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441.
The current study represents the first investigation of the suitability of wolf hair as indicator tissue for metal exposure and accumulation within NW Spanish ecosystems. Dead animals, which were not specifically killed for these purposes, were necropsied, and further toxicological analyses were performed in order to establish the heavy metal content (Pb, Cd, and Zn) in liver, kidney, and hair, by means of inductively coupled plasma optical emission spectrometry. Two different factors, gender and age, were considered in order to determine their influence on heavy metal accumulation. Mean liver, kidney and hair concentrations of both toxic element, Cd (0.528, 2.692, and 0.026 ppm) and Pb (4.108, 0.031, and 0.196 ppm) considered on a dry weight basis, were situated below the established as acute toxicity levels for mammals. The highest concentrations were quantified for Zn, with means ranging from a maximum in hair samples (150.9 ppm) to a minimum in kidney samples (25.81 ppm). When the variable of gender and age were considered, female and adult wolves had higher concentrations of Cd in all the considered organs, although differences were only statistically significant for kidney. Neither the sex nor the age had a significant effect on Pb and Zn concentrations. A significant positive correlation (p?<?0.05) was identified between hair and liver Pb concentrations, as well as between hair and kidney Cd concentrations, thus suggesting the interest of the noninvasive sample for future ecotoxicological biomonitoring studies.  相似文献   
442.
443.
This paper theorizes how and why safety climate can be conceived as both a leading and a lagging indicator of safety events (i.e., accidents, injuries). When safety climate is conceived as a leading indicator, a prospective design is utilized and safety climate data are correlated with accidents/injuries that occur in the future. When safety climate is conceived as a lagging indicator, retrospective designs are used in which safety climate data are correlated with prior accidents/injuries. We examine the research literature to reveal that safety climate has been investigated as both a leading and a lagging indicator, but it is usually only examined as one or the other within a given study and has been examined as a lagging indicator most frequently. Consistent with our theorizing, prospective designs yield stronger relationships than retrospective designs, suggesting that safety climate is a better leading indicator than lagging indicator; however, it is clearly both. Implications for safety climate research and study design are discussed.  相似文献   
444.
The Environmental Laboratories Automation Software System or PALMA (Spanish abbreviation) was developed by a multidisciplinary team in order to support the main tasks of heterogeneous air quality control networks. The software process for PALMA development, which can be perfectly applied to similar multidisciplinary projects, was (a) well-defined, (b) arranged between environmental technicians and informatics, (c) based on quality guides, and (d) clearly user-centred. Moreover, it introduces some interesting advantages with regard to the classical step-by-step approaches. PALMA is a web-based system that allows 'off-line' and automated telematic data acquisition from distributed inmission stations belonging not only to homogeneous but also to heterogeneous air quality control networks. It provides graphic and tabular representations for a comprehensive and centralised analysis of acquired data, and considers the daily work that is associated with such networks: validation of the acquired data, alerts with regard to (periodical) tasks (e.g., analysers verification), downloading of files with environmental information (e.g., dust forecasts), etc. The implantation of PALMA has provided qualitative and quantitative improvements in the work performed by the people in charge of the considered control network.  相似文献   
445.
A solid phase extraction and gas chromatography with negative chemical ionization mass spectrometry in scan mode (GC-NCI-MS) method was developed to identify and quantify for the first time low levels of organochlorine pesticides (OCs) in plasma samples of less than 100 microl from wild birds. The method detection limits ranged from 0.012 to 0.102 pg/microl and the method reporting limit from 0.036 to 0.307 pg/microl for alpha, gamma, beta and delta-hexachlorocyclohexane (HCH), heptachlor, aldrin, heptachlor epoxide, endosulfan I, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE), dieldrin, endrin, endosulfan-II, endrin-aldehyde and endosulfan-sulfate. Pesticide levels in small serum samples from individual Falco sparverius, Sturnella neglecta, Mimus polyglottos and Columbina passerina were quantified. Concentrations ranged from not detected (n/d) to 204.9 pg/microl for some OC pesticides. All levels in the food web in and around cultivated areas showed the presence of pesticides notwithstanding the small areas for agriculture existing in the desert of Baja California peninsula.  相似文献   
446.
One of the most significant environmental problems arising from landfills is the emission of methane into the atmosphere. In this study, methane emissions from a currently in-use Spanish landfill were modeled as well as being experimentally measured using a two-step method. The first step involved a qualitative walkover survey to detect where gases were being emitted on the surface of the landfill. The second stage comprised a quantitative analysis of these surface methane emissions at a selected number of points on the landfill surface using a specially designed flux chamber. The statistical analysis of the data obtained was based on the Sichel function and resulted in an average emission rate of 74.9 g·m?2·day?1, with 27.8 and 202.1 g·m?2·day?1 as the lower and upper limits of the 95% confidence interval, respectively. The total emission for the landfill, with an emitting surface of 335,000 m2, is 9.16 × 103 ton/yr. These values have been compared with those from three different models, with the model results being above the calculated mean emissions measured at the landfill, but below the upper confidence limit at 95%.

Implications: One of the main environmental problems arising from the presence of landfills is the emission of biogas (which mainly contains methane and carbon dioxide) into the atmosphere. Several experimental methods as well as models have been developed to quantify these emissions. In this work, the authors have compared the results obtained using experimental measurements with those provided by some local and international models using the default parameters proposed. The results obtained from the experimental method are in accordance with those provided by the models, although the models could be slightly overestimating these emissions.  相似文献   

447.
Mercury is responsible for serious episodes of environmental pollution throughout the world, especially in the Amazon. This toxicity has led regulatory agencies to focus on fish as the target organism for protecting the health of humans and other sensitive organisms. Unfortunately, in the Amazon area, different sampling strategies and the wide variety of sampling areas and fish species make it extremely difficult to determine relationships across geographic regions or over time to ascertain historical trends. Thus, the aim of this work was to achieve three main objectives: a comparative study of mercury contamination in fish of Itaituba (Tapajós, located downstream of the largest gold-mining region in Amazon) and Belém (an area non-exposed to mercury pollution of anthropogenic origin), perform an analysis of inorganic mercury (IHg) versus monomethylmercury (MeHg) contents, and, finally, compare mercury contamination in Tapajós over time. Five piscivorous species were obtained in Itaituba and Belém. Also, four non-piscivorous species were collected in Itaituba. For the first time, mercury speciation showed that (1) current MeHg levels in piscivorous species in Tapajós are higher than those of the non-exposed area, (2) piscivorous species from Itaituba (dourada, filhote, and sarda) contained mercury levels above the World Health Organization safety limit (~17 %) and/or above the US Environmental Protection Agency tissue residue criterion (40 %), (3) increased MeHg is usually accompanied by increased IHg, and (4) the mean total mercury concentrations for piscivorous species in Itaituba were within the same range and, associated uncertainties as those previously reported, although a remarkable decreasing trend over time was observed for mean total Hg concentrations in non-piscivorous species from Itaituba. The present study supports the importance of continuous monitoring of both populations in the Amazon Rivers. Our results will better assist the development of preventive strategies and governmental actions to confront the problem of mercury contamination in the Amazon.  相似文献   
448.
The strategy for decreasing volatile organic compound emissions in Mexico has been focused much more on tailpipe emissions than on evaporative emissions, so there is very little information on the contribution of evaporative emissions to the total volatile organic compound inventory. We examined the magnitudes of exhaust and evaporative volatile organic compound emissions, and the species emitted, in a representative fleet of light-duty gasoline vehicles in the Metropolitan Area of Mexico City. The US “FTP-75” test protocol was used to estimate volatile organic compound emissions associated with diurnal evaporative losses, and when the engine is started and a journey begins. The amount and nature of the volatile organic compounds emitted under these conditions have not previously been accounted in the official inventory of the area. Evaporative emissions from light-duty vehicles in the Metropolitan Area of Mexico City were estimated to be 39 % of the total annual amount of hydrocarbons emitted. Vehicles built before 1992 (16 % of the fleet) were found to be responsible for 43 % of the total hydrocarbon emissions from exhausts and 31 % of the evaporative emissions of organic compounds. The relatively high amounts of volatile organic compounds emitted from older vehicles found in this study show that strong emission controls need to be implemented in order to decrease the contribution of evaporative emissions of this fraction of the fleet.  相似文献   
449.
Anecdotal evidence suggests that socioeconomic shocks strongly affect wildlife populations, but quantitative evidence is sparse. The collapse of socialism in Russia in 1991 caused a major socioeconomic shock, including a sharp increase in poverty. We analyzed population trends of 8 large mammals in Russia from 1981 to 2010 (i.e., before and after the collapse). We hypothesized that the collapse would first cause population declines, primarily due to overexploitation, and then population increases due to adaptation of wildlife to new environments following the collapse. The long‐term Database of the Russian Federal Agency of Game Mammal Monitoring, consisting of up to 50,000 transects that are monitored annually, provided an exceptional data set for investigating these population trends. Three species showed strong declines in population growth rates in the decade following the collapse, while grey wolf (Canis lupus) increased by more than 150%. After 2000 some trends reversed. For example, roe deer (Capreolus spp.) abundance in 2010 was the highest of any period in our study. Likely reasons for the population declines in the 1990s include poaching and the erosion of wildlife protection enforcement. The rapid increase of the grey wolf populations is likely due to the cessation of governmental population control. In general, the widespread declines in wildlife populations after the collapse of the Soviet Union highlight the magnitude of the effects that socioeconomic shocks can have on wildlife populations and the possible need for special conservation efforts during such times. Declinación Rápida de las Poblaciones de Mamíferos Mayores después del Colapso de la Unión Soviética  相似文献   
450.
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, a species extinction risk assessment tool, has been guiding conservation efforts for over 5 decades. It is widely assumed to have been instrumental in preventing species from moving closer to extinction and driving recoveries. However, the impact of the IUCN Red List in guiding conservation has not been evaluated. We conducted, transcribed, and coded interviews with experts who use the IUCN Red List across a range of sectors to understand how the list is used in conservation. We developed a theory of change to illustrate how and why change is expected to occur along causal pathways contributing to the long-term goal of the IUCN Red List and an evaluation framework with indicators for measuring the impact of the IUCN Red List in generating scientific knowledge, raising awareness among stakeholders, designating priority conservation sites, allocating funding and resources, influencing development of legislation and policy, and guiding targeted conservation action (key themes). Red-list assessments were the primary input leading to outputs (scientific knowledge, raised awareness), outcomes (better informed priority setting, access to funding and resource availability, improved legislation and policy), and impact (implemented conservation action leading to positive change) that have resulted in achievement of IUCN Red List goals. To explore feasibility of attributing the difference made by the IUCN Red List across themes, we studied increased scientific knowledge, raised awareness, access to funding and resource allocation, and increased conservation activity. The feasibility exploration showed increased scientific knowledge over time identified through positive trends in publications referring to the IUCN Red List in the literature; raised awareness of the list following high IUCN activity identified by peaks in online search activity; an increased proportion of conservation funding bodies requesting IUCN Red List status in the application process; and, based on interviews with Amphibian Specialist Group members, red-list assessments were essential in connecting relevant stakeholders and ensuring conservation action. Although we identified the IUCN Red List as a vital tool in global conservation efforts, it was challenging to measure specific impacts because of its ubiquitous nature. We are the first to identify the influence of the IUCN Red List on conservation.  相似文献   
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