Increased demands for cleaner burning energy, coupled with the relatively recent technological advances in accessing unconventional hydrocarbon-rich geologic formations, have led to an intense effort to find and extract natural gas from various underground sources around the country. One of these sources, the Marcellus Shale, located in the Allegheny Plateau, is currently undergoing extensive drilling and production. The technology used to extract gas in the Marcellus Shale is known as hydraulic fracturing and has garnered much attention because of its use of large amounts of fresh water, its use of proprietary fluids for the hydraulic-fracturing process, its potential to release contaminants into the environment, and its potential effect on water resources. Nonetheless, development of natural gas extraction wells in the Marcellus Shale is only part of the overall natural gas story in this area of Pennsylvania. Conventional natural gas wells, which sometimes use the same technique, are commonly located in the same general area as the Marcellus Shale and are frequently developed in clusters across the landscape. The combined effects of these two natural gas extraction methods create potentially serious patterns of disturbance on the landscape. This document quantifies the landscape changes and consequences of natural gas extraction for Somerset County and Westmoreland County in Pennsylvania between 2004 and 2010. Patterns of landscape disturbance related to natural gas extraction activities were collected and digitized using National Agriculture Imagery Program (NAIP) imagery for 2004, 2005/2006, 2008, and 2010. The disturbance patterns were then used to measure changes in land cover and land use using the National Land Cover Database (NLCD) of 2001. A series of landscape metrics is also used to quantify these changes and is included in this publication.

关键词：大气；天然气开采；能源利用

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In 1963, the Atomic Energy Commission (AEC), predecessor to the US Department of Energy (DOE), implemented Operation Roller Coaster on the Tonopah Test Range (TTR) and an adjacent area of the Nevada Test and Training Range (NTTR) (formerly the Nellis Air Force Range (NAFR)). Operation Roller Coaster consisted of four tests in which chemical explosions were detonated in the presence of nuclear devices to assess the dispersal of radionuclides and evaluate the effectiveness of storage structures to contain the ejected radionuclides. These tests resulted in dispersal of plutonium over the ground surface downwind of the test ground zero. Three tests, Clean Slate 1, 2, and 3, were conducted on the TTR in Cactus Flat; the fourth, Double Tracks, was conducted in Stonewall Flat on the NTTR. DOE is working to clean up and close all four sites. Substantial cleaned up has been accomplished at Double Tracks and Clean Slate 1. Cleanup of Clean Slate 2 and 3 is on the DOE planning horizon for some time in the next several years.

关键词：大气；空气检测；气候变化

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In response to the Energy Independence and Security Act (Public Law 110-40, 2007), the U.S. Geological Survey (USGS) conducted a national assessment of potential geologic storage resources for carbon dioxide (CO2). Storage of CO2 in subsurface saline formations is one important method to reduce greenhouse gas emissions and curb global climate change (Benson and Cook, 2005). The assessment methodology describes the probabilistic model developed to calculate potential storage resources in subsurface saline formations. This report documents both the methodology updates and the details of methodology implementation and is meant to supplement the Brennan and others (2010) methodology and the national assessment final reports. The final reports will include (1) an assessment results report with all output results, a description of the assessment, and analysis; (2) an assessment summary report; and (3) an assessment data report, which will include data inputs and outputs, assessment forms, resource allocations, and figures.

关键词：大气；二氧化碳存储；温室气体

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From June through August 2012, National Institute for Occupational Safety and Health (NIOSH) researchers and the Silica/Milling-Machines Partnership coordinated by the National Asphalt Pavement Association (NAPA) conducted field testing of a vacuum cutting system (VCS) on a Wirtgen W 210i cold milling machine. The tests included 11 total days of air sampling across four different highway construction sites in Wisconsin. At each site, full-shift personal breathing zone sampling for respirable crystalline silica was conducted for the operator and ground man during the course of normal employee work activities. The arithmetic mean respirable crystalline silica exposure for the operator was 0.0071 mg/m3 with an upper 95% confidence limit of 0.011 mg/m3. The arithmetic mean respirable crystalline silica exposure for the ground man was 0.0066 mg/m3 with an upper 95% confidence limit of 0.0093 mg/m3. The geometric mean respirable crystalline silica exposure for the operator was 0.0061 mg/m3 with an upper 95% confidence limit of 0.019 mg/m3. The geometric mean respirable crystalline silica exposure for the ground man was 0.0061 mg/m3 with an upper 95% confidence limit of 0.013 mg/m3. All 22 full-shift personal breathing zone samples collected from the operator and ground man were below currently published regulatory and recommended occupational exposure limits for respirable crystalline silica. Based on the results of this study, NIOSH researchers recommend that Wirtgen should consider making the VCS system a standard feature on all Wirtgen half-lane and larger milling machines. NIOSH researchers also recommend that other manufacturers of half-lane and larger cold milling machines should consider implementing local exhaust ventilation as a control for silica exposures.

关键词：大气；气体防护；气体健康

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The HHE Program evaluated employee concerns about exposures and health problems at a tire manufacturing plant. After evaluating the ventilation system, investigators determined that the general and local exhaust systems were operating properly. 

关键词：大气；室内气体；气体健康

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After more than a decade of producing a nominal 10 km aerosol product based on the dark target method, the MODIS aerosol team will be releasing a nominal 3 km product as part of their Collection 6 release. The new product differs from the original 10 km product only in the manner in which reflectance pixels are ingested, organized and selected by the aerosol algorithm. Overall, the 3 km product closely mirrors the 10 km product. However, the finer resolution product is able to retrieve over ocean closer to islands and coastlines, and is better able to resolve fine aerosol features such as smoke plumes over both ocean and land. In some situations, it provides retrievals over entire regions that the 10 km product barely samples. In situations traditionally difficult for the dark target algorithm, such as over bright or urban surfaces the 3 km product introduces isolated spikes of artificially high aerosol optical depth (AOD) that the 10 km algorithm avoids. Over land, globally, the 3 km product appears to be 0.01 to 0.02 higher than the 10 km product, while over ocean, the 3 km algorithm is retrieving a proportionally greater number of very low aerosol loading situations. Based on collocations with ground-based observations for only six months, expected errors associated with the 3 km land product are determined to be greater than for the 10 km product: 0.05 0.25 AOD. Over ocean, the suggestion is for expected errors to be the same as the 10 km product: 0.03 0.05 AOD. The advantage of the product is on the local scale, which will require continued evaluation not addressed here. Nevertheless, the new 3 km product is expected to provide important information complementary to existing satellite-derived products and become an important tool for the aerosol community.

关键词：大气；气溶胶；空气治理

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This document consists of eight papers that explore the transport of toxic inhalation hazard materials, carbon dioxide and sulfur oxides emissions from container shipping, transportation asset sensitivity to extreme weather events and climate change, damage to offshore pipeline by ship factors, safety risk analysis of maritime transportation, spatial analysis of maritime accidents, human behavior in vessel maneuver simulations, and mariner near misses and design.

关键词：大气；人类活动；空气变化

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The HHE Program evaluated exposures to volatile organic compounds, mold, airborne particles, and formaldehyde in the autopsy suite, histology laboratory, and toxicology laboratory at a medical examiner's office.

关键词：大气；室内气体；气体健康

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As airport operations continue to expand as infrastructure is modified to meet the growing demand for air travel, they need to balance their growth with environmental constraints. Although the main environmental concern continues to be noise, a more comprehensive approach needs to be implemented to better understand the effects of airport growth and changes. Indeed, the implementation of new aircraft and navigation technologies under the Next Generation Air Transportation System (NextGen) will require both noise and emissions, as well as fuel burn, to be assessed in order to fully understand the effects from such complex new technologies.

关键词：大气；空气污染；空气优化

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Transport development bring a negative impact on human survival ecological environment, such as destruction of vegetation, air pollution, soil erosion and other environmental issues.The actuality proves that the use of tunnel development of underground space can improve traffic quality, while also protecting the environment.Therefore, tunnel engineering and utilization of undergrotmd space are to protect the ecological environment to be effective ways for realizing economic sustainable development of economy.In this paper, based on the practical application at home and abroad, for the big cities, mountain areas, river waters, the suitability evaluation and beneficial discussion about the transportation by using tunnel to protect the ecological environment are of great practical significance to protect and improve the ecological environment.

关键词：大气；生态环境；大气污染

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