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171.
Due to increasing atmospheric concentrations of participates, five of Allegheny County’s seven monitoring areas were placed on first stage air pollution alert by November 18,1975. The Liberty Borough area reached second stage alert, and then emergency stage the morning of November 19. An investigation was mounted to determine whether these emergency levels of par-ticulates had an effect upon the pulmonary function of school children sufficiently severe that it would require several days for pulmonary function to return to normal. Beginning November 20 in two schools and November 21 in four additional schools, the three-quarter second forced expiratory volume (FEV.75) and the forced vital capacity (FVC) of approximately 270 parochial school children in fourth, fifth, and sixth grades were tested daily through November 26. Two schools, approximately 80 children, were in control areas; the remaining children were exposed to high or very high levels of particulate air pollution with significant levels of sulfur oxides. If a severe effect of pollution on pulmonary function occurred, one would expect daily measurements to tend upward in children in the four schools in polluted areas and to remain more or less steady in the two control areas. Analyses of the data yielded no indications of such an effect of air pollution upon the lung function of the school children studied. Pulmonary function values declined very slightly in all six schools over the study period. Unexplained variability over a weekend was observed.  相似文献   
172.
The information presented in this paper is concerned with the effects of ambient ozone on crop yield reduction and the resultant economic losses. Yield data for nine crops within the South Coast Air Basin (SCAB) of California were obtained for the 12-year period, 1964 through 1975. Ozone concentrations, temperature, precipitation, and relative humidity data were related to the yields by using regression models. Estimated yield reductions due to ozone for 1975, varied from zero to 57% depending on crop and location. Economic welfare losses calculated from the yield reductions were $57.3 and $45.7 million for producer’s and consumer’s surplus, respectively. The total loss from ozone to agriculture related economic sectors determined by input-output analysis was $276 million in the SCAB and $36.6 million in the remainder of the state.  相似文献   
173.
With the intent of improving agricultural revenues and solidifying her place as an ecotourism destination, it has been proposed that the island nation of The Commonwealth of Dominica convert all agriculture to organic production. This study explores Dominica’s current and potential domestic demand for organic and/or “locally grown” produce. Surveys were conducted with Dominican consumers to assess their opinions and willingness to pay for these products, and evaluated using a maximum likelihood estimation procedure. On average, Dominican consumers are willing to pay 17.5 % more for organic, and 12 % more for locally grown, produce. These results were varied significantly across demographic segments of the sampled population, respondent tastes and preferences, the health status of their family, and the extent to which they were early adopters of new products. Despite several expected challenges of a successful transition to organic, implementation of this policy may offer a net positive welfare increase for Dominica’s permanent residents. Results from this analysis suggest that, from the perspective of domestic consumers, Dominica should continue to pursue the possibility of becoming an “Organic Island.”  相似文献   
174.
175.
This article reconsiders the challenge of environmental communication by inquiring into the fundamental rhetorical difficulty of thinking in terms of ecology. We discuss two essential yet bewildering aspects of ecology: its focus on interconnection and its use of multiple scales. On this basis, we distil six rhetorical recommendations: a shift from appealing to pre-existing values to avenues for transforming values; a shift from arguments from authority to addressing legitimate resistances; a shift from a focus on mutual agreement to a mutual bewilderment; a shift from intellectual comprehension to personal experience; a shift from negative effects to positive connections; and, finally, a shift from a focus on political results to local transformations. We experiment with this rhetorical approach through two applications: for critical reassessments of past articulations we consider the Gaia Hypothesis and Deep Ecology, and for current refinements to environmental problems we consider controversies around Marcellus Shale gas development  相似文献   
176.
A typical onsite wastewater treatment system consists of a septic tank and a soil treatment unit to treat wastewater before it is discharged through the vadose zone to an aquifer. A tool was developed for the purpose of predicting the fate and transport of nitrogen in soil treatment units (STUMOD or Soil Treatment Unit Model). STUMOD calculates nitrogen species concentrations and the fraction of total nitrogen reaching the aquifer or a specified soil depth. Input data include parameters for hydraulics and nutrient transport and transformation. An analytical solution is used to calculate the profile of pressure based on Darcy’s equation and the relationships between suction head, unsaturated hydraulic conductivity, and soil moisture. Chemical transport is based on simplification of the advection–dispersion equation. STUMOD is relatively simple to use but accounts for important processes such as ammonium sorption, nitrification, and denitrification. STUMOD accounts for the effect of soil moisture content (a surrogate for redox conditions) on nitrification and denitrification reactions. The model has provisions to handle the influence of temperature and organic carbon content on nitrogen transformation. Model outputs, generated based on input parameters obtained from extensive literature review, were compared to a numerical model and data from laboratory tests and field sites. Both measured data and STUMOD outputs show a relatively higher removal in clayey soils compared to sandy soils. Consistent with literature data for most soils, STUMOD predicted ammonium conversion to nitrate within the first foot below the trench infiltrative surface.  相似文献   
177.
The terrestrial chapter of the Circumpolar Biodiversity Monitoring Programme (CBMP) has the potential to bring international multi-taxon, long-term monitoring together, but detailed fundamental species information for Arctic arthropods lags far behind that for vertebrates and plants. In this paper, we demonstrate this major challenge to the CBMP by focussing on spiders (Order: Araneae) as an example group. We collate available circumpolar data on the distribution of spiders and highlight the current monitoring opportunities and identify the key knowledge gaps to address before monitoring can become efficient. We found spider data to be more complete than data for other taxa, but still variable in quality and availability between Arctic regions, highlighting the need for greater international co-operation for baseline studies and data sharing. There is also a dearth of long-term datasets for spiders and other arthropod groups from which to assess status and trends of biodiversity. Therefore, baseline studies should be conducted at all monitoring stations and we make recommendations for the development of the CBMP in relation to terrestrial arthropods more generally.  相似文献   
178.
Three studies used digital color photographs to compare responses to natural scenes, skylines after dark, and skylines during the day (seven of each). Study 1 had 59 respondents rate the pleasantness of each scene. They gave similar ratings to Night Skylines and Natural Scenes, and rated each as more pleasant than the Day Skylines. Study 2 had 56 other participants choose from each of seven sets of each kind of scene the one they would most like to have as a framed print in their home or office, and to report the reasons. Participants chose Night Skylines most often, followed by Natural Scenes and then Day Skylines. While participants most often picked attractive as a reason for their choice, those who chose Night Skylines also picked exciting as the reason, and those who picked Natural Scenes also picked relaxing or peaceful as a reason. Study 3 obtained ratings of selected formal features of each scene. The 23 judges rated the Natural scenes as more natural, orderly, open, and curvilinear, less complex, and as having smoother transitions than either Day or Night Skylines; and they judged the Night Skylines as higher in complexity but lower in order than Day Skylines. The results suggest that preferences in relation to the scene categories may well depend on a mix of their formal characteristics and their content.  相似文献   
179.
The aim of this study was to explore the relationship between pro-environmental behaviour and two forms of emotional association: attachment to place and connectedness to nature. This relationship is explored in the context of farmers' management of native vegetation on their properties. A postal survey was conducted to measure the extent to which farmers felt connected to nature and to their property. The survey also measured vegetation management behaviours and associated valued outcomes. A total of 141 farmers in northwest Victoria, Australia, completed the survey. Results showed that vegetation protection behaviours increased with connectedness to nature (CNS), although CNS accounted for only a modest amount of the variation in behaviour. Place attachment was not related to management behaviours. Further analysis suggested that the relationship between CNS and management behaviour was mediated by importance given to environmental benefits of vegetation management. The findings lend weight to studies showing a relationship between CNS and more simple conservation behaviours (e.g. recycling). The findings are also consistent with frameworks suggesting that emotional association with nature leads to an expanded sense of self and greater valuing of non-human species, and so to pro-environment behaviour. This demonstrates the importance of using a range of instrumental and more affective strategies to promote conservation behaviours.  相似文献   
180.
Alkyl nitrates (C1–C5) were measured at two sites (near urban and rural) in southeast England during the Tropospheric Organic Chemistry Experiment (TORCH). Methyl nitrate was the dominant species during both campaigns accounting for on average about one third of the total measured alkyl nitrates. High mixing ratios (>50 pptv) and variability of methyl nitrate were observed at the near urban site (TORCH1) that were not seen at the rural site (TORCH2) and which could not be explained by local photochemical production or direct emissions. The diurnal variation of methyl nitrate during TORCH1 showed a morning maximum that would be consistent with nighttime chemistry followed by transport to the surface by boundary layer dynamics. Similarly, elevated morning mixing ratios were also observed during TORCH2 although the magnitudes were much smaller. As a result, methyl nitrate could represent a tracer for nighttime chemistry seen at the ground the following day. At both campaigns, the dominant source of short chain alkyl nitrates and carbonyl precursor radicals (≤C4) were from decomposition of larger compounds. The magnitude of the source increased with decreasing carbon number consistent with increasing total precursor abundance. Non-photochemical emissions of acetaldehyde and acetone could not be accounted for by automobile exhaust emissions alone and indicated that other direct sources are likely important in this environment.  相似文献   
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