Short-term air pollution levels and sickle cell disease hospital encounters in South Carolina: A case-crossover analysis.

BACKGROUND: Sickle cell disease (SCD) is a genetic disorder and symptoms may be sensitive to environmental stressors. Although it has been hypothesized that exposure to outdoor air pollution could trigger acute SCD events, evidence is limited. METHODS: We obtained SCD administrative data on hospital encounters in South Carolina from 2002 to 2019. We estimated outdoor air pollutant (particulate matter<2.5 µm (PM2.5), ozone (O3), and PM2.5 elemental carbon (EC) concentrations at residential zip codes using spatio-temporal models. Using a random bi-directional, fixed-interval case-crossover study design, we investigated the relationship between air pollution exposure over 1-, 3-, 5-, 9-, and14-day periods with SCD hospital encounters. RESULTS: We studied 8410 patients with 144,129 hospital encounters. We did not observe associations among all patients with SCD and adults for PM2.5, O3, and EC. We observed positive associations among children for 9- and 14-day EC (OR: 1.05 (95% confidence interval (CI): 1.02, 1.08) and OR: 1.05 (95% CI: 1.02, 1.09), respectively) and 9- and 14-day O3 (OR: 1.04 (95%CI: 1.00, 1.08)) for both. CONCLUSIONS: Our findings suggest that short-term (within two-weeks) levels of EC and O3 and may be associated with SCD hospital encounters among children. Two-pollutant model results suggest that EC is more likely responsible for effects on SCD than O3. More research is needed to confirm our findings.

Perceptions of mindfulness practices as a support for individuals managing caregiving responsibilities and chronic disease: A qualitative study.

OBJECTIVES: Explore the lived experience of individuals managing and/or caregiving for someone with a chronic disease and their perceptions of developing a mindfulness program for stress reduction. METHODS: Sixteen participants with chronic disease and/or caregivers participated. Participants completed eligibility screening, demographic questionnaires, and semi-structured interviews (30-60 min each) online or by phone. Interviews (n = 16) were audio recorded, transcribed, and analyzed using thematic analysis and NVivo® 12. Survey data were analyzed using SPSS® 28. RESULTS: Four themes emerged: (a) Chronic disease management and stress-perspectives on life's stressors; (b) Stress reduction techniques/perceptions of mindfulness-knowledge and implementation of stress reduction practices and familiarity with mindfulness; (c) Mindfulness program acceptability, barriers, and facilitators-interest, barriers, and facilitators to attending; (d) Mindfulness program structure-logistics to increase access and appeal to diverse audiences. DISCUSSION: Mindfulness has the potential for addressing the complexities of stress associated with disease management. Targeting mindfulness programs for populations with chronic disease management and caregiving responsibilities should include: Consideration of group formats with participation limited to this population, structuring programs to overcome barriers (i.e., culturally appropriate location), and equipping members of the community being served as instructors to ensure culturally relevant instruction.

Impacts of long-term ambient particulate matter and gaseous pollutants on circulating biomarkers of inflammation in male and female health professionals.

BACKGROUND: Systemic inflammation may serve as a biological mechanism linking air pollution to poor health but supporting evidence from studies of long-term pollutant exposure and inflammatory cytokines is inconsistent. OBJECTIVE: We studied associations between multiple particulate matter (PM) and gaseous air pollutants and pro- and anti-inflammatory cytokines within two nationwide cohorts of men and women. METHODS: Data were obtained from 16,151 women in the Nurses' Health Study and 7,930 men in the Health Professionals' Follow-up Study with at least one measure of circulating adiponectin, C-Reactive Protein (CRP), Interleukin-6 (IL-6) or soluble tumor necrosis-factor receptor-2 (sTNFR-2). Exposure to PM with aerodynamic diameter ≤2.5, 2.5-10, and ≤10 µm (PM2.5, PM2.5-10, PM10) and nitrogen dioxide (NO2) was estimated using spatio-temporal models and were linked to participants' addresses at the time of blood draw. Averages of the 1-, 3-, and 12-months prior to blood draw were examined. Associations between each biomarker and pollutant were estimated from linear regression models adjusted for individual and contextual covariates. RESULTS: In adjusted models, we observed a 2.72% (95% CI: 0.43%, 5.95%), 3.11% (-0.12%, 6.45%), and 3.67% (0.19%, 7.26%) increase in CRP associated with a 10 µg/m3 increase in 1-, 3-, and 12- month averaged NO2 in women. Among men, there was a statistically significant 5.96% (95% CI: 0.07%, 12.20%), 6.99% (95% CI: 0.29%, 14.15%), and 8.33% (95% CI: 0.35%, 16.94%) increase in CRP associated with a 10 µg/m3 increase in 1-, 3-, and 12-month averaged PM2.5-10, respectively. Increasing PM2.5-10 was associated with increasing IL-6 and sTNFR-2 among men over shorter exposure durations. There were no associations with exposures to PM2.5 or PM10, or with adiponectin. Findings were robust to sensitivity analyses restricting to disease-free controls and non-movers. CONCLUSIONS: Across multiple long-term pollutant exposures and inflammatory markers, associations were generally weak. Focusing on specific pollutant-inflammatory mechanisms may clarify pathways.

The relationship between traffic-related air pollution exposures and allostatic load score among youth with type 1 diabetes in the SEARCH cohort.

OBJECTIVE: We investigated the effects of chronic exposures to particulate and traffic-related air pollution on allostatic load (AL) score, a marker of cumulative biological risk, among youth with type 1 diabetes. RESEARCH DESIGN AND METHODS: Participants were drawn from five clinical sites of the SEARCH for Diabetes in Youth (SEARCH) study (n = 2338). Baseline questionnaires, anthropometric measures, and a fasting blood test were taken at a clinic visit between 2001 and 2005. AL was operationalized using 10 biomarkers reflecting cardiovascular, metabolic, and inflammatory risk. Annual residential exposures to PM2.5 and proximity to heavily-trafficked major roadways were estimated for each participant. Poisson regression models adjusted for sociodemographic and lifestyle factors were conducted for each exposure. RESULTS: No significant associations were observed between exposures to PM2.5 or proximity to traffic and AL score, however analyses were suggestive of effect modification by race for residential distance to heavily-trafficked major roadways (p = 0.02). In stratified analyses, residing <100, 100-<200 and 200-<400 m compared to 400 m or more from heavily-trafficked major roadways was associated with 11%, 26% and 14% increases in AL score, respectively (95% CIs: -4, 29; 9, 45; -1, 30) for non-white participants compared to 6%, -2%, and -2% changes (95% CIs: -2, 15; -10, 7; -8, 6) for white participants. CONCLUSIONS: Among this population of youth with type 1 diabetes, we did not observe consistent relationships between chronic exposures to particulate and traffic-related air pollution and changes in AL score, however associations for traffic-related pollution exposures may differ by race/ethnicity and warrant further examination.

Defining and Intervening on Cumulative Environmental Neurodevelopmental Risks: Introducing a Complex Systems Approach.

BACKGROUND: The combined effects of multiple environmental toxicants and social stressor exposures are widely recognized as important public health problems contributing to health inequities. However cumulative environmental health risks and impacts have received little attention from U.S. policy makers at state and federal levels to develop comprehensive strategies to reduce these exposures, mitigate cumulative risks, and prevent harm. An area for which the inherent limitations of current approaches to cumulative environmental health risks are well illustrated is children's neurodevelopment, which exhibits dynamic complexity of multiple interdependent and causally linked factors and intergenerational effects. OBJECTIVES: We delineate how a complex systems approach, specifically system dynamics, can address shortcomings in environmental health risk assessment regarding exposures to multiple chemical and nonchemical stressors and reshape associated public policies. DISCUSSION: Systems modeling assists in the goal of solving problems by improving the "mental models" we use to make decisions, including regulatory and policy decisions. In the context of disparities in children's cumulative exposure to neurodevelopmental stressors, we describe potential policy insights about the structure and behavior of the system and the types of system dynamics modeling that would be appropriate, from visual depiction (i.e., informal maps) to formal quantitative simulation models. A systems dynamics framework provides not only a language but also a set of methodological tools that can more easily operationalize existing multidisciplinary scientific evidence and conceptual frameworks on cumulative risks. Thus, we can arrive at more accurate diagnostic tools for children's' environmental health inequities that take into consideration the broader social and economic environment in which children live, grow, play, and learn. https://doi.org/10.1289/EHP7333.

Relationship of leukaemias with long-term ambient air pollution exposures in the adult Danish population.

BACKGROUND: Few population-based epidemiological studies of adults have examined the relationship between air pollution and leukaemias. METHODS: Using Danish National Cancer Registry data and Danish DEHM-UBM-AirGIS system-modelled air pollution exposures, we examined whether particulate matter (PM2.5), black carbon (BC), nitrogen dioxide (NO2) and ozone (O3) averaged over 1, 5 or 10 years were associated with adult leukaemia in general or by subtype. In all, 14,986 adult cases diagnosed 1989-2014 and 51,624 age, sex and time-matched controls were included. Separate conditional logistic regression models, adjusted for socio-demographic factors, assessed exposure to each pollutant with leukaemias. RESULTS: Fully adjusted models showed a higher risk of leukaemia with higher 1-, 5- and 10-year-average exposures to PM2.5 prior to diagnosis (e.g. OR per 10 µg/m3 for 10-year average: 1.17, 95% CI: 1.03, 1.32), and a positive relationship with 1-year average BC. Results were driven by participants 70 years and older (OR per 10 µg/m3 for 10-year average: 1.35, 95% CI: 1.15-1.58). Null findings for younger participants. Higher 1-year average PM2.5 exposures were associated with higher risks for acute myeloid and chronic lymphoblastic leukaemia. CONCLUSION: Among older adults, higher risk for leukaemia was associated with higher residential PM2.5 concentrations averaged over 1, 5 and 10 years prior to diagnosis.

Long-term exposure to particulate air pollution and brachial artery flow-mediated dilation in the Old Order Amish.

BACKGROUND: Atmospheric particulate matter (PM) has been associated with endothelial dysfunction, an early marker of cardiovascular risk. Our aim was to extend this research to a genetically homogenous, geographically stable rural population using location-specific moving-average air pollution exposure estimates indexed to the date of endothelial function measurement. METHODS: We measured endothelial function using brachial artery flow-mediated dilation (FMD) in 615 community-dwelling healthy Amish participants. Exposures to PM < 2.5 µm (PM2.5) and PM < 10 µm (PM10) were estimated at participants' residential addresses using previously developed geographic information system-based spatio-temporal models and normalized. Associations between PM exposures and FMD were evaluated using linear mixed-effects regression models, and polynomial distributed lag (PDL) models followed by Bayesian model averaging (BMA) were used to assess response to delayed effects occurring across multiple months. RESULTS: Exposure to PM10 was consistently inversely associated with FMD, with the strongest (most negative) association for a 12-month moving average (- 0.09; 95% CI: - 0.15, - 0.03). Associations with PM2.5 were also strongest for a 12-month moving average but were weaker than for PM10 (- 0.07; 95% CI: - 0.13, - 0.09). Associations of PM2.5 and PM10 with FMD were somewhat stronger in men than in women, particularly for PM10. CONCLUSIONS: Using location-specific moving-average air pollution exposure estimates, we have shown that 12-month moving-average estimates of PM2.5 and PM10 exposure are associated with impaired endothelial function in a rural population.

Inflammation and acute traffic-related air pollution exposures among a cohort of youth with type 1 diabetes.

BACKGROUND: Evidence remains equivocal regarding the association of inflammation, a precursor to cardiovascular disease, and acute exposures to ambient air pollution from traffic-related particulate matter. Though youth with type 1 diabetes are at higher risk for cardiovascular disease, the relationship of inflammation and ambient air pollution exposures in this population has received little attention. OBJECTIVES: Using five geographically diverse US sites from the racially- and ethnically-diverse SEARCH for Diabetes in Youth Cohort, we examined the relationship of acute exposures to PM2.5 mass, Atmospheric Dispersion Modeling System (ADMS)-Roads traffic-related PM concentrations near roadways, and elemental carbon (EC) with biomarkers of inflammation including interleukin-6 (IL-6), c-reactive protein (hs-CRP) and fibrinogen. METHODS: Baseline questionnaires and blood were obtained at a study visit. Using a spatio-temporal modeling approach, pollutant exposures for 7 days prior to blood draw were assigned to residential addresses. Linear mixed models for each outcome and exposure were adjusted for demographic and lifestyle factors identified a priori. RESULTS: Among the 2566 participants with complete data, fully-adjusted models showed positive associations of EC average week exposures with IL-6 and hs-CRP, and PM2.5 mass exposures on lag day 3 with IL-6 levels. Comparing the 25th and 75th percentiles of average week EC exposures resulted in 8.3% higher IL-6 (95%CI: 2.7%,14.3%) and 9.8% higher hs-CRP (95%CI: 2.4%,17.7%). We observed some evidence of effect modification for the relationships of PM2.5 mass exposures with hs-CRP by gender and with IL-6 by race/ethnicity. CONCLUSIONS: Indicators of inflammation were associated with estimated traffic-related air pollutant exposures in this study population of youth with type 1 diabetes. Thus youth with type 1 diabetes may be at increased risk of air pollution-related inflammation. These findings and the racial/ethnic and gender differences observed deserve further exploration.

Development of outcome-specific criteria for study evaluation in systematic reviews of epidemiology studies.

INTRODUCTION AND OBJECTIVE: Systematic review tools that provide guidance on evaluating epidemiology studies are receiving increasing attention and support because their application facilitates improved quality of the review, consistency across reviewers, and transparency for readers. The U.S. Environmental Protection Agency's Integrated Risk Information System (IRIS) Program has developed an approach for systematic review of evidence of health effects from chemical exposures that includes structured approaches for literature search and screening, study evaluation, data extraction, and evidence synthesis and integration. This approach recognizes the need for developing outcome-specific criteria for study evaluation. Because studies are assessed at the outcome level, a study could be considered high quality for one investigated outcome, and low quality for another, due to differences in the outcome measures, analytic strategies, how relevant a certain bias is to the outcome, and how the exposure measure relates to the outcome. The objective of this paper is to illustrate the need for outcome-specific criteria in study evaluation or risk of bias evaluation, describe the process we used to develop the criteria, and summarize the resulting criteria. METHODS: We used a process of expert consultation to develop several sets of outcome-specific criteria to guide study reviewers, improve consistency, and ensure consideration of critical issues specific to the outcomes. The criteria were developed using the following domains: outcome assessment, exposure measurement (specifically timing of exposure in relation to outcome; other exposure measurement issues would be addressed in exposure-specific criteria), participant selection, confounding, analysis, and sensitivity (the study's ability to detect a true effect or hazard). RESULTS: We discuss the application of this process to pregnancy-related outcomes (preterm birth, spontaneous abortion), other reproductive-related outcomes (male reproductive hormones, sperm parameters, time to pregnancy, pubertal development), chronic disease (diabetes, insulin resistance), and acute or episodic conditions (asthma, allergies), and provide examples of the criteria developed. For each outcome the most influential methodological considerations are highlighted including biological sample collection and quality control, sensitivity and specificity of ascertainment tools, optimal timing for recruitment into the study (e.g., preconception, specific trimesters), the etiologically relevant window for exposure assessments, and important potential confounders. CONCLUSIONS: Outcome-specific criteria are an important part of a systematic review and will facilitate study evaluations by epidemiologists with experience in evaluating studies using systematic review methods who may not have extensive discipline-specific experience in the outcomes being reviewed.

Accelerometer and GPS Data to Analyze Built Environments and Physical Activity.

Purpose: Most built environment studies have quantified characteristics of the areas around participants' homes. However, the environmental exposures for physical activity (PA) are spatially dynamic rather than static. Thus, merged accelerometer and global positioning system (GPS) data were utilized to estimate associations between the built environment and PA among adults. Methods: Participants (N = 142) were recruited on trails in Massachusetts and wore an accelerometer and GPS unit for 1-4 days. Two binary outcomes were created: moderate-to-vigorous PA (MVPA vs. light PA-to-sedentary); and light-to-vigorous PA (LVPA vs. sedentary). Five built environment variables were created within 50-meter buffers around GPS points: population density, street density, land use mix (LUM), greenness, and walkability index. Generalized linear mixed models were fit to examine associations between environmental variables and both outcomes, adjusting for demographic covariates. Results: Overall, in the fully adjusted models, greenness was positively associated with MVPA and LVPA (odds ratios [ORs] = 1.15, 95% confidence interval [CI] = 1.03, 1.30 and 1.25, 95% CI = 1.12, 1.41, respectively). In contrast, street density and LUM were negatively associated with MVPA (ORs = 0.69, 95% CI = 0.67, 0.71 and 0.87, 95% CI = 0.78, 0.97, respectively) and LVPA (ORs = 0.79, 95% CI = 0.77, 0.81 and 0.81, 95% CI = 0.74, 0.90, respectively). Negative associations of population density and walkability with both outcomes reached statistical significance, yet the effect sizes were small. Conclusions: Concurrent monitoring of activity with accelerometers and GPS units allowed us to investigate relationships between objectively measured built environment around GPS points and minute-by-minute PA. Negative relationships between street density and LUM and PA contrast evidence from most built environment studies in adults. However, direct comparisons should be made with caution since most previous studies have focused on spatially fixed buffers around home locations, rather than the precise locations where PA occurs.

Sociodemographic and Environmental Determinants of Indoor Versus Outdoor Active Play Among Children Living in the Washington, DC Area.

BACKGROUND: Sociodemographic and environmental factors play important roles in determining both indoor and outdoor play activities in children. METHODS: The Built Environment and Active Play Study assessed neighborhood playability for children (7-12 y), based on parental report of their children's active play behaviors, neighborhood characteristics, and geographic locations. Simple logistic regression modeling tested the associations between sociodemographic characteristics and the frequency of and access to venues for indoor and outdoor play. RESULTS: Children of higher socioeconomic status were almost 3 times more likely to live more than a 30-minute walk from indoor recreational facilities compared with their less affluent peers (odds ratio [OR] = 2.9; 95% confidence interval [CI], 1.2-6.8). Non-Hispanic black children were less likely to live more than 30 minutes from indoor facilities (OR = 0.21; 95% CI, 0.08-0.57) and more were likely to engage in indoor activity (OR = 3.40; 95% CI, 1.17-9.88) than were white children. Boys were substantially more likely to play outdoors at a playing fields compared with girls (OR = 5.37; 95% CI, 2.10-13.69). CONCLUSIONS: Findings from this study could be used to enhance indoor and outdoor activity spaces for children and to reduce disparities in access to such spaces.

Case-crossover analysis of short-term particulate matter exposures and stroke in the health professionals follow-up study.

BACKGROUND: Stroke is a leading cause of morbidity and mortality in the United States. Associations between short-term exposures to particulate matter (PM) air pollution and stroke are inconsistent. Many prior studies have used administrative and hospitalization databases where misclassification of the type and timing of the stroke event may be problematic. METHODS: In this case-crossover study, we used a nationwide kriging model to examine short-term ambient exposure to PM10 and PM2.5 and risk of ischemic and hemorrhagic stroke among men enrolled in the Health Professionals Follow-up Study. Conditional logistic regression models were used to obtain estimates of odds ratios (OR) and 95% confidence intervals (CI) associated with an interquartile range (IQR) increase in PM2.5 or PM10. Lag periods up to 3 days prior to the stroke event were considered in addition to a 4-day average. Stratified models were used to examine effect modification by patient characteristics. RESULTS: Of the 727 strokes that occurred between 1999 and 2010, 539 were ischemic and 122 were hemorrhagic. We observed positive statistically significant associations between PM10 and ischemic stroke (ORlag0-3 = 1.26; 95% CI: 1.03-1.55 per IQR increase [14.46 µg/m3]), and associations were elevated for nonsmokers, aspirin nonusers, and those without a history of high cholesterol. However, we observed no evidence of a positive association between short-term exposure to PM and hemorrhagic stroke or between PM2.5 and ischemic stroke in this cohort. CONCLUSIONS: Our study provides evidence that ambient PM10 may be associated with higher risk of ischemic stroke and highlights that ischemic and hemorrhagic strokes are heterogeneous outcomes that should be treated as such in analyses related to air pollution.

Accelerometer and GPS Analysis of Trail Use and Associations With Physical Activity.

BACKGROUND: Concurrent use of accelerometers and global positioning system (GPS) data can be used to quantify physical activity (PA) occurring on trails. This study examined associations of trail use with PA and sedentary behavior (SB) and quantified on trail PA using a combination of accelerometer and GPS data. METHODS: Adults (N = 142) wore accelerometer and GPS units for 1-4 days. Trail use was defined as a minimum of 2 consecutive minutes occurring on a trail, based on GPS data. We examined associations between trail use and PA and SB. On trail minutes of light-intensity, moderate-intensity, and vigorous-intensity PA, and SB were quantified in 2 ways, using accelerometer counts only and with a combination of GPS speed and accelerometer data. RESULTS: Trail use was positively associated with total PA, moderate-intensity PA, and light-intensity PA (P < .05). On trail vigorous-intensity PA minutes were 346% higher when classified with the combination versus accelerometer only. Light-intensity PA, moderate-intensity PA, and SB minutes were 15%, 91%, and 85% lower with the combination, respectively. CONCLUSIONS: Adult trail users accumulated more PA on trail use days than on nontrail use days, indicating the importance of these facilities for supporting regular PA. The combination of GPS and accelerometer data for quantifying on trail activity may be more accurate than accelerometer data alone and is useful for classifying intensity of activities such as bicycling.

Neighborhood characteristics, food deserts, rurality, and type 2 diabetes in youth: Findings from a case-control study.

Little is known about the influence of neighborhood characteristics on risk of type 2 diabetes (T2D) among youth. We used data from the SEARCH for Diabetes in Youth Case-Control Study to evaluate the association of neighborhood characteristics, including food desert status of the census tract, with T2D in youth. We found a larger proportion of T2D cases in tracts with lower population density, larger minority population, and lower levels of education, household income, housing value, and proportion of the population in a managerial position. However, most associations of T2D with neighborhood socioeconomic characteristics were attributable to differences in individual characteristics. Notably, in multivariate logistic regression models, T2D was associated with living in the least densely populated study areas, and this finding requires further exploration.

Dietary quality and markers of inflammation: No association in youth with type 1 diabetes.

BACKGROUND: Systemic inflammation is a key process underlying cardiovascular disease (CVD) development, and CVD risk is significantly elevated in persons with type 1 diabetes (T1D). Youth with T1D exhibit increased levels of inflammation. Studies in persons without diabetes suggest that dietary quality influences inflammation, yet little is known about dietary influences on inflammation in youth with T1D. METHODS: This study evaluated the association of four distinct dietary quality indices (Dietary Approaches to Stop Hypertension (DASH), Healthy Eating Index 2010 (HEI2010), modified KIDMED and Total Antioxidant Capacity (TAC)) with biomarkers of inflammation (C-reactive protein (CRP), fibrinogen and interleukin-6 (IL-6)) in a sample of 2520 youth with T1D participating in the SEARCH for Diabetes in Youth Study. RESULTS: Average diet quality was moderate to poor, with mean scores of 43 (DASH, range 0-80), 55 (HEI2010, range 0-100), 3.7 (mKIDMED, range 3-12) and 7237 (TAC). None of the four diet quality scores was associated with the selected biomarkers of inflammation in any analyses. Evaluation of a non-linear relationship or interactions with BMI or levels of glycemic control did not alter the findings. Replication of analyses using longitudinal data yielded consistent findings with our cross-sectional results. CONCLUSIONS: Biomarkers of inflammation in youth with T1D may not be directly influenced by dietary intake, at least at the levels of dietary quality observed here. More work is needed to understand what physiologic mechanisms specific to persons with T1D might inhibit the generally beneficial influence of high dietary quality on systemic inflammation observed in populations without diabetes.

Summertime extreme heat events and increased risk of acute myocardial infarction hospitalizations.

Few studies have examined the association between exposure to extreme heat events and risk of acute myocardial infarction (AMI) or demonstrated which populations are most vulnerable to the effects of extreme heat. We defined extreme heat events as days when the daily maximum temperature (TMAX) exceeded the location- and calendar day-specific 95th percentile of the distribution of daily TMAX during the 30-year baseline period (1960-1989). We used a time-stratified case-crossover design to analyze the association between exposure to extreme heat events and risk of hospitalization for AMI in the summer months (June-August) with 0, 1, or 2 lag days. There were a total of 32,670 AMI hospitalizations during the summer months in Maryland between 2000 and 2012. Overall, extreme heat events on the day of hospitalization were associated with an increased risk of AMI (lag 0 OR=1.11; 95% CI: 1.05-1.17). Results considering lag periods immediately before hospitalization were comparable, but effect estimates varied among several population subgroups. As extreme weather events are expected to become more frequent and intense in response to our changing climate, community-specific adaptation strategies are needed to account for the differential susceptibility across ethnic subgroups and geographic areas.

Exposure to Traffic-Related Air Pollution in Relation to Progression in Physical Disability among Older Adults.

BACKGROUND: Physical disability is common though not inevitable in older age and has direct bearing on a person's ability to perform activities essential for self-care and independent living. Air pollution appears to increase the risk of several chronic diseases that contribute to the progression of disability. OBJECTIVE: We evaluated long-term exposure to traffic-related air pollution (TRAP) in relation to progression in physical disability. METHODS: We conducted our investigation within the Chicago Health and Aging Project. We measured participants' exposures to TRAP using two surrogates: residential proximity to major roads (1993 onwards) and ambient concentrations of oxides of nitrogen (NOX; 1999 onwards), predicted via a geographic information systems-based spatiotemporal smoothing model (cross-validation R2 = 0.87) that incorporated community-based monitoring and resolved intraurban exposure gradients at a spatial scale of tens of meters. Participants' lower-extremity physical ability was assessed every 3 years (1993-2012) via tandem stand, chair stand, and timed walking speed. RESULTS: In multivariable-adjusted analyses (n = 5,708), higher long-term NOX exposure was associated with significantly faster progression in disability. Compared with the 5-year decline in physical ability score among participants in the lowest quartile of NOX exposure, decline among those in the highest exposure quartile was 1.14 units greater (95% confidence interval [CI]: -1.86, -0.42), equivalent to 3 additional years of decline among those in the lowest exposure quartile. The association was linear across the continuum of NOX exposure: per 10-ppb increment in exposure, the 5-year decline in physical ability score was 0.87 unit greater (95% CI: -1.35, -0.39). Proximity to a major road was not associated with disability progression (n = 9,994). CONCLUSIONS: These data join a growing body of evidence suggesting that TRAP exposures may accelerate aging-related declines in health. CITATION: Weuve J, Kaufman JD, Szpiro AA, Curl C, Puett RC, Beck T, Evans DA, Mendes de Leon CF. 2016. Exposure to traffic-related air pollution in relation to progression in physical disability among older adults. Environ Health Perspect 124:1000-1008; http://dx.doi.org/10.1289/ehp.1510089.

Short-term exposure to ambient ozone and stroke hospital admission: A case-crossover analysis.

We evaluated the association between short-term exposure to ambient ozone air pollution and stroke hospital admissions among adult residents of South Carolina (SC). Data on all incident stroke hospitalizations from 2002 to 2006 were obtained from the SC Office of Research and Statistics. Ozone exposure data were obtained from the US Environmental Protection Agency's Hierarchical Bayesian Model. A semi-symmetric bidirectional case-crossover design was used to examine the association between ozone exposure on lag days 0-2 (0 to 2 days before admission) and stroke hospitalization. Conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). No significant associations were observed between short-term ozone exposure and hospitalization for all stroke (e.g., lag day 0: OR=0.98; 95% CI=0.96, 1.00) or ischemic stroke (lag day 0: OR=0.98; 95% CI=0.96, 1.01). Risk of hospitalization for hemorrhagic stroke appeared to be higher among African Americans than European Americans; however, the majority of these associations did not reach statistical significance. Among adults in SC from 2002 to 2006, there was no evidence of an association between ozone exposure and risk of hospitalization for all stroke or ischemic stroke; however, African Americans may have an increased risk of hemorrhagic stroke.

Effect Modification of Long-Term Air Pollution Exposures and the Risk of Incident Cardiovascular Disease in US Women.

BACKGROUND: Ambient air pollution exposures have been frequently linked to cardiovascular disease (CVD) morbidity and mortality. However, less is known about the populations most susceptible to these adverse effects. METHODS AND RESULTS: We assessed the associations of long-term particulate matter (PM) exposures with incident CVD in a nationwide cohort of 114 537 women in the Nurses' Health Study, and performed analyses to identify subpopulations at the greatest risk. Residential address level time-varying monthly exposures to PM2.5, PM10, and PM2.5 to 10 microns in diameter were estimated from spatio-temporal prediction models. In multivariable models, increases in all size fractions of PM were associated with small, but not statistically significant, increased risks of total CVD, coronary heart disease, and stroke. PM-associated CVD risks were statistically significantly higher among women with diabetes as compared to those without (P-for-interaction <0.0001 for PM10 and PM2.5 and 0.007 for PM2.5 to 10). For each 10 µg/m(3) increase in 12-month average PM2.5, PM2.5 to 10, and PM10, the multivariable adjusted hazard ratios were 1.44 (95% CI: 1.23 to 1.68), 1.17 (95% CI: 1.05 to 1.30), and 1.19 (95% CI: 1.10 to 1.28) among women with diabetes. There were also suggestions of higher risks among older (≥70 years) women, the obese, and those living in the Northeast and South. Smoking status and family history did not consistently modify the association between PM and CVD, and risks were most elevated with exposures in the previous 12 months. CONCLUSIONS: In this nationwide cohort, women with diabetes were identified as the subpopulation most sensitive to the adverse cardiovascular health effects of PM.