Background Recent work has examined behavioral reactivity associated with personal awareness of electronic sensors monitoring the use of environmental health products, including cookstoves. These studies suggest that sensors could be used as behavior change tools. Objective We present a human-centered design approach toward the development of a household air quality feedback technology intended to improve consistent and exclusive use of liquid petroleum gas (LPG) stoves provided as part of a health efficacy study. Methods We found through a consultation process that households may be behaviorally triggered by reminders of the health and environmental impacts of cooking practices and may respond to both auditory and visual feedback. Based on these insights, we designed and validated a system linking air particulate monitoring with persistent visual feedback and a dynamic audio alarm. Results Data collected over 14 days in participants households show that the system is able to detect sudden rises in household indoor air pollution and to communicate that information to household members. Significance This device could be used as a tool to raise awareness of air pollution associated in order to stimulate adoption of cleaner cooking technologies.

Low-cost, field-deployable, near-time methods for assessing water quality are not available when and where waterborne infection risks are greatest. We describe the development and testing of a novel device for the measurement of tryptophan-like fluorescence (TLF), making use of recent advances in deep-ultraviolet light emitting diodes (UV-LEDs) and sensitive semiconductor photodiodes and photomultipliers. TLF is an emerging indicator of water quality that is associated with members of the coliform group of bacteria and therefore potential fecal contamination. Following the demonstration of close correlation between TLF and E. coli in model waters and proof of principle with sensitivity of 4 CFU/mL for E. coli, we further developed a two-LED flow-through configuration capable of detecting TLF levels corresponding to “high risk” fecal contamination levels (>10 CFU/100 mL). Findings to date suggest that this device represents a scalable solution for remote monitoring of drinking water supplies to identify high-risk drinking water in near-time. Such information can be immediately actionable to reduce risks.

Waterborne disease is a significant contributor to the global burden of disease, in particular among high-risk populations in developing nations. State-of-the-art methods for the enumeration of microbial pathogens in drinking water sources have important limitations, including high initial cost, 24-48 hour delays in results, high staffing and facility requirements, and training requirements which all become especially problematic in the developing nation context.A number of alternative approaches to microbial water quality testing have been proposed, with the goal of decreasing the required testing time, decreasing overall costs, leveraging appropriate technology approaches, or improving sensitivity or specificity of the water quality testing method. One approach that may offer solutions to some of these limitations involves the deployment of sensor networks using fluorescent spectroscopy to detect intrinsic protein fluorescence in water samples as a proxy for microbial activity. In recent years, a number of researchers have found significant and meaningful correlations between indicator bacteria species and the protein fluorescence of drinking water samples. Additionally, advances in the semiconductor industry could be used to drive down the cost of such sensors. This technology may also be extensible to other water quality parameters, including dissolved organic matter or the presence of fluorescent pollutants.In this thesis, a literature review describes the fundamentals of fluorescence spectroscopy, historical and recent work regarding the fluorescence of the amino acid tryptophan and associated bacterial fluorescence, possible mechanisms for this ii association, and potential applications of this technology for drinking water quality monitoring and waste water process control. Extensibility of the technology is also discussed.Next, experimental methodology in reproduction of similar results is described.Samples were taken from seven (7) surface water sources and tested using membrane filtration and an off-the-shelf fluorescence spectrometer to help examine the association between the presence of indicator bacteria and the tryptophan fluorescence of the water sample. The results, showing an association of R 2 = 0.560, are compared to the results of recent similar experiments.Finally, two prototypes are described, including their design requirements and data from prototype testing. The results of the testing are briefly discussed, and next steps are outlined with the goal of developing a low-cost, in-situ microbial water quality sensor using fluorescence spectroscopy principles.iii Dedication Dedicated to my parents, who taught me to start with the written word in my search for understanding; and who taught me to see even the biggest problems as surmountable and critical. And to my brothers and sisters, who have shown me a halfdozen fascinating ways of interacting with and impacting the world. I'm proud of every one of you.iv

Several approaches have been proposed in the literature supporting product design applied in low-income settings. These approaches have typically focused on individual- and household-level beneficiaries, with an emphasis on participatory, human-centered co-design methods. In this paper, we present a design approach that is, in contrast, focused on supporting providers of improved water, sanitation, and energy services. We establish requirements for design in these contexts, especially addressing design iteration. We describe sets of feedback systems between designers and various sources of expert knowledge, codifying roles of design stakeholders in this context. We demonstrate these principles across three case studies: a sanitation service monitoring technology in Kenya; a water flowmeter technology in Kenya; and a water storage monitoring technology in Sierra Leone.

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