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71.
Ribeira Bay is located approximately 130 km south of the city of Rio de Janeiro and receives discharges of liquid effluent from the Angra dos Reis nuclear power plant (NPP) site, where two pressurized water reactors are located. To test whether the presence of anthropogenic radionuclides in sediments in Ribeira Bay could be correlated to the NPP operations, we sampled seven sediment cores and determined accumulation rates and chronologies. Only one sediment core did not exhibit a superficial mixing layer; this sample was used for dating purposes. Cesium-137 and 207Bi were observed in this sediment profile, but their presence was associated with atmospheric fall-out rather than the nearby NPP. The exponential decay of 210Pb concentration with sediment layer depth was verified below a superficial mixing layer for all other sediment cores. Calculated accumulation rates ranged from 1.2 mm y−1 in the inner bay to 6.2 mm y−1 close to its entrance.  相似文献   
72.
Gondim, Rubens S., Marco A.H. de Castro, Aline de H.N. Maia, Sílvio R.M. Evangelista, and Sérgio C. de F. Fuck, Jr., 2012. Climate Change Impacts on Irrigation Water Needs in the Jaguaribe River Basin. Journal of the American Water Resources Association (JAWRA) 48(2): 355‐365. DOI: 10.1111/j.1752‐1688.2011.00620.x Abstract: Climate change is conceptually referred to as a modification to the average of climate variables and their natural variability, due to both natural and anthropogenic driving forces, such as greenhouse gas emissions. Climate change potentially impacts rainfall, temperature, and air humidity, which have relationship with plant evapotranspiration and consequently to irrigation water needs (IWN). The purpose of this research is to assess climate change impacts on irrigation water demand, based on climatic impacts stemming from future greenhouse gas emission scenarios. The study area includes eight municipalities in the Jaguaribe River Basin, located in the Ceará State of semiarid northeast Brazil. The FAO Penman‐Monteith method is used for the calculation of a reference evapotranspiration with limited climatic data. IWN projections are calculated using bias‐corrected climate projections for monthly rainfall and surface temperature derived from the United Kingdom’s Hadley Centre Regional Climate Model simulations. The increase in the average IWN is projected to be 7.9 and 9.1% over the period 2025‐2055 for the A2 and B2 scenarios, respectively with respect to 1961‐1990 baseline.  相似文献   
73.
Albatrosses and petrels (Procellariiformes) are migratory oceanic birds of considerable conservational interest. Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were assessed in the subcutaneous fat, liver and muscle of 100 birds belonging to eight species of Procellariiformes collected during their migration period in southern Brazil, one of the most important feeding areas for these species. Although the profiles of PCBs and OCPs were similar among the individuals, with predominance of penta, hexa and heptachlorobiphenyls and pp-DDE, organochlorine concentrations exhibited a high degree of intra-species variability. The influence of body condition during the migration period in the distribution of organochlorine contaminants was also evaluated, showing that it is a significant factor in the variation and redistribution of these compounds in the tissues of these birds. The intense use of lipid reserves associated to the contamination from organochlorine compounds could be a troubling factor for seabirds with extended breeding periods and that spend most of their lives at sea migrating long distances, such as most of Procellariiformes. Studies on contamination are necessary to improve the knowledge of the threats to these birds and their populations as well as to contribute with information about persistent organic pollutants in the South Atlantic marine environment.  相似文献   
74.
Intensive beef production has increased during recent decades in Brazil and may substantially increase both methane (CH4) and nitrous oxide (N2O) emissions from manure management. However, the quantification of these gases and methods for extrapolating them are scarce in Brazil. A case study examines CH4 and N2O emissions from one typical beef cattle feedlot manure management continuum in Brazil and the applicability of Manure-DNDC model in predicting these emissions for better understand fluxes and mitigation options. Measurements track CH4 and N2O emissions from manure excreted in one housing floor holding 21 animals for 78 days, stockpiled for 73 days and field spread (360 kg N ha?1). We found total emissions (CH4 + N2O) of 0.19 ± 0.10 kg CO2eq per kg of animal live weight gain; mostly coming from field application (73%), followed housing (25%) and storage (2%). The Manure-DNDC simulations were generally within the statistical deviation ranges of the field data, differing in ?28% in total emission. Large uncertainties in measurements showed the model was more accurate estimating the magnitude of gases emissions than replicate results at daily basis. Modeled results suggested increasing the frequency of manure removal from housing, splitting the field application and adopting no-tillage system is the most efficient management for reducing emissions from manure (up to about 75%). Since this work consists in the first assessment under Brazilian conditions, more and continuous field measurements are required for decreasing uncertainties and improving model validations. However, this paper reports promising results and scientific perceptions for the design of further integrated work on farm-scale measurements and Manure-DNDC model development for Brazilian conditions.  相似文献   
75.
Blubber samples from 33 Guiana dolphins (Sotalia guianensis) from three estuaries (Guanabara, Sepetiba/Ilha Grande and Paranaguá Bays) of Southern and Southeastern Brazil were analyzed for organochlorine compounds (DDTs, PCBs and HCB). The sampled individuals were incidentally captured in gillnet fishery between 1995 and 2005. The concentrations (in ng/g lipids) varied from 652 to 23 555 for ΣDDT; from 765 to 99 175 for ΣPCB; and from <4.4 to 156 for HCB. The results have shown that cetaceans from Brazil present organochlorine concentrations that are comparable to those reported for highly industrialized regions of Northern Hemisphere. Using discriminant analysis it was possible to verify that the dolphin populations from the three bays present different organochlorine accumulation patterns. This feature allows the use of this set of pollutants as an auxiliary tool for identification of different populations of the species off Brazilian Coast.  相似文献   
76.
Objective: The objective of this study was to estimate the effect of the Brazilian zero-tolerance drinking and driving law on mortality rates due to road traffic accidents according to the type of victim, sex, and age.

Methods: An interrupted time series design was used to compare yearly mortality rates due to road traffic accidents in Rio de Janeiro, Brazil, before and after the zero-tolerance drinking and driving law came into effect on June 19, 2008. Yearly mortality rates were compared according to the type of victim: pedestrian, cyclist, motorcyclist, and vehicle occupant. We used the Prais-Winsten procedure of autoregression in the analysis of time series; the outcome of this analysis was the annual percentage change in the rates. Overall and stratified analyses were conducted to investigate whether the zero-tolerance drinking and driving law may have had a distributional effect on mortality rates due to road traffic accidents depending on sex and age group; a significance level of P < .01 was accepted.

Results: From 1999 to 2016, there were 15,629 deaths due to road traffic accidents in Rio de Janeiro. The effect of the zero-tolerance drinking and driving law on overall mortality rates due to road traffic accidents in Rio de Janeiro was not statistically significant. However, among cyclists and motorcyclists aged ≥60 years and among pedestrians of both sexes and aged ≥20 years, the effect of the zero-tolerance drinking and driving law was to decrease mortality due to road traffic accidents at a yearly rate.

Conclusion: There is evidence of reduced mortality rates due to road traffic accidents among cyclists and motorcyclists aged ≥60 years and among pedestrians of both sexes aged ≥20 years in the second major Brazilian capital 9 years after the zero-tolerance drinking and driving law was adopted.  相似文献   

77.
Located on the northeast Brazilian coast, Olinda is one of UNESCO’s World Heritage Sites, which is economically dependent on tourism, commerce, industry, and the informal economy. Despite its environmental and socioeconomic importance, the city of Olinda (understanding the coast as part of it) has suffered several environmental and human disturbances over the last decades. This work describes the environmental and social status of Olinda’s beaches and makes recommendations concerning the development of an Integrated Coastal Management Plan for this coastal zone of the Brazilian littoral. The methodology adopted in this study is based on field campaigns (social, physical, chemical, and biological data collection), local observations, and the collection of sea contention building project data from city hall. The results showed that along the seven studied beaches, the main problems were related to the: (i) building of coastal protections, (ii) inefficient sewage disposal systems, (iii) inefficient urban management, and (iv) natural events (equinoctial spring tides and precipitation/evaporation rates). Casa Caiada beach showed the best hydrologic conditions as a consequence of its morphology and it presents facilities that attract housing and recreation investments (by private and public sectors) valuing and improving local use conditions. The obtained data showed that the studied beaches need an urgent action plan to minimize the environmental degradation of Olinda’s littoral and to promote sustainable development of the local coastal environments.  相似文献   
78.
Atmospheric Hg transfer to the forest soil through litterfall was investigated in a primary rainforest at Ilha Grande (Southeast Brazil) from January to December 1997. Litter mass deposition reached 10.0 t ha−1 y−1, with leaves composing 50–84% of the total litter mass. Concentrations of Hg in the total fallen litter varied from 20 to 244 ng g−1, with higher concentrations during the dry season, between June and August (225 ± 17 ng g−1), and lower concentrations during the rainy season (99 ± 54 ng g−1). This seasonal variability was reflected in the Hg flux through litterfall, which corresponded to a Hg input to the forest floor of 122 μg m−2 y−1, with average Hg deposition of 16.5 ± 1.5 μg m−2 month−1 during and just after the dry season (June–September) and 7.0 ± 3.6 μg m−2 month−1 in the rest of the year. The variability in meteorological conditions (determining atmospheric Hg availability to foliar scavenging) may explain the pulsed pattern of Hg deposition, since litterfall temporal variability was generally unrelated with such deposition, except by a peak in litterfall production in September. Comparisons with regional data on Hg atmospheric deposition show that litterfall promotes Hg deposition at Ilha Grande two to three orders of magnitude higher than open rainfall deposition in non-industrialized areas and approximately two times higher than open rainfall deposition in industrialized areas in Rio de Janeiro State. The observed input suggests that atmospheric Hg transfer through litterfall may explain a larger fraction of the total Hg input to forest soils in Southeast Brazil than those recorded at higher latitudes.  相似文献   
79.
ABSTRACT

Although Brazilian Quilombolas possess specific land rights referring to their past as African slaves, the realization of such rights often fails due to the absence of land surveys, clarified institutional competencies and the general lack of power under which minorities suffer. Additional factors such as an expanding commercial agriculture contributing to land and water degradation and new actors introducing new logics intransparent to traditional populations often aggravate the situation. In order to identify options for traditional populations to overcome a development-deadlock typical for peripheral regions, the case of a Quilombo in Pará/Brazil will be analysed that has been struggling since decades with conflicting land tenure legislations and institutions. Starting from an inter- and transdisciplinary qualitative research process, scenario building by backcasting can represent an innovative approach to organize the central conflicts which have to be solved in order to overcome the development deadlock of the Quilombo Vila Formosa in Pará.  相似文献   
80.
The Cerrado is one of the most threatened biomes in South America. To create protection actions on any scale, understanding drivers and consequences of land cover and land use (LC and LU) is essential. This study defines the composition and configuration of a Cerrado landscape watershed from 1975 to 2011. Using Landsat images and socioeconomic census data, we determined the forces acting on LC and LU change processes and their consequences. LC classes differ from LU classes for landscape dominance and processes. Economic opportunities drove LU change and its spatial distribution was related to soil, streams, and roads. Deforestation was the main cause of forest loss but forest degradation was also important, with both presenting different patterns. The spatial distribution of bare soil was related to pasture in degradation and streams. Bare soil distribution was related to pasture in degradation and streams. We concluded that broad scale factors drove changes, but local features determined distribution, and that watershed conservation plans should act on different scales, with management being spatially explicit.  相似文献   
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