Indoor environment program. 1994 annual report

Buildings use approximately one-third of the energy consumed in the United States. The potential energy savings derived from reduced infiltration and ventilation in buildings are substantial, since energy use associated with conditioning and distributing ventilation air is about 5.5 EJ per year. However, since ventilation is the dominant mechanism for removing pollutants from indoor sources, reduction of ventilation can have adverse effects on indoor air quality, and on the health, comfort, and productivity of building occupants. The Indoor Environment Program in LBL`s Energy and Environment Division was established in 1977 to conduct integrated research on ventilation, indoor air quality, and energy use and efficiency in buildings for the purpose of reducing energy liabilities associated with airflows into, within, and out of buildings while maintaining or improving occupant health and comfort. The Program is part of LBL`s Center for Building Science. Research is conducted on building energy use and efficiency, ventilation and infiltration, and thermal distribution systems; on the nature, sources, transport, transformation, and deposition of indoor air pollutants; and on exposure and health risks associated with indoor air pollutants. Pollutants of particular interest include radon; volatile, semivolatile, and particulate organic compounds; and combustion emissions, including environmental tobacco smoke, CO, and NO{sub x}

Indoor environment program - 1995 annual report

Buildings use approximately one-third of the energy consumed in the United States. The potential energy savings derived from reduced infiltration and ventilation in buildings are substantial, since energy use associated with conditioning and distributing ventilation air is about 5.5 EJ per year. However, since ventilation is the dominant mechanism for removing pollutants from indoor sources, reduction of ventilation can have adverse effects on indoor air quality, and on the health, comfort, and productivity of building occupants. The Indoor Environment Program in LBL`s Energy and Environment Division was established in 1977 to conduct integrated research on ventilation, indoor air quality, and energy use and efficiency in buildings for the purpose of reducing energy liabilities associated with airflows into, within, and out of buildings while maintaining or improving occupant health and comfort. The Program is part of LBL`s Center for Building Science. Research is conducted on building energy use and efficiency, ventilation and infiltration, and thermal distribution systems; on the nature, sources, transport, transformation, and deposition of indoor air pollutants; and on exposure and health risks associated with indoor air pollutants. Pollutants of particular interest include radon; volatile, semivolatile, and particulate organic compounds; and combustion emissions, including environmental tobacco smoke, CO, and NO{sub x}

Toxic Volatile Organic Compounds in Environmental Tobacco Smoke:Emission Factors for Modeling Exposures of California Populations

The primary objective of this study was to measure emission factors for selected toxic air in environmental tobacco smoke (ETS) using a room-sized environmental chamber. The emissions of 23 volatile organic compounds (VOCs), including 1,3-butadiene, three aldehydes and two vapor-phase N-nitrosarnines were determined for six commercial brands of cigarettes and reference cigarette 1R4F. The commercial brands were selected to represent 62.5% of the cigarettes smoked in California. For each brand, three cigarettes were machine smoked in the chamber. The experiments were conducted over four hours to investigate the effects of aging. Emission factors of the target compounds were also determined for sidestream smoke (SS). For almost all target compounds, the ETS emission factors were significantly higher than the corresponding SS values probably due to less favorable combustion conditions and wall losses in the SS apparatus. Where valid comparisons could be made, the ETS emission factors were generally in good agreement with the literature. Therefore, the ETS emission factors, rather than the SS values, are recommended for use in models to estimate population exposures from this source. The variabilities in the emission factors (pgkigarette) of the selected toxic air contaminants among brands, expressed as coefficients of variation, were 16 to 29%. Therefore, emissions among brands were generally similar. Differences among brands were related to the smoked lengths of the cigarettes and the masses of consumed tobacco. Mentholation and whether a cigarette was classified as light or regular did not significantly affect emissions. Aging was determined not to be a significant factor for the target compounds. There were, however, deposition losses of the less volatile compounds to chamber surfaces

Considerations for design of source apportionment studies

This report recommends procedures for source and ambient sampling and analysis in source apportionment studies. The recommendations are based on the results of receptor model studies of atmospheric particles in urban areas, especially a recent study of Houston, TX, undertaken as part of the Mathematical and Empirical Receptor Models Workshop (Quail Roost II). The recommendations are presented at three levels of increasing cost and detail of information obtained. Existing mass emissions inventories combined with chemically resolved test data from similar sources (not necessarily in the same locale) can be used to initially estimate the sources of elements present on ambient particles. To aid local users in construction of chemically resolved emission estimates, the U.S. Environmental Protection Agency (EPA) is compiling a library of compositions and size distributions of particulate emissions from major source types. More reliable source characterization can be achieved if the actual sources are tested directly. EPA should develop and publish detailed procedures for source sampling that would be more appropriate for receptor model use than are existing standard methods. Source and ambient sampling should be conducted by similar methods. If possible, particles from sources should be collected in a way that simulates changes that would normally occur before they reach distant receptors (e.g. by diluting and cooling the particles from hot sources). It is recommended that particulate samples be routinely collected in two size fractions by use of virtual impactors and that all samples be subjected, at a minimum, to mass and X-ray fluorescence analyses. Additional measurements are suggested for obtaining more detailed information: neutron activation analysis; X-ray diffraction; automated particle classification by electron microscopy; analyses for classes of organic species, ^(14)C and thermally released carbonaceous species; and real-time observation of several gases during sample collection. Methods for collecting meteorological data in parallel with ambient samples are described, as are methods for incorporating such data into the source identification process

Use of Volatile Tracers to Determine the Contribution ofEnvironment Tobacco Smoke to Concentrations of Volatile Organic Compoundsin Smoking Environments

Three volatile nitrogen-containing compounds, 3-ethenylpyridine (3-EP), pyridine and pyrrole, were investigated as potential tracers for determining the contribution of environmental tobacco smoke (ETS) to concentrations of volatile organic compounds (VOCs) in indoor environments with smoking. The source emission rates of the three tracers and ten selected VOCs in ETS were first measured in a room-size environmental chamber for a market-weighted selection of six commercial cigarettes. The ratios of the emission rates of the tracers to the emission rates of the selected VOCs were calculated and compared among the six brands. The utility of the tracers was then evaluated in a field study conducted in five office buildings. Samples for VOCs were collected in designated smoking areas and adjoining non-smoking areas, air change rates were measured, and smoking rates were documented. Concentrations of the three tracers in the smoking areas were calculated using a mass-balance model and compared to their measured concentrations. Based on this comparison, 3-EP was selected as the most suitable tracer for the volatile components of ETS, although pyrrole is also potentially useful. Using 3-EP as the tracer, the contributions of ETS to the measured concentrations of the selected VOCs in the smoking areas were estimated by apportionment. ETS was estimated to contribute 57 to 84 percent (4.1 to 26 pg m{sup -3}) of the formaldehyde concentrations, 44 to 69 percent (0.9 to 5.8 pg m{sup -3}) of the 2-butanone concentrations, 37 to 58 percent (1.3 to 8.2 pg m{sup -3}) of the benzene concentrations, and 20 to 69 percent (0.5 to 3.0 pg m{sup -3}) of the styrene concentrations. The fractional contributions of ETS to the concentrations of acetone, toluene, ethylbenzene, xylene isomers and d-limonene were all less than 50 percent

Teachers as writers: a systematic review

This paper is a critical literature review of empirical work from 1990-2015 on teachers as writers. It interrogates the evidence on teachers’ attitudes to writing, their sense of themselves as writers and the potential impact of teacher writing on pedagogy or student outcomes in writing. The methodology was carried out in four stages. Firstly, educational databases keyword searches located 438 papers. Secondly, initial screening identified 159 for further scrutiny, 43 of which were found to specifically address teachers’ writing identities and practices. Thirdly, these sources were screened further using inclusion/exclusion criteria. Fourthly, the 22 papers judged to satisfy the criteria were subject to in-depth analysis and synthesis. The findings reveal that the evidence base in relation to teachers as writers is not strong, particularly with regard to the impact of teachers’ writing on student outcomes. The review indicates that teachers have narrow conceptions of what counts as writing and being a writer and that multiple tensions exist, relating to low self-confidence, negative writing histories, and the challenge of composing and enacting teacher and writer positions in school. However, initial training and professional development programmes do appear to afford opportunities for reformulation of attitudes and sense of self as writer