Recebido em 2/2/07; aceito em 14/6/07; publicado na web em 9/11/07Butyltin compounds were investigated in surface sediments from 17 stations in Todos os Santos Bay. Analytical conditions for organotin determination in marine sediments were optimized for GC with pulsed flame photometric detection. Detection limits were: 5.4 μg kg -1 for TBT; 0.2 μg kg -1 for DBT; and 2.1 μg kg -1 for MBT, using a 610-nm filter. In general, TBT concentrations were low and in the range of

This article aims to analyze and understand the relationship between water and health in rural communities located in the watershed of Cumaru stream, in the municipality Igarapé-Açu, Northeast of Pará state. The harvesting and treatment of the water conducted by the rural population for human consumption were assessed, considering their practices of sanitary sewer, since these aspects have direct impact on their health. This study is based on field research with a quantitative approach. Closed questionnaire was used to raise the sources of water harvesting, rural sanitation, and use of agricultural inputs. We used participant observation, when focusing on the functioning of the agricultural establishment, to observe from various angles the relationship between water and health. We noted that the vulnerability of the water resources accessed by the population is a factor that contributes to the contamination of the sources, therefore a threat to the health of the rural population. However, the perception of the population is notable regarding deeper water sources, such as tube wells, which are priorities for water harvesting. ResumoEste artigo visa analisar e compreender a relação entre água e saúde em comunidades rurais situadas na microbacia do igarapé Cumaru, município de Igarapé-Açu (PA), nordeste paraense. São avaliados a captação e o tratamento de água para o consumo humano, considerando as práticas de esgoto sanitá-rio realizadas cotidianamente pela população rural dessa microbacia, visto que têm implicação direta na saúde da população local. Este trabalho baseia-se em pesquisa de campo com uma abordagem quali-quantitativa. Utilizou-se questionário fechado para o levantamento das fontes de captação, saneamento rural e usos de insumos agrícolas. Foram consideradas observações feitas por agricultores familiares da região ao focar o funcionamento do estabelecimento agrícola, a fim de observar de diversos ângulos a relação entre água e saúde no seu entendimento. Observou-se que a vulnerabilidade das fontes de água acessadas pela população é um fator que contribui para a contaminação das fontes, caracterizando consequentemente uma ameaça à saúde da população rural. Entretanto, nota-se a percepção da população quanto às fontes de água mais profundas, como poços tubulares, sendo estes prioritários para captação de água para ingestão.

No abstract

Oil palm plantations are rapidly expanding in the tropics because of insatiable global demand for fruit oil to be used in food, biofuels and cosmetics. Here we show that three tissue-specific volatiles can be quantified in ambient air above an African-American hybrid oil palm plantation in Brazil and linked photosynthesis (isoprene), floral scent (estragole), and for the first time, fruit oil processing (6-methyl-5-hepten-2-one, MHO). Plant enclosure techniques verified their tissue specific emission sources with ambient concentrations displaying distinct diurnal patterns above the canopy. Isoprene concentrations were near zero at night, but dramatically increased during the day while estragole showed elevated concentrations at night suggesting a light-independent, temperature-driven emission pattern from flowers. MHO also showed elevated concentrations at night and both estragole and MHO increased during the day. Our observations demonstrate that the African-American oil palm hybrid is strong isoprene emitter and suggest that MHO is a specific oxidation product of lycopene released during the industrial processing of palm oil. This study highlights the potential value of quantifying volatile oil palm signals in the atmosphere as a novel, non-invasive method to better understand biological functioning and its interactions with the environment including carbon assimilation, floral-insect interactions, and fruit oil production/ processing.

Land-use intensification in the "Zona Bragantina" region, an area in the eastern Brazilian Amazon, has accelerated landscape changes from primary forest to a mixture of different land uses: native forest (riparian vegetation), secondary forest, pasture, annual cropland, perennial cropland, bare soil and fallow vegetation, with negative consequences for the stability and equilibrium of river systems. This study examined the temporal and spatial variation of dissolved organic carbon (DOC) and metal concentrations in stream water of the Cumaru (ICU) and São João (ISJ) watersheds from May 2014 to April 2015, to understand the chemical changes in forests and agro-ecosystems during one year. In both watersheds, higher concentrations of dissolved metals (aluminum, sodium, barium, calcium, iron, potassium, magnesium, copper and zinc) and DOC were measured in the rainy season, with considerable variability due to precipitation events. Furthermore, strong spatial variation was observed, with lower conductivity, higher pH, and higher concentrations of DOC and dissolved metals in the downstream reaches, especially for DOC in a small reservoir below a dam in ISJ. Significant human intervention was located in these downstream areas, including nearby agriculture and pasture, and use of stream resources for domestic activity. Sandy soil in these areas likely facilitated leachate processes, mainly in deforested areas, supporting the increased movement of metals from the land to the stream.

O estudo objetiva avaliar a dinâmica de nitrogênio e carbono dissolvidos em lixiviado da serrapilheira e precipitação, nas microbacias do Cumaru e São João (cerca de 12 km do município de Igarapé-Açu, no nordeste paraense), sob 4 diferentes manejos para cada microbacia: vegetação ripária, capoeira, sistema agroflorestal (SAF) e sistema de corte e trituração. As amostras foram coletadas mensalmente de fevereiro de 2014 a abril de 2015. O lixiviado da serrapilheira foi obtido pela solução escoada sob a camada de serrapilheira no solo em quadrantes de 1x1 m, enquanto que a precipitação se coletou por calhas conectadas a galões, sendo verificado in loco os parâmetros físico-químicos e analisado em laboratório, após adição de preservantes e filtragem: Carbono Orgânico Dissolvido (COD), Carbono Inorgânico Dissolvido (CID), Nitrogênio Orgânico Dissolvido (NOD), amônio (NH4+) e nitrato (NO3-). Onde verificou-se interferência dos períodos de transição climatológica sob a disponibilidade de nutrientes e os parâmetros físico-químicos avaliados; sendo as épocas mais chuvosas responsáveis por altas na acidez, na lixiviação e no consumo de oxigênio, já as menos chuvosas apresentaram elevação nos teores dos nutrientes analisados (especialmente em sistemas naturais e mais diversificados), exceto os ânions nitrogenados. Os SAFs e sistemas corte e trituração (menor proporção) atuaram significativamente no aproveitamento dos nutrientes lixiviados sob o solo.

No abstract

ABSTRACT-This research evaluated the phytotoxic effect of the hexane (H.E), ethyl acetate (EtOAc.E) and methanolic (MeOH.E) crude extracts of the Tephrosia cinerea leaves on the seed germination of seeds using two weed species, Mimosa pudica (Malícia) and Senna obtusifolia (Mata-pasto), as test plants. The compounds were isolated using classic chromatography techniques and the structural elucidation of the compounds was performed by 1 H and 13 C NMR (1D and 2D) techniques. The ethyl acetate and methanolic extracts of T. cinerea were the most active, as they inhibited the germination of seeds in 92.0% and 81.0% respectively of malícia and mata-pasto, the ethyl acetate extract inhibited germination by 81.0% and the methanolic extract by 32.0%. The chemical study led to isolation of cinnamic acid and rotenone from the ethyl acetate extract, and mixture containing triacylglycerol and β-sitosterol fatty acids from the hexane extract and the disaccharide trehalose from methanolic extract.