排序方式: 共有26条查询结果,搜索用时 15 毫秒
21.
P.M. Lemieux C.W. Lee J.V. Ryan 《Journal of the Air & Waste Management Association (1995)》2013,63(12):2129-2137
ABSTRACT Emissions of polychlorinated dibenzo-p-dioxins and poly-chlorinated dibenzofurans (PCDDs/Fs) from incinerators and other stationary combustion sources are of environmental concern because of the toxicity of certain PCDD/F congeners. Measurement of trace levels of PCDDs/Fs in combustor emissions is not a trivial matter. Development of one or more simple, easy-to-measure, reliable indicators of stack PCDD/F concentrations not only would enable incinerator operators to economically optimize system performance with respect to PCDD/F emissions, but could also provide a potential technique for demonstrating compliance status on a more frequent basis. This paper focuses on one approach to empirically estimate PCDD/F emissions using easy-to-measure volatile organic C2 chlorinated alk-ene precursors coupled with flue gas cleaning parameters. Three data sets from pilot-scale incineration experiments were examined for correlations between C2 chlorinated alk-enes and PCDDs/Fs. Each data set contained one or more C2 chloroalkenes that were able to account for a statistically significant fraction of the variance in PCDD/F emissions. Variations in the vinyl chloride concentrations were able to account for the variations in the PCDD/F concentrations strongly in two of the three data sets and weakly in one of the data sets. 相似文献
22.
23.
Determining the viability of marine protists using a combination of vital, fluorescent stains 总被引:1,自引:0,他引:1
Determining the viability of protists and small microzooplankton has long been a focus of studies in marine biology and ecology.
It is especially relevant in the issue of shipborne invasive species, and impending international guidelines and various national
regulations on the allowable concentrations of organisms in discharged ballast water have spurred the growth of an industry
that develops and manufactures ballast water management systems. The success of management systems and ability of ships to
meet ballast water discharge standards is determined by the number of viable organisms in treated water. Here, we propose
combining two vital, fluorescent stains (fluorescein diacetate [FDA] and 5-chloromethylfluorescein diacetate [CMFDA]) with
direct microscopic observation to enumerate viable organisms ≥10 and <50 μm in minimum dimension (nominally protists). This
approach was validated in four locations in the United States to determine the efficacy of the stains. Although the accuracy
of the stains varied by geographic location and the taxonomic composition of the planktonic assemblage, combining fluorescent
stains is a robust, powerful tool that can be optimized for the species present at each location. While this method was developed
for analyzing viable organisms in treated ballast water, it may also be used or adapted for any field of research that examines
a broad taxonomic range of autotrophic and heterotrophic plankton. 相似文献
24.
Climate change will pose increasingly significant challenges to managers of parks and other forms of protected areas around
the world. Over the past two decades, numerous scientific publications have identified potential adaptations, but their suitability
from legal, policy, financial, internal capacity, and other management perspectives has not been evaluated for any protected
area agency or organization. In this study, a panel of protected area experts applied a Policy Delphi methodology to identify
and evaluate climate change adaptation options across the primary management areas of a protected area agency in Canada. The
panel identified and evaluated one hundred and sixty five (165) adaptation options for their perceived desirability and feasibility.
While the results revealed a high level of agreement with respect to the desirability of adaptation options and a moderate
level of capacity pertaining to policy formulation and management direction, a perception of low capacity for implementation
in most other program areas was identified. A separate panel of senior park agency decision-makers used a multiple criterion
decision-facilitation matrix to further evaluate the institutional feasibility of the 56 most desirable adaptation options
identified by the initial expert panel and to prioritize them for consideration in a climate change action plan. Critically,
only two of the 56 adaptation options evaluated by senior decision-makers were deemed definitely implementable, due largely
to fiscal and internal capacity limitations. These challenges are common to protected area agencies in developed countries
and pervade those in developing countries, revealing that limited adaptive capacity represents a substantive barrier to biodiversity
conservation and other protected area management objectives in an era of rapid climate change. 相似文献
25.
Sources, fate, and toxic hazards of oxygenated polycyclic aromatic hydrocarbons (PAHs) at PAH-contaminated sites 总被引:4,自引:0,他引:4
Lundstedt S White PA Lemieux CL Lynes KD Lambert IB Oberg L Haglund P Tysklind M 《Ambio》2007,36(6):475-485
In this paper we show that oxygenated polycyclic aromatic hydrocarbons (oxy-PAHs) are important cocontaminants that should be taken into account during risk assessment and remediation of sites with high levels of PAHs. The presented data, which have been collected both from our own research and the published literature, demonstrate that oxy-PAHs are abundant but neglected contaminants at these sites. The oxy-PAHs show relatively high persistency and because they are formed through transformation of PAHs, their concentrations in the environment may even increase as the sites are remediated by methods that promote PAH degradation. Furthermore, we show that oxy-PAHs are toxic to both humans and the environment, although the toxicity seems to be manifested through other effects than those known to be important for polycyclic aromatic compounds in general, that is, mutagenicity and carcinogenicity. Finally, we present data that support the hypothesis that oxy-PAHs are more mobile in the environment than PAHs, due to their polarity, and thus have a higher tendency to spread from contaminated sites via surface water and groundwater. We believe that oxy-PAHs should be included in monitoring programs at PAH-contaminated sites, even if a number of other toxicologically relevant compounds that may also be present, such as nitro-PAHs and azaarenes, are not monitored. This is because oxy-PAH levels are difficult to predict from the PAH levels, because their environmental behavior differs substantially from that of PAHs, and oxy-PAHs may be formed as PAHs are degraded. 相似文献
26.
Christopher J. Lemieux Mark Groulx Elizabeth Halpenny Heather Stager Jackie Dawson Emma J. Stewart 《Environmental Communication: A Journal of Nature and Culture》2018,12(5):653-671
Rapid environmental change in vulnerable destinations has stimulated a new form of travel termed “last chance tourism” (LCT). Studies have examined the risks of LCT, while leaving potential opportunities within this new tourism market largely underexplored. Results of survey (n?=?399) research in Jasper National Park, Canada reveal that a LCT motivation influences decisions to visit this iconic Canadian destination, and suggest that this motivation is linked to a desire to learn about the impacts of climate change on the Athabasca Glacier. Findings suggest there may be short to medium term opportunities associated with LCT, including promoting climate change ambassadorship through management interventions. This paper discusses a range of possible education, interpretive, and outreach activities that might be employed at LCT destinations. It outlines the relative merits (or what we refer to as “uneasy benefits”) of promoting the glacier and other LCT destinations within a protected areas management and climate change adaptation context. 相似文献