关键词：铬渣；稳定/固定化；碱激发矿渣；零价铁；浸出

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以凹凸棒土（凹土，ATP）为原料，采用浸渍法制备Fe3+负载凹土（Fe/ATP），表征了其结构与形貌，研究了凹土和Fe/ATP对土壤中镉（Cd）的吸附效果，以浸出浓度作为稳定化评价指标，通过吸附前后凹土和Fe/ATP形貌等特征的变化探讨了稳定化修复Cd机制。结果表明，加入质量比20%的凹土和Fe/ATP，Cd的浸出浓度分别降低了45%和91%，说明Fe/ATP对土壤中Cd有显著的稳定化作用。形貌表征分析表明，凹土主要通过结构中的水、-OH基团和晶格缺陷来稳定Cd，而Fe/ATP对土壤中Cd稳定化作用可能主要来自-OH基团以及Fe-O中桥氧的贡献。凹土与氧化铁均为土壤中天然矿物，廉价易得且环境友好，制备方法简单易实现，该复合材料用于Cd污染土壤的稳定化修复具有较好的应用前景。

关键词：凹土；Fe/ATP；土壤；镉；浸出浓度；稳定化机制

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关键词：丛枝菌根真菌；蜈蚣草；铀；吸收；污染

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关键词：岩溶地下河；水化学；硫同位素；氮氧同位素；示踪来源

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关键词：β-In2S3；水热反应；光催化降解；土霉素；太阳光

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On May 22, 2013, the National Institute for Occupational Safety and Health (NIOSH) received a request for technical assistance from the shelter manager at a large homeless shelter in Dallas, Texas, linked to an ongoing tuberculosis outbreak. The request asked NIOSH to assess the heating, ventilation, and air-conditioning (HVAC) systems and make recommendations to improve overall environmental controls at the shelter. During an on-site evaluation of the homeless shelter in June 2013, we collected physical and ventilation measurements in all key areas of the facility. We focused on areas where shelter guests typically congregate or spend significant amounts of time. We recorded the make and model number of all air-handling units (AHUs) providing air to the facility, and visually inspected the units. When possible, we measured the air flow rate through supply diffusers and return grilles. The AHUs in place were state-of-the-art and were controlled by a modern building automation system. The ventilation systems were well maintained and functional during our visit, and all AHUs were equipped with proper filter configurations. Despite their excellent condition and maintenance, certain aspects of the ventilation systems' operation could potentially contribute to airborne disease transmission among shelter guests. During our visit, it appeared the AHUs were not providing adequate outdoor air to the occupied spaces under certain occupancy and environmental conditions, as is required by the Dallas Mechanical Code and ASHRAE standards. In addition to alleviating odors and maintaining occupant comfort, outdoor air serves to dilute infectious aerosols, such as Mycobacterium tuberculosis droplet nuclei that are responsible for TB transmission. Since the TB outbreak began, the shelter has taken numerous steps to improve administrative controls, particularly when it comes to identifying guests showing signs and symptoms of TB. We recommend additional improvements to the administrative and environmental controls at the shelter. From a ventilation standpoint, we suggest that all occupied spaces at the shelter complex be supplied adequate amounts of outdoor air, as prescribed by the Dallas Mechanical Code and ASHRAE standards.

关键词：大气；健康危害；大气污染

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The Health Hazard Evaluation Program received a request from employees at a medical office building. They were concerned about indoor environmental quality and exposure to sewer gas, specifically hydrogen sulfide. The medical office building was a four-story, concrete masonry office building constructed in the 1960s that had been renovated twice; the three main floors were converted into offices and exam rooms. The building was surrounded by manholes that had been identified as sources of odors. The building was within 30 feet of a 24-inch trunk line that carried sewage from approximately 60% of the surrounding area toward the wastewater treatment facility. Most of the building's current plumbing was the original cast iron waste and vent piping, which can become brittle and crack with age. We visited the facility in April 2013 and measured hydrogen sulfide, carbon dioxide, temperature, and humidity levels throughout the building. We also inspected the building's heating, ventilation, and air-conditioning system. We did not detect hydrogen sulfide in the building. We found that carbon dioxide concentrations generally increased when moving further away from the supply air discharge point on each floor; outdoor air supplied to each floor was not uniformly distributed. Temperature and humidity were within ANSI/ASHRAE recommended levels. We found problems with duct dampers, heat pumps, and the computerized control system, and determined that air flowed from the restrooms into the hallways. We found odor sources within and near the building such as dry drain traps and manholes.

关键词：大气；空气污染；室内环境

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The U.S. Environmental Protection Agency (EPA) developed a year 2007 air quality modeling platform in support of the Tier 3 Motor Vehicle Emission and Fuel Standards. The air quality modeling platform consists of all of the emissions inventories, ancillary files needed for emissions modeling, and the meteorological, initial condition, and boundary condition files needed to run the air quality model. This platform uses all Criteria Air Pollutants (CAPs) and a select set of Hazardous Air Pollutants (HAPs). This document focuses on the emissions modeling components of the 2007 platform, including the emission inventories and the ancillary data and the approaches used to transform emission inventories for use in air quality modeling.

关键词：大气；机动车；燃料

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There is increasing evidence that improved health outcomes may be a significant co-benefit of land use plans and transport policies that increase active transport (or active travel)--walking, biking or other physical activity for the purpose of transportation--as they reduce greenhouse gas emissions (GHGs). A greater understanding of these benefits may broaden the constituency for regional planning that supports local and national GHG reduction goals. In this study, California's activity-based travel demand model (ABM) is applied to (1) demonstrate how this new generation of travel models can be used to produce the active travel data (age and sex distributions) required by comparative risk assessment models to estimate health outcomes for alternative land use and transport plans and to (2) identify the magnitude of change in active travel that may be possible from land use, transit, and vehicle pricing policies for California and its five major regions for a future 2035 time horizon. The results of this study suggest that distance-based vehicle pricing may increase walking by about 10% and biking by about 17%, and concurrently GHG from VMT may be reduced by about 16%. Transit expansion and supportive development patterns may increase active travel by about 2% to 3% for both walk and bike modes while also reducing VMT by about 4% on average. The combination of all three policies may increase time spent walking by about 13% and biking by about 19%, and reduce VMT by about 19%.

关键词：大气；温室气体；空气污染

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The Health Hazard Evaluation Program received a request from the manager of a federal government office complex. Employees were concerned about health problems including cancer, gallbladder problems, and chronic obstructive pulmonary disease. Some employees believed their health problems were associated with contamination of the buildings, soil, and groundwater from an adjoining weapons component manufacturing agency. The entire complex consisted of 13 buildings with the largest structure at the site containing over 1 million square feet across three floors. This structure contained two main areas: (1) Buildings 1 and 2 (office and warehouse space where most of the complex's employees worked) and (2) the weapons component agency. A floor-to-ceiling fire wall physically separated Buildings 1 and 2 from the weapons component agency. We reviewed environmental sampling records, did a visual inspection of Building 1 and 2 ventilation systems, spoke with employees about their health. We also tested former and current employees with sarcoidosis (an inflammatory disease that is nearly identical to chronic beryllium disease) for sensitization to beryllium, which was used for weapons manufacturing. Our evaluation found (1) no reports of employee overexposures to volatile organic compounds, polychlorinated biphenyls, beryllium or other metals, solvents, formaldehyde, or radon; (2) no evidence of beryllium sensitization among 22 persons tested; and (3) no cancer excess or abnormal pattern of disease. We noted that (1) Buildings 1 and 2 have separate ventilation systems from the weapons component agency and (2) potentially contaminated exhaust air from the weapons component agency was unlikely to enter the outdoor air intake(s) for Building 1 and 2. We recommended the employer encourage employees to learn about their personal cancer risk factors and educate employees on what they can do to reduce their risk for cancer. We also advised the employer to stop all investigations of cancer incidence and routine air and surface wipe sampling for chemicals.

关键词：大气；空气污染；健康

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