abstract: Americans spend upwards of 90% of their time indoors, hence indoor air quality (IAQ) and the impact of IAQ on human health is a major public health concern. IAQ can be negatively impacted by outdoor pollution infiltrating indoors, the emission of indoor pollutants, indoor atmospheric chemistry and poor ventilation. Energy saving measures like retrofits to seal the building envelope to prevent the leakage of heated or cooled air will impact IAQ. However, existing studies have been inconclusive as to whether increased energy efficiency is leading to detrimental IAQ. In this work, field campaigns were conducted in apartment homes in Phoenix, Arizona to evaluate IAQ as it relates to particulate matter (PM), carbonyls, and tobacco specific nitrosamines (TSNA). To investigate the impacts of an energy efficiency retrofit on IAQ, indoor and outdoor air quality sampling was carried out at Sunnyslope Manor, a city-subsidized senior living apartment complex. Measured indoor formaldehyde levels before the building retrofit exceeded reference exposure limits, but in the long term follow-up sampling, indoor formaldehyde decreased for the entire study population by a statistically significant margin. Indoor PM levels were dominated by fine particles and showed a statistically significant decrease in the long term follow-up sampling within certain resident subpopulations (i.e. residents who reported smoking and residents who had lived longer at the apartment complex). Additionally, indoor glyoxal and methylglyoxal exceeded outdoor concentrations, with methylglyoxal being more prevalent pre-retrofit than glyoxal, suggesting different chemical pathways are involved. Indoor concentrations reported are larger than previous studies. TSNAs, specifically N'-nitrosonornicotine (NNN), 4-(methyl-nitrosamino)-4-(3-pyridyl)-butanal (NNA) and 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanone (NNK) were evaluated post-retrofit at Sunnyslope Manor. Of the units tested, 86% of the smoking units and 46% of the non-smoking units had traces of at least one of the nitrosamines. / Dissertation/Thesis / Doctoral Dissertation Chemistry 2014

abstract: Vapor intrusion (VI) pathway assessment often involves the collection and analysis of groundwater, soil gas, and indoor air data. There is temporal variability in these data, but little is understood about the characteristics of that variability and how it influences pathway assessment decision-making. This research included the first-ever collection of a long-term high-frequency indoor air data set at a house with VI impacts overlying a dilute chlorinated solvent groundwater plume. It also included periodic synoptic snapshots of groundwater and soil gas data and high-frequency monitoring of building conditions and environmental factors. Indoor air trichloroethylene (TCE) concentrations varied over three orders-of-magnitude under natural conditions, with the highest daily VI activity during fall, winter, and spring months. These data were used to simulate outcomes from common sampling strategies, with the result being that there was a high probability (up to 100%) of false-negative decisions and poor characterization of long-term exposure. Temporal and spatial variability in subsurface data were shown to increase as the sampling point moves from source depth to ground surface, with variability of an order-of-magnitude or more for sub-slab soil gas. It was observed that indoor vapor sources can cause subsurface vapor clouds and that it can take days to weeks for soil gas plumes created by indoor sources to dissipate following indoor source removal. A long-term controlled pressure method (CPM) test was conducted to assess its utility as an alternate approach for VI pathway assessment. Indoor air concentrations were similar to maximum concentrations under natural conditions (9.3 μg/m3 average vs. 13 μg/m3 for 24 h TCE data) with little temporal variability. A key outcome was that there were no occurrences of false-negative results. Results suggest that CPM tests can produce worst-case exposure conditions at any time of the year. The results of these studies highlight the limitations of current VI pathway assessment approaches and demonstrate the need for robust alternate diagnostic tools, such as CPM, that lead to greater confidence in data interpretation and decision-making. / Dissertation/Thesis / Doctoral Dissertation Civil and Environmental Engineering 2015

M.Tech. (Building Science) / A cross sectional survey was conducted in an air-conditioned building and a naturally ventilated building to establish the prevalence of Sick Building Syndrome (SBS) in these Johannesburg buildings. Numerous studies conducted in other countries have found that the prevalence of SBS symptoms are usually higher in sealed airconditioned buildings than naturally ventilated buildings. The study was conducted in two stages namely a questionnaire and indoor environmental survey which was conducted in both buildings. The results of the questionnaire survey showed that: ' All symptom prevalences in both building populations were very closely related, however the SBS symptoms in building B were more common than air-conditioned building. The indoor environmental survey measured the following parameters: carbon dioxide, carbon monoxide, nitrogen dioxide, nitric oxide, total nitrogen oxides, total non methane hydrocarbons, respirable dust, asbestos, sound levels. No measurements were above any threshold limit values or relevant scientifically acceptable standards, however in the air-conditioned building levels of some pollutants were higher than the naturally ventilated building. The study found that the prevailences of SBS type symptoms in the naturally ventilated building were higher than those in the air-conditioned building. The type of building population could also affect the outcome as has been found by researchers in the United Kingdom. The predominant population in the naturally ventilated building consisted of government employees which could have affected symptom prevalence.

Over the last several years studies have shown that the quality of indoor air may be worse than outdoor air. People spend as much as 90% of their time indoors, therefor, the associated health risk due to indoor air pollution may be greater than the risk due to outdoor air pollution. Building designs have altered dramatically over the last two decades resulted in "tighter" buildings that rely on sophisticated mechanical systems to provide for the quantity of air required throughout the building. These changes over the years could result in an increased number of complaints received regarding Sick Building Syndrome symptoms. The World Health Organization (WHO) estimates that up to 30% of office buildings world-wide may have significant problems regarding poor indoor air quality (IAQ). This study involves a literature study of the major indoor air pollutants regarding the source of the pollutant, the associated health effects, the measuring techniques available and the results of previous studies conducted on the specific pollutant. Measurements will be taken in two sealed buildings, one an old and the other a new building to identify the major pollutants. A questionnaire was compiled specifically for building occupants and completed by the occupants of both buildings. From the results obtained a step-by-step method for solving indoor air quality (IAQ) problems was proposed. The method was applied and evaluated in a case study of a problem building where indoor air quality related problems were experienced. The results of the study revealed that the major indoor air pollutants are present in old as well as new buildings. The study also revealed that some office workers might be more susceptible than others to the medical reactions cause to human beings by these pollutants. Some concentrations are higher in new buildings than in old buildings. The responses from the questionnaire was evaluated against the results obtained from the measurement study. The step-by-step method in the case study provided a more systematic approach at solving IAQ problems at buildings. Solving indoor air quality problems is a very practical issue and does not necessarily require an investment of expensive high technology equipment, but might merely require a practical approach. Environmental Health Officers can play a major role in providing expert advice when scrutinizing building plans. Environmental Health Officers should empower themselves with the knowledge to do inspections or investigations in office buildings by using the step-by-step method for investigating indoor air quality problems. By addressing indoor air quality problems in buildings, the workers in healthy buildings can increase their productivity with lasting effects on a company’s bottom line.

京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第17794号 / エネ博第277号 / 新制||エネ||58(附属図書館) / 30601 / 京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻 / (主査)教授 東野 達, 教授 坂 志朗, 教授 米田 稔 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

Though the high prevalence of biomass fuel use in the developing world is widely known, the use of burning biomass for cooking and heating in the developed world is under-recognized. Combustion materials including coal and wood are also used for heating in some areas of the United States. We conducted a pilot study to assess the feasibility of conducting indoor environmental monitoring in rural Appalachia. We sought to explore the type of biomass being used for home heating and its impact upon indoor air quality in non-heating and heating seasons. Residential indoor air monitoring for particulate matter (PM) and nitrogen dioxide (NO) was conducted in Lee County, Virginia. Homes had evidence of poor indoor air quality with high concentrations of indoor PM and a large burden of cigarette smoking. Further characterization of indoor combustion material use in this region to determine the health impacts associated with such exposures is warranted.

This thesis is designed to introduce beginning and experienced heating, ventilation and air conditioning (HVAC) engineers to common indoor air quality (IAQ) problems and solutions. The bulk of the work is a literature review of common pollutants, pollutant sources, HVAC equipment and systems, and remediation techniques. Pollutants covered include fungi, bacteria, dust mites, viruses, biofilms, microbiological volatile organic compounds (MVOC?s), volatile organic compounds (VOC?s), carbon dioxide, ozone, and radon. The HVAC systems covered are ventilation, direct expansion (DX), desiccant dehumidification, and system filters. The remediation techniques discussed are proper hygiene and maintenance, increased ventilation, humidity control, and proper selection of building materials.

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Testing was conducted on the pre-prototype unit of an innovative indoor air pollution abatement system which used catalytic ozonation as a mechanism for oxidation and removal of organic contaminants. The system was evaluated for carbonyl production when the system was challenged with chemicals used to simulate polluted indoor air. Carbonyl compounds, which are potentially toxic partial oxidation products, were monitored using EPA Method I P-SA. The objectives of the study were to qualitatively and quantitatively determine if carbonyls were formed in the airstream when the system was operated, and if so, to determine what factors affected the concentrations of these compounds. Trials were conducted using benzene and 2-butanol as challenge chemicals. A variety of test conditions were used to determine factors affecting carbonyl concentrations, including temperature, presence of challenge chemicals, sample location, relative humidity, presence of ozone in the airstream, and two interaction variables. No carbonyls were detected in the airstream within the air cleaning system when benzene was used as the challenge chemical. When 2-butanol was used, four carbonyls were detected at various stages of the system, under varying conditions. The carbonyls detected during these trials were formaldehyde, acetaldehyde, acetone, and butanone. Statistical analyses of the data indicated that the pre-prototype unit of the air cleaning system caused increased levels of acetaldehyde and butanone, and possibly formaldehyde, in the airstream when challenged with 2-butanol. Acetone concentrations in the system were affected only by humidity conditions. / Master of Science