Refine search
Results 1-10 of 24
How the redox state of tobacco ‘Bel-W3’ is modified in response to ozone and other environmental factors in a sub-tropical area?
2011
Dias, Ana P.L. | Dafré, Marcelle | Rinaldi, Mirian C.S. | Domingos, Marisa
This study intended to determine whether the redox state in plants of Nicotiana tabacum ‘Bel-W3’ fluctuates in response to the environmental factors in a sub-tropical area contaminated by ozone (São Paulo, SE – Brazil) and which environmental factors are related to this fluctuation, discussing their biomonitoring efficiency. We comparatively evaluated the indicators of redox state (ascorbic acid, glutathione, superoxide dismutase, ascorbate peroxidase, and glutathione reductase) and leaf injury in 17 field experiments performed in 2008. The redox state was explained by the combined effects of chronic levels of O₃ and meteorological variables 4–6 days prior to the plant sampling. Moderate leaf injury was observed in most cases. The redox state of tobacco decreases few days after their placement in the sub-tropical environment, causing them to become susceptible to oxidative stress imposed by chronic doses of O₃. Its bioindicator efficiency would not be diminished in such levels of atmospheric contamination.
Show more [+] Less [-]Assessment of organochlorine pesticide residues in Atlantic Rain Forest fragments, Rio de Janeiro, Brazil
2011
Quinete, Natalia Soares | de Oliveira, Elba dos Santos | Fernandes, Daniella R. | Avelar, Andre de Souza | Santelli, Ricardo Erthal
A superficial water quality survey in a watershed of the Paraíba do Sul River, the main water supply for the most populated cities of southeastern Brazil, was held in order to assess the impact of the expansion of agricultural activity in the near border of the Atlantic Rain Forest. The aim of this study was to investigate the presence of priority organochlorine pollutants in soils and superficial waters of Atlantic rainforest fragments in Teresópolis, Rio de Janeiro State. Soil sample preparations were compared by using ultrasound, microwave assisted extraction and Soxhlet extraction. Recoveries of matrix spiked samples ranged from 70 to 130%. Analysis of a certified soil material showed recoveries ranging from 71 to 234%. Although low concentrations of organochlorine residues were found in water and soil samples, this area is of environmental importance and concern, thus demanding a monitoring program of its compartments.
Show more [+] Less [-]Bioindication of atmospheric trace metals – With special references to megacities
2011
Markert, Bernd | Wuenschmann, Simone | Fraenzle, Stefan | Graciana Figueiredo, Ana Maria | Ribeiro, Andreza P. | Wang, Meie
After considering the particular problems of atmospheric pollution in megacities, i.e. agglomerations larger than 5 mio. inhabitants, with urbanization of World’s population going on steadily, possibilities of active biomonitoring by means of green plants are discussed. Based on specific definitions of active and passive bioindication the chances of monitoring heavy metals in Sao Paulo megacity were demonstrated (first results published before). This is to show that there is need for increased use of bioindication to tackle the particular problems of megacities concerning environmental “health”, the data to be processed according to the Multi-Markered-Bioindication-Concept (MMBC). Comparison to other work shows this approach to be reasonable.
Show more [+] Less [-]Diversity of shrub tree layer, leaf litter decomposition and N release in a Brazilian Cerrado under N, P and N plus P additions
2011
Jacobson, Tamiel Khan Baiocchi | Bustamante, Mercedes Maria da Cunha | Kozovits, Alessandra Rodrigues
This study investigated changes in diversity of shrub-tree layer, leaf decomposition rates, nutrient release and soil NO fluxes of a Brazilian savanna (cerrado sensu stricto) under N, P and N plus P additions. Simultaneous addition of N and P affected density, dominance, richness and diversity patterns more significantly than addition of N or P separately. Leaf litter decomposition rates increased in P and NP plots but did not differ in N plots in comparison to control plots. N addition increased N mass loss, while the combined addition of N and P resulted in an immobilization of N in leaf litter. Soil NO emissions were also higher when N was applied without P. The results indicate that if the availability of P is not increased proportionally to the availability of N, the losses of N are intensified.
Show more [+] Less [-]Characterization of organic matter in sediment cores of the Todos os Santos Bay, Bahia, Brazil, by elemental analysis and ¹³C NMR
2011
Costa, A.B. | Novotny, E.H. | Bloise, A.C. | de Azevedo, E.R. | Bonagamba, T.J. | Zucchi, M.R. | Santos, V.L.C.S. | Azevedo, A.E.G.
The impact of human activity on the sediments of Todos os Santos Bay in Brazil was evaluated by elemental analysis and ¹³C Nuclear Magnetic Resonance (¹³C NMR). This article reports a study of six sediment cores collected at different depths and regions of Todos os Santos Bay. The elemental profiles of cores collected on the eastern side of Frades Island suggest an abrupt change in the sedimentation regime. Autoregressive Integrated Moving Average (ARIMA) analysis corroborates this result. The range of depths of the cores corresponds to about 50years ago, coinciding with the implantation of major onshore industrial projects in the region. Principal Component Analysis of the ¹³C NMR spectra clearly differentiates sediment samples closer to the Subaé estuary, which have high contents of terrestrial organic matter, from those closer to a local oil refinery. The results presented in this article illustrate several important aspects of environmental impact of human activity on this bay.
Show more [+] Less [-]Gillnet fisheries as a major mortality factor of Magellanic penguins in wintering areas
2011
Cardoso, Luis Gustavo | Bugoni, Leandro | Mancini, Patrícia Luciano | Haimovici, Manuel
The incidental capture in fisheries is probably the main conservation problem affecting seabirds. While the capture of albatrosses and petrels on longline hooks is well-known worldwide, the bycatch of diving seabirds in gillnets is an overlooked conservation problem. During a winter coastal fishing trip, the capture of Magellanic penguins (Spheniscus magellanicus) was recorded in driftnet and bottom setnet fisheries for the first time in southern Brazil. The highest captures rates were found in driftnets, from 146.5 to 545.5penguins/km² of net and a total of 56 dead penguins were recorded. In the bottom gillnet, a total of 12 birds were killed and the capture rates varied from 41.7 to 125.0penguins/km² of net. Although preliminary, the results presented in this paper were consistent between sets. If we consider the magnitude of driftnet and setnet fishing fleets, and that most dead penguins were adults, the impact upon Magellanic penguin populations is probably significant.
Show more [+] Less [-]Specific profiles of polybrominated diphenylethers (PBDEs) and polychlorinated biphenyls (PCBs) in fish and tucuxi dolphins from the estuary of Paraíba do Sul River, Southeastern Brazil
2011
Quinete, Natalia | Lavandier, Ricardo | Dias, Patrick | Taniguchi, Satie | Montone, Rosalinda | Moreira, Isabel
Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are ubiquitous pollutants in the environment and subject of several studies due to their adverse effects as endocrine disruptors. Despite the concern over widespread distribution of PBDEs even in sparsely populated regions of the world, few studies have reported their occurrence in Brazil. In this study, PBDEs and PCBs levels were measured in selected fish species and dolphins from Paraiba do Sul River, Brazil. BDE 47 and 85 were the predominant congeners. Low chlorinated congeners showed the highest concentrations in fish; however dolphins presented the highest proportion of PCBs 153, followed by 138 and 180. The daily intake of PBDEs and PCBs was estimated for the population of this region. PCB daily intake through consumption of croaker was above the limits set by the Brazilian Ministry of Agriculture, raising great concern over the existence of a source of PCB contamination in Brazil.
Show more [+] Less [-]Metal distribution in sediment cores from São Paulo State Coast, Brazil
2011
Silva, Paulo S.C. | Damatto, Sandra R. | Maldonado, Caio | Fávaro, Deboráh I.T. | Mazzilli, Barbara P.
Ten sediment core samples with lengths ranging from 35 to 100cm were collected in the Baixada Santista region and analyzed to determine As, Br, Co, Cr, Cs, Fe, Rb, Sb, Ta, Th, U, Zn and rare earths (Sc, Ce, Eu, La, Lu, Nd, Sm, Tb and Yb) level concentrations using instrumental neutron activation analysis (INAA). The studied region is located in the southeastern coast of São Paulo State and is comprised of a densely urbanized area, the largest industrial complex of the country, with a predominance of petrochemical and fertilizer plants. It is also home to Brazil’s most important and busiest port. The conclusions found that the As, La, Sm, Ne, Ce, Eu, Hf, Ta, Th, and U elements have a high background level in the region and that Fe and Zn were the main indicators of anthropogenic contribution in the sediments.
Show more [+] Less [-]Total mercury in sediments and in Brazilian Ariidae catfish from two estuaries under different anthropogenic influence
2011
Azevedo, Juliana S. | Braga, Elisabete S. | Favaro, Deborah T. | Perretti, Adriana R. | Rezende, Carlos Eduardo | Souza, Cristina Maria M.
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.
Show more [+] Less [-]Polycyclic aromatic hydrocarbons (PAHs) in a large South American industrial coastal area (Santos Estuary, Southeastern Brazil): Sources and depositional history
2011
Martins, César C. | Bícego, Márcia C. | Mahiques, Michel M. | Figueira, Rubens C.L. | Tessler, Moyses G. | Montone, Rosalinda C.
Located in southeastern Brazil, the Santos Estuary has the most important industrial and urban population area of South America. Since the 1950’s, increased urbanization and industrialization near the estuary margins has caused the degradation of mangroves and has increased the discharge of sewage and industrial effluents. The main objectives of this work were to determine the concentrations and sources of polycyclic aromatic hydrocarbons (PAHs) in sediment cores in order to investigate the input of these substances in the last 50years. The PAHs analyses indicated multiple sources of these compounds (oil and pyrolitic origin), basically anthropogenic contributions from biomass, coal and fossil fuels combustion. The distribution of PAHs in the cores was associated with the formation and development of Cubatão industrial complex and the Santos harbour, waste disposal, world oil crisis and the pollution control program, which results in the decrease of organic pollutants input in this area.
Show more [+] Less [-]