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291.
A comprehensive monitoring campaign to assess aldehydes and BTEX concentrations was performed during 12 months, in the Tijuca district (Rio de Janeiro), an area with commercial activities and a high flux of vehicles. The mean concentrations of formaldehyde and acetaldehyde were 151 and 30 ppb, respectively. The high formaldehyde/acetaldehyde ratio was attributed to extensive use of compressed natural gas (CNG). The number of CNG vehicles in the metropolitan Region of Rio de Janeiro increased from 23000 in January 2001 to 161000 in January 2005. Monitoring data show that, for the same period, methane and formaldehyde concentrations increased while NO(x) and CO levels diminished. Mean concentrations for benzene, toluene, ethylbenzene, m,p-xylene and o-xylene, were 1.1, 4.8, 3.6, 10.4 and 3.0 micro gm(-3), respectively. Benzene and toluene concentrations were lower than the values determined in 1996, for the same location. The levels of ethylbenzene and xylenes determined in this work are similar to values obtained in 1996. This fact may be explained as a consequence of changes in the gasoline composition.  相似文献   
292.
We have developed a small, light, passive, inexpensive, datalogging particle monitor called the "UCB" (University of California Berkeley particle monitor). Following previously published laboratory assessments, we present here results of tests of its performance in field settings at high particle concentrations. We demonstrate the mass sensitivity of the UCB in relation to gravimetric filter-based PM(2.5) mass estimates as well as commercial light-scattering instruments co-located in field chamber tests and in kitchens of wood-burning households. The coefficient of variation of the unadjusted UCB mass response in relation to gravimetric estimates was 15%. Although requiring adjustment for differences in sensitivity, inter-monitor performance was consistently high (r(2) > 0.99). Moreover, the UCB can consistently estimate PM(2.5) mass concentrations in wood-burning kitchens (Pearson r(2) = 0.89; N = 99), with good agreement between duplicate measures (Pearson r(2) = 0.94; N = 88). In addition, with appropriate cleaning of the sensing chamber, UCB mass sensitivity does not decrease with time when used intensively in open woodfire kitchens, demonstrating the significant potential of this monitor.  相似文献   
293.
The objective of this work was to determine the dissipation of fenoxycarb and pyriproxyfen in fresh and canned peaches in order to know the levels of residues that can reach consumers in real circumstances. Two field dissipation studies were carried out, one of them at the pre-harvest interval (PHI) with good agricultural practice (GAP) and the other one in a situation of critical agricultural practice (CAP). Two canning dissipation studies were carried out for samples from both agricultural situations in an industrial pilot plant and the dissipation was determined in each relevant step. An analytical methodology was used including acetone-dichloromethane extraction, purification and analysis by liquid chromatography and diode array detection (LC-DAD) with a limit of quantification (LOQ) of 0.05 mg/kg. It was validated under SANCO/10232/2006 Guidelines. These pesticides complied with the official maximum residue limits (MRLs) in peaches at the PHI with good agricultural practices. In hypothetical situation of a second application at the PHI, fenoxycarb and pyriproxyfen residues were above the MRLs in peaches. The canning study reduced the residues to no detectable levels in the cans for consumers.  相似文献   
294.
Economic and financial aspects of mine closure   总被引:1,自引:0,他引:1  
Today, mine reclamation is a key component to a successful mine plan. Most of the industrialized nations have recognized the need to make mining activities relatively environmentally friendly, if they want to continue to benefit from the economic gains from mineral resource development. Countries such as the United States, Canada, Australia and South Africa are leaders in the field and have implemented relatively sophisticated legislation to ensure environmentally correct mine closure. These countries rely on a combination of strict control strategies and economic penalties to ensure compliance. Yet, from the firm's perspective, reclamation activities are counterproductive as they cut into profits. In order to attract economic development and earn much needed economic capital, most of the rest of the world, particularly the developing countries, lack effective mine closure legislation. The traditional command and control type of legislation that is sometimes used is either vague and therefore avoided, or not enforced appropriately, resulting in an undesirable level of environmental degradation. With the use of case studies from Brazil, this article shows that direct controls are effective in some instances and not in others. It proposes that economic and financial tools may be more effective than the traditional direct controls in getting firms to comply with environmental standards, particularly in developing countries where environmental compliance is more difficult to achieve. It explains the use of performance bonding as one type of economic incentive that has proven to be an effective environmental policy in mine planning and closure. The authors additionally push beyond the typical style of performance bonds to introduce a flexible bonding and insurance system that allows governments to maintain strict environmental standards but limits firms financial exposure during the mining process. Such a system learns from the successes of the industrialized countries that use performance bonding and is sensitive to the needs of developing nations to attract investment yet maintain environmental integrity.  相似文献   
295.
In November 2002, the Prestige oil tanker was wrecked in front of Galician coast (NW of Spain), spilling near 63,000 tons of heavy oil until February 2003. Contamination produced was very extensive (70% of Galician beaches were reached by the oil) but heterogeneous, alternating intensely affected zones with neighbour locations where the repercussion was minimal. The objective of this study was to monitor sea environment contamination caused by Prestige oil spill during an 11-month period (August 2003-June 2004, nine samplings) in two locations of Galician coast with different geographical properties (Lira and Ancoradoiro beaches), by means of chemical determination of total polycyclic aromatic hydrocarbons (TPAH) in seawater, and using as exposure biomarker TPAH content in mussel (Mytilus galloprovincialis) tissues, and as effect biomarker DNA damage in mussel gills, evaluated by the comet assay. In addition, recovery ability of the mussels was determined after a 7-day stay in the laboratory. TPAH contents in seawater were very high in the earliest samplings, but then they maintained below 200 ng L(-)(1), similar to reference seawater. However, TPAH levels in mussel tissues were more variable: they increased again from January 2004, probably due to the adverse meteorological conditions that turned over the sea bottom and dispersed the oil accumulated in sediments. In most samplings, these levels decreased during the recovery stage. DNA damage in oil-exposed mussels was significantly higher than in reference mussels, both before and after the recovery phase, but they did not differ to one another. Comet tail length was slightly reduced during the recovery stage, indicative of a certain DNA repair in exposed mussels. This study showed up the importance of monitoring sea contamination events during an extended time, not only in evaluating the presence of the contaminants in the environment but also in determining their bioaccumulation and their effect on the exposed organisms.  相似文献   
296.
This work deals with an approach for the water quality restoration with emphasis on the removal of organochlorine pesticides and eutrophic conditions in tropical rivers, causing influence on the management of the central-regional aqueduct, as a source of water supply for human consumption (4 million people) and industrial production in the states of Carabobo, Cojedes and Aragua, Venezuela, testing the phytoremediation techniques through Vetiveria zizanioides (VZ) species and coupled bioreactors, Sequencing Batch Reactor (SBR) followed by an Upflow Anaerobic Filter in Three Separate Stages (UAF-3SS). Five rivers are involved known as Chirgua, Paito Guacara, Ereigüe, and Tucutunemo, whose waters have been classified as hypereutrophic, and containing organochlorine pesticides (OCPs). As a sample, for Tucutunemo River, OCPs included to DDT (dichlorodiphenyltrichloroethane) and its isomers and DRINs (Aldrin, Endrin and Dieldrin) dissolved in water and sorbed on sediments, which were measured during the dry and rainy seasons in the period 2013 to 2016, in three monitoring stations distributed in a reach of 15 km. The results indicated that p.p′-DDT concentration dissolved in water was increased up to 10 times from rainy to dry seasons, indicating that a permanent use of it is being carried out by farmers in the agricultural activity development. Steady concentrations of the DTT isomers (e.g., p.p′-DDD and p.p′-DDE) and Aldrin isomers (e.g., Dieldrin) demonstrated that the anaerobic and aerobic biodegradation processes occurred along the river and between climatic seasons. At experimental scale, VZ hydroponic system developed over a period of 6 months for the removal of nutrients demonstrated moderately low to high removal efficiencies. With respect coupled bioreactors, each bioreactor has been experimentally tested, demonstrating satisfactory performance in Chemical Oxygen Demand (COD) removal from industrial wastewater containing recalcitrant and inhibitory substances (46%–98%), which was estimated in the influent ranging from 3500 to 5500 mg/L, evidencing that coupling of bioreactors might lead to a effluent COD complying with environmental regulations.  相似文献   
297.
The successful implementation of the Convention on Biological Diversity's post-2020 Global Biodiversity Framework will rely on effective translation of targets from global to national level and increased engagement across diverse sectors of society. Species conservation targets require policy support measures that can be applied to a diversity of taxonomic groups, that link action targets to outcome goals, and that can be applied to both global and national data sets to account for national context, which the species threat abatement and restoration (STAR) metric does. To test the flexibility of STAR, we applied the metric to vascular plants listed on national red lists of Brazil, Norway, and South Africa. The STAR metric uses data on species’ extinction risk, distributions, and threats, which we obtained from national red lists to quantify the contribution that threat abatement and habitat restoration activities could make to reducing species’ extinction risk. Across all 3 countries, the greatest opportunity for reducing plant species’ extinction risk was from abating threats from agricultural activities, which could reduce species’ extinction risk by 54% in Norway, 36% in South Africa, and 29% in Brazil. Species extinction risk could be reduced by a further 21% in South Africa by abating threats from invasive species and by 21% in Brazil by abating threats from urban expansion. Even with different approaches to red-listing among countries, the STAR metric yielded informative results that identified where the greatest conservation gains could be made for species through threat-abatement and restoration activities. Quantifiably linking local taxonomic coverage and data collection to global processes with STAR would allow national target setting to align with global targets and enable state and nonstate actors to measure and report on their potential contributions to species conservation.  相似文献   
298.
The UN Decade of Ecosystem Restoration is poised to trigger the recovery of ecosystem services and transform structural injustices across the world in a way unparalleled in human history. The inclusion of diverse Indigenous and local communities to co-create robust native seed supply systems is the backbone to achieve the goals for the Decade. Here we show how community-based organizations have co-developed native seed supply strategies for landscape restoration from the bottom-up. We draw on the interconnections over two decades of seed networks in Brazil and the emerging Indigenous participation in native seed production in Australia. From an environmental justice perspective, we provide a participatory seed supply approach for local engagement, noting local geographical, social and cultural contexts. Meeting large-scale restoration goals requires the connection between local seed production and collaborative platforms to negotiate roles, rights and responsibilities between stakeholders. An enduring native seed supply must include a diversity of voices and autonomy of community groups that builds equitable participation in social, economic, and environmental benefits.  相似文献   
299.
A total of 32 samples of surficial soil were collected from 16 playground areas in Madrid (Spain), in order to investigate the importance of the geochemistry of the soil on subsequent bioaccessibility of trace elements. The in vitro bioaccessibility of As, Co, Cr, Cu, Ni, Pb and Zn was evaluated by means of two extraction processes that simulate the gastric environment and one that reproduces a gastric?+?intestinal digestion sequence. The results of the in vitro bioaccessibility were compared against aqua regia extractions (“total” concentration), and it was found that total concentrations of As, Cu, Pb and Zn were double those of bioaccessible values, whilst that of Cr was ten times higher. Whereas the results of the gastric?+?intestinal extraction were affected by a high uncertainty, both gastric methods offered very similar and consistent results, with bioaccessibilities following the order: As?=?Cu?=?Pb?=?Zn?>?Co?>?Ni?>?Cr, and ranging from 63 to 7?%. Selected soil properties including pH, organic matter, Fe and CaCO3 content were determined to assess their influence on trace element bioaccessibility, and it was found that Cu, Pb and Zn were predominantly bound to organic matter and, to a lesser extent, Fe oxides. The former fraction was readily accessible in the gastric solution, whereas Fe oxides seemed to recapture negatively charged chloride complexes of these elements in the gastric solution, lowering their bioaccessibility. The homogeneous pH of the playground soils included in the study does not influence trace element bioaccessibility to any significant extent except for Cr, where the very low gastric accessibility seems to be related to the strongly pH-dependent formation of complexes with organic matter. The results for As, which have been previously described and discussed in detail in Mingot et al. (Chemosphere 84: 1386–1391, 2011), indicate a high gastric bioaccessibility for this element as a consequence of its strong association with calcium carbonate and the ease with which these bonds are broken in the gastric solution. The calculation of risk assessments are therefore dependant on the methodology used and the specific environment they address. This has impacts on management strategies formulated to ensure that the most vulnerable of society, children, can live and play without adverse consequences to their health.  相似文献   
300.
Marine top predators are common at offshore bathymetric features such as islands, atolls, and seamounts, where most pelagic reef fish reside, while certain sharks perform inter-island movements between these formations. Scalloped hammerhead sharks are known to school in great numbers at small islands and seamounts in the eastern tropical Pacific (ETP) and are very susceptible to fisheries while moving into the open sea. It is, therefore, essential to understand hammerhead inter-island movements and environmental effects to provide baseline information for their conservation and management within and beyond an insular marine protected area. Movements of scalloped hammerheads were analyzed in the Galapagos Marine Reserve (GMR) and ETP, and environmental factors were linked to their movements. Hammerheads were tagged (N = 134) with V16 coded pingers (July 2006 to July 2010) in the northern Galapagos and detected at listening stations around four islands in the GMR and two isolated islands in the ETP, 700 and 1,200 km away. Hammerheads formed daytime schools at specific locations, but dispersed at night. Overall, more daytime than nighttime detections were recorded at all receivers in the northern Galapagos Islands, and more detections in the up-current sides of these islands. Hammerheads remained more days at the northern islands during part of the warm season (December–February) compared to the cool; however, fewer individuals were present in March–June. Movement modes were diel island excursions (24-h cycles) in the northern Galapagos and inter-island in the GMR and ETP at different scales: (1) short back-and-forth (<50 km, SBF), <5 days cycles, (2) medium distance (50–300 km, MDT), 5–20 days, and (3) long distance (>300 km, LDT), 15–52 days. The high degree of inter-island connectivity of hammerheads within the northern GMR is striking compared to the almost nil movement to the central GMR. A seasonal migratory pattern to locations offshore is indicated by (1) fewer hammerheads observed in the northern GMR during part of the warm season (March–June) and (2) evidence of LDT movements from the northern GMR to other islands in the ETP. LDT movements of mature female hammerheads are possibly associated with pupping areas. Our results indicate that currents, season, and individual behavior mainly drive inter-island movements of hammerheads at small (SBF) and medium (MDT) scales. These findings have important implications for the management of a highly mobile and endangered top predator within a marine protected area and beyond.  相似文献   
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