Browsing by Subject "Sanitation"

Despite the threats to morbidity, mortality, and human capital accumulation posed by environmental risks, investments in environmental health technologies remain low. This is especially evident in low- and middle-income countries, which disproportionately shoulder the burden of environmental risk exposure and consequence. Households face competing risks associated with poor air and water quality, necessitating choices about how to invest in technologies to reduce the consequences associated with their exposures. Yet, even in areas where access to environmental health technologies such as improved cookstoves, latrines, and insecticide-treated bednets has expanded and products are subsidized to make them more affordable, adoption and use of these technologies often lag. This dissertation examines some of the conditions that impact environmental health technology adoption and use decisions as well as the health implications of low investment.

In Chapter 1, I ask how air pollution exposure drives consumption behaviors and impacts health outcomes. I examine this question in the short term--asking how behavior and health respond to a large, yet transitory, spike in ambient air pollution--as well as over time--considering the responses to average ambient air pollution levels over a period of 19 years. I leverage variation in air pollution resulting from forest fire emissions in Indonesia between 1996 and 2015 to generate short-term exposure spikes and average exposures over time, and I combine these exposures with four waves household and individual-level survey data. I implement a cross-sectional, difference-in-difference analysis to estimate the immediate effects of an unexpectedly severe forest fire season in 2015, finding increased fuel demands among the most-exposed households as well as declines in lung capacity among emissions-affected children. I extend my analysis across the panel using an instrumental variables approach to estimate consequences of average exposure over time. I find that households facing higher average ambient air pollution exposures are more likely to utilize clean cooking fuels such as LPG. Even with these behavioral adjustments, more-exposed individuals face significant reductions in lung capacity. In line with existing literature, I find negative health implications resulting from short-term exposure shocks; however, my analysis demonstrates that these respiratory consequences are not fleeting, particularly in areas that experience elevated average ambient air pollution levels.

In Chapter 2, I turn to environmental risks posed by limited access to improved sanitation technologies to examine how social influences impact household sanitation decisions. Using three waves of data collected immediately before, a few months after, and a few years after a randomized latrine promotion campaign in rural Orissa, India, I evaluate the extent to which social influences impact sanitation choices. I find that a ten percentage point decrease in neighbors' open defecation reduces a household's likelihood of open defecation by 3-4 percentage points. The sanitation intervention decreased open defecation in the short term; however, this treatment was less effective in neighborhoods with higher rates of open defecation due to strong social effects. Disaggregating social effects by gender, I find that both women and men respond to sanitation behaviors among male neighbors in the short term and female neighbors in the longer term, perhaps because men have more control over initial latrine purchasing decisions while women are more influential in sustaining latrine use over time.

Finally, in Chapter 3, I expand on my analysis of social influences and sanitation practices and examine how households make decisions to contribute to collective action for sanitation. In this chapter, I analyze data from an experimental public goods game I designed and implemented among over 1500 households in rural Bihar and Orissa, India. I randomly assigned each of the 70 villages in the sample into groups that are either homogeneous or heterogeneous by gender for game play. In the context of rural India, individuals are more likely to frequently interact with and make decisions in front of others of the same gender. Thus, splitting the groups in this way provides a proxy for peer or social groups. Participants chose how much to contribute to improved sanitation by making decisions in the game that are associated with actual sanitation and hygiene choices they face every day. Payoffs were awarded after each round, and payoff amounts were dependent on both individual contributions and aggregated group contributions, generating a setting in which the benefits participants received were connected. Comparing the game behavior among participants in groups that were homogeneous and heterogeneous by gender, I find evidence that contributions to collective action for sanitation are higher in gender homogenous groups. Female participants drive this difference, and it is more distinct in the first round of game play. I also find evidence that preferences for improved sanitation as elicited during the experimental games are reflective of actual improved sanitation practices at the household level.

The problem of inadequate sanitation in less developed countries has dire health consequences such as diarrheal diseases. A household-scale sanitation system consisting of an anaerobic digester, heat exchanger, and biogas-powered heater, was developed to provide a simple, potentially low cost and low carbon-footprint solution to this problem. A conceptual model was developed to predict the effectiveness of the heat sterilization system in reaching the appropriate temperatures to significantly inactivate pathogens such as E. coli, helminthe ova, and viruses. Lab experiments with a stainless steel heater and exchanger were used to establish model parameters and to verify the model. Though the model sometimes predicts higher or lower values than the experimental data, probably due to uncertainties in pathogen decay constants and in the different heat transfer coefficients, the model adequately predicts temperature across the heat exchanger and heater, and can provide a preliminary estimate of pathogen inactivation within the system. Both disinfection experiments showed the system reduces E. coli concentrations to below the WHO limit, which was predicted by the model.

The United States Environmental Protection Agency (EPA) defines environmental justice (EJ) as “The fair treatment and meaningful involvement of all people regardless of race, color, national origin, or income, with respect to the development, implementation, and enforcement of environmental laws, regulations, and policies.” Environmental injustices are not just a symptom of environmental conditions themselves, but are a manifestation of legal, economic, political, and social structures of oppression.

Globally, there are over 4.5 billion people who lack access to safely managed sanitation, with the largest burden of inadequate infrastructure being most greatly felt by communities which are marginalized based on income, indigeneity, and race. The work herein explores three different case studies of engagement with environmental injustices, leveraging academic environmental science and engineering, with three different theories of change: philanthropy-led research, academic-led research, and community-led research, respectively.

Case 1: The Philippines has poor access to improved sanitation, declining national food security, and water scarcity during the dry seasons. Although the country does not contribute as much to man-induced climate change, the Philippines is considered to be one of the most vulnerable countries to be disproportionately affected by climate change, further exacerbating lack of access to sanitation. Through the Gates Foundation’s Reinvent the Toilet Challenge theory of change to privatize innovative technologies to develop for-profit businesses around innovative sanitation systems, a novel modular laboratory anaerobic digestate nitrification and denitrification post-treatment bioreactor system was is developed and operated for 200 days. The system achieved a combined removal of chemical oxygen demand (COD), total nitrogen (TN), and phosphorus (PO4-P) up to 84%, 69%, and 89%, respectively, and have successfully recovered vital nutrients for agricultural development by precipitating ammonium magnesium phosphate hydrate, a documented valuable slow-release solid fertilizer.

Case 2: A predominately African American community in Wake County, North Carolina which, despite being surrounded by White neighborhoods with municipal water distribution lines, relies on private wells for their water supply and relies on on-site septic tanks for sanitation needs. Residents have reason to believe that both on-site water and sanitation infrastructure are compromised, and contamination is of concern. An academic-led community assessment was conducted to determine exposure to standard pathogens and chemical contaminants using culture-based and qPCR methods. Cross contamination septic tanks and wells were evaluated by comparing antibiotic resistance gene profiles, microbial source tracking, and geostatistical models. From samples of 14 household wells, 6 tested positive for total coliforms, 4 for E.coli, 10 for sucralose, and 80% and 20% of total E.coli isolates tested positive for antibiotic resistance to amoxicillin and ceftriaxone, respectively.

Case 3: Lowndes County is a predominantly Black rural county in Alabama which has a rich history and present climate of racial discrimination, economic oppression, and social activism. Over 80 % of the county relies on on-site sanitation infrastructure and most of them are failing, exposing many to raw wastewater. Under the Center of Rural Enterprise and Environmental Justice’s ownership and management, a community assessment of exposure to untreated sewage was conducted using samples from residential drinking water, surface swabs, public surface waters, and both residential and public soil samples using culture-based and qPCR methods. From samples of 43 households, 68% and 55% of houses had detectable presence of human fecal matter in their residential soils and on their doorsteps, respectively. Of the 18 publicly accessible surface waters which were sampled, 50% had detectable amounts of human fecal matter present.

To assess justice and equity components of the theories of change, each case study was contextualized within an equity framework and recommendations are presented regarding the execution of these strategies. Although different theories of change have various broader implications and limitations, the work herein supports the notion that environmental science and engineering can be utilized to address environmental injustices if inclusive and equitable frameworks are used in the research processes.

Introduction: Municipalities often struggle to build and maintain basic infrastructure for informal slums in urban cities for its most vulnerable populations. One impact of inadequate water and sanitation access is the creation of an environment that breeds water borne pathogens that are the agents of infectious disease. Escherichia coli is a common bacteria found in water, often as an indicator of fecal contamination in the water supply. This study looks at one of the most common diseases found in women that results from E. coli growth, urinary tract infection. Specifically, this study aims to examine and describe factors of water, sanitation, and hygiene that are associated with positive E. coli urine results among women. The study took place in Ahmedabad, Gujarat, one of India's wealthier cities, in which heavy investments have been made in improving slum settlements throughout the rapidly expanding city.

Method: This was a cross-sectional study of 250 women recruited from households in urban Ahmedabad from October to December 2017. To determine positive cases of E. coli urinary tract infection, urine samples were collected from each participant. A commercial laboratory performed the urine analyses using a culture method. The threshold for positive cases was 10,000 CFU/mL or greater for E. coli. To obtain information on the water, sanitation, and hygiene practices, each participant completed a structured survey that included questions on demographics, working environment, reproductive health, sanitation access, family relationships, public toilets and social customs.

Results: Of the 250 participants, 23 (9.2%) were above the 100,000 CFU/mL threshold for E. coli, and therefore defined as a positive case. There were 124 (49.6%) participants who attempted a treat method, such as over the counter medicine or home self-treatments, for feminine health in the last three month. There were three factors that significantly correlated with positive cases. The first was the location of the handwashing facility, which could be either inside or outside of the dwelling. The second factor was antibiotic use in the last three weeks. The third factor was a participant living in a home with a child under the age of 5 years old, who experienced diarrhea.

Conclusion: This study identified a higher point prevalence of positive E. coli urine cultures than what we would want or would have expected for a sample population that all had access to piped water and a toilet inside of the dwelling. There is evidence to suggest that hygiene management around water use has an impact on a woman's susceptibility for E. coli causing infections in the urinary tract. Because half of the participants sought a form of treatment over the last three months for feminine health, a longitudinal study that tracks these women over a three month period, could provide relevant information on the incidence of new infections as well as prolonged urinary tract infections, particularly since multi-drug resistant E. coli infections are on the rise.