Skewed riskscapes and gentrified inequities: environmental exposure disparities in Seattle, Washington

A Shift in Approach to Addressing Public Health Inequities and the Effect of Societal Structural and Systemic Drivers on Social Determinants of Health

Social determinants of health (SDOH) are the conditions in which people are born, grow, live, work, and age that influence health outcomes, and structural and systemic drivers of health (SSD) are the social, cultural, political, and economic contexts that create and shape SDOH. With the integration of constructs from previous examples, we propose an SSD model that broadens the contextual effect of these driving forces or factors rooted in the Centers for Disease Control and Prevention's SDOH framework. Our SSD model (1) presents systems and structures as multidimensional, (2) considers 10 dimensions as discrete and intersectional, and (3) acknowledges health-related effects over time at different life stages and across generations. We also present an application of this SSD model to the housing domain and describe how SSD affect SDOH through multiple mechanisms that may lead to unequal resources, opportunities, and consequences contributing to a disproportionate burden of disease, illness, and death in the US population. Our enhanced SDOH framework offers an innovative and promising model for multidimensional, collaborative public health approaches toward achieving health equity and eliminating health disparities.

Disparities in greenspace associated with sleep duration among adolescent children in Southern California

More than half of adolescent children do not get the recommended 8 hours of sleep necessary for optimal growth and development. In adults, several studies have evaluated effects of urban stressors including lack of greenspace, air pollution, noise, nighttime light, and psychosocial stress on sleep duration. Little is known about these effects in adolescents, however, it is known that these exposures vary by socioeconomic status (SES). We evaluated the association between several environmental exposures and sleep in adolescent children in Southern California.

Methods

In 2010, a total of 1476 Southern California Children's Health Study (CHS) participants in grades 9 and 10 (mean age, 13.4 years; SD, 0.6) completed a questionnaire including topics on sleep and psychosocial stress. Exposures to greenspace, artificial light at night (ALAN), nighttime noise, and air pollution were estimated at each child's residential address, and SES was characterized by maternal education. Odds ratios and 95% confidence intervals (95% CIs) for sleep outcomes were estimated by environmental exposure, adjusting for age, sex, race/ethnicity, home secondhand smoke, and SES.

Results

An interquartile range (IQR) increase in greenspace decreased the odds of not sleeping at least 8 hours (odds ratio [OR], 0.86 [95% CI, 0.71, 1.05]). This association was significantly protective in low SES participants (OR, 0.77 [95% CI, 0.60, 0.98]) but not for those with high SES (OR, 1.16 [95%CI, 0.80, 1.70]), interaction P = 0.03. Stress mediated 18.4% of the association among low SES participants.

Conclusions

Residing in urban neighborhoods of greater greenness was associated with improved sleep duration among children of low SES but not higher SES. These findings support the importance of widely reported disparities in exposure and access to greenspace in socioeconomically disadvantaged populations.

Urban health inequality in shifting environment: systematic review on the impact of gentrification on residents' health

The impacts of changing neighborhoods, and the influence of neighborhood stability on residents' health have not received enough attention in the literature; one of the most important aspects is gentrification. Research on the impact of gentrification on residents' health has gradually increased in recent years, mainly from North America. Based on the guidelines of PRISMA 2020 and SCIE, 66 papers were included for analysis, six aspects of selected studies are discussed: the research design, theoretical framework, methods of analysis, definition and measurement of gentrification effects, and impact pathways. In general, most of the literature in this field can be seen as using an ecological research design, of which cross-sectional research accounts for a large proportion. The identified effects vary in their direction as well as strength due to difference in population, temporal, and geographical characteristics. Gentrification could affect health outcomes through the combination of economic, social, and physical environment factors. Existing research could be improved in the following aspects: (1) The definition and measurement of gentrification should be both generic and site-specific; Various measurement methods should be compared to enhance the robustness of the results. Furthermore, more consideration should be given to the impact of spatial issues; (2) As for health outcomes, it is suggested to expand the scope of the discussion of health outcomes and strengthen the biological explanation of the influencing mechanisms. It is also necessary to determine the research time points according to the characteristics of the incubation period of different diseases; (3) As for research design, applying longitudinal research design is more likely to improve the reliability; (4) Theoretical frameworks should be addressed to link the definition and measurement of gentrification, patterns of health outcomes, methodology and pathways.

Spatial predictors of heavy metal concentrations in epiphytic moss samples in Seattle, WA

The use of bio-indicators is an emerging, cost-effective alternative approach to identifying air pollution and assessing the need for additional air monitoring. This community science project explores the use of moss samples as bio-indicators of the distribution of metal air particulates in two residential neighborhoods of the industrial Duwamish Valley located in Seattle, WA (USA). We applied geographically weighted regression to data from 61 youth-collected samples to assess the location-specific area-level spatial predictors of the concentrations of 25 elements with focus on five heavy metals of concern due to health and environmental considerations. Spatial predictors included traffic volume, industrial land uses, major roadways, the airport, dirt roads, the Duwamish River, impervious surfaces, tree canopy cover, and sociodemographics. Traffic volume surrounding sample locations was the most consistent positive predictor of increasing heavy metal concentration. Greater distance from the heavy-industry corridor surrounding the Duwamish River predicted lower concentrations of all metals, with statistically significant associations for chromium and lead in some areas. As the distance from dirt roads increased, the concentration of arsenic and chromium decreased significantly. Percent tree canopy within 200 m of sample locations was a significant protective factor for cadmium concentrations. In addition, percent people of color was significantly positively associated with increasing lead, chromium and nickel concentrations. Our findings underscore the potential influence of heavy industry and mobile sources on heavy metal concentrations, the buffering potential of trees in local environments, and persistent opportunity to improve environmental justice.

Adapting the environmental risk transition theory for urban health inequities: An observational study examining complex environmental riskscapes in seven neighborhoods in Global North cities

Theories of epidemiologic transition analyze the shift in causes of mortality due to changes in risk factors over time, and through processes of urbanization and development by comparing risk factors between countries or over time. These theories do not account for health inequities such as those resulting from environmental injustice, in which minority and lower income residents are more likely to be exposed to environmental hazards or have less access to environmental goods. Neighborhoods with histories of environmental injustice are also at risk for gentrification as they undergo environmental improvements and new greening projects. We aimed to understand how environmental injustice, urban renewal and green gentrification could inform the understanding of epidemiologic risk transitions. We examined 7 case neighborhoods in cities in the United States and Western Europe which were representative in terms of city region and type, which 1) had experienced a history of environmental injustice and 2) exhibited evidence of recent processes of urban renewal and/or gentrification. In each city, we conducted semi-structured qualitative interviews (n = 172) with city representatives, activists, non-profits, developers and residents. Respondents reported health implications of traditional (heavy pollutants, poor social conditions), transitional (decontamination, new amenities), new (gentrification, access to amenities), and emerging (displacement, climate-related risks, re-emergence of traditional exposures) exposures. Respondents reported renewed, complexified and overlapping exposures leading to poor mental and physical health and to new patterns of health inequity. Our findings point to the need for theories of environmental and epidemiologic risk transitions to incorporate analysis of trends 1) on a city-scale, acknowledging that segregation and patterns of environmental injustice have created unequal conditions within cities and 2) over a shorter and more recent time period, taking into account worsening patterns of social inequity in cities.

At the Water's Edge: Coastal Settlement, Transformative Adaptation, and Well-Being in an Era of Dynamic Climate Risk

With accelerating climate change, US coastal communities are experiencing increased flood risk intensity, resulting from accelerated sea level rise and stronger storms. These conditions place pressure on municipalities and local residents to consider a range of new disaster risk reduction programs, climate resilience initiatives, and in some cases transformative adaptation strategies (e.g., managed retreat and relocation from highly vulnerable, low-elevation locations). Researchers have increasingly understood that these climate risks and adaptation actions have significant impacts on the quality of life, well-being, and mental health of urban coastal residents. We explore these relationships and define conditions under which adaptation practices will affect communities and residents. Specifically, we assess climate and environmental stressors, community change, and well-being by utilizing the growing climate change literature and the parallel social science literature on risk and hazards, environmental psychology, and urban geography work, heretofore not widely integrated into work on climate adaptation.

Toward Environmental Justice in Civic Science: Youth Performance and Experience Measuring Air Pollution Using Moss as a Bio-Indicator in Industrial-Adjacent Neighborhoods

This article reports on an interdisciplinary evaluation of the pilot phase of a community-driven civic science project. The project investigates the distribution of heavy metals in air pollution using moss growing on street trees as a bio-indicator in two industrial-adjacent neighborhoods in Seattle, Washington (USA). One goal of the ongoing project is to meaningfully engage local urban youths (eighth to twelfth grade) in the scientific process as civic scientists, and teach them about environmental health, environmental justice, and urban forestry concepts in a place-based, urban-oriented environmental research project. We describe the collaborative context in which our project developed, evaluate the quality of youth-collected data through analysis of replicate samples, and assess participants’ learning, career interests, and overall appraisal of the pilot. Our results indicate that youth scientists collected usable samples (with acceptable precision among repeated samples), learned project content (with statistically significant increases in scores of test-style survey questions; p = 0.002), and appraised their engagement favorably (with 69% of participants reporting they liked the project). We observed few changes in career interests, however. We discuss our intention to use these preliminary insights to further our community-driven education, research, and action model to address environmental injustices.

Gentrification: A Priority for Environmental Justice and Health Equity Research

Although gentrification is occurring at increasing rates across the United States, our understanding of what this means for public health is limited. While positive changes, such as increases in property values and reduced crime rates occur, negative consequences, such as residential displacement, also ensue. Individuals living through gentrification experience major changes in social and environmental conditions often in short periods of time, which can result in disrupted social networks and stress, both associated with decrements in health. As neighborhoods across the United States undergo revitalization, understanding health effects of gentrification, positive and negative, is paramount. We posit that gentrification may be beneficial in some aspects of health and detrimental in others. To address current challenges in the gentrification-health literature, we recommend future research: 1) examine the gentrification processes and stages; 2) integrate built, natural, and social environment metrics; and 3) assess mediating and moderating associations. As gentrification expands across the United States, research conducted in this area is poised for timely contributions to equitable development and urban planning policies.

Defining gentrification for epidemiologic research: A systematic review

Neighborhoods have a profound impact on individual health. There is growing interest in the role of dynamic changes to neighborhoods-including gentrification-on the health of residents. However, research on the association between gentrification and health is limited, partly due to the numerous definitions used to define gentrification. This article presents a systematic review of the current state of literature describing the association between gentrification and health. In addition, it provides a novel framework for addressing important next steps in this research. A total of 1393 unique articles were identified, 122 abstracts were reviewed, and 36 articles published from 2007-2020 were included. Of the 36 articles, 9 were qualitative, 24 were quantitative, and 3 were review papers. There was no universally accepted definition of gentrification; definitions often used socioeconomic variables describing demographics, housing, education, and income. Health outcomes associated with gentrification included self-reported health, preterm birth, mental health conditions, alcohol use, psychosocial factors, and health care utilization, though the direction of this association varied. The results of this review also suggest that the impact of gentrification on health is not uniform across populations. For example, marginalized populations, such as Black residents and the elderly, were impacted more than White and younger residents. In addition, we identified multiples gaps in the research, including the need for a conceptual model, future mechanistic studies, and interventions.

"Clear action requires clear thinking": A systematic review of gentrification and health research in the United States

Gentrification is a process in which formerly declining, under-resourced, neighborhoods experience reinvestment and in-migration of increasingly affluent new residents, with understudied implications for individual health and health-protective community resources for low-income and minority residents. Increased attention on urban health inequities have propelled research on the relationship between gentrification and health. Yet, there are significant challenges inherent in the study of gentrification given its non-linear process occurring at multiple levels and via various mechanisms in a complex web of urban systems. How then have empirical studies addressed questions regarding the relationship between gentrification and health and wellness from a conceptual and methodological standpoint? Applying key search terms to PubMed and Web of Science, we identified 546 papers published in the United States. This review is guided by three foundational premises informing the inclusion and exclusion of articles. These include: 1. a clear definition of gentrification and explicit health outcome; 2. identification of a specific geographic context (United States) in which gentrification occurs, and 3. use of a social determinants of health framework to identify potential health outcomes of interest. 17 papers met our inclusion criteria. Through systematic content analysis using MaxQDA software, we evaluated the included studies using three critical frames: 1. conceptualization of gentrification; 2. mechanisms linking gentrification and health; and 3. spatio-temporal considerations. Based on this analysis, we identify the strengths and limitations of existing research, and offer three methodological approaches to strengthen the current literature on gentrification and health. We recommend that future studies: 1. explicitly identify the mechanisms and levels at which processes can occur and systems are organized; 2. incorporate space and time into the analytical strategy and 3. articulate an epistemological standpoint driven by their conceptualization of the exposure and identification of the relevant mechanism and outcome of interest.

Environmental Justice in Industrially Contaminated Sites. A Review of Scientific Evidence in the WHO European Region

In the WHO European Region the topic of contaminated sites is considered a priority among environment and health themes. Communities living in or close to contaminated sites tend to be characterized by a high prevalence of ethnic minorities and by an unfavorable socioeconomic status so rising issues of environmental justice. A structured review was undertaken to describe the contents of original scientific studies analyzing distributive and procedural justice in industrially contaminated sites carried out in the WHO European Region in the period 2010⁻2017. A systematic search of the literature was performed. In total, 14 articles were identified. Wherever assessments on environmental inequalities were carried out, an overburden of socioeconomic deprivation or vulnerability, with very few exemptions, was observed. The combined effects of environmental and socioeconomic pressures on health were rarely addressed. Results show that the studies on environmental and health inequalities and mechanisms of their generation in areas affected by industrially contaminated sites in the WHO European Region are in their early stages, with exemption of UK. Future efforts should be directed to improve study strategies with national and local assessments in order to provide evidence for equity-oriented interventions to reduce environmental exposure and related health risks caused by industrial contamination.

The burden of carcinogenic air toxics among Asian Americans in four US metro areas

This study investigated disparities in residential exposure to carcinogenic air pollutants among Asian Americans, including Asian ancestry subgroups, in four US metro areas with high proportions of Asians, i.e., Honolulu, Los Angeles, San Francisco Bay Area, and Seattle. Generalized estimating equations adjusting for socioeconomic status, population density and clustering show that a greater proportion of Asian Americans in census tracts was associated with significantly greater health risk in all four metro areas. Intracategorical disparities were uncovered for Asian ancestry. A greater proportion Korean was positively associated with risk in four metro areas; greater proportion Chinese and Filipino were positively associated with risk in three of the four metro areas. While Asian Americans are infrequently examined in environmental justice research, these results demonstrate that Asian Americans experience substantial distributional environmental injustices in these four metro areas and that ancestry is an important dimension of intracategorical complexity.

Ambient Air Pollution and Asthma-Related Outcomes in Children of Color of the USA: a Scoping Review of Literature Published Between 2013 and 2017

PURPOSE OF REVIEW

Given racial disparities in ambient air pollution (AAP) exposure and asthma risk, this review offers an overview of the literature investigating the ambient air pollution-asthma relationship in children of color between 2013 and 2017.

RECENT FINDINGS

AAP is likely a key contributor to the excess burden of asthma in children of color due to pervasive exposure before birth, at home, and in school. Recent findings suggest that psychosocial stressors may modify the relationship between AAP and asthma. The effect of AAP on asthma in children of color is likely modulated by multiple unique psychosocial stressors and gene-environment interactions. Although children of color are being included in asthma studies, more research is still needed on impacts of specific criteria pollutants throughout the life course. Additionally, future studies should consider historical factors when analyzing current exposure profiles.

Changes in Transportation-Related Air Pollution Exposures by Race-Ethnicity and Socioeconomic Status: Outdoor Nitrogen Dioxide in the United States in 2000 and 2010

BACKGROUND

Disparities in exposure to air pollution by race-ethnicity and by socioeconomic status have been documented in the United States, but the impacts of declining transportation-related air pollutant emissions on disparities in exposure have not been studied in detail.

OBJECTIVE

This study was designed to estimate changes over time (2000 to 2010) in disparities in exposure to outdoor concentrations of a transportation-related air pollutant, nitrogen dioxide (NO2), in the United States.

METHODS

We combined annual average NO2 concentration estimates from a temporal land use regression model with Census demographic data to estimate outdoor exposures by race-ethnicity, socioeconomic characteristics (income, age, education), and by location (region, state, county, urban area) for the contiguous United States in 2000 and 2010.

RESULTS

Estimated annual average NO2 concentrations decreased from 2000 to 2010 for all of the race-ethnicity and socioeconomic status groups, including a decrease from 17.6 ppb to 10.7 ppb (-6.9 ppb) in nonwhite [non-(white alone, non-Hispanic)] populations, and 12.6 ppb to 7.8 ppb (-4.7 ppb) in white (white alone, non-Hispanic) populations. In 2000 and 2010, disparities in NO2 concentrations were larger by race-ethnicity than by income. Although the national nonwhite-white mean NO2 concentration disparity decreased from a difference of 5.0 ppb in 2000 to 2.9 ppb in 2010, estimated mean NO2 concentrations remained 37% higher for nonwhites than whites in 2010 (40% higher in 2000), and nonwhites were 2.5 times more likely than whites to live in a block group with an average NO2 concentration above the WHO annual guideline in 2010 (3.0 times more likely in 2000).

CONCLUSIONS

Findings suggest that absolute NO2 exposure disparities by race-ethnicity decreased from 2000 to 2010, but relative NO2 exposure disparities persisted, with higher NO2 concentrations for nonwhites than whites in 2010. https://doi.org/10.1289/EHP959.