesses the importance of groundwater discharge to dissolved nutrient levels in Mangueira Lagoon. A transect of an irrigation canal in the margin of Lagoon demonstrated a strong geochemical gradient due to high groundwater inputs in this area. Using 222Rn as a quantitative groundwater tracer, we observed that the flux of dissolved inorganic nitrogen (DIN), silicate and phosphate (1178 and 1977; 26190 and 35652; 167 and 188 mol d-1 for winter and summer, respectively) can continually supply/sustain primary production. The irrigation canals act as an artificial underground tributary and represent a new source of nutrients to coastal lagoons.

Métodos para análises de HPA e BTEX em águas subterrâneas de postos de revenda de combustíveis: um estudo de caso em Campo Grande, MS, Brasil

Two methods using headspace solid-phase microextraction and gas chromatography - mass spectrometry were developed for the determination of polycyclic aromatic hydrocarbons (PAH) and BTEX. Best results were obtained using DVB/CAR/PDMS fiber, with 10 min extraction at 25 °C and 0.15 min desorption at 260 °C (BTEX), and PDMS/DVB fiber, with 60 min extraction at 90 °C, 10% NaCl and 5 min desorption at 270 °C (PAH). LOD intervals were 3x10-2 - 5x10-2 µg L-1 (BTEX) and 1.6x10-3 - 1.4 µg L-1 (PAH). The methods were applied to forty-five groundwater samples from monitoring wells of gas stations and only benzene level exceeded the limit established by Brazilian regulations.