A Novel Interdisciplinary Design Framework Incorporating Plant-Associated Microbial Metabolisms to Shape Indoor Environmental Quality
Date of Award
Spring 2024
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Architecture
First Advisor
Dyson, Anna
Abstract
Urban Health Context Overview, Chapter I: Over 50% of humans currently live in cities, a proportion projected to grow to 68% by 2050 (WHO). Over the course of this urbanization “megatrend”, environmental, systemic factors have evolved that fundamentally alter urban environmental quality and biodiversity. This relationship between urbanization and poor environmental quality requires energy intensive building-integrated systems to improve habitability and alleviate impacts to human health and wellbeing. Despite such efforts, 91% of urban inhabitants breathe polluted air, estimated to shorten millions of lifespans yearly. Simultaneously, urban patterns of environmental biodiversity negatively impact human-associated microbial ecosystems (microbiomes) with significant negative health outcomes. The Interdisciplinarity of Exposure: Urban inhabitants spend 90% of their lives indoors, illustrating the urgency of understanding the mechanisms of indoor environmental quality (IEQ), exposure, and health outcomes. Single-discipline studies have separately connected airborne pollutant and poor environmental microbial diversity exposures to non-communicable diseases ranging from respiratory illnesses and atopic skin conditions to cancer and metrics of immune health. However, methodological frameworks have not yet sufficiently characterized the complex interrelationships between urban microbial environments, airborne exposures, and health outcomes to deliver actionable design criteria to engineers and architects. Chapter II provides a literature review illustrating the urgency for chemical and microbiome exposures to be analyzed simultaneously from human heath, exposure, and experimental perspectives. Bioremediating IEQ with Active Plant-Based Systems: Current mechanical, physiochemical air handling systems are extremely energetically intensive and alleviate indoor air pollution through ventilation and filtration. This often leads to complex interactions between indoor and outdoor pollutants, and actively worsens indoor microbial diversity, a broader IEQ metric. A potential alternative, highly engineered active airflow systems containing metabolically diverse plants and associated microorganisms, was investigated by NASA research scientists in the 1960s. Building-integrated vegetated systems may synthetically address many intractable urban environmental challenges: Studies indicate photosynthetic vegetation and diverse root-associated microbial ecosystems contain metabolisms capable of reducing many indoor pollutants HVAC systems miss. Preliminary evidence even suggests such systems may simultaneously increase human-associated microbial diversity and markers of immune health. Although promising, this research is still largely dependent on laboratory experiments, and is criticized for lacking in complexity and scale to allow for extrapolation into “real-world” applications. Many gaps remain in our understanding of how fundamental bioremediation mechanisms may interface with building-scale air handling systems, air quality chemistry and microbiomes at the scale of human exposure. Chapter III proposes novel methods to collect and analyze chemical and microbiome exposures and a data-analysis approach capable of identifying potential bi-directional relationships between microbiome metabolism and airborne chemical exposures. Chapter IV is an interdisciplinary experimental framework utilizing the chapter III methods to collect simultaneous CO2, chemical, and microbiome exposures enacted by a building-integrated vegetated system within an office environment testbed. Environmental Design Parameters and Performance: Active plant-based bioremediation system performance fundamentally depends upon variable, environmentally-dependent metabolisms of living plants and microorganisms. For example, differences in lighting intensity and angle alter photosynthetic rates and CO2 removal capacities of bioremediation systems. Despite such dependence, few studies have characterized these impacts. Chapter V explores how environmental design parameters, including engineering the growth media, shaping plant and microbial metabolisms, and modulating airflow and lighting design might be utilized to shape bioremediation performance of future systems. Original Contributions: The presented work applied a novel ecosystemic approach, bringing interdisciplinary teams together in a new way to better understand how ecosystems in architecture can be designed to improve human health and wellbeing. Three original contributions were developed within indoor environmental bioremediation research: An interdisciplinary framework with an experimental and analytic approach capable of capturing complex interrelationships between chemical and microbial exposures; Preliminary evidence of simultaneous impacts of a building-integrated bioremediation system on indoor CO2 concentrations and spatialized microbiome abundance, and; A demonstration of the considerable influence fundamental system design characteristics have on active vegetated system performance, including (a) microorganisms with unique metabolic signatures and known human health benefits within three growth media designs, (b) growth media influence on performance and plant physiology, and (c) the potential to optimize performance metrics such as CO2 sequestration by utilizing environmental design parameters such as airflow modulation and lighting design. Future Work: If the performance relationships demonstrated in these systems can be scaled to occupied buildings, then significant societal benefits could result from dramatically improved urban indoor environmental quality, reducing the instance of communicable and non-communicable diseases associated with urban life. The presented work provides a framework for designing with living systems, representing a radical paradigm shift in the way that we manage urban air quality, biodiversity, and building energy systems.
Recommended Citation
Ledins, Phoebe Mankiewicz, "A Novel Interdisciplinary Design Framework Incorporating Plant-Associated Microbial Metabolisms to Shape Indoor Environmental Quality" (2024). Yale Graduate School of Arts and Sciences Dissertations. 1305.
https://elischolar.library.yale.edu/gsas_dissertations/1305
