Disparities In Exposure Research Articles

Racial Disparities in Adversity During Childhood and the False Appearance of Race-Related Differences in Brain Structure.

Black Americans in the United States are disproportionately exposed to childhood adversity compared with White Americans. Such disparities may contribute to race-related differences in brain structures involved in regulating the emotional response to stress, such as the amygdala, hippocampus, and prefrontal cortex (PFC). The authors investigated neuroanatomical consequences of racial disparities in adversity. The sample included 7,350 White American and 1,786 Black American children (ages 9-10) from the Adolescent Brain Cognitive Development Study (public data release 2.0). Structural MRI data, parent and child self-reports of adversity-related measures, and U.S. Census neighborhood data were used to investigate the relationship between racial disparities in adversity exposure and race-related differences in brain structure. Black children experienced more traumatic events, family conflict, and material hardship on average compared with White children, and their parents or caregivers had lower educational attainment, lower income, and more unemployment compared with those of White children. Black children showed lower amygdala, hippocampus, and PFC gray matter volumes compared with White children. The volumes of the PFC and amygdala, but not the hippocampus, also varied with metrics of childhood adversity, with income being the most common predictor of brain volume differences. Accounting for differences in childhood adversity attenuated the magnitude of some race-related differences in gray matter volume. The results suggest that disparities in childhood adversity contribute to race-related differences in gray matter volume in key brain regions associated with threat-related processes. Structural alterations of these regions are linked to cognitive-affective dysfunction observed in disorders such as posttraumatic stress disorder. More granular assessments of structural inequities across racial/ethnic identities are needed for a thorough understanding of their impact on the brain. Together, the present findings may provide insight into potential systemic contributors to disparate rates of psychiatric disease among Black and White individuals in the United States.

Observed inequality in thermal comfort exposure and its multifaceted associations with greenspace in United States cities

Increasing exposure to heat stress threatens the health and well-being of urban residents. However, existing studies on measuring human thermal comfort exposure remain uncertain without considering fine-scale human-heat interaction and its long-term dynamics. To inform this issue, we proposed a population-weighted exposure assessment framework with the integration of high-resolution land surface temperature and population data to evaluate human exposure to thermal comfort and the associated inequality across 398 major cities over 2000–2020 in the United States, and further explored the multifaceted associations between greenspace and thermal comfort. Results show that 199 United States cities (50.00 %) experience severe heat stress (i.e., thermal comfort exposure <0.44) and 99 of which (24.87 %) are unevenly exposed to heat stress (i.e., Gini index of thermal comfort exposure >0.36). Temporal analysis from 2000 to 2020 reveals that human exposure to thermal comfort decreases by a mean magnitude of −0.00081 yr−1, and the associated inequality level decreases by a mean magnitude of −0.00153 yr−1. By linking urban greenspace and heat exposure, we find that greenspace has multifaceted associations with heat stress, with a highly positive correlation between greenspace and thermal comfort (i.e., comfort regulation by physical cooling effect) and a coincided exposure inequality between greenspace and thermal comfort. This study offers an alternative framework to characterize fine-scale human exposure to thermal comfort across space and time, provides observational evidence of thermal comfort exposure inequality in the United States cities, and highlights the need for prioritizing greening policies and actions to mitigate heat stress and exposure disparity.

Making the invisible visible: Using a qualitative system dynamics model to map disparities in cumulative environmental stressors and children's neurodevelopment

BackgroundThe combined effects of multiple environmental toxicants and social stressor exposures are widely recognized as important public health problems, likely contributing to health inequities. However, US policy makers at state and federal levels typically focus on one stressor exposure at a time and have failed to develop comprehensive strategies to reduce multiple co-occurring exposures, mitigate cumulative risks and prevent harm. This research aimed to move from considering disparate environmental stressors in isolation to mapping the links between environmental, economic, social and health outcomes as a dynamic complex system using children's exposure to neurodevelopmental toxicants as an illustrative example. Such a model can be used to support a broad range of child developmental and environmental health policy stakeholders in improving their understanding of cumulative effects of multiple chemical, physical, biological and social environmental stressors as a complex system through a collaborative learning process. MethodsWe used system dynamics (SD) group model building to develop a qualitative causal theory linking multiple interacting streams of social stressors and environmental neurotoxicants impacting children's neurodevelopment. A 2 1/2-day interactive system dynamics workshop involving experts across multiple disciplines was convened to develop the model followed by qualitative survey on system insights. ResultsThe SD causal map covered seven interconnected themes: environmental exposures, social environment, health status, education, employment, housing and advocacy. Potential high leverage intervention points for reducing disparities in children's cumulative neurotoxicant exposures and effects were identified. Workshop participants developed deeper level of understanding about the complexity of cumulative environmental health risks, increased their agreement about underlying causes, and enhanced their capabilities for integrating diverse forms of knowledge about the complex multi-level problem of cumulative chemical and non-chemical exposures. ConclusionGroup model building using SD can lead to important insights to into the sociological, policy, and institutional mechanisms through which disparities in cumulative impacts are transmitted, resisted, and understood.

Modeling expected air quality impacts of Oregon's proposed expanded clean fuels program

The public health burden of traffic-related air pollution falls most heavily on the population living closest to major transportation corridors, which leads to exposure disparities between different socio-economic groups across the United States. The state of Oregon has adopted climate policies to reduce transportation fuel carbon intensity (CI). These climate policies have the potential co-benefit of reducing air pollution exposure disparities for different socio-economic groups. Here we analyze the emissions and air quality outcomes of three future year (2035) scenarios for transportation fuels in Oregon: (i) a Business as usual (BAU) scenario, (ii) a Clean Fuels Program (CFP) scenario that represents adoption and successful achievement of a proposed 25% reduction in carbon intensity in 2035; and (iii) a maximum ambition scenario (CFP MAX) that builds on the CFP scenario to achieve a 37% CI reduction by adopting low carbon fuels more aggressively, especially for heavy duty vehicles. Transportation emissions under all scenarios were estimated using the MOVES model for every county in Oregon. Detailed emissions with 4 km spatial resolution were then developed for each scenario by scaling the National Emissions Inventory (NEI) for the year 2017 based on the emissions derived from the MOVES analysis. Air quality in 2035 was simulated using the UCD/CIT chemical transport model that enables a detailed analysis of PM2.5 and PM0.1 components and sources. Exposure fields were analyzed using the BenMAP model to predict public health outcomes. Environmental justice analysis was conducted by race/ethnicity categories and income categories obtained from the American Community Survey (ACS). Results suggest that adoption of low-carbon transportation fuels will improve air quality in Oregon, yielding public health benefits equivalent to approximately $80M/yr. Adoption of low carbon transportation fuels will also reduce disparities in exposure to transportation-related air pollution between residents in different race/ethnicity categories by ∼14% in Portland and ∼20% in Salem. Adoption of low-carbon fuels reduces PM2.5 mass disparity by 10% in Salem, but does not have a significant effect in Portland, because on-road mobile sources contribute to less than 3% of the total PM2.5 mass disparity in this city. The analysis reveals that the spatial distribution of each race/ethnicity group in each city is the primary factor that determines the impact of low carbon fuel adoption on exposure disparity.

Sociodemographic Disparities in Ambient Particulate Matter Exposure in Austria

Sociodemographic Disparities in Ambient Particulate Matter Exposure in Austria

Environmental Health, Racial/Ethnic Health Disparity, and Climate Impacts of Inter-Regional Freight Transport in the United States.

We quantify and compare three environmental impacts from inter-regional freight transportation in the contiguous United States: total mortality attributable to PM2.5 air pollution, racial-ethnic disparities in PM2.5-attributable mortality, and CO2 emissions. We compare all major freight modes (truck, rail, barge, aircraft) and routes (∼30,000 routes). Our study is the first to comprehensively compare each route separately and the first to explore racial-ethnic exposure disparities by route and mode, nationally. Impacts (health, health disparity, climate) per tonne of freight are the largest for aircraft. Among nonaircraft modes, per tonne, rail has the largest health and health-disparity impacts and the lowest climate impacts, whereas truck transport has the lowest health impacts and greatest climate impacts─an important reminder that health and climate impacts are often but not always aligned. For aircraft and truck, average monetized damages per tonne are larger for climate impacts than those for PM2.5 air pollution; for rail and barge, the reverse holds. We find that average exposures from inter-regional truck and rail are the highest for White non-Hispanic people, those from barge are the highest for Black people, and those from aircraft are the highest for people who are mixed/other race. Level of exposure and disparity among racial-ethnic groups vary in urban versus rural areas.

LIFE EVENTS AND CARDIOVASCULAR DISEASE EVENTS: THE STUDY OF WOMEN'S HEALTH ACROSS THE NATION

Abstract Cardiovascular disease (CVD) is the number one cause of death for women, and major life events across midlife may contribute to CVD risk. The present study aimed to test whether greater exposure to major life events across nearly two decades of longitudinal follow-up would be associated with higher risk of clinical cardiovascular disease events. 3,222 middle-aged women from the multi-ethnic Study of Women’s Health Across the Nation reported and provided up to 15 years of major life events, non-fatal incident CVD events, traditional biobehavioral and sociodemographic factors, and death certificates. Cox proportional hazards models were used to test the association between average annual life events and incident fatal and nonfatal CVD events. Each additional major life event was associated with a 1.16-fold (95% CI: 1.08-1.23) increase in CVD events. CVD risk will be discussed considering evidence of racial/ethnic disparities in exposure to major life events.

RACIAL AND ETHNIC DISPARITIES IN COVID-19 DISRUPTIONS TO SOCIAL ACTIVITIES AMONG OLDER ADULTS IN THE UNITED STATES

Abstract Racial disparities in COVID-19 exposure, illness, hospitalization and mortality have been well-documented, however, less is known about potential disparities in the pandemic’s effect on social activities. Data from the early release of the 2020 Health and Retirement Study (HRS) were used to examine the relationship between race (White/African American/other) and ethnicity (Hispanic/Non-Hispanic) and COVID-19 disruptions to social activities (N=4,500). Participants were asked, “due to the coronavirus pandemic, did you experience any of these changes in activities: 1) unable to visit a family member in a care facility, nursing home or group home, 2) family celebrations canceled/restricted, 3) unable to visit a close family member in the hospital, 4) unable to attend in-person funeral or religious service for a family member or friend, 5) unable to visit family after birth of a baby (1=yes, 0=no/not relevant) and, “overall, how stressful have changes in contacts with family and friends been for you?” (1=not at all stressful, 5=extremely stressful). Results from logistic regression controlling for age and gender showed that relative to Whites, African Americans had significantly higher odds of all disruptions except for family celebrations and relative to non-Hispanics, Hispanics had significantly higher odds of three types of disruptions. OLS regression results showed that only Hispanics had higher average stress due to these changes. These findings indicate that in addition to the previously documented disparities in COVID-19, older African Americans and Hispanics experienced greater disruptions to social activities. These impacts could further influence both short and long-term physical and mental health.

Impacts of Air Pollution on the Respiratory System of Adults in Relation to Socioeconomic Status

Air pollution has a significant impact on respiratory health, yet comprehensive summaries of specific impacts are limited. This study reviews previous research done on this link, while connecting it to socioeconomic factors. Common air pollutants, such as particulate matter, have a large impact on respiratory health and can exacerbate diseases and medical conditions, such as coughing, wheezing, chronic obstructive pulmonary disease, asthma, and cystic fibrosis. Specifically, PM10 pollutants can deposit in the upper airways, and PM2.5 can reach deep into the lungs, leading to many complications. The efficacy of measures taken to combat these issues are also discussed. In recent years, governments have introduced national climate policies and green-space designs in urban municipalities to reduce negative health outcomes. These measures accomplish this goal to a limited degree but require further investment and development. To outline how socioeconomic status impacts air pollution-related respiratory illnesses, our study discusses five studies investigating socioeconomic disparities in air pollution exposure in various parts of the world. Evidence shows that low-income people typically reside in areas with high air pollution because housing is more affordable. This provides an opportunity for new research in social determinants of health to better understand its connection with human health.

Prenatal socioenvironmental exposures and autism spectrum disorder: A web of confusion.

Although evidence of heritability for autism spectrum disorder (ASD) is strong, studies of twin pairs suggest that at least some portion of the etiology is attributable to environmental factors, either directly or through interaction with genes. Given the multitude of environmental and psychosocial exposures that have been reported to increase atypical neurodevelopment in offspring, in this article, we summarize what prenatal air pollutant, chemical, and occupational exposures and psychosocial stressors have been reportedly associated with ASD and co-occurring neurodevelopmental disorders. We highlight consistencies in reported associations and recommend areas for research to close gaps in our understanding of environmental risk for ASD. Because this issue is of particular importance in historically marginalized communities and low- and middle-income countries, we also discuss the importance of environmental justice issues and exposure disparities in research, and we advocate for prioritizing policies to reduce disparities and improve service provision in vulnerable populations.

Linking Historical Discriminatory Housing Patterns to the Contemporary Alcohol Environment.

Research on alcohol outlet density consistently shows greater disparities in exposure in disinvested communities. Likewise, structural racism via discriminatory housing practices has created many of the issues that beset contemporary disinvested neighborhoods. Little work, however, has examined the relationship between housing practices and alcohol outlet disparities. The central premise of our work is that these discriminatory and inequitable practices create distinctions in the alcohol environment, and that such disparities have implications for work on alcohol policy.Here we link alcohol outlet density with a spatial database examining redlining, blockbusting, and gentrification in Baltimore, Maryland, and Flint, Michigan (two cities with common experiences of urban disinvestment over the last 50 years). Standard measures are used to account for the impacts of neighborhood racial, socioeconomic, and housing composition in a multilevel model.Our findings highlight that gentrification and redlining are strongly associated with alcohol outlet density, while blockbusting is not. Gentrification and redlining also frequently co-occur in inner-urban areas, while the more suburban phenomenon of blockbusting rarely overlaps with either.These findings further contextualize nascent work on structural racism in housing that illustrates important disparities along the lines of these distinct practices. Future work should consider how legacy impacts of discriminatory housing patterns impact our communities today.

Impacts of wind power on air quality, premature mortality, and exposure disparities in the United States.

Understanding impacts of renewable energy on air quality and associated human exposures is essential for informing future policy. We estimate the impacts of U.S. wind power on air quality and pollution exposure disparities using hourly data from 2011 to 2017 and detailed atmospheric chemistry modeling. Wind power associated with renewable portfolio standards in 2014 resulted in $2.0 billion in health benefits from improved air quality. A total of 29% and 32% of these health benefits accrued to racial/ethnic minority and low-income populations respectively, below a 2021 target by the Biden administration that 40% of the overall benefits of future federal investments flow to disadvantaged communities. Wind power worsened exposure disparities among racial and income groups in some states but improved them in others. Health benefits could be up to $8.4 billion if displacement of fossil fuel generators prioritized those with higher health damages. However, strategies that maximize total health benefits would not mitigate pollution disparities, suggesting that more targeted measures are needed.

Pavement resurfacing and supply chains are significant contributors to PM2.5 exposure from road transportation: evidence from the San Francisco Bay Area

There are hundreds of millions of kilometers of paved roads and many people live in proximity. Pollution from road transportation is a well-documented problem potentially leading to chronic health impacts. However, research on the raw material production, construction, operation, maintenance, and end-of-life phases of paved roads, and corresponding supply chains, is generally limited to energy consumption and greenhouse gas emissions. No previous research efforts on the life-cycle stages of pavements and road operation connect pollutant emission inventories to intake of inhaled pollutants and resulting damages to exposed populations. We have developed a first-of-its-kind model quantifying human exposure to fine particulate matter (PM2.5) due to emissions from routine pavement resurfacing and vehicle operation. We utilize the Intervention Model Pollution Source-Receptor Matrix to calculate marginal changes in ground-level PM2.5 concentrations and resulting exposure intake from a spatially resolved primary and secondary PM2.5 emission precursors inventory. Under a scenario of annual road-resurfacing practices within the San Francisco Bay Area in California (population: 7.5 million), resurfacing activities, material production and delivery (i.e. cement, concrete, aggregate, asphalt, bitumen), and fuel (i.e. gasoline, diesel) supply chains contribute almost 65% to the annual PM2.5 intake from all the sources included in the study domain (the remaining 35% being due to on-road tailpipe emissions). Exposure damages range from $170 to $190 million (2019 USD). Complete electrification of on-road mobile sources would reduce annual intake by 64%, but a sizable portion would remain from material supply chains, construction activities, and brake and tire wear. Future mitigation policies should be enacted equitably. Results show that people of color experience higher-than-average PM2.5 exposure disparities from the emission sources included in the study, particularly from material production.

How magnitude of PM2.5 exposure disparities have evolved across Chinese urban-rural population during 2010–2019

Rapid industrialization and urbanization in China not only facilitate economic progress, but also aggravate environmental pollution and disparity. Particulate matter (especially PM2.5) pollution has attracted considerable attention in recent years owing to its serious adverse health impact. However, the spatial disparity and socioeconomic inequality between urban and rural population owing to PM2.5 pollution have rarely been quantified. In this study, PM2.5 exposures to urban and rural population in China during 2010–2019 were estimated respectively using satellite data and the convolutional neural network. The association between socioeconomic indexes and PM2.5 exposure was then examined with the geographic detectors, considering the tremendous disparity in socioeconomic development between rural and urban communities. The regional difference and urban-rural disparity in PM2.5 exposure was finally quantified based on Theil index. The results show PM2.5 exposure and its spatial difference have decreased significantly during the decade, with the concentration decreasing by 26% (from 48 to 35 μg/m3) and the Theil index decreasing from 0.13 to 0.05. The inter-provincial difference dominates the overall spatial variation in 2010, changing to intra-provincial difference in 2019. We also find that China has faced environmental inequality in PM2.5 exposure between urban and rural community in the past decade, manifesting that the urban population suffered from higher PM2.5 levels than the rural population, while the inequality had decreased significantly by 2019. This is consistent with the pattern that PM2.5 exposures increase with socioeconomic development in the early stage, and stabilize or decrease in the late stage. The results suggest that China should abandon the old path of “pollute first and control later” on rural revitalization strategy, otherwise rural population may experience higher exposure than urban population, plunging rural communities into the “environment-health-poverty” trap.

Fifteen Years of Community Exposure to Heavy-Duty Emissions: Capturing Disparities over Space and Time.

Disparities in exposure to traffic-related air pollution have been widely reported. However, little work has been done to simultaneously assess the impact of various vehicle types on populations of different socioeconomic/ethnic backgrounds. In this study, we employed an extreme gradient-boosting approach to spatially distribute light-duty vehicle (LDV) and heavy-duty truck emissions across the city of Toronto from 2006 to 2020. We examined associations between these emissions and different marginalization indices across this time span. Despite a large decrease in traffic emissions, disparities in exposure to traffic-related air pollution persisted over time. Populations with high residential instability, high ethnic concentration, and high material deprivation were found to reside in regions with significantly higher truck and LDV emissions. In fact, the gap in exposure to traffic emissions between the most residentially unstable populations and the least residentially unstable populations worsened over time, with trucks being the larger contributor to these disparities. Our data also indicate that the number of trucks and truck emissions increased substantially between 2019 and 2020 whilst LDVs decreased. Our results suggest that improvements in vehicle emission technologies are not sufficient to tackle disparities in exposure to traffic-related air pollution.

Racial/Ethnic Disparities in Exposure, Disease Susceptibility, and Clinical Outcomes during COVID-19 Pandemic in National Cohort of Adults, United States.

We examined racial/ethnic disparities for COVID-19 seroconversion and hospitalization within a prospective cohort (n = 6,740) in the United States enrolled in March 2020 and followed-up through October 2021. Potential SARS-CoV-2 exposure, susceptibility to COVID-19 complications, and access to healthcare varied by race/ethnicity. Hispanic and Black non-Hispanic participants had more exposure risk and difficulty with healthcare access than white participants. Participants with more exposure had greater odds of seroconversion. Participants with more susceptibility and more barriers to healthcare had greater odds of hospitalization. Race/ethnicity positively modified the association between susceptibility and hospitalization. Findings might help to explain the disproportionate burden of SARS-CoV-2 infections and complications among Hispanic/Latino/a and Black non-Hispanic persons. Primary and secondary prevention efforts should address disparities in exposure, vaccination, and treatment for COVID-19.

Exposure to animal feeding operations including concentrated animal feeding operations (CAFOs) and environmental justice in Iowa, USA

Health consequences of intensive livestock industry and implications for environmental justice are of great concern in Iowa, USA, which has an extensive history of animal feeding operations (AFOs). We examined disparities in exposure to AFOs including concentrated AFOs (CAFOs) with several environmental justice metrics and considered exposure intensity based on animal units (AUs). Using data on permitted AFOs from the Iowa Department of Natural Resources, we evaluated environmental disparities by multiple environmental justice metrics (e.g. race/ethnicity, socio-economic status (SES), income inequality (Gini index), racial isolation, and educational isolation) using 2010 Census tract-level variables. We used an exposure metric incorporating the density and intensity as the sum of AUs within each Census tract. We investigated exposure disparities by comparing distributions of environmental justice metrics based on operation type (e.g. confinement, open feedlot, large CAFOs), animal type, and Census tract-level AFOs exposure intensity categories (i.e. from low exposure (quartile 1) to high exposure (quartile 4)). AFOs in Iowa were located in areas with lower percentages of racial/ethnic minority persons and high SES communities. For example, the percent of the population that is non-Hispanic Black was over 9 times higher in Census tracts without AFOs than tracts with AFOs (5.14% vs. 0.55%). However, when we considered AFO exposure intensity within the areas having AFO exposure, areas with higher AFO exposure had higher percentages of racial/ethnic minority persons (e.g. Hispanic) and low SES communities (e.g. higher educational isolation) compared to areas with lower AFO exposure. Findings by AFO type (e.g. large CAFO, medium CAFO) showed similar patterns of the distribution of environmental justice metrics as the findings for AFOs overall. We identified complex disparities with higher exposure to non-disadvantaged subpopulations when considering areas with versus without AFOs, but higher exposure to disadvantaged communities within areas with AFOs.

Chemicals of concern in personal care products used by women of color in three communities of California.

Personal care products (PCPs) may contain chemicals associated with adverse health effects. Prior studies found differences in product use by race/ethnicity and suggest some women are disproportionately exposed to chemicals of concern (CoCs). We quantified chemicals linked to cancer, reproductive or developmental harm, or endocrine disruption in PCPs used by women of color. We documented PCPs in stores frequented by Black, Latina, and Vietnamese women in their communities in California and CoCs on ingredient labels of 546 unique hair, skin, makeup, nail, deodorant/perfume, and intimate care products. Community partners chose 31 products for a combined targeted and suspect screen (National Institute of Standards and Technology mass spectral library search) two-dimensional gas chromatography time-of-flight mass spectrometry (GCxGC-TOFMS) analysis to detect chemicals not on ingredient labels. We found that 65% of labels included CoCs, and 74% of labels had undisclosed ingredients listed as "fragrance." The most prevalent chemicals were parabens, cyclosiloxanes, and formaldehyde releasers. GCxGC-TOFMS found additional CoCs, including fragrances, solvents, preservatives, ultraviolet filters, and contaminants. These findings contribute to awareness of potentially hazardous chemicals in PCPs, can help estimate disparities in chemical exposure, and complement research on health inequities due to chemical exposures from various contributors. This study is one of the first detailed assessments of chemicals of concern found in various types of PCPs used by several racial/ethnic groups. We found that over half of the 546 products selected by community partners as marketed to and/or used by them contained ingredients linked to cancer, reproductive or developmental harm, or endocrine disruption. Laboratory analysis identified additional chemicals in a subset of products, including unlabeled fragrance chemicals and contaminants. Elucidating exposures to chemicals in PCPs is important for risk assessment and health inequity research.

Harm perceptions of secondhand e-cigarette aerosol among youth in the United States

E-cigarette use among youth remains a public health concern. Although extant literature has examined the perceived harms of cigarette use and secondhand smoke, perceptions of harms associated with secondhand e-cigarette aerosol (SHA) are not well understood. Therefore, we used data from the 2020 U.S. National Youth Tobacco Survey (n = 13,292) in which participants indicated whether SHA caused no harm, little harm, some harm, or a lot of harm. We dichotomized SHA harm perceptions as harmless vs harmful. We included sociodemographics (i.e., age, sex, race/ethnicity, sexual orientation, urbanicity), e-cigarette use characteristics, and SHA exposure as covariates and estimated associations between SHA harm perceptions and each covariate using adjusted logistic regression. Most youth perceived SHA as harmful (87.9 %) compared to harmless (12.1 %). Older youth (vs younger youth) had higher odds of perceiving SHA as harmless, whereas male (vs female) youth had 49 % higher odds (95 % CI: 1.29–1.72) of perceiving SHA as harmless. As the number of days of e-cigarette use in the past 30 days increased (vs non-users), odds of perceiving SHA as harmless increased. Youth exposed to SHA (vs no exposure) in the past 30 days had 35 % higher odds of perceiving SHA as harmless (95 % CI: 1.16–1.57). To conclude, youth SHA harm perceptions varied overall and by sociodemographic characteristics, e-cigarette use, and SHA exposure. Educational campaigns to inform youth of the health risks associated with e-cigarettes and SHA are needed to reduce overall nicotine intake and disparities in nicotine exposure.

Location-specific strategies for eliminating US national racial-ethnic PM2.5 exposure inequality

Air pollution levels in the United States have decreased dramatically over the past decades, yet national racial-ethnic exposure disparities persist. For ambient fine particulate matter ([Formula: see text]), we investigate three emission-reduction approaches and compare their optimal ability to address two goals: 1) reduce the overall population average exposure ("overall average") and 2) reduce the difference in the average exposure for the most exposed racial-ethnic group versus for the overall population ("national inequalities"). We show that national inequalities in exposure can be eliminated with minor emission reductions (optimal: ~1% of total emissions) if they target specific locations. In contrast, achieving that outcome using existing regulatory strategies would require eliminating essentially all emissions (if targeting specific economic sectors) or is not possible (if requiring urban regions to meet concentration standards). Lastly, we do not find a trade-off between the two goals (i.e., reducing overall average and reducing national inequalities); rather, the approach that does the best for reducing national inequalities (i.e., location-specific strategies) also does as well as or better than the other two approaches (i.e., sector-specific and meeting concentration standards) for reducing overall averages. Overall, our findings suggest that incorporating location-specific emissions reductions into the US air quality regulatory framework 1) is crucial for eliminating long-standing national average exposure disparities by race-ethnicity and 2) can benefit overall average exposures as much as or more than the sector-specific and concentration-standards approaches.