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91.
Over 313,000 people are working at jobs produced in part as a result of clean air regulations, according to a study just completed by the Industrial Gas Cleaning Institute. The study mitigates arguments that clean air regulations have caused the loss of jobs. According to IGCI President Robert G. Huntington, the Clean Air Act has actually created a substantial number of jobs in the pollution control equipment, engineering, and construction industries as well.  相似文献   
92.
A variety of emerging chemicals of concern are released continuously to surface water through the municipal wastewater effluent discharges. The ability to rapidly determine bioaccumulation of these contaminants in exposed fish without sacrificing the animal (i.e. in vivo) would be of significant advantage to facilitate research, assessment and monitoring of their risk to the environment. In this study, an in vivo solid phase micro-extraction (SPME) approach was developed and applied to the measurement of a variety of emerging contaminants (carbamazepine, naproxen, diclofenac, gemfibrozil, bisphenol A, fluoxetine, ibuprofen and atrazine) in fish. Our results indicated in vivo SPME was a potential alternative extraction technique for quantitative determination of contaminants in lab exposures and as well after exposure to two municipal wastewater effluents (MWWE), with a major advantage over conventional techniques due to its ability to non-lethally sample tissues of living organisms.  相似文献   
93.
An adaptive management approach is necessary but not sufficient to address the long-term challenges of the Greater Yellowstone Ecosystem (GYE). Adaptive management, in turn, has its own particular challenges, of which we focus on two: science input, and stakeholder engagement. In order to frame our discussion and subsequent recommendations, we place the current management difficulties into their historical context, with special emphasis on the 1990 Vision document, which attempted a broad synthesis of management goals for the ecosystem. After examining these two key challenges in the context of the GYE, we make several recommendations that would allow for more effective ecosystem management in the long term. First, we recommend adoption of the GYE as a site for long-term science research and monitoring with an emphasis on integrative research, long-term federal funding, and public dissemination of data. Second, we conclude that a clearer prioritization of legislative mandates would allow for more flexible ecosystem management in the GYE, a region where conflicting mandates have historically led to litigation antithetical to effective ecosystem management. Finally, we recommend a renewed attempt at an updated Vision for the Future that engages stakeholders (including local landholders) substantively from the outset.  相似文献   
94.
Emissions inventories of fine particulate matter (PM2.5) were compared with estimates of emissions based on data emerging from U.S. Environment Protection Agency Particulate Matter Supersites and other field programs. Six source categories for PM2.5 emissions were reviewed: on-road mobile sources, nonroad mobile sources, cooking, biomass combustion, fugitive dust, and stationary sources. Ammonia emissions from all of the source categories were also examined. Regional emissions inventories of PM in the exhaust from on-road and nonroad sources were generally consistent with ambient observations, though uncertainties in some emission factors were twice as large as the emission factors. In contrast, emissions inventories of road dust were up to an order of magnitude larger than ambient observations, and estimated brake wear and tire dust emissions were half as large as ambient observations in urban areas. Although comprehensive nationwide emissions inventories of PM2.5 from cooking sources and biomass burning are not yet available, observational data in urban areas suggest that cooking sources account for approximately 5-20% of total primary emissions (excluding dust), and biomass burning sources are highly dependent on region. Finally, relatively few observational data were available to assess the accuracy of emission estimates for stationary sources. Overall, the uncertainties in primary emissions for PM2.s are substantial. Similar uncertainties exist for ammonia emissions. Because of these uncertainties, the design of PM2.5 control strategies should be based on inventories that have been refined by a combination of bottom-up and top-down methods.  相似文献   
95.
The growth of transgenic canola (Brassica napus) expressing a gene for the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase was compared to non-transformed canola exposed to flooding and elevated soil Ni concentration, in situ. In addition, the ability of the plant growth-promoting bacterium Pseudomonas putida UW4, which also expresses ACC deaminase, to facilitate the growth of non-transformed and transgenic canola under the above mentioned conditions was examined. Transgenic canola and/or canola treated with P. putida UW4 had greater shoot biomass compared to non-transformed canola under low flood-stress conditions. Under high flood-stress conditions, shoot biomass was reduced and Ni accumulation was increased in all instances relative to low flood-stress conditions. This is the first field study to document the increase in plant tolerance utilizing transgenic plants and plant growth-promoting bacteria exposed to multiple stressors.  相似文献   
96.
Chronic toxicity of As, Co, Cr and Mn to Hyalella azteca can be described using a saturation-based mortality model relative to total-body or water metal concentration. LBC25s (total-body metal concentrations resulting in 25% mortality in 4 weeks) were 125, 103, 152 and 57,900 nmol g-1 dry weight for As, Co, Cr and Mn respectively. LC50s (metal concentrations in water resulting in 25% mortality in 4 weeks) were 5600, 183, 731, and 197,000 nmol L-1, respectively. A hormesis growth response to As exposure was observed. Growth was a more variable endpoint than mortality for all four toxicants; however, confidence limits based on growth and mortality all overlapped, except Cr which had no effect on growth. Mn toxicity was greater in glass test containers compared to plastic. Bioaccumulation of As, Co, Cr, and Mn was strongly correlated with, and is useful for predicting, chronic mortality.  相似文献   
97.
Much work has been done on gaseous emissions and leaching of nitrogenous compounds from whole soil profiles and also from soil surface measurements which are assumed to be mainly due to topsoil activity. In soils with an impervious clay subsoil, the boundary between the topsoil and subsoil may provide an interface for microbial activity, including N transformations. In this study, we investigated movement and transformations of two reactive N species (nitrate and urea) at the subsoil interface using a series of replicate, intact soil blocks, under two contrasting watering regimes. We measured fluxes in both liquid and gaseous phases and demonstrated that nitrate reaching the subsoil interface does not necessarily leach into water systems, but may denitrify immediately and could, therefore, add to atmospheric pollution through N2O production. On the other hand, ammonium reaching the subsoil interface either directly, or after mineralization, appears to be more mobile than expected and has the potential to pollute watercourses.  相似文献   
98.
Summary The safety hazards arising from accidental losses of packaged dangerous goods from ships have been identified by government departments and inter-governmental organizations. In the last decade at least 80 people in southern England have been advised to seek precautionary medical examination or treatment following exposure to the contents of packages washed ashore.A questionnaire survey in which coastal local authorities participated, collected data showing the types and quantities of packaged dangerous goods recovered on beaches in England and Wales. A total of 254 packages was reported; 131 containing dangerous goods listed in the International Maritime Dangerous Goods Code. Only 8 percent of these packages carried both hazard warning and substance identification markings in accordance with the Code. The most dangerous substances included 842l of ether and a small quantity of acetaldehyde. The local authorities concerned had received very few advance warnings of dangerous deck cargo losses, although an International Maritime Organization (IMO) cargo loss reporting scheme was in operation during the survey period.A revision of existing regulations governing the carriage of packaged dangerous goods by sea is recommended including improvements in marking and labelling standards, mandatory reporting of losses at sea and the establishment of a convention on liability and compensation arrangements.Trevor Dixon is Senior Lecturer in Environmental Studies at Buckinghamshire College of Higher Education and Director of the Keep Britain Tidy Group, Marine Litter Research Programme. Tim' Dixon, the second author, is employed by The Nature Conservancy Council at 17, Rubislaw Terrace, Aberdeen AB1 1XE, UK.  相似文献   
99.
100.
An emerging evaporation technology uses a powerful axial fan and high‐pressure spray nozzles to propel a fine mist into the atmosphere at high air and water flow rates. Commercial units have been deployed at several locations in North America and worldwide since the mid‐1990s, typically in arid or semiarid climates. A commercial spray evaporator was field tested at the U.S. Department of Energy's Savannah River Site in South Carolina to develop quantitative performance data under relatively humid conditions. A semiempirical correlation was developed from eight tests from March through August 2003. For a spray rate of 250 L/min (66 gpm) and continuous year‐round operation at the Savannah River Site, the predicted average evaporation rate is 48 L/min (13 gpm). © 2006 Washington Savannah River Company  相似文献   
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