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501.
The Windsor, Ontario Exposure Assessment Study evaluated the contribution of ambient air pollutants to personal and indoor exposures of adults and asthmatic children living in Windsor, Ontario, Canada. In addition, the role of personal, indoor, and outdoor air pollution exposures upon asthmatic children's respiratory health was assessed. Several active and passive sampling methods were applied, or adapted, for personal, indoor, and outdoor residential monitoring of nitrogen dioxide, volatile organic compounds, particulate matter (PM; PM < or = 2.5 microm [PM2.5] and < or = 10 microm [PM10] in aerodynamic diameter), elemental carbon, ultrafine particles, ozone, air exchange rates, allergens in settled dust, and particulate-associated metals. Participants completed five consecutive days of monitoring during the winter and summer of 2005 and 2006. During 2006, in addition to undertaking the air pollution measurements, asthmatic children completed respiratory health measurements (including peak flow meter tests and exhaled breath condensate) and tracked respiratory symptoms in a diary. Extensive quality assurance and quality control steps were implemented, including the collocation of instruments at the National Air Pollution Surveillance site operated by Environment Canada and at the Michigan Department of Environmental Quality site in Allen Park, Detroit, MI. During field sampling, duplicate and blank samples were also completed and these data are reported. In total, 50 adults and 51 asthmatic children were recruited to participate, resulting in 922 participant days of data. When comparing the methods used in the study with standard reference methods, field blanks were low and bias was acceptable, with most methods being within 20% of reference methods. Duplicates were typically within less than 10% of each other, indicating that study results can be used with confidence. This paper covers study design, recruitment, methodology, time activity diary, surveys, and quality assurance and control results for the different methods used.  相似文献   
502.
Bisphenol A (BPA; 4-[2-(4-hydroxyphenyl)propan-2-yl]phenol) is a substance typically used in the plastic industry. It is used in the production of epoxy resins, polycarbonate, or fire retardants or as a stabilizer and an antioxidant in numerous types of plastics. Bisphenol A is introduced into the environment via municipal and industrial wastewater. Because of its hydrophobic properties, BPA has the potential for sorption on activated sludge during the biological wastewater treatment processes. This study investigated the degradation of BPA by means of UV-radiation and in the UV/H2O2 process with the presence and absence of hydrocarbonate ions (HCO3(-)) as hydroxyl radicals (OH*) scavengers. The calculated value of quantum yield was equal to 0.18, and the value of BPA rate constant with hydroxyl radicals was equal to 3.3 x 10(9) M(-1) s(-1).  相似文献   
503.
Environmental Science and Pollution Research - In 2008, the Mulberry River, a National Wild and Scenic River, was listed as impaired due to low pH (below pH&nbsp;6.0). Over the last...  相似文献   
504.
Energy saving is becoming a rising priority as a response to climate change and fossil fuel depletion in recent years. However, despite energy-related behaviour change being an important part of many environmental education initiatives, “energy literacy” among citizens remains patchy in both the USA and the UK, with evidence of strong positive attitudes but less consistent knowledge. Whilst it is clear that increasing knowledge does not automatically produce behaviour changes, potential questions must be asked about the logic of focusing solely on behaviour without simultaneously exploring and enhancing understanding of energy issues. This research, undertaken at a higher education institution with a strong focus on sustainability, illustrates the potential risks of targeting behaviour change and individual action at the expense of increasing knowledge, or encouraging collaborative and democratic endeavours. Results from an online survey indicate widespread misconceptions about energy which may reduce the effectiveness of energy-saving behaviours, alongside variable levels of motivation and engagement with energy issues. Respondents report a strong belief in the efficacy of personal changes, yet uncertainty about their capacity to influence business and government alongside a persistent faith in science to provide solutions to energy issues. The paper concludes by reflecting on the challenges arising from these findings for understanding agency and effectiveness in energy relationships.  相似文献   
505.
This article presents a methodology to calculate the social cost of sustainability metrics with environmental footprint evaluation tools. Measuring the impacts of a remediation project on society is challenging because the methods by which these impacts can be measured have not been established. To perform a complete sustainability assessment of a project's life cycle, costs borne by society in terms of environmental, economic, and community impacts must be evaluated. Two knowledge gaps have been identified among the sustainability assessments currently being performed during a remediation project's life cycle: (1) lack of methodologies available to evaluate impacts on the socioeconomic aspects of remediation and (2) lack of sustainability assessments conducted during the site characterization stage. Sustainability assessments were conducted on two case studies using the methodology proposed in this article: one during the site characterization stage and the other during remedial action. The results of this study demonstrated that costs borne by society from a remediation project are significant and metric specific. This study also highlighted the benefits of conducting a sustainability assessment at the site characterization stage using environmental footprint analysis tools, cost benefit analysis, and an evaluation of costs borne by society. © 2013 Wiley Periodicals, Inc.  相似文献   
506.
Miller PA  Smith B 《Ambio》2012,41(Z3):281-291
The Arctic land area has warmed by > 1 °C in the last 30 years and there is evidence that this has led to increased productivity and stature of tundra vegetation and reduced albedo, effecting a positive (amplifying) feedback to climate warming. We applied an individual-based dynamic vegetation model over the Arctic forced by observed climate and atmospheric CO(2) for 1980-2006. Averaged over the study area, the model simulated increases in primary production and leaf area index, and an increasing representation of shrubs and trees in vegetation. The main underlying mechanism was a warming-driven increase in growing season length, enhancing the production of shrubs and trees to the detriment of shaded ground-level vegetation. The simulated vegetation changes were estimated to correspond to a 1.75 % decline in snow-season albedo. Implications for modelling future climate impacts on Arctic ecosystems and for the incorporation of biogeophysical feedback mechanisms in Arctic system models are discussed.  相似文献   
507.
In response to concerns regarding the health of streams and receiving waters, the United States Environmental Protection Agency established a total maximum daily load for nitrogen in the Chesapeake Bay watershed for which practices must be in place by 2025 resulting in an expected 25% reduction in load from 2009 levels. The response of total nitrogen (TN) loads delivered to the Bay to nine source reduction and land use change scenarios was estimated using a Spatially Referenced Regression on Watershed Attributes model. The largest predicted reduction in TN load delivered to the Bay was associated with a scenario in which the mass of TN as fertilizer applied to agricultural lands was decreased. A 25% decrease in the mass of TN applied as fertilizer resulted in a predicted reduction in TN loading to the Bay of 11.3%, which was 2.5–5 times greater than the reductions predicted by other scenarios. Eliminating fertilizer application to all agricultural land in the watershed resulted in a predicted reduction in TN load to the Bay of 45%. It was estimated that an approximate 25% reduction in TN loading to the Bay could be achieved by eliminating fertilizer applied to the 7% of subwatersheds contributing the greatest fertilizer‐sourced TN loads to the Bay. These results indicate that management strategies aimed at decreasing loading from a small number of subwatersheds may be effective for reducing TN loads to the Bay, and similar analyses are possible in other watersheds.  相似文献   
508.
To assess the impacts of the decline in sulphur (S) deposition over the past 20 years in Ontario, soil chemistry and sugar maple (Acer saccharum Marsh) foliar chemistry were measured at 17 sites in south and central Ontario in 2005 and compared with archived samples collected in 1986. Foliar S concentrations were lower in 2005, reflecting the decline in S deposition whereas foliar N remained unchanged, reflecting the lack of change in N deposition in Ontario. Mineral soil pH, exchangeable base cations were lower in 2005 whereas total S, N and cation exchange capacity (CEC) were unchanged. Foliar concentrations of Ca were positively related to soil Ca levels in the A-horizon and were lower in 2005. Despite evidence of increasing soil acidity and losses of calcium, foliar base cation concentrations at most sites were adequate for sugar maple and forest health in terms of canopy appearance (Decline Index) improved.  相似文献   
509.
下辽河平原多熟种植农业生态模式知识库研建   总被引:1,自引:0,他引:1  
本文以下辽河平原为背景,应用专家系统开发工具建立了多熟种植农业生态模式知识库,提出了建立该专家系统知识库的步骤:包括知识获取、知识表达、编码及证实。该专家系统知识库的建立能将有关多熟种植领域的专门知识和领域专家的经验以可接受的方式传递给农业决策者,从而提高农业决策的自动化和科学化。  相似文献   
510.
In addition to the loss of human life, the tsunami event of 26 December 2004 caused extensive damage to coastal areas. The scale of the disaster was such that remote sensing may be the only way to determine its effects on the landscape. This paper presents the results of a neural network-based mapping of part of the region of Aceh, Sumatra. Before-and-after satellite imagery, combined with a novel neural network methodology, enabled a characterisation of landscape change. The neural network technique used a threshold of acceptance for identification, in combination with a bootstrapped identification method for identifying problem pixels. Map analysis allowed identification of urban areas that were inaccessible by road, and which aid agencies could therefore only reach by air or sea. The methods used provide a rapid and effective mapping ability and would be a useful tool for aid agencies, insurance underwriters and environmental monitoring.  相似文献   
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