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41.
Different strategies of multivariate analysis of metals concentrations (Mn, Fe, Ni, V, Co, Cu, Cd, Hg, Pb, Na, K) in mussel samples from different spanish markets are used to interpret a data base and identify differences between species and origin of the samples. Principal Component Analysis and Potential curves are applied to properly classify unknown samples from representative mussels samples (Mytilus edulis and Perna canaliculus). Also, Principal Components Analysis is used as display method to visualize the relation between the variables and objects of interest.  相似文献   
42.
The focus of this study was to characterize the concentration levels of selected PCBs and compare them to compiled data in order to contribute to the international database. The sampling site is located in the outskirts of Madrid and can be considered an open urban area. 32 samples of air were taken from February 1998 to June 1998 by using a high volume air sampler. Glass fiber filters and polyurethane foam (PUF) were used to collect the paniculate and gas phase material, respectively. PUF plugs were Soxhlet extracted and filters were ultrasonically extracted by using pesticide-grade hexane and dichloromethane, respectively. The cleanup procedure was carried out on a florisil column with hexane and hexane/dichloromethane as elution solvents. GC/MS in a selected ion monitoring mode was used for quantification and 29 selected PCBs congeners were analyzed.  相似文献   
43.
Environment, Development and Sustainability - This paper estimates the genuine progress indicator (GPI) for the state of Rio de Janeiro (RJ), Brazil, from 2002 to 2016 as an alternative indicator...  相似文献   
44.
Agricultural fire for land preparation is central in the livelihoods of subsistence farmers practicing shifting cultivation. Achieving a good agricultural burn, one in which the biomass is thoroughly consumed within the chosen area, depends on specific weather conditions. Fire use decisions are also shaped by institutions that define the timing and rules for fire use but also constrain the alternatives and shape adaptive capacities. Global and regional climate changes interact with the institutional framing of fire management affecting local fire use and burn outcomes. These effects are documented and analyzed to suggest adaptations to existing governance systems. We examined subsistence farmers’ socio-ecological vulnerability in the Calakmul municipality, located in southeastern Mexico. Using interviews with farmers and government agents, as well as participatory mapping and observation of agricultural burns, we studied fire management knowledge, practices and burn outcomes. Our results describe a continuum of burn outcomes covering good agricultural burns, uncontrolled burns leading to wildfires and “malquemados” literally poorly burned areas. Malquemados represent unsuccessful combustion associated with excess moisture that results in scorched vegetation. We discuss how unexpected early rains trigger effects that cascade through space and the ecological, economic and cultural domains. We argue that fire management has been historically approached from a conservation standpoint yet agricultural fire use and wildfire prevention should also be addressed from a rural development perspective. This shift in fire management would lead to the proper inclusion of the entire array of burn outcomes in studies and policies addressing farmers’ vulnerability amplified by synergistic effects between climate variability and institutional change.  相似文献   
45.
Despite the often mentioned environmental benefits associated with transition from fossil fuels to renewable energy sources, their use for electricity production has non-negligible negative environmental impacts. The most commonly mentioned in surveys concern different types of landscape impacts, impacts on the fauna and flora, and noise. These impacts differ by size and location of plants, and by source of energy, rendering the policy decision complex. In addition, there are other welfare issues to take into consideration, as positive and negative environmental impacts are not evenly distributed among population groups. This paper proposes to compare the welfare impacts of renewable energy sources controlling for the type of renewable as well as the specific environmental impact by source. To this end, two discrete-choice experiments are designed and applied to a national sample of the Portuguese population. In one case, only individual negative impacts of renewables are used, and in another case, the negative impacts interact with a specific source. Results show the robustness of discrete-choice experiments as a method to estimate the welfare change induced by the impacts of renewable energy sources. Overall, respondents are willing to pay to reduce the environmental impacts, thus making compensation for local impacts feasible. Moreover, the estimations reveal that respondents are significantly sensitive to the detrimental environmental effects of specific renewable energy sources, being willing to pay more to use these sources of energy relative to others.  相似文献   
46.
Metal contamination of farming soils affected by industry   总被引:50,自引:0,他引:50  
The contents of nine elements (As, Cd, Cr, Cu, Hg, Ni, Pb, Sb and Zn) have been assayed in the farming soils of Suszec commune (southern Poland). This area is affected by the main industrial centre of Poland (the Upper Silesian Industrial Region), the Czech Republic (Trzyniec smelter) and local contamination sources (coal mine). The contamination of the soils was assessed on the basis of geoaccumulation index, enrichment factor, contamination factor and degree of contamination. The tests revealed elevated contents of cadmium, lead, arsenic, antimony and mercury. The contents of the other elements were similar to the levels in the Earth's crust or pointed to metal depletion in the soil (EF<1).  相似文献   
47.
The aim of the study was to compare radon concentrations in neighbouring hospital buildings which were constructed in different years during the period 1963-2000 and are located in areas with similar radon potential. The value of arithmetic mean (AM) radon concentration in soil gas amounted to 14,464 Bq m(-3). In a hospital built 40 years ago, the AM radon concentration in the cellar was 38.4+/-36.7 Bq m(-3) and on higher levels it was 17.1+/-10.3 Bq m(-3). In a hospital built 16 years ago, these values equaled 45.5+/-47.2 Bq m(-3) and 20.4+/-12.5 Bq m(-3), respectively. In the newest hospital, built three years ago, radon concentration (AM) in a cellar was 32.3+/-27.4 Bq m(-3) and the respective value on higher levels amounted to 20.4+/-12.6 Bq m(-3). When comparing radon concentrations in the cellars, no statistically significant differences were found. Similarly, no statistically significant differences were observed between radon concentrations measured on higher levels in investigated hospital buildings.  相似文献   
48.
The Almaraz nuclear power plant (Spain) uses the water of Arrocampo reservoir for cooling, and consequently raises the radioactive levels of the aquatic ecosystem of this reservoir. From July 2002 to June 2005, monthly samples of surface water, bulrushes (Typha latifolia) and carp (Cyprinus carpio) were collected from this reservoir. They were analyzed to determine the temporal evolution of the levels of 3H in surface water and of its transfer from the surface water to free-water in the tissues (TFWT) of the aforementioned two organisms. The tritium levels in the surface water oscillate with a biannual period, with their values in the study period ranging between 53 and 433 Bq/L. The incorporation of tritium to bulrushes and carp was fairly similar, the respective mean concentration factors being 0.74 and 0.8 (unitless, as Bq/L tissue water per Bq/L reservoir water). The temporal evolution of the levels fairly closely followed that observed for the surface water tritium, although detailed analysis showed the dominant periodicity for the bulrushes to be annual. This difference reflects the influence on the incorporation of tritium to bulrushes of diverse environmental and metabolic factors, especially evapotranspiration and the seasonal growth of this plant.  相似文献   
49.
New best estimates for the solid–liquid distribution coefficient (Kd) for a set of radionuclides are proposed, based on a selective data search and subsequent calculation of geometric means. The Kd best estimates are calculated for soils grouped according to the texture and organic matter content. For a limited number of radionuclides this is extended to consider soil cofactors affecting soil–radionuclide interaction, such as pH, organic matter content, and radionuclide chemical speciation. Correlations between main soil properties and radionuclide Kd are examined to complete the information derived from the best estimates with a rough prediction of Kd based on soil parameters. Although there are still gaps for many radionuclides, new data from recent studies improve the calculation of Kd best estimates for a number of radionuclides, such as selenium, antimony, and iodine.  相似文献   
50.
Environmental Science and Pollution Research - Mercury (Hg) is a great concern for marine environments. Bird feathers have been widely used to assess Hg pollution. In this study, we determine...  相似文献   
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