Asthma, a chronic respiratory disease affecting millions of people worldwide, can vary in severity depending on individual triggers such as Carbon Dioxide, Particulate Matter, dust mites, tobacco smoke, and indoor household activities such as cooking, cleaning, use of heating, and window opening, which can have a negative impact on indoor air quality (IAQ) and exacerbate asthma symptoms. Investigating the relationship between IAQ and asthma severity, a case study was conducted on five asthmatic participants from Bradford, UK. IAQ was measured using IoT indoor air quality monitoring devices. Indoor activities were recorded using a daily household activities questionnaire, and asthma severity was assessed using the Asthma Control Questionnaire (ACQ). Machine learning prediction models were used to analyse various IAQ parameters, such as particulate matter, carbon dioxide, and humidity levels, to identify the most significant predictors of asthma severity with IAQ. The study aimed to develop targeted interventions to improve IAQ and reduce the burden of asthma. Results showed that higher asthma severity scores were associated with increased indoor activity and higher levels of indoor air pollution. Some interventions were implemented to improve ventilation hours, significantly improving IAQ and reducing asthma symptoms, particularly those with more severe asthma. The findings indicate that interventions targeting IAQ, and indoor activities can effectively reduce asthma severity, with up to a 60% reduction in symptoms for asthma patients.

The primary objective of ventilation in a building is to ensure that the Indoor Air Quality (IAQ), together with the heating system, keep the thermal climate at an acceptable level. Meaning the deployment of ventilation air at the appropriate temperature rate supplied to meet the thermal climate into the parts of the building where residents reside. In Sweden, the two most commonly used ventilation strategies are stack ventilation and forced extract ventilation. Both methods utilize exhaust openings in kitchens and sanitary areas, while fresh air is drawn from either permeable external walls or through inlets located near windows and as distant as possible from the exhaust openings (Manz & Huber, 2000). Stack-effect ventilation, also known as buoyancy ventilation, utilizes convective forces. Thus, vertical interior openings such as stairways or atriums play an essential role in the distribution of air and its suitability. Utilizing additional building elements such as a chimney enhances the stack-effect ventilation by elevating the height of the “vertical core” of warm air within the structure. The disparity in density (the difference in temperature between hot and cold) increases as a result of the amplification of pressure disparities (Liu et al., 2010). Hence, larger differences in pressure between the inside and outside will result in an increased driving force for the stack effect by enhancing the convective currents. The principle operates by drawing cooler air from the exterior,generally from the bottom or sides of the building, into the building. The air is then gradually heated and ascends through the vertical core due to convective forces, before being ultimately discharged through the chimney (Savin & Jardinier, 2009). The architectural proposal seeks to adhere to sustainable building development by employing deliberate steps that incorporate a combination of principles and strategies based on the theory of convection. In order to acquire knowledge and validation, an extensive investigation of case studies was carried out, with the works of Philippe Rahm serving as the fundamental basis for further development. Furthermore, a laboratory environment was established to conduct physical tests as well as virtual simulations (CFD) in order to gain deeper understanding and accuracy regarding the relationship between convective forces and geometry. The thesis set out to place a bet based on the notion of consciousness, in terms of implementation of chosen principles, using materials with low embodied carbon, and employing a strategic geometric relationship. This approach enabled the design of an architectural proposal that is both responsive and educative, while also addressing the existing knowledge gap between different professions.

<p dir="ltr">People spend approximately 90% of their time indoors, where they are exposed to a wide variety of particle- and gas-phase air pollutants. The COVID-19 pandemic has intensified the chemical disinfection of high-touch surfaces in occupational workplaces and residential buildings. The use of chemical disinfectants may introduce more pollutants into the indoor environment. These intensive disinfection activities may lead to high human exposure to the released VOC mixtures and potentially adverse effects on the health of disinfection workers and occupants. Thus, it is critical to characterize the VOC mixtures and estimate human exposure during the building disinfection events with various disinfectant products and different disinfection cases and exposure scenarios. This dissertation aims to (1.) evaluate and characterize the VOC emissions during the building disinfections; (2.) assess the low-cost sensor performance to measure VOCs via the PTR-TOF-MS during building disinfections; (3.) compare the VOC measurements and human exposure between breathing zone and bulk air experiment setups; (4.) evaluate the impact of indoor emissions on human exposure during different usage cases of building disinfection.</p><p dir="ltr">To achieve these objectives, this thesis presents three studies based on a field experiment campaign conducted at the Purdue Zero Energy Design Guidance for Engineer (zEDGE) Tiny House in the fall of 2020. First, this thesis presents a study to evaluate the real-time performance of PID in sensing indoor VOC mixtures during building disinfection events through co-location measurements with a PTR-TOF-MS during spray-based disinfectants. The measurements demonstrated that the PID was successful in identifying VOC emission events during the application of the disinfectants. Thus, PIDs may be suitable for integration with building automation systems for ventilation control. The PID response was less than the PTR-TOF-MS response, suggesting that the PID could more efficiently detect many components of the emitted VOC mixtures. Detailed correlation analysis between the PID and PTR-TOF-MS responses provides a basis for improving the reliability of PIDs in estimating VOC concentrations through the application of product-specific correction factors.</p><p dir="ltr">Secondly, this thesis conducts an experimental case study to demonstrate the application of PTR-TOF-MS for mobile breathing zone (BZ) monitoring of VOCs in workplace environments during disinfection activities. Worker inhalation exposure to VOCs was evaluated by attaching the PTR-TOF-MS sampling line to the researcher’s BZ while the disinfection activity was carried out throughout the building. The results show significant spatiotemporal variations in VOC concentrations can occur in the worker’s BZ during multi-surface disinfection events. The application of high-resolution monitoring techniques, such as PTR-TOF-MS, is needed to advance the characterization of worker exposures and develop appropriate mitigation strategies for volatile disinfectant chemicals.</p><p><br></p><p dir="ltr">Lastly, this thesis provides a comprehensive evaluation study on human exposure to VOCs during PAA-based building disinfection events via real-time measurement and disinfection event modeling. The results revealed that PAA-based surface disinfection can lead to an excessive increase in PAA concentrations. BZ experiments demonstrated a spatiotemporal variation in PAA concentrations. The missing mass inhaled measured by the PAA monitor indicated that the human inhalation exposure identified by BZ experiments may be much higher than in bulk air (BA) experiments; thus, a mobile measurement in their breathing zones can better understand the occupants’ exposure to PAA during a building disinfection event. The disinfection event modeling indicated that PAA-based building disinfection may lead to excessive human exposure when using high dilution ratios and/or turning off mechanical ventilation. Such exposure could potentially leave a severe or even irreversible effect on occupant health. These findings suggested that a disinfection protection plan/protocol is necessary for workers, ensuring a required dilution for a disinfectant solution and enough ventilation rate for a safe PAA disinfection event. For the general public who may have difficulties developing professional disinfection procedures, pre-diluted disinfection products with a warning of turning on ventilation could be a more suitable alternative for PAA-based disinfection.</p>

Prior research has shown that indoor air quality (IAQ) impacts cognitive performance. At Cal Poly, many older buildings are unable to maintain appropriate IAQ because of their outdated ventilation systems and the increasing number of students in the rooms. This work analyzes the IAQ of different buildings at Cal Poly, with a focus on Building 20. Carbon dioxide, temperature, and relative humidity inside classrooms are collected using an integrated circuit sensor and a microcontroller. A total of 38 hours of data was collected, with 22 of those hours in Building 20 specifically. We find that unlike temperature and relative humidity, CO2 levels routinely exceed 1,000 ppm—a concentration that hinders cognitive function. A questionnaire distributed to Cal Poly students suggests that while students can recognize poor IAQ in classrooms, they erroneously attribute these poor conditions to temperature and humidity instead of CO2. This data is then used to propose a system which can collect long-term data based on optimal placement, storage, and power requirements.

Background: This dissertation comprises research conducted on two distinct projects. Project I focuses on the connection between household air pollution (HAP) from cooking with biomass fuels and blood pressure (BP); this research is situated in the context of a large randomized trial of a cookstove intervention in Ghana, West Africa. The setting of Project II, meanwhile, is the residential environment of New York City, where we explore temperature and humidity conditions in homes and relate these conditions to summertime heat wave risk and to the survival and transmission of respiratory viruses in the winter. Although these projects are quite distinct, each relates to the complex relationship between climate change and health. Reducing HAP to improve health (the focus of Project I) will simultaneously reduce climate change through a reduction in emissions of short-lived climate pollutants into the atmosphere. Meanwhile, furthering our understanding of heat and humidity levels inside urban residences (the focus of Project II) is crucial to our ability to protect health in light of projections for a changing climate. Domestic activities associated with heating, cooling, and cooking are thus very relevant both to human health and to climate change mitigation and adaptation. Objectives and Methods: Our overall objective for Project I was to investigate exposure- response relationships between HAP and BP in a cohort of pregnant women taking part in the Ghana Randomized Air Pollution and Health Study (GRAPHS). We first explored this association in a cross-sectional study (Chapter 1), in which we used 72-hour personal monitoring to ascertain levels of exposure among the GRAPHS women to carbon monoxide (CO), one of the pollutants emitted by traditional wood-fed cooking fires. These exposure data were collected at enrollment into the GRAPHS study, prior to the initiation of cooking with improved cookstoves. We investigated the association between these “baseline” CO exposure levels and the women’s blood pressure at enrollment into GRAPHS. A limitation of this study was that BP was only measured once. We followed this with a second study of 44 women drawn from the same cohort (Chapter 2), for whom we designed BP protocols using 24-hour ambulatory blood pressure monitoring (ABPM), the current gold standard for clinical diagnosis of hypertension. As we were not aware of any prior research in Africa that had employed ABPM, we also designed a parallel BP protocol using home blood pressure monitoring (HBPM) equipment for comparison with ABPM. The use of ABPM with concurrent personal CO monitoring enabled us to investigate hourly associations between CO exposure and changes in BP. We also evaluated BP in these women both before and after the cookstove intervention; this allowed us to investigate whether any changes in BP were associated with switching to an improved cookstove. Our objectives for Project II were to understand the distribution of temperature and humidity conditions in a range of New York City homes during the summer and winter seasons, to evaluate the impact of structural and behavioral factors (e.g. building size, use of air conditioning, and use of humidifiers) on these conditions, and to build models that could help predict indoor conditions from more readily available outdoor measurements. We conducted this research in two ways. We first analyzed a set of indoor temperature and humidity measurements that were collected in 285 New York City apartments during portions of summers 2003-2011 and used these data to simulate indoor conditions during two heat wave scenarios, one of which was more moderate and the other of which was more extreme (Chapter 3). Second, we designed and conducted a new study in which temperature and humidity were monitored in a set of 40 NYC apartments between 2013 and 2015 (Chapters 4-6). This second study enabled us extend our research into the winter season, and also to explore how factors such as air conditioning and humidifier use impacted indoor temperature and humidity. We also investigated relationships between the monitored conditions, self-reported perceptions of the indoor environment, and symptoms that were experienced among household members. Results: In the cross-sectional analysis of CO and BP in the GRAPHS cohort (Chapter 1), we found a significant positive association between CO exposure and diastolic blood pressure (DBP): on average, each 1 ppm increase in exposure to CO was associated with 0.43 mmHg higher DBP [0.01, 0.86]. A non-significant positive trend was also observed for systolic blood pressure (SBP). In our study of the acute relationship between CO exposure and BP (Chapter 2), we determined that peak CO exposure (defined as above the 90th percentile of the exposure distribution, or an average of 4.1ppm) in the two hours prior to BP measurement was associated with elevations in hourly systolic BP (4.3 mmHg [95% CI: 1.1, 7.4]) and diastolic BP (4.5 mmHg [95% CI: 1.9, 7.2]), as compared to BP following lower CO exposures. We also observed a non-significant trend toward lower BP following initiation of cooking with an improved cookstove. Lastly, we demonstrated that ABPM was a feasible and well-tolerated tool for BP assessment in a rural West African setting. For Project II in New York City, we first determined that there was a great deal of variability in indoor summer heat index (HI) between homes in association with similar outdoor conditions, and that this variability increased with increasing outdoor heat (Chapter 3). Our simulation of a moderate heat wave led us to conclude that the hottest 5% of the homes would reach peak indoor heat index (HI) values of 39°C. In a more extreme heat wave simulation, HI in the hottest 5% of homes reached a peak of 41oC and did not drop below 34oC for the entire nine- day simulated heat wave period. Our second indoor monitoring study yielded the following findings: in the summer season (Chapter 4), we found significant differences in indoor temperature and heat index according to the type of air conditioning (AC) in the home. Homes with central AC were the coolest, followed by homes with ductless AC, window AC, and no AC. Apartments on the top floor of a building were significantly hotter than other apartments regardless of the presence of AC. During the winter season (Chapter 5), median vapor pressure in our sample of apartments was 6.5mb. Comparing humidity levels in the apartments to a threshold of 10mb vapor pressure that has been proposed as protective against influenza virus transmission, levels of absolute humidity in the homes remained below this threshold for 86% of the winter: a total of over three months. Residential use of humidifiers was not associated with higher indoor humidity levels. Larger building size (above 100 units) was significantly associated with lower humidity, while the presence of a radiator heating system was non-significantly associated with higher humidity. Lastly, perceptions of indoor temperature and measured temperature were significantly associated in both the summer and the winter (Chapter 6), while sleep quality was inversely related to measured indoor temperature in the summer season only. Reports of heat- stress symptoms were associated with perceived, but not measured, temperature in the summer season. Conclusions: The work presented in this dissertation adds to a growing body of evidence on the importance of exposures in the domestic environment to health and well-being. The research reported here on household air pollution in Ghana documents an exposure-response relationship between air pollution from cookstoves and elevations in blood pressure, on both a chronic and an acute basis. As elevated BP is a known risk factor for cardiovascular disease (CVD), our research provides support for a plausible factor linking HAP exposure to CVD. Meanwhile, our research on temperature and humidity in New York City residences provides concrete data to supplement the very slim literature to date documenting these conditions in the home environment, where Americans spend over half their time. We conclude, first, that AC may not be fully protective against summertime heat risk, and second, that the levels of humidity we observed in residential environments are consistent with levels that have been shown to promote enhanced survival and transmission of respiratory viruses in experimental settings. We suggest that interventions that can reduce exposure to household air pollution and excess indoor heat can also mitigate climate change, and that with thoughtful planning we can improve health at the same time as we foster resiliency in the face of a changing climate.

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

Forty-three (43) schools in the City of Richmond were used for this study. The rooms in these schools that were selected for testing were those rooms in which complaints about air quality were made by school staff. Tests were done to find out the counts of the different mold species present in these schools. Air-O-Cell (AOC) samples were taken in all schools, swab samples were taken in a few and in the rest biotapes were used. Samples that were taken were analyzed and interpreted at AmeriSci Laboratories, an accredited industrial hygiene laboratory. Documentation was done for the sampling methods. Statistical analysis was run on the data received. Tables of results were made, discussions done and conclusions drawn from the laboratory results.The null hypothesis for this study is that "Total inside mold counts are not elevated above the total outside mold counts in Richmond Public Schools" and the alternative hypothesis is that "Total inside mold counts are elevated above the total outside mold counts in Richmond Public Schools". Biodiversity of molds in the indoor environment should be equal to biodiversity of molds in the outdoor environment for each of the classrooms sampled. Also, Total indoor mold counts exceeding 1000 counts/m3 means that particular school could be faced with a mold problem. In conclusion, it was found out that 58% of the schools sampled could be faced with mold problems, thereby rejecting the null hypothesis, and 42% had no mold problems at all, supporting the null hypothesis. Cladosporium was the most dominant mold genus in the schools and the school with the highest total count of molds in the rooms sampled was Maggie Walker School. Recommendations were then made to reduce the abundance of molds in Richmond Public Schools.

Hospitals and healthcare facilities are very specific times of microenvironments, which requiring monitoring air quality. People who use healthcare facilities are due to a weakened immune system very sensitive to air quality. Acceptable indoor air quality in healthcare facilities may have adverse effects on job performance at the personnel and their errors may have very serious consequences. The aim of this paper is to evaluate the main components of the inner microclimate (temperature and relative air humidity) and concentrations of carbon dioxide in the environment of selected healthcare facilities in the Czech Republic and to compare the results with the related legislation. The measurements were carried out in two hospitals and nine private medical offices from December 2011 to March 2013. The results showed that the values of microclimate factors and the concentration of carbon dioxide in the environment of patient rooms were different in cold and warm part of the year. In the patient rooms the levels of relative humidity diverged from the legal requirements mostly in winter - while those of temperature in summer. The concentration of carbon dioxide was affected by the occupancy rate and the size of the rooms. Air quality in the operating theater was primarily characterized by very low relative...