Microbial growth is a major cause of Indoor Air Quality (IAQ) problems. The implications of mold growth range from unacceptable musty smells and defacement of interior finishes, to structural damage and adverse health effects, not to mention lengthy litigation processes. Mold is likely to occur when a favorable combination of humidity, temperature, and substrate nutrient are maintained long enough. As many modern buildings use products that increase the likelihood of molds (e.g., paper and wood based products), reported cases have increased in recent years. Despite decades of intensive research efforts to prevent mold, modern buildings continue to suffer from mold infestation. The main reason is that current prescriptive regulations focus on the control of relative humidity only. However, recent research has shown that mold occurrences are influenced by a multitude of parameters with complex physical interactions. The set of relevant building parameters includes physical properties of building components, aspects of building usage, certain materials, occupant behavior, cleaning regime, HVAC system components and their operation, and other. Mold occurs mostly as the unexpected result of an unforeseen combination of the uncertain building parameters. Current deterministic mold assessment studies fail to give conclusive results. These simulations are based on idealizations of the building and its use, and therefore unable to capture the effect of the random, situational, and sometimes idiosyncratic nature of building use and operation. The presented research takes a radically different approach, based on the assessment of the uncertainties of all parameters and their propagation through a mixed set of simulations using a Monte Carlo technique. This approach generates a mold risk distribution that reveals the probability of mold occurrence in selected trouble spots in a building. The approach has been tested on three building cases located in Miami and Atlanta. In all cases the new approach was able to show the circumstances under which the mold risk could increase substantially, leading to a set of clear specifications for remediation and, in for new designs, to A/E procurement methods that will significantly reduce any mold risk.

Indoor air quality has become an important health concern due to the number of indoor pollutants and the realization that even minimal exposures to volatile organic compounds may produce direct or indirect adverse health outcomes. Young people are most vulnerable to these poisonous chemicals as they spend much of their times indoors at homes, schools, nurseries and in day care centers. Exposure to volatile organic compounds indoors has been related to asthma and other respiratory symptoms. The adverse effects of air pollution on respiratory health in South Durban have been described in a number of studies. In 2000, a study in the South Durban Basin at Settlers Primary School demonstrated both a high prevalence of respiratory diseases amongst schoolchildren as well as an association between ambient air pollutants and other adverse health outcomes. The South Durban Health Study subsequently undertook a health risk assessment and an epidemiological study investigating this association further on behalf of the eThekwini Municipality. The study highlighted that relatively moderate ambient concentration of N02, NO, PMIO and S02 were strongly and significantly associated with a reduction in lung function among children with persistent asthma. Moreover, attending primary school in South Durban was significantly associated with increased risk from persistent asthma when compared to schools in North Durban. METHODS The descriptive study measured the total volatile organic compound levels within selected homes and schools of asthmatic children in South and North Durban. Recommendations for reducing or mitigating indoor total volatile organic compound exposures were made. The study involved a secondary analysis of data obtained from the South Durban Health Study. The monitoring for total volatile organic compounds within homes and classrooms was undertaken using passive samplers during a 72-hour period and analyzed using a gaschromatography/ mass spectrometry method. Temperature and humidity was assessed using temperature and humidity sensors. Statistical analysis was performed using SPSS version 13. The dataset comprised 140 total volatile organic compound samples from homes and 14 from classrooms. Total volatile organic compounds were measured in microgram per cubic meter (g/m3), temperature in degrees Celsius and relative humidity in percentage of moisture. RESULTS Total volatile organic compounds with levels in households ranging from 17g/m3 to 1440g/m3 and in classrooms ranging from 48g/m3 to 5292g/m3 were measured. The mean levels detected were significantly different in homes and classrooms / Thesis (MMed.)-University of KwaZulu-Natal, Durban, 2008.

Potential determinants of exposure to culturable airborne fungal and bacterial aerosols and carbon dioxide were examined as an aid to the interpretation and evaluation of indoor air quality assessments. Concentration measurments for culturable bioaerosols and CO2 were evaluated against published standards and guidelines. METHOD: All 39 schools from one British Columbia school district were enrolled in the study to ensure different building ages and construction materials, but the same maintenance protocols, were included. Schools were randomly assigned to winter, spring or fall sampling. Data collected included: number of occupants and patterns of occupancy, CO2 levels, temperature and relative humidity, total suspended particles, and air exchange rates using tracer gas (SF6) decay. Other characteristics of the classrooms included the presence or absence of forced air heat, carpets, live animals or aquaria, plants, and the siting of the school or portable classroom. Culturable indoor and outdoor aerosols of fungi and bacteria were collected. Determinants of exposure were modelled by constructing multiple linear regression equations for indoor fungi, indoor bacteria and indoor carbon dioxide. RESULTS: The multiple regression models were able to explain a considerable proportion of the variance for the outcomes of interest (total R2 = 0.59 for mesophilic fungi, 0.61 for bacteria, and 0.68 for CO2). Increased outdoor temperature and outdoor fungal counts were associated with higher concentrations for indoor fungi. Variables describing ventilation and conditions of occupancy were significant to all outcomes of interest but functioned differently in the models. For example, fungal concentration was higher in the presence of natural ventilation, but lower with increased mechanical ventilation. In contrast, CO2 was lower with both ventilation types, and lower with higher outdoor temperature. CONCLUSIONS: Using variables measured during an indoor air quality investigation, predictive models can be constructed which are useful in identifying determinants of bioaerosol and bioeffluent concentrations. Ranges of bioaerosol and bioeffluent concentrations for high occupancy buildings in a coastal temperate zone may differ from guidelines written for other indoor settings and climate zones.

The objectives of this study are to determine the non-methane volatile organic carbon emissions from the parts used in the interiors of buses at different temperatures and to analyze the components of these emissions. The total non-methane volatile organic carbon (NMVOC) concentrations in various sections of a bus were measured in order to determine the indoor air pollution in the bus. Different samples of the materials used in the interior parts of the buses were provided by the manufacturing company and they were tested in the METU Air Pollution Laboratory in order to see what hydrocarbon components make up this total NMVOC concentration.The results of experiments showed that the leading constituent emitted from the test pieces was toluene. Benzene concentration was very low. This is very important since benzene is a carcinogen and it has very low indoor concentration limits determined by OSHA and NIOSH. When the concentrations of the total NMVOC emitted from various parts are examined, it was seen that the most of the VOC emissions occur from the floor materials and ventilation channel. After measurements were done in two buses the average indoor total NMVOC concentrations were found as 21.15 &plusmn / 5.8 ppmv (as C3H8) and 46.04 &plusmn / 9.2 ppmv (as C3H8) in the first and second bus, respectively. Suggestions were made to the manufacturing company for some replacement of solvents and adhesives, and measurements were repeated with the newly manufactured parts for the bus. The highest concentrations were observed for toluene in these measurements, too. However, the toluene concentration was at least 40% lower than the initial values. Benzene concentrations were again very low. The average indoor total NMVOC concentrations were found as 10.41 &plusmn / 2 ppmv (as C3H8) in the measurements done in the bus decorated with new materials. This concentration was about 50% and 25% of the values measured in the first and the second bus at the beginning of the study, respectively.

Diss. (sammanfattning) Linköping : Univ., 2004. / Härtill 6 uppsatser.

Lisensiaatintyö -- Kuopion yliopisto. Ympäristötieteiden laitos. / Includes bibliographical references (p. 69-76). Also available on the World Wide Web.

Potential determinants of exposure to culturable airborne fungal and bacterial aerosols and carbon dioxide were examined as an aid to the interpretation and evaluation of indoor air quality assessments. Concentration measurments for culturable bioaerosols and CO2 were evaluated against published standards and guidelines. METHOD: All 39 schools from one British Columbia school district were enrolled in the study to ensure different building ages and construction materials, but the same maintenance protocols, were included. Schools were randomly assigned to winter, spring or fall sampling. Data collected included: number of occupants and patterns of occupancy, CO2 levels, temperature and relative humidity, total suspended particles, and air exchange rates using tracer gas (SF6) decay. Other characteristics of the classrooms included the presence or absence of forced air heat, carpets, live animals or aquaria, plants, and the siting of the school or portable classroom. Culturable indoor and outdoor aerosols of fungi and bacteria were collected. Determinants of exposure were modelled by constructing multiple linear regression equations for indoor fungi, indoor bacteria and indoor carbon dioxide. RESULTS: The multiple regression models were able to explain a considerable proportion of the variance for the outcomes of interest (total R2 = 0.59 for mesophilic fungi, 0.61 for bacteria, and 0.68 for CO2). Increased outdoor temperature and outdoor fungal counts were associated with higher concentrations for indoor fungi. Variables describing ventilation and conditions of occupancy were significant to all outcomes of interest but functioned differently in the models. For example, fungal concentration was higher in the presence of natural ventilation, but lower with increased mechanical ventilation. In contrast, CO2 was lower with both ventilation types, and lower with higher outdoor temperature. CONCLUSIONS: Using variables measured during an indoor air quality investigation, predictive models can be constructed which are useful in identifying determinants of bioaerosol and bioeffluent concentrations. Ranges of bioaerosol and bioeffluent concentrations for high occupancy buildings in a coastal temperate zone may differ from guidelines written for other indoor settings and climate zones. / Graduate and Postdoctoral Studies / Graduate

The thesis analyses heat loss caused by ventilation for various volumes of ventilated air. Number of model cases were analyzed (class room, fit center, auditorium in the cinema and an apartment). Every scenario was analyzed with the heat recuperation and without it. Annual energetic balance and influence of heat recuperation was evaluated for every model case thereafter. Simulations of ventilation energy consumption were carried out in the TRNSYS 16 program.

This thesis comprises three chapters on topics in development economics. The first chapter studies access to maternal healthcare in markets with vertically differentiated public and private providers. The second chapter studies the efficacy of induction stoves in reducing indoor air pollution in rural households when faced with erratic power supply. Finally, the third chapter studies the role of financial incentives in correcting disparities in sex ratios. All three chapters study the context of India but are representative of important development issues in low-income countries. The first chapter titled "Equilibrium Effects of Subsidizing Public Services" studies one of India's largest welfare schemes Janani Suraksha Yojana (JSY) that incentivized pregnant women in India to access institutional maternal care at public hospitals. We argue that governments can make complementary investments to improve welfare gains from large scale policies. JSY did not improve health outcomes despite a substantial increase in the take-up of institutional care. We document three equilibrium responses that explain this policy failure. First, JSY led to a mismatch of risk across health facilities -- high-risk mothers sorted out of highest quality care at private facilities. Second, in line with the literature, public sector quality deteriorated as a result of congestion. This resulted in lower quality care for both marginal as well as infra-marginal patients at public hospitals. We show that only mothers with high socio-economic status adapted to the worsening quality of care at public hospitals by sorting into more expensive private hospitals. Third, despite increased competition, private hospitals maintained high prices, crowding out riskier and poorer mothers. We do not find evidence that private hospitals improved healthcare quality to justify higher prices. The second chapter titled "Electric Stoves as a Solution for Household Air Pollution" is an interdisciplinary field-based research study that studies the role of reliable electricity in inducing rural Indian households to switch away from dirty cooking fuels towards a clean cooking technology, induction cookstoves, thereby reducing the exposure to high levels of indoor air pollution. We collected minute-by-minute data on electricity availability, electric induction stove use, and kitchen and outdoor particulate pollution in a sample of rural Indian households for one year. Using within household-month variation generated by unpredictable outages, we estimate the effects of electricity availability and electric induction stove use on kitchen PM2.5 concentration at each hour of the day. Electricity availability reduces kitchen PM2.5 by up to 50 ??/?3, which is between 10 and 20 percent of peak concentrations during cooking hours. Induction stove use instrumented by electricity availability reduces PM2.5 in kitchens by 200-450 ??/?3 during cooking hours. The final chapter titled "Can Large-Scale Conditional Cash Transfers Resolve the Fertility-Sex Ratio Trade-off? Evidence from India" studies a large-scale conditional cash transfer (CCT) scheme Ladli Laxmi Yojana that offered cash incentives to households upon the birth of girl children. The policy also offered substantial incentive for investing in girls' education. In my evaluation of the Ladli Laxmi Yojana in Madhya Pradesh, India. I find that financial incentives aimed at the girl child increased average fertility by about 0.15 children per household (on baseline average of 0.93 children) children per household and improved sex-ratio by 3%. This points to the well known fertility-sex ratio trade-off. Moreover, these effects are quite opposite to a similar CCT scheme in Haryana (Anukriti, 2018) suggesting context dependence of such policies.

Firewood is a dominant household fuel type used in many developing countries. Even in countries where there is improved access to electricity, most households still rely on firewood for their energy needs. Harvesting of some wood is illegal, however the high poverty rate, absence of alternative fuels and lack of law enforcement means even the protected wood species will continue to be used, with consequent pressure on the forests. Furthermore, the combustion of firewood for domestic use takes place in poorly ventilated homes emitting hazardous pollutants, which causes indoor air pollution and affect human health. The use of firewood as a household fuel can be superimposed nearly perfectly on that of socioeconomic development. Additionally, the use of household firewood is invariably associated with poverty in countries, in communities within a country and in households within a community. Indoor air pollution studies on human health should then consider socio-economic factors which seem to be one of the determinants of both firewood use and ill health, a determinant which is often neglected in most indoor air pollution studies. Domestic inhalation of firewood smoke is one of the mechanisms linking socio-economic (poverty) to disease. The current study sought to determine a baseline of wood usage and health risks caused by volatile organic compounds in Senwabarwana villages. This study integrated observations, ethnobotanical meta-analysis and experimental into one comprehensive integrated environmental health risk assessment framework to assess the risks associated with exposure to volatile organic compounds from firewood combustion. Basic information about firewood usage, socio-economic dynamics and perceived health problems related to volatile organic compounds was collected using a structured questionnaire. The Vac-U-Chamber was used to sample the air. The results show that firewood is extensively used in poorly ventilated kitchens for cooking and home heating in Senwabarwana villages. Ten priority firewood plant species are frequently used in the study area, namely Mohweleri (Combretum apiculatum), Moretshe (Dichrostachys cinera), Motswiri (Combretum imberbe), Mokgwa (Acacia burkei), Mushu (Acacia tortilis), Motshe (Cussonia paniculate), Mokata (Combretum hereroense), Mphata (Lonchocarpus capassa), Mokgalo (Ziziphus mucronate) and Mogwana (Grewia monticola), in their order of preference. The results also indicated thirteen common reasons or factors that influence the hoice of firewood plant species by households, the main four being: (i) the embers formed during combustion, (ii) heat value, (iii) low ash content and (iv) availability of the firewood plant species. Further analysis revealed several uses and ranking thereof, including reviewing the national status and legal profile of each identified plant species. The study found that most of the firewood species used in Senwabarwana Village were indigenous. Major drivers of firewood use are household income, educational status of breadwinners, family sizes, and place of residence, fuel affordability and accessibility, among others. Concentrations of benzene, toluene, ethylbenzene and xylene per plant species were studied to assess the risk exposed to the Senwabarwana community. Literature indicates that these pollutants have several health effects associated with acute exposure such as eye, nose and throat irritation, headaches, dizziness, nausea and vomiting. Both hazard quotient and hazard index were found to be less than one indicating no risk exists with the use of plant species used for firewood in Senwabarwana even to sensitive individuals. The risk of developing health effects due to the presence of the studied volatile organic compounds can be assessed as negligible. Since firewood is a more convenient source of energy, it is recommended that the size of the windows be extended for ventilation. Agroforesty should also be implemented as a conservation method. The wood that emits less concentration of pollutants be used for firemaking. / Environmental Sciences