This report is the sixteenth volume in the series Acute Exposure Guideline Levels for Selected Airborne Chemicals. In the Bhopal disaster of 1984, approximately 2,000 residents living near a chemical plant were killed and 20,000 more suffered irreversible damage to their eyes and lungs following accidental release of methyl isocyanate. The toll was particularly high because the community had little idea what chemicals were being used at the plant, how dangerous they might be, or what steps to take in an emergency. This tragedy served to focus international attention on the need for governments to identify hazardous substances and to assist local communities in planning how to deal with emergency exposures.

关键词：大气；化学物质；空气污染

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Critical Issues in Aviation and the Environment 2014 consists of 12 individually authored sections, representing the authoring experts opinions on issues that address the major environmental components affected by aviation activities, sustainable solutions that have evolved and continue to be developed to minimize environmental impacts, and the key processes that link aviation and the environment. As in past versions, the focus of this e-circular is on the state of science, rather than policy, and on identification of priority research with potential to yield benefits during the next several years to several decades. This e-circular focuses on research conducted in the United States, although international activities are discussed where public or private entities in this country are closely involved. A wide range of published and unpublished material, public information, and individual contributions was collected to prepare these papers, as noted in the additional resources at the end of each section. Due to scope constraints, the critical issues portions of each section do not necessarily address all potentially critical issues in a given field.

关键词：大气；空气污染；环境保护

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Workplace exposure to respirable crystalline silica can cause silicosis, a progressive lung disease marked by scarring and thickening of the lung tissue. Quartz is the most common form of crystalline silica. Crystalline silica is found in several construction materials, such as brick, block, mortar and concrete. Construction tasks that cut, break, grind, abrade, or drill those materials have been associated with overexposure to dust containing respirable crystalline silica. Fiber-cement products can contain as much as 50% crystalline silica, and cutting this material has been shown to cause excessive exposures to respirable crystalline silica. NIOSH scientists are conducting a study to develop engineering control recommendations for respirable crystalline silica from cutting fiber-cement siding. This site visit was part of that study.

关键词：大气；空气污染；环境保护

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With funds from this grant, Youngstown State University has purchased a Quantachrome iQ Chemisorption Analyzer and built a Chemical Reactor with Gas Chromatographer for catalyst characterization. PI has been involved in the purchase and installation of the instruments. The two new instruments were fully operational in the spring of 2013 and have so far been used for student research. For the research projects, we found that the nucleation and oxidation of Ce(OH)3 are critical steps which needs careful control in order to synthesize different morphological CeO2 nanocrystals. The combination of stirring and oxidation of suspension could destroy the nucleation and growth of Ce(OH)3, resulting in the formation of irregular CeO2 nanocrystals during the hydrothermal reactions. We demonstrated a general route for shape-controlled synthesis of CeO2 nanocrystals via mediation of the Ce(OH)3 seed before hydrothermal reactions. It was revealed that the shape of CeO2 support plays a critical role in metal-CeO2 catalytic activity for low-temperature CO oxidation. Out of this project, six refereed and four proceeding papers were published, along with several oral presentations made by PI and students.

关键词：大气；汽车催化转换器；空气清洁

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An amine sorbent, prepared by impregnation of polyethyleneimine on silica, was tested for steam stability. The stability of the sorbent was investigated in a fixed bed reactor using multiple steam cycles of 90 vol.% H2O/He at 105 aC and the gas effluent was monitored with a mass spectrometer. CO2 uptake of sorbent was found to decrease with repeated exposure to steam. Characterization of the spent sorbent using N2 physisorption, SEM, and thermogravimetric analysis (TGA), showed that the decrease in CO2 loading can possibly be attributed to a reagglomeration of the amine in the pores of the silica. No support effect was found in this study. The commercial SiO2 used, Cariact G10, was found to be stable under the conditions used. While it was found that subjecting the sorbent to several steam cycles decreased its CO2 uptake, a continuous exposure of the sorbent to steam did not have a significant performance impact. A silanated sorbent, consisting of a mixture of PEI and aminopropyl-triethoxysilane on SiO2 support, was also investigated for steam stability. Similarly to the non-silanated sorbent, the CO2 loading.

关键词：大气；一氧化碳；空气治理

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Changes in operations can save 5-30% of building energy use at low cost, yet these changes are often not implemented. Little attention has been directed toward understanding why. This project focuses on how building operators approach energy use and conservation in their work, viewing the building as a social system. It draws on interviews, a workshop, surveys, and case studies, learning from operators, facilities staff, researchers, policymakers and occupants. We found two clusters of obstacles to lowered energy use. First, while building operators have the technical means to reduce energy use, social, organizational and technical constraints limit ability and motivation. These include low status, customer service practices, poor feedback on occupant environment, little energy data, and technology shortcomings. A second cluster of obstacles rests on the fact that current combinations of buildings, management, and expectations leave many occupants dissatisfied with indoor environment. Recommendations call for shifting the focus of energy use reduction strategies to better include building operators, who are in an ideal position to shape and vet solutions. These include (1) increasing status and visibility of building operators; (2) improving ability to see how energy is used; and (3) attending to indoor environment in coordination with energy efficiency.

关键词：大气；空气健康；建筑

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The goal of the project is to build up a modeling tool to quantify soil greenhouse gases (GHG) emitted from agricultural production in California (CA) under current climate, soil and management conditions. We conducted (1) field data collection and analysis, (2) model calibration, validation and comparison tests, (3) regional simulation, and (4) tool development to help ARB with greenhouse gas inventory and mitigation studies. As nitrous oxide (N2O) is the major greenhouse gas for CA agricultural production, we focused our analyses on N2O emissions.

关键词：大气；温室气体；排放标准

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Reducing the environmental impact of facilities and operations has become an important function for many organizations. In many cases, such as utility and fuel use, reducing these impacts can also be coupled to financial savings. The Kansas Department of Transportation (KDOT) has determined that conducting an energy and CO2 audit of its building and vehicle fleets will aid in assessing KDOT energy use, prepare for any future regulations regarding CO2 emissions, and help identify areas for increased savings through reduced use of commercial resources (primarily energy and fuel). Phase 1 of this project established baseline carbon and energy data from three major sources: the total energy embodied in the construction, operation and repair of KDOT-owned buildings, the total energy embodied in KDOT use of utilities (electricity,  water and natural gas) and the energy expended in the operation of KDOT’s vehicle fleet and other associated equipment.

关键词：大气；碳排放；燃料

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This project was motivated by the continuing need to improve ambient air quality. As of December 2012, more than 74 million Americans live in areas that violate the National Ambient Air Quality Standard for fine particulate matter (or PM2.5). Organic aerosol often contributes between 30 and 60% of ambient fine particulate matter. However, the sources of ambient organic aerosols are not well understood and state-of-the-art chemical transport models often underpredict the measured organic aerosol concentrations by a factor of 2 or more. Better understanding of the sources of organic aerosols may be needed for the development of effective control strategies. This report describes results from a three-phase test program that characterized the emissions from on-road gasoline vehicles, on-road diesel vehicles, and small off-road engines. The overarching goal of the project was to investigate the atmospheric transformations of mobile source emissions to better quantify their contribution to ambient PM levels in other words to link tailpipe to ambient. This was done by characterizing the tailpipe emissions from in-use sources and by investigating the atmospheric evolution of the emissions using dilution tunnels and smog chambers.

关键词：大气；空气污染；燃料控制

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Post combustion CO(sub 2) capture is most commonly carried out using an amine solution that results in a high parasitic energy cost in the stripper unit due to the need to heat the water which comprises a majority of the amine solution. It is also well known that amine solvents suffer from stability issues due to amine leaching and poisoning by flue gas impurities. Solid sorbents provide an alternative to solvent systems that would potentially reduce the energy penalty of carbon capture. However, the cost of using a particular sorbent is greatly affected by the usable lifetime of the sorbent. This work investigated the stability of a primary amine-functionalized ion exchange resin in the presence of O(sub 2) and SO(sub 2), both of which are constituents of flue gas that have been shown to cause degradation of various amines in solvent processes. The CO(sub 2) capture capacity was measured over multiple capture cycles under continuous exposure to two simulated flue gas streams, one containing 12 vol% CO(sub 2), 4% O(sub 2), 84% N(sub 2), and the other containing 12.5 vol% CO(sub 2), 4% O(sub 2), 431 ppm SO(sub 2), balance N(sub 2) using a custom-built packed bed reactor. The resin maintained its CO(sub 2) capture capacity of 1.31 mol/kg over 17 capture cycles in the presence of O(sub 2) without SO(sub 2). However, the CO(sub 2) capture capacity of the resin decreased rapidly under exposure to SO(sub 2) by an amount of 1.3 mol/kg over 9 capture cycles. Elemental analysis revealed the resin adsorbed 1.0 mol/kg of SO(sub 2). Thermal regeneration was determined to not be possible. The poisoned resin was, however, partially regenerated with exposure to 1.5M NaOH for 3 days resulting in a 43% removal of sulfur, determined through elemental analysis, and a 35% recovery of CO(sub 2) capture capacity. Evidence was also found for amine loss upon prolonged (7 days) continuous exposure to high temperatures (120 (number)14;C) in air. It is concluded that desulfurization of the flue gas stream prior to CO(sub 2) capture will greatly improve the economic viability of using this solid sorbent in a post-combustion CO(sub 2) capture process.

关键词：大气；碳排放；吸附剂

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