Health effects attributed to outdoor fine particulate matter (PM_2.5) rank it among the risk factors with the highest health burdens in the world, annually accounting for over 3.2 million premature deaths and over 76 million lost disability-adjusted life years. Existing PM_2.5 monitoring infrastructure cannot, however, be used to resolve variations in ambient PM_2.5 concentrations with adequate spatial and temporal density, or with adequate coverage of human time-activity patterns, such that the needs of modern exposure science and control can be met. Small, inexpensive, and portable devices, relying on newly available off-the-shelf sensors, may facilitate the creation of PM_2.5 datasets with improved resolution and coverage, especially if many such devices can be deployed concurrently with low system cost.

Datasets generated with such technology could be used to overcome many important problems associated with exposure misclassification in air pollution epidemiology. Chapter 2 presents an epidemiological study of PM_2.5 that used data from ambient monitoring stations in the Los Angeles basin to observe a decrease of 6.1 g (95% CI: 3.5, 8.7) in population mean birthweight following in utero exposure to the Southern California wildfires of 2003, but was otherwise limited by the sparsity of the empirical basis for exposure assessment. Chapter 3 demonstrates technical potential for remedying PM_2.5 monitoring deficiencies, beginning with the generation of low-cost yet useful estimates of hourly and daily PM_2.5 concentrations at a regulatory monitoring site. The context (an urban neighborhood proximate to a major goods-movement corridor) and the method (an off-the-shelf sensor costing approximately USD $10, combined with other low-cost, open-source, readily available hardware) were selected to have special significance among researchers and practitioners affiliated with contemporary communities of practice in public health and citizen science. As operationalized by correlation with 1h data from a Federal Equivalent Method (FEM) β-attenuation data, prototype instruments performed as well as commercially available equipment costing considerably more, and as well as another reference instrument under similar conditions at the same timescale (R² = 0.6). Correlations were stronger when 24 h integrating times were used instead (R² = 0.72).

Chapter 4 replicates and extends the results of Chapter 3, showing that similar calibrations may be reasonably exchangeable between near-roadway and background monitoring sites. Chapter 4 also employs triplicate sensors to obtain data consistent with near-field (< 50 m) observations of plumes from a major highway (I-880). At 1 minute timescales, maximum PM_2.5 concentrations on the order of 100 μg m^-3 to 200 μg m^-3 were observed, commensurate with the magnitude of plumes from wildfires on longer timescales, as well as the magnitude of plumes that might be expected near other major highways on the same timescale. Finally, Chapter 4 quantifies variance among calibration parameters for a large sample of the sensors, as well as the error associated with the remote transfer of calibrations between two sufficiently large sets (± 10 % for n = 12). These findings suggest that datasets generated with similar sensors could also improve upstream scientific understandings of fluxes resulting from indoor and outdoor emissions, atmospheric transformations, and transport, and may also facilitate timely and empirical verification of interventions to reduce emissions and exposures, in many important contexts (e.g., the provision of improved cookstoves; congestion pricing; mitigation policies attached to infill development; etc.). They also demonstrate that calibrations against continuous reference monitoring equipment could be remotely transferred, within practical tolerances, to reasonably sized and adequately resourced participatory monitoring campaigns, with minimal risk of disruption to existing monitoring infrastructure (i.e., established monitoring sites). Given a collaborator with a short window of access to a reference monitoring site, this would overcome a nominally important barrier associated with non-gravimetric, in-situ calibration of continuous PM_2.5 monitors. Progressive and disruptive prospects linked to a proliferation of comparable sensing technologies based on commodity hardware are discussed in Chapter 5.

In an era of growing interest in transdisciplinary collaboration, evidence-based decision-making, open government, and social impact strategies responding to political and economic challenges, Health Impact Assessment (HIA) is increasingly relevant. HIA sits at the juncture of a number of paradigms for democratic processes for dealing with uncertainty and adding value in decision-making. It draws from a rich history of impact assessment that has accounted for multiple bottom lines. While HIA has gained attention as a specific tool, it is also recognized as part of a suite of more ecological and equitable approaches to health. HIA developers are asking both how to make it work better, so that ultimately government will work better.

This research examines the state of HIA in the United States. It examines the earliest efforts to train a variety practitioners across the country, acknowledging multiple opportunities for capacity-building and many influences on effective HIA practice. More importantly, it identifies a broad definition of effectiveness. Research on HIA practice builds on this, finding that practice is not fully aligned with standards but not necessarily deficient. While objectives should guide HIA processes, the research on training and practice highlights resources as a key driver. The third component of this research considers the resource constraints of public health in general and the opportunities to leverage outside resources using the paradigm of HIA.

In moving the field forward, frameworks for community-based prevention and transdisciplinary education can inform HIA capacity-building. Evaluation of both processes and outcomes will be useful. While methodological challenges remain, the institutionalization of partnerships, processes, and indicators will support public health goals. The definition and standardization of HIA practice must be balanced with efforts to expand its utility in new areas such as community development. In such cases the HIA process and paradigm can leverage investments by estimating returns in health and social denominations. HIA also helps solve the "wrong pocket" problem by accounting for outcomes across sectors and institutions. If used wisely, HIA will be a critical component of health in all policy, sustainability agendas, and social impact strategies.

Cooking and heating remain the most energy intensive activities among the world's poor, and thus improved access to clean energies for these tasks has been highlighted as a key requirement of attaining the major objectives of the UN Millennium Development Goals. A move towards clean energy technologies such as biogas systems (which produce methane from human and animal waste) has the potential to provide immediate benefits for the control of neglected tropical diseases. Here, an assessment of the parasitic disease and energy benefits of biogas systems in Sichuan Province, China, is presented, highlighting how the public health sector can leverage the proliferation of rural energy projects for infectious disease control.

Methodology/Findings:

First, the effectiveness of biogas systems at inactivating and removing ova of the human parasite Schistosoma japonicum is experimentally evaluated. Second, the impact of biogas infrastructure on energy use and environmental quality as reported by surveyed village populations is assessed, as is the community acceptance of the technology. No viable eggs were recovered in the effluent collected weekly from biogas systems for two months following seeding with infected stool. Less than 1% of ova were recovered viable from a series of nylon bags seeded with ova, a 2-log removal attributable to biochemical inactivation. More than 90% of Ascaris lumbricoides ova (used as a proxy for S. japonicum ova) counted at the influent of two biogas systems were removed in the systems when adjusted for system residence time, an approximate 1-log removal attributable to sedimentation. Combined, these inactivation/removal processes underscore the promise of biogas infrastructure for reducing parasite contamination resulting from nightsoil use. When interviewed an average of 4 years after construction, villagers attributed large changes in fuel usage to the installation of biogas systems. Household coal usage decreased by 68%, wood by 74%, and crop waste by 6%. With reported energy savings valued at roughly 600 CNY per year, 2–3 years were required to recoup the capital costs of biogas systems. In villages without subsidies, no new biogas systems were implemented.

Conclusions:

Sustainable strategies that integrate rural energy needs and sanitation offer tremendous promise for long-term control of parasitic diseases, while simultaneously reducing energy costs and improving quality of life. Government policies can enhance the financial viability of such strategies by introducing fiscal incentives for joint sanitation/sustainable energy projects, along with their associated public outreach and education programs.

300 million adults and 16 million children in China are now obese. The rapid economic development, urbanization and associated environmental changes occurring in China are thought to be responsible for this growing obesity epidemic. My dissertation research has gradually developed into four interconnected parts which are presented in Chapter 1, 2, 3 and future work. First (Chapter 1), culturally specific food environment survey instruments were developed and used to document the longitudinal changes in food availability in six representative neighborhoods in Kunming via field audits. Second (Chapter 2), to pilot test our integrated methodology, a 12-person cohort was recruited in Kunming, and individual dietary behavior was modeled and topologies were proposed. Third (Chapter 3), to further test our methodology on a larger cohort aiming to examine the relationship between food environment and sugar-sweetened beverage consumption, we worked with Carolina Population Center on their China Beverage Validation Study in urban and rural Shanghai. Lastly (future work), to examine the health impacts of the changing food environment, a 300 adolescent cohort was recruited from two high schools in Kunming, and followed for two years. Their dietary, physical activity, mental, social and physical changes were assessed via traditional research surveys, smartphone-based activity tracking and Internet datamining. Preliminary results on the cohort’s BMIs are presented.

China’s cities have been growing both in size and population at an unprecedented rate over the last three decades. The evolving urban landscape has important consequences for public health. However, the relationships among the physical environment, human behaviors, environmental exposures, and health are understudied in Chinese populations. Furthermore, more evidence from Chinese studies is needed to inform the design of urban environments and public health programs that promote and improve both mental and physical health.

This dissertation examines how urban development trends in China affect health and quality of life. I approached this question by conducting a cross-sectional socio-behavioral and health survey of 1608 adults in 20 neighborhoods in Xi’an, China in 2013. This cross-sectional study includes residents of four types of neighborhoods that represent different stages of China’s urbanization: work-units, lane and courtyard housing, and two forms of commodity housing (high-density high rises and low-density high rises) neighborhoods. Although cross-sectional in design, this dissertation leverages the temporal history of the neighborhoods present in Xi’an to explore the relationships of development trends with behaviors and health. In particular, I examine the relationships between the natural and built environments and urban health. In addition, I identify neighborhood-specific factors that public health practitioners and urban planners might target to improve health.

First, I apply land use regression (LUR) methodology and the deletion/substitution/addition (DSA) algorithm to select predictive models and create concentration surfaces for four pollutants: PM2.5, NO2, SO2, and O3. The LUR models identified substantial areas of Xi’an that had annual PM2.5, SO2, and NO2 concentrations exceeding current health standards set by the World Health Organization (WHO), providing more evidence for the potential health risks from ambient air pollution in Chinese cities.

Because consistent and reliable air quality monitoring networks are rarely able to keep pace with urbanization in China, new technologies are needed to complement the existing methods of environmental management in cities. Thus, I also test the validity of a new low cost particulate matter sensor (PUWP) for use in high concentration areas like Xi’an. The PUWP sensor performed well as compared to mature PM monitors and could be used to rapidly screen for air pollution “hotspots” in large areas where setting up extensive monitoring stations is challenging. The analysis also observed a sinusoidal relationship between sensor response and PM2.5 concentrations, indicating gradual saturation in the optical sensor’s ability to detect ambient concentrations in high PM environments above 300 µg/m3.

In addition, I present the results of the cross-sectional socio-behavioral and health survey where I examine the associations between self-reported perceptions of the built environment and quality of life, and assess whether these associations differ across the four types of neighborhoods. Neighborhood built environment was strongly associated with both mental and physical-health related quality of life in the commodity housing neighborhoods (high and low-density). In particular, pedestrian infrastructure, diversity of resources, access to and from the neighborhood, and neighborhood safety had the highest positive associations with increased mental health in the high-density high-rise neighborhoods. In the work-unit neighborhoods, increased access to and from the neighborhood was found to be a significantly associated with both mental and physical health. Pedestrian infrastructure, diversity of neighborhood resources, and esthetics were found to be positively associated with mental health in lane/courtyard neighborhoods.

Finally, results from the LUR analysis are also used in an exposure assessment of ambient air pollution for the 20 surveyed neighborhoods. I examine the role of neighborhood air pollution in modifying the associations between leisure-time physical activity (LTPA) and adverse health impact and quality of life. Neighborhood ambient air pollution is included in health effects models in two ways: 1) categorical single pollutant and 2) categorical mixtures models. Increasing LTPA levels are associated with lower odds of adverse health impacts and higher reported quality of life. However, the health and quality of life benefits of physical activity are potentially lower in areas where ambient PM2.5 and O3 are elevated. In addition, single pollutant models are poor proxies of mixtures of pollutants, which indicate a need for considering multi-pollutant exposures in epidemiological studies.

Collectively, these results suggest the built, natural, and social environments should be considered simultaneously as potential targets of intervention to improve quality of life and health in Chinese cities.

Background

Given the rapid pace of urbanization and Westernization and the increasing prevalence of obesity, there is a need for research to better understand the influence of the built environment on overweight and obesity in world’s developing regions. Culturally-specific food environment survey instruments are important tools for studying changing food availability and pricing. Here, we present findings from an effort to develop and evaluate food environment survey instruments for use in a rapidly developing city in southwest China.

Methods

We developed two survey instruments (for stores and restaurants), each designed to be completed within 10 minutes. Two pairs of researchers surveyed a pre-selected 1-km stretch of street in each of three socio-demographically different neighborhoods to assess inter-rater reliability. Construct validity was assessed by comparing the food environments of the neighborhoods to cross-sectional height and weight data obtained on 575 adolescents in the corresponding regions of the city.

Results

273 food establishments (163 restaurants and 110 stores) were surveyed. Sit-down, take-out, and fast food restaurants accounted for 40%, 21% and 19% of all restaurants surveyed. Tobacco and alcohol shops, convenience stores and supermarkets accounted for 25%, 12% and 11%, respectively, of all stores surveyed. We found a high percentage of agreement between teams (>75%) for all categorical variables with moderate kappa scores (0.4-0.6), and no statistically significant differences between teams for any of the continuous variables. More developed inner city neighborhoods had a higher number of fast food restaurants and convenience stores than surrounding neighborhoods. Adolescents who lived in the more developed inner neighborhoods also had a higher percentage of overweight, indicating well-founded construct validity. Depending on the cutoff used, 19% to 36% of male and 10% to 22% of female 16-year old adolescents were found to be overweight.

Conclusions

The prevalence of overweight Chinese adolescents, and the food environments they are exposed to, deserve immediate attention. To our knowledge, these are the first food environment surveys developed specifically to assess changing food availability, accessibility, and pricing in China. These instruments may be useful in future systematic longitudinal assessments of the changing food environment and its health impact in China.

Background

Methods

Results

Conclusions