Disentangling impacts of multiple pollutants on acute cardiovascular events in New York city: A case-crossover analysis.

BACKGROUND: Ambient air pollution contributes to an estimated 6.67 million deaths annually, and has been linked to cardiovascular disease (CVD), the leading cause of death. Short-term increases in air pollution have been associated with increased risk of CVD event, though relatively few studies have directly compared effects of multiple pollutants using fine-scale spatio-temporal data, thoroughly adjusting for co-pollutants and temperature, in an exhaustive citywide hospitals dataset, towards identifying key pollution sources within the urban environment to most reduce, and reduce disparities in, the leading cause of death worldwide. OBJECTIVES: We aimed to examine multiple pollutants against multiple CVD diagnoses, across lag days, in models adjusted for co-pollutants and meteorology, and inherently adjusted by design for non-time-varying individual and aggregate-level covariates, using fine-scale space-time exposure estimates, in an exhaustive dataset of emergency department visits and hospitalizations across an entire city, thereby capturing the full population-at-risk. METHODS: We used conditional logistic regression in a case-crossover design - inherently controlling for all confounders not varying within case month - to examine associations between spatio-temporal nitrogen dioxide (NO2), fine particulate matter (PM2.5), sulfur dioxide (SO2), and ozone (O3) in New York City, 2005-2011, on individual risk of acute CVD event (n = 837,523), by sub-diagnosis [ischemic heart disease (IHD), heart failure (HF), stroke, ischemic stroke, acute myocardial infarction]. RESULTS: We found significant same-day associations between NO2 and risk of overall CVD, IHD, and HF - and between PM2.5 and overall CVD or HF event risk - robust to all adjustments and multiple comparisons. Results were comparable by sex and race - though median age at CVD was 10 years younger for Black New Yorkers than White New Yorkers. Associations for NO2 were comparable for adults younger or older than 69 years, though PM2.5 associations were stronger among older adults. DISCUSSION: Our results indicate immediate, robust effects of combustion-related pollution on CVD risk, by sub-diagnosis. Though acute impacts differed minimally by age, sex, or race, the much younger age-at-event for Black New Yorkers calls attention to cumulative social susceptibility.

Spatial Patterning of Spontaneous and Medically Indicated Preterm Birth in Philadelphia.

Preterm birth (PTB) remains a key public health issue that disproportionately affects Black individuals. Since spontaneous PTB (sPTB) and medically indicated PTB (mPTB) may have different causes and interventions, we quantified racial disparities for sPTB and mPTB, and we characterized the geographic patterning of these phenotypes, overall and according to race/ethnicity. We examined a pregnancy cohort of 83,952 singleton births at 2 Philadelphia hospitals from 2008-2020, and classified each PTB as sPTB or mPTB. We used binomial regression to quantify the magnitude of racial disparities between non-Hispanic Black and non-Hispanic White individuals, then generated small area estimates by applying a Bayesian model that accounts for small numbers and smooths estimates of PTB risk by borrowing information from neighboring areas. Racial disparities in both sPTB and mPTB were significant (relative risk of sPTB = 1.83, 95% confidence interval: 1.70, 1.98; relative risk of mPTB = 2.20, 95% confidence interval: 2.00, 2.42). The disparity was 20% greater in mPTB than sPTB. There was substantial geographic variation in PTB, sPTB, and mPTB risks and racial disparity. Our findings underscore the importance of distinguishing PTB phenotypes within the context of public health and preventive medicine. Future work should consider social and environmental exposures that may explain geographic differences in PTB risk and disparities.

Perception Matters: Perceived vs. Objective Air Quality Measures and Asthma Diagnosis among Urban Adults.

Urban air pollution is consistently linked to poorer respiratory health, particularly in communities of lower socioeconomic position (SEP), disproportionately located near highways and industrial areas and often with elevated exposures to chronic psychosocial stressors. Fewer studies, however, have considered air pollution itself as a psychosocial stressor and whether pollution may be impacting health through both direct physiologic and psychosocial pathways. We examined data on perceived air pollution exposures from a spatially representative survey of New York City adults through summer and winter 2012 (n = 1183) using residence-specific ambient nitrogen dioxide (NO2) and fine particulate matter (PM2.5) exposure estimates. We used logistic regression to compare associations for perceived and objective air quality on self-reported asthma and general health, adjusting for sociodemographics and mental health. In models including all exposure metrics, we found small but significant associations for perceived air quality (OR = 1.12, 95% CI: 1.04-1.22) but not for NO2 or PM2.5. Neither perceived nor objective pollution was significantly associated with self-reported general health. Results suggest that perceived air quality may be significantly associated with adult asthma, more so than objective air pollution and after adjusting for mental health-associations not observed for self-reported general health.

Does Urban Greenspace Reduce Mortality Inequalities Based on Poverty, Race, or Both in Philadelphia, PA?

While past research suggests that urban greenspace is associated with weaker income-based mortality inequities, little is known about associations with racial inequities, which may be distinct owing to historical and contemporary forms of racism. We quantified the extent to which different measures of greenspace modified socioeconomic and racial/ethnic inequities in all-cause and cardiovascular disease mortality. For every residential census tract in Philadelphia, PA (N = 376), we linked counts of all-cause and cardiovascular mortality (years 2008-2015) with measures of greenspace (proportion tree canopy or grass/shrub cover, proportion residents reporting park access, and the normalized difference vegetation index measure of overall greenness) and American Community Survey-based measures of sociodemographic composition (proportion of residents living in poverty, proportion identifying as non-Hispanic Black, and the index of concentration at the extremes (ICE) representing racialized economic deprivation). We used age- and sex-adjusted negative binomial models, with the natural logarithm of age-specific population counts as an offset, to quantify the magnitude of inequities by each composition variable, overall and stratified by categories of each greenspace measure. Inequities in mortality were weaker among neighborhoods with higher proportion grass/shrub cover or overall greenness. The most substantially narrowed inequities were those by the ICE. Mortality inequities did not differ substantially by perceived park access, and tree canopy was associated with weaker ICE-based inequities only. In this ecologic analysis, neighborhood greenspace was associated with weaker mortality inequities. However, associations varied across greenspace type and sociodemographic composition metrics, with generally stronger associations with overall greenness and grass/shrub coverage, and for ICE-basedinequities.

High ambient temperatures associations with children and young adult injury emergency department visits in NYC.

Injury is a significant health burden for children and young adult and may be an increasing concern in a warming climate. Research reveals many impacts to children's health associated with hot weather and heatwave events, including a growing literature on the association between high ambient temperature and injury, which may vary by intent such as injury resulting from violence. However, little is known about how this association varies across different types of injury and subgroups of young people. We examined relationships between warm season ambient temperature and intentional and unintentional injury among children and young adults in New York City (NYC). Within a case-crossover design, our study observed injury-related emergency department (ED) visits from the New York Statewide Planning and Research Cooperative System administrative dataset. Injuries were categorized as unintentional or intentional injuries during the warm season (May through September) in NYC from 2005 to 2011 among patients (0, 1-4, 5-9, 10-14, 15-19, 20-25 years old (y.o.)). Conditional logistic regression models with distributed lag non-linear functions were used to model the cumulative odds ratio (OR) injury-related ED visit over 0-5 lag days. Analyses were stratified by age group and sex to understand how associations vary across young people of different age and sex. There were a total of 572 535 injury-related ED visits. The largest effect of elevated temperature (daily minimum 77°F vs 48°F) was for unintentional injury among 5-9 y.o. (OR 1.32, 95% CI 1.23, 1.42) and for intentional injury among 20-25 y.o. (OR 1.54, 95% CI 1.28, 1.85). Further stratified analyses revealed that the highest risk of unintentional injury was among 5-9 y.o. males and 20-25 y.o. males for intentional injury. Our results suggest that high ambient temperatures are associated with higher odds of unintentional and intentional injuries among children. This work adds to a growing body of literature demonstrating the adverse impacts of heat on children, and suggests the need for messaging to parents and children about adopting adaptive strategies to prevent injuries when it is hot outside.

Neighborhood violence and socioeconomic deprivation influence associations between acute air pollution and temperature on childhood asthma in New York city.

Ambient air pollution, temperature, and social stressor exposures are linked with asthma risk, with potential synergistic effects. We examined associations for acute pollution and temperature exposures, with modification by neighborhood violent crime and socioeconomic deprivation, on asthma morbidity among children aged 5-17 years year-round in New York City. Using conditional logistic regression in a time-stratified, case-crossover design, we quantified percent excess risk of asthma event per 10-unit increase in daily, residence-specific exposures to PM2.5, NO2, SO2, O3, and minimum daily temperature (Tmin). Data on 145,834 asthma cases presenting to NYC emergency departments from 2005 to 2011 were obtained from the New York Statewide Planning and Research Cooperative System (SPARCS). Residence- and day-specific spatiotemporal exposures were assigned using the NYC Community Air Survey (NYCCAS) spatial data and daily EPA pollution and NOAA weather data. Point-level NYPD violent crime data for 2009 (study midpoint) was aggregated, and Socioeconomic Deprivation Index (SDI) scores assigned, by census tract. Separate models were fit for each pollutant or temperature exposure for lag days 0-6, controlling for co-exposures and humidity, and mutually-adjusted interactions (modification) by quintile of violent crime and SDI were assessed. We observed stronger main effects for PM2.5 and SO2 in the cold season on lag day 1 [4.90% (95% CI: 3.77-6.04) and 8.57% (5.99-11.21), respectively]; Tmin in the cold season on lag day 0 [2.26% (1.25-3.28)]; and NO2 and O3 in the warm season on lag days 1 [7.86% (6.66-9.07)] and 2 [4.75% (3.53-5.97)], respectively. Violence and SDI modified the main effects in a non-linear manner; contrary to hypotheses, we found stronger associations in lower-violence and -deprivation quintiles. At very high stressor exposures, although asthma exacerbations were highly prevalent, pollution effects were less apparent-suggesting potential saturation effects in socio-environmental synergism.

Temperature and mental health-related emergency department and hospital encounters among children, adolescents and young adults.

AIMS: We examine the association between high ambient temperature and acute mental health-related healthcare encounters in New York City for children, adolescents and young adults. METHODS: This case-crossover study included emergency department (ED) visits and hospital encounters with a primary diagnosis of any mental health disorder during warm-season months (June-August) in New York City from 2005 to 2011 from patients of three age groups (6-11, 12-17 and 18-25 years). Using a distributed lag non-linear model over 0-5 lag days, by fitting a conditional logistic regression for each age group, we calculated the cumulative odds ratios of mental health encounters associated with an elevated temperature. Analyses were stratified by race/ethnicity, payment source and mental health categories to elucidate vulnerable subpopulations. RESULTS: In New York City, there were 82,982 mental health-related encounters for young people aged 6 to 25 years during our study period months. Elevated temperature days were associated with higher risk of mental health-related ED and hospital encounters for the 6- to 11-year-olds (odds ratio [OR]: 1.28, 95% confidence interval [CI]: 1.13-1.46), for the 12- to 17-year-olds (OR: 1.17, 95% CI: 1.09-1.25) and for the 18- to 25-year-olds (OR: 1.09, 95% CI: 1.04-1.15). Children with reaction disorders, adolescents with anxiety and bipolar disorders, young adults with psychosis and reaction disorders and Black and non-Hispanic children and adolescents showed vulnerability to elevated temperature. CONCLUSIONS: We found that elevated ambient temperatures were associated with acute mental health ED or hospital encounters across childhood, adolescence and young adulthood.

Associations of greenspace use and proximity with self-reported physical and mental health outcomes during the COVID-19 pandemic.

Research has shown that the COVID-19 pandemic affected individual's mental and physical health. The aim of this study was to estimate associations between greenspace use and proximity with perceived mental and physical health during the COVID-19 pandemic. We surveyed metropolitan Philadelphia residents, October 20-December 1, 2020, about walking time to the nearest greenspace from their home, frequency of greenspace use in the past 30 days, change in frequency of greenspace use during the COVID-19 pandemic, and perceived physical and mental health outcomes. We ran unadjusted and adjusted log-binomial regression models to derive Risk Ratio (RR) and 95% Confidence Intervals (CI) estimates of associations of loneliness, physical and mental health outcomes with: (1) self-reported walking time to nearest greenspace; (2) reported greenspace use frequency; and (3) changes in greenspace use frequency. Of 485 survey participants, 244 (51.4%) reported feeling lonelier, 147 (31.37%) reported higher perceived stress, 261 (54.9%) reported worsened mental health, and 137 (28.7%) reported worsened physical health during vs. before the start of pandemic-restrictions in mid-March of 2020. After adjustment for gender, age, and change in financial status, RR estimates suggested modest protective associations between visiting greenspaces more frequently during vs. before the pandemic and worsened mental (RR: 0.84, 95% CI: 0.70-1.00), and physical health (RR 0.77, 95% CI: 0.56-1.10), and loneliness (RR: 0.91, 95% CI: 0.75-1.1) and perceived stress (RR 0.83, 95% CI: 0.61-1.13). Shorter walking distances to the nearest greenspace were associated with reduced risk of reporting worsened physical health and higher perceived stress; however, living shorter walking distances from greenspace were not associated with protection against worsened mental health or loneliness. These results suggest that active greenspace use may provide mental and physical health protection, particularly during a stressful public health crisis.

Clean fleets, different streets: evaluating the effect of New York City's clean bus program on changes to estimated ambient air pollution.

BACKGROUND: Motor vehicles, including public transit buses, are a major source of air pollution in New York City (NYC) and worldwide. To address this problem, governments and transit agencies have implemented policies to introduce cleaner vehicles into transit fleets. Beginning in 2000, the Metropolitan Transit Agency began deploying compressed natural gas, hybrid electric, and low-sulfur diesel buses to reduce urban air pollution. OBJECTIVE: We hypothesized that bus fleet changes incorporating cleaner vehicles would have detectable effects on air pollution concentrations between 2009 and 2014, as measured by the New York City Community Air Survey (NYCCAS). METHODS: Depot- and route-specific information allowed identification of areas with larger or smaller changes in the proportion of distance traveled by clean buses. Data were assembled for 9670 300 m × 300 m grid cell areas with annual concentration estimates for nitrogen oxide (NO), nitrogen dioxide (NO2), and black carbon (BC) from NYCCAS. Spatial error models adjusted for truck route presence and total traffic volume. RESULTS: While concentrations of all three pollutants declined between 2009 and 2014 even in the 39.7% of cells without bus service, the decline in concentrations of NO and NO2 was greater in areas with more bus service and with higher proportional shifts toward clean buses. Conversely, the decline in BC concentration was slower in areas with more bus service and higher proportional clean bus shifts. SIGNIFICANCE: These results provide evidence that the NYC clean bus program impacted concentrations of air pollution, particularly in reductions of NO2. Further work can investigate the potential impact of these changes on health outcomes in NYC residents. IMPACT STATEMENT: Urban air pollution from diesel-burning buses is an important health exposure. The New York Metropolitan Transit Agency has worked to deploy cleaner buses into their fleet, but the impact of this policy has not been evaluated. Successful reductions in air pollution are critical for public health.

Benzene and NO2 Exposure during Pregnancy and Preterm Birth in Two Philadelphia Hospitals, 2013-2017.

Infants born preterm are at risk of neonatal morbidity and mortality. Preterm birth (PTB) can be categorized as either spontaneous (sPTB) or medically indicated (mPTB), resulting from distinct pathophysiologic processes such as preterm labor or preeclampsia, respectively. A growing body of literature has demonstrated the impacts of nitrogen dioxide (NO2) and benzene exposure on PTB, though few studies have investigated how these associations may differ by PTB subtype. We investigated the associations of NO2 and benzene exposure with sPTB and mPTB among 18,616 singleton live births at two Philadelphia hospitals between 2013 and 2017. Residential NO2 exposure was estimated using a land use regression model and averaged over the patient's full pregnancy. Benzene exposure was estimated at the census tract level using National Air Toxics Assessment (NATA) exposure data from 2014. We used logistic mixed-effects models to calculate odds ratios for overall PTB, sPTB, and mPTB separately, adjusting for patient- and tract-level confounders. Given the known racial segregation and PTB disparities in Philadelphia, we also examined race-stratified models. Counter to the hypothesis, neither NO2 nor benzene exposure differed by race, and neither were significantly associated with PTB or PTB subtypes. As such, these pollutants do not appear to explain the racial disparities in PTB in this setting.

Association of ambient extreme heat with pediatric morbidity: a scoping review.

Global climate change is leading to higher ambient temperatures and more frequent heatwaves. To date, impacts of ambient extreme heat on childhood morbidity have been understudied, although-given children's physiologic susceptibility, with smaller body surface-to-mass ratios, and many years of increasing temperatures ahead-there is an urgent need for better information to inform public health policies and clinical approaches. In this review, we aim to (1) identify pediatric morbidity outcomes previously associated with extreme heat, (2) to identify predisposing co-morbidities which may make children more susceptible to heat-related outcomes, and (3) to map the current body of available literature. A scoping review of the current full-text literature was conducted using the Arksey and O'Malley framework Int J Soc Res Methodol 8:19-32, (2015). Search terms for (1) pediatric population, (2) heat exposures, (3) ambient conditions, and (4) adverse outcomes were combined into a comprehensive PubMed and Medline literature search. Of the 1753 publications identified, a total of 20 relevant studies were ultimately selected based on selection criteria of relevance to US urban populations. Most identified studies supported positive associations between high extreme temperature exposures and heat-related illness, dehydration/electrolyte imbalance, general symptoms, diarrhea and digestion disorders, infectious diseases/infections, asthma/wheeze, and injury. Most studies found no association with renal disease, cardiovascular diseases, or diabetes mellitus. Results were mixed for other respiratory diseases and mental health/psychological disorders. Very few of the identified studies examined susceptibility to pre-existing conditions; Cystic Fibrosis was the only co-morbidity for which we found significant evidence. Further research is needed to understand the nuances of associations between extreme heat and specific outcomes-particularly how associations may vary by child age, sex, race/ ethnicity, community characteristics, and other pre-existing conditions.

What Is "Socioeconomic Position (SEP)," and How Might It Modify Air Pollution-Health Associations? Cohering Findings, Identifying Challenges, and Disentangling Effects of SEP and Race in US City Settings.

PURPOSE OF REVIEW: Environmental epidemiology has long considered socioeconomic position (SEP) to be an important confounder of pollution effects on health, given that, in the USA, lower-income and minority communities are often disproportionately exposed to pollution. In recent decades, a growing literature has revealed that lower-SEP communities may also be more susceptible to pollution. Given the vast number of material and psychosocial stressors that vary by SEP, however, it is unclear which specific aspects of SEP may underlie this susceptibility. As environmental epidemiology engages more rigorously with issues of differential susceptibility, it is pertinent to define SEP more clearly, to disentangle its many aspects, and to move towards identifying causal components. Myriad stressors and exposures vary with SEP, with effects accumulating and interacting over the lifecourse. Here, we ask: In the context of environmental epidemiology, how do we meaningfully characterize"SEP"? RECENT FINDINGS: In answering this question, it is critical to acknowledge that SEP, stressors, and pollution are differentially distributed by race in US cities. These distributions have been shaped by neighborhood sorting and race-based residential segregation rooted in historical policies and processes (e.g., redlining), which have served to concentrate wealth and opportunities for education and employment in predominantly-white communities. As a result, it is now profoundly challenging to separate SEP from race in the urban US setting. Here, we cohere evidence from our recent and on-going studies aimed at disentangling synergistic health effects among SEP-related stressors and pollutants. We consider an array of SEP-linked social stressors, and discuss persistent challenges in this epidemiology, many of which are related to spatial confounding among multiple pollutants and stressors. Combining quantitative results with insights from qualitative data on neighborhood perceptions and stress (including violence and police-community relations), we offer a lens towards unpacking the complex interplay among SEP, community stressors, race, and pollution in US cities.

Research on COVID-19 and air pollution: A path towards advancing exposure science.

The COVID-19 pandemic has resulted in an extraordinary incidence of morbidity and mortality, with almost 6 million deaths worldwide at the time of this writing (https://covid19.who.int/). There has been a pressing need for research that would shed light on factors - especially modifiable factors - that could reduce risks to human health. At least several hundred studies addressing the complex relationships among transmission of SARS-CoV-2, air pollution, and human health have been published. However, these investigations are limited by available and consistent data. The project goal was to seek input into opportunities to improve and fund exposure research on the confluence of air pollution and infectious agents such as SARS-CoV-2. Thirty-two scientists with expertise in exposure science, epidemiology, risk assessment, infectious diseases, and/or air pollution responded to the outreach for information. Most of the respondents expressed value in developing a set of common definitions regarding the extent and type of public health lockdown. Traffic and smoking ranked high as important sources of air pollution warranting source-specific research (in contrast with assessing overall ambient level exposures). Numerous important socioeconomic factors were also identified. Participants offered a wide array of inputs on what they considered to be essential studies to improve our understanding of exposures. These ranged from detailed mechanistic studies to improved air quality monitoring studies and prospective cohort studies. Overall, many respondents indicated that these issues require more research and better study design. As an exercise to solicit opinions, important concepts were brought forth that provide opportunities for scientific collaboration and for consideration for funding prioritization. Further conversations on these concepts are needed to advance our thinking on how to design research that moves us past the documented limitations in the current body of research and prepares us for the next pandemic.

High ambient temperature and child emergency and hospital visits in New York City.

BACKGROUND: Emerging literature has documented heat-related impacts on child health, yet few studies have evaluated the effects of heat among children of different age groups and comparing emergency department (ED) and hospitalisation risks. OBJECTIVES: To examine the differing associations between high ambient temperatures and risk of ED visits and hospitalisations among children by age group in New York City (NYC). METHODS: We used New York Statewide Planning and Research Cooperative System (SPARCS) data on children aged 0-18 years admitted to NYC EDs (n = 2,252,550) and hospitals (n = 228,006) during the warm months (May-September) between 2005 and 2011. Using a time-stratified, case-crossover design, we estimated the risk of ED visits and hospitalisations associated with daily maximum temperature (Tmax) for children of all ages and by age group. RESULTS: The average Tmax over the study period was 80.3°F (range 50°, 104°F). Tmax conferred the greatest risk of ED visits for children aged 0-4, with a 6-day cumulative excess risk of 2.4% (95% confidence interval [CI] 1.7, 3.0) per 13°F (ie interquartile range) increase in temperature. Children and adolescents 5-12 years (0.8%, 95% CI 0.1, 1.6) and 13-18 years (1.4%, 95% CI 0.6, 2.3) are also sensitive to heat. For hospitalisations, only adolescents 13-18 years had increased heat-related risk, with a cumulative excess risk of 7.9% (95% CI 2.0, 14.2) per 13°F increase in Tmax over 85°F. CONCLUSIONS: This urban study in NYC reinforces that young children are particularly vulnerable to effects of heat, but also demonstrates the sensitivity of older children and adolescents as well. These findings underscore the importance of focussing on children and adolescents in targeting heat illness prevention and emergency response activities, especially as global temperatures continue to rise.

Gender Differences in Impacts of Place-Based Neighborhood Greening Interventions on Fear of Violence Based on a Cluster-Randomized Controlled Trial.

Maintained green space in underserved urban neighborhoods may be an important environmental pathway to improving community health and safety, though effects may vary across population subgroups and by time of day. We examined survey responses from 442 participants (178 men and 264 women), living near vacant lots in a cluster-randomized controlled trial of a cleaning and greening intervention, on perceived safety during the day and at night. At the intervention sites after the intervention, only men reported feeling less unsafe during the day. Women reported more fear, and men reported less fear, after the intervention, although these results and tests for effect modification were not statistically significant. The clean-and-green intervention may have allayed fears for men during the day and supported their ease of movement throughout their neighborhoods. However, at night, it may have had the opposite effect on women. Though our study was under-powered, not designed to test associations stratified by gender, directions and magnitudes of associations differed substantially, indicating a need for further investigations into potential gender differences in the benefits of green space, to inform and better tailor interventions to improve perceived safety for all.

Social status and susceptibility to wildfire smoke among outdoor-housed female rhesus monkeys: A natural experiment.

INTRODUCTION: Wildfire smoke (WFS) exposure is a growing threat to human health, and lower socioeconomic position (SEP) has been shown to increase pollution susceptibility. Studies of SEP-related susceptibility, however, are often compromised due to spatial confounding between lower-SEP and pollution. Here we examine outdoor-housed nonhuman primates, living in natural social hierarchy in a common location, born during years of high vs. low WFS, to examine the separate and combined effects of WFS and social rank, an analog to SEP, on lung and immune function. METHODS: Twenty-one females were born during extreme WFS events in summer 2008; 22 were born in summer 2009, during low WFS. Pulmonary function and circulating cytokines were measured three years later, in adolescence. We estimated fine particulate (PM2.5) and ozone exposures during each animal's first 90 days and three years of age using regulatory data. Early-life social status was estimated using maternal rank at birth, as rank in females is relatively stable throughout life, and closely approximates mother's rank. We tested associations among WFS exposure, rank, and endpoints using linear regression and ANOVA. RESULTS: Higher WFS exposure in infancy was, on average, associated with lower functional residual capacity (FRC), residual volume (RV), tissue compliance (Ct), and IL-8 secretion in adolescence. Higher social rank conferred significantly higher expiratory reserve volume (ERV) and functional residual capacity (FRC) solely among those born in the high-WFS year (2008). Differences in effects of rank between years were not significant after adjustment for multiple comparisons. CONCLUSIONS: Exposure to WFS in infancy generally conferred lower adolescent respiratory volumes and inflammatory cytokines. Higher rank conferred higher respiratory volumes only among females born during WFS, suggesting the possibility that the health benefits of rank may be more apparent under environmental challenge.