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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The U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office (NNSA/NFO) operates the Nevada National Security Site (NNSS) and North Las Vegas Facility (NLVF). From 1951 through 1992, the NNSS was the continental testing location for U.S. nuclear weapons. The release of radionuclides from NNSS activities has been monitored since the initiation of atmospheric testing. Limitation to underground detonations after 1962 greatly reduced radiation exposure to the public surrounding the NNSS. After nuclear testing ended in 1992, NNSS radiation monitoring focused on detecting airborne radionuclides from historically contaminated soils. These radionuclides are derived from re-suspension of soil (primarily by wind) and emission of tritium-contaminated soil moisture through evapotranspiration. Low amounts of legacy-related tritium are also emitted to air at the NLVF, an NNSS support complex in North Las Vegas. To protect the public from harmful levels of man-made radiation, the Clean Air Act, National Emission Standards for Hazardous Air Pollutants (NESHAP) (Title 40 Code of Federal Regulations (CFR) Part 61 Subpart H) (CFR 2010a) limits the release of radioactivity from a U.S. Department of Energy (DOE) facility to that which would cause 10 millirem per year (mrem/yr) effective dose equivalent to any member of the public. This limit does not include radiation unrelated to NNSS activities. Unrelated doses could come from naturally occurring radioactive elements, from sources such as medically or commercially used radionuclides, or from sources outside of the United States, such as the damaged Fukushima nuclear power plant in Japan in 2011.

关键词：大气；有害气体；大气污染

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This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, orusefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement,recommendation, or favoring by the United States Government orany agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

关键词：大气；燃料燃烧；废气排放

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In China, motor vehicle emissions have been identified as the major source of urban air pollution. Thus, estimation of emissions and their impact on air quality is necessary. Vehicle emissions vary strongly with region and depend on local vehicle operation and emission performance. This paper uses the MOVES (Motor Vehicle Emission Simulator) model, released by the US. Environmental Protection Agency, for the estimation of vehicle emission factors in Shanghai, China. To achieve a convincing emission result, vehicle operation is extracted from massive taxi Global Positioning System (GPS) data, and the emission inventory from MOVES is revised according to China's vehicle emission standards. In addition, deterioration factors are calculated on the basis of vehicle condition. Comprehensive emission factors are generated for Shanghai light-duty vehicles at various average speed levels. The results indicate that emission factors for hydrocarbons, carbon monoxide, and oxides of nitrogen of in-use light vehicles in China are 0.1 to 0.25 g/km, 4 to 7 g/km, and 0.4 to 0.8 g/km, respectively. These amounts are 15, 1.9, and 5.9 times higher than those in the United States, respectively. By 2012, the Environmental Protection Bureau had established 10 monitoring sites in Shanghai and released data for real-tune concentrations of particulate matter less than 2.5 μm in diameter, particulate matter less than 10 μm in diameter, nitrogen dioxide (NO_2), and sulfur dioxide to the public. On the basis of the new release of data, a field study estimating near-road air quality was conducted with MOVES and the air dispersion model AERMOD. The concentration result shows that the accuracy of near-road NO_2 estimation is improved with taxi GPS data and the revised MOVES emission inventory. The study explores the extended application of MOVES by offering a procedure for applying MOVES in non-U.S. regions.

关键词：大气；空气污染；出租车

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