Ambient Fine Particulate Matter Air Research Articles

Penalized distributed lag interaction model: Air pollution, birth weight, and neighborhood vulnerability

AbstractMaternal exposure to air pollution during pregnancy has a substantial public health impact. Epidemiological evidence supports an association between maternal exposure to air pollution and low birth weight. A popular method to estimate this association while identifying windows of susceptibility is a distributed lag model (DLM), which regresses an outcome onto exposure history observed at multiple time points. However, the standard DLM framework does not allow for modification of the association between repeated measures of exposure and the outcome. We propose a distributed lag interaction model that allows modification of the exposure‐time‐response associations across individuals by including an interaction between a continuous modifying variable and the exposure history. Our model framework is an extension of a standard DLM that uses a cross‐basis, or bi‐dimensional function space, to simultaneously describe both the modification of the exposure‐response relationship and the temporal structure of the exposure data. Through simulations, we showed that our model with penalization out‐performs a standard DLM when the true exposure‐time‐response associations vary by a continuous variable. Using a Colorado, USA birth cohort, we estimated the association between birth weight and ambient fine particulate matter air pollution modified by an area‐level metric of health and social adversities from Colorado EnviroScreen.

Abstract 12441: Ambient Fine Particulate Matter Air Pollution but Not Ozone is Associated With Elevated Risk of All-Cause Hospitalization in Patients With a Prior Diagnosis of Atrial Fibrillation

Introduction: Short-term increases (days to weeks) in fine particulate matter (PM 2.5 ) air pollution are associated with atrial fibrillation (AF) episodes. We previously reported that PM 2.5 was not associated with severe AF measured as emergency or inpatient hospitalization for the primary diagnosis of AF. Mild AF, though, may influence all-cause hospitalizations. This study evaluated if short-term increases in PM 2.5 and ozone were associated with all-cause hospitalization at 11 Intermountain Health hospitals in patients with AF, and if this differed between wildfire (June-Oct.) and winter inversion (Nov.-March) seasons. Methods: Patients carrying an AF diagnosis (N=347,157) were evaluated for all-cause hospitalization and, secondarily, AF hospitalization (N=25,601) and first AF diagnosis (N=77,893). PM 2.5 levels were measured from January 1, 1999 to March 31, 2022 (ozone: 2006-2022) in subjects residing on Utah’s Wasatch Front. Using the case-crossover design that matched individual-level characteristics, Poisson regression also adjusted for weather variables. Results: Mean age was 72±15 years and 51.0% were female. Overall, PM 2.5 increases at a lag of 0 days, 1 day, 3-day moving average (mAvg) (days 0-2), and 7-day mAvg (days 0-6) were associated with all-cause hospitalization [respectively: odds ratio (OR)=1.010, 1.008, 1.011, 1.009 per +10 μg/m 3 ; p=0.0004, 0.006, 0.0004, 0.028]. Associations differed by seasons (Figure). Regressions entering both ozone and PM 2.5 mildly increased PM 2.5 ORs for all-cause hospitalization. PM 2.5 was not associated with first AF diagnosis. Increases in ozone were not associated with higher risk of any outcome. Conclusions: Short-term increases in PM 2.5 air pollution were associated with all-cause hospitalization in patients with a prior AF diagnosis. Lag structure varied for wildfire and inversion seasons, with greater effect sizes in wildfire season. Increases in ozone did not associate with elevated risk.

Spatial environmental factors predict cardiovascular and all-cause mortality: Results of the SPACE study.

BackgroundEnvironmental exposures account for a growing proportion of global mortality. Large cohort studies are needed to characterize the independent impact of environmental exposures on mortality in low-income settings.MethodsWe collected data on individual and environmental risk factors for a multiethnic cohort of 50,045 individuals in a low-income region in Iran. Environmental risk factors included: ambient fine particular matter air pollution; household fuel use and ventilation; proximity to traffic; distance to percutaneous coronary intervention (PCI) center; socioeconomic environment; population density; local land use; and nighttime light exposure. We developed a spatial survival model to estimate the independent associations between these environmental exposures and all-cause and cardiovascular mortality.FindingsSeveral environmental factors demonstrated associations with mortality after adjusting for individual risk factors. Ambient fine particulate matter air pollution predicted all-cause mortality (per μg/m3, HR 1.20, 95% CI 1.07, 1.36) and cardiovascular mortality (HR 1.17, 95% CI 0.98, 1.39). Biomass fuel use without chimney predicted all-cause mortality (reference = gas, HR 1.23, 95% CI 0.99, 1.53) and cardiovascular mortality (HR 1.36, 95% CI 0.99, 1.87). Kerosene fuel use without chimney predicted all-cause mortality (reference = gas, HR 1.09, 95% CI 0.97, 1.23) and cardiovascular mortality (HR 1.19, 95% CI 1.01, 1.41). Distance to PCI center predicted all-cause mortality (per 10km, HR 1.01, 95% CI 1.004, 1.022) and cardiovascular mortality (HR 1.02, 95% CI 1.004, 1.031). Additionally, proximity to traffic predicted all-cause mortality (HR 1.13, 95% CI 1.01, 1.27). In a separate validation cohort, the multivariable model effectively predicted both all-cause mortality (AUC 0.76) and cardiovascular mortality (AUC 0.81). Population attributable fractions demonstrated a high mortality burden attributable to environmental exposures.InterpretationSeveral environmental factors predicted cardiovascular and all-cause mortality, independent of each other and of individual risk factors. Mortality attributable to environmental factors represents a critical opportunity for targeted policies and programs.

Association of Ambient Fine Particulate Matter Air Pollution With Kidney Transplant Outcomes

Increased levels of ambient fine particulate matter (PM2.5) air pollution are associated with increased risks for detrimental health outcomes, but risks for patients with kidney transplants (KTs) remain unknown. To investigate the association of PM2.5 exposure with KT outcomes. This retrospective cohort study was conducted using data on patients who received KTs from 2004 to 2016 who were identified in the national US transplant registry and followed up through March 2021. Multiple databases were linked to obtain data on PM2.5 concentration, KT outcomes, and patient clinical, transplant, and contextual factors. Data were analyzed from April 2020 through July 2021. Exposures included post-KT time-dependent annual mean PM2.5 level (in 10 μg/m3) and mean PM2.5 level in the year before KT (ie, baseline levels) in quartiles, as well as baseline annual mean PM2.5 level (in 10 μg/m3). Acute kidney rejection (ie, rejection within 1 year after KT), time to death-censored graft failure, and time to all-cause death. Multivariable logistic regression for kidney rejection and Cox analyses with nonlinear assessment of exposure-response for death-censored graft failure and all-cause death were performed. The national burden of graft failure associated with PM2.5 levels greater than the Environmental Protection Agency recommended level of 12 μg/m3 was estimated. Among 112 098 patients with KTs, 70 522 individuals (62.9%) were older than age 50 years at the time of KT, 68 117 (60.8%) were men, and the median (IQR) follow-up was 6.0 (3.9-8.9) years. There were 37 265 Black patients (33.2%), 17 047 Hispanic patients (15.2%), 48 581 White patients [43.3%]), and 9205 patients (8.2%) of other race or ethnicity. The median (IQR) baseline PM2.5 level was 9.8 (8.3-11.9) μg/m3. Increased baseline PM2.5 level, compared with quartile 1 baseline PM2.5 level, was not associated with higher odds of acute kidney rejection for quartile 2 (adjusted odds ratio [aOR], 0.99; 95% CI, 0.92-1.06) but was associated with increased odds for quartile 3 (aOR, 1.11; 95% CI, 1.04-1.20) and quartile 4 (aOR, 1.13; 95% CI, 1.05-1.23). Nonlinear assessment of exposure-response for graft failure and death showed no evidence for nonlinearity. Increased PM2.5 levels were associated with increased risk of death-censored graft failure (adjusted hazard ratio [aHR] per 10 μg/m3 increase, 1.17; 95% CI, 1.09-1.25) and all-cause death (aHR per 10 μg/m3 increase, 1.21; 95% CI, 1.14-1.28). The national burden of death-censored graft failure associated with PM2.5 above 12 μg/m3 was 57 failures (95% uncertainty interval, 48-67 failures) per year among patients with KTs. This cohort study found that PM2.5 level was an independent risk factor associated with acute rejection, graft failure, and death among patients with KTs. These findings suggest that efforts toward decreasing levels of PM2.5 concentration may be associated with improved outcomes after KT.

Association of Cardiovascular Disease and Long-Term Exposure to Fine Particulate Matter (PM2.5) in the Southeastern United States

There is a well-documented association between ambient fine particulate matter air pollution (PM2.5) and cardiovascular disease (CVD) morbidity and mortality. Exposure to PM2.5 can cause premature death and harmful and chronic health effects such as heart attack, diabetes, and stroke. The Environmental Protection Agency sets annual PM2.5 standards to reduce these negative health effects. Currently above an annual average level of 12.0 µg/m is considered unhealthy. Methods. We examined the association of long-term exposure to PM2.5 and CVD in a cohort of 44,610 individuals who resided in 12 states recruited into the Southern Community Cohort Study (SCCS). The SCCS was designed to recruit Black and White participants who received care from Federally Qualified Health Centers; hence, they represent vulnerable individuals from low-income families across this vast region. This study tests whether SCCS participants who lived in locations exposed to elevated ambient levels of PM2.5 concentrations were more likely to report a history of CVD at enrollment (2002–2009). Remotely sensed satellite data integrated with ground monitoring data provide an assessment of the average annual PM2.5 in urban and rural locations where the SCCS participants resided. We used multilevel logistic regression to estimate the associations between self-reported CVD and exposure to elevated ambient levels of PM2.5. Results. We found a 13.4 percent increase in the odds of reported CVD with exposure to unhealthy levels of PM2.5 exposure at enrollment. The SCCS participants with medical histories of hypertension, hypercholesterolemia, and smoking had, overall, 385 percent higher odds of reported CVD than those without these clinical risk factors. Additionally, Black participants were more likely to live in locations with higher ambient PM2.5 concentrations and report high levels of clinical risk factors, thus, they may be at a greater future risk of CVD. Conclusions: In the SCCS participants, we found a strong relation between exposures to high ambient levels of PM2.5 and self-reported CVD at enrollment.

Ambient fine particulate matter air pollution and the risk of preterm birth: A multicenter birth cohort study in China

Preterm birth (PTB), defined as live birth before the 37th week of gestation, is believed to have profound impacts on the infant's health in later life. Air pollution has been suggested to be a potential risk factor of PTB, but the evidence was inconsistent. In this multicenter birth cohort study, we aimed to examine the association between fine particulate matter (PM2.5) exposure during pregnancy and PTB in China. A total of 5976 live births were identified between Jan. 2009 and Feb. 2011 from 8 provinces in China. Residential exposures to PM2.5 were assigned based on satellite remote sensing estimates. Cox proportional hazards regressions were employed to explore the correlation for each trimester as well as the entire pregnancy. A total of 443 (7.4%) preterm births were observed. The average PM2.5 during pregnancy was 57.2 ± 8.8 μg/m3. We found exposure to PM2.5 during the whole pregnancy (hazard ratio, HR = 1.262; 95% CI: 1.087–1.465) and in the first trimester (HR = 1.114; 95% CI: 1.007–1.232) was associated with higher risk of PTB. The associations of PM2.5 were stronger for subjects with older maternal or paternal age, lower maternal pre-pregnancy BMI, and lower family income. This study adds supports to the cumulating evidence linking PM2.5 exposure and elevated PTB risk. Measures of air pollution reduction are needed during pregnancy, especially at early stage of pregnancy to prevent adverse birth outcomes.

Ambient fine particulate matter air pollution and the risk of hospitalization among COVID-19 positive individuals: Cohort study

BackgroundEcologic analyses suggest that living in areas with higher levels of ambient fine particulate matter air pollution (PM2.5) is associated with higher risk of adverse COVID-19 outcomes. Studies accounting for individual-level health characteristics are lacking. MethodsWe leveraged the breadth and depth of the US Department of Veterans Affairs national healthcare databases and built a national cohort of 169,102 COVID-19 positive United States Veterans, enrolled between March 2, 2020 and January 31, 2021, and followed them through February 15, 2021. Annual average 2018 PM2.5 exposure, at an approximately 1 km2 resolution, was linked with residential street address at the year prior to COVID-19 positive test. COVID-19 hospitalization was defined as first hospital admission between 7 days prior to, and 15 days after, the first COVID-19 positive date. Adjusted Poisson regression assessed the association of PM2.5 with risk of hospitalization. ResultsThere were 25,422 (15.0%) hospitalizations; 5,448 (11.9%), 5,056 (13.0%), 7,159 (16.1%), and 7,759 (19.4%) were in the lowest to highest PM2.5 quartile, respectively. In models adjusted for State, demographic and behavioral factors, contextual characteristics, and characteristics of the pandemic a one interquartile range increase in PM2.5 (1.9 µg/m3) was associated with a 10% (95% CI: 8%–12%) increase in risk of hospitalization. The association of PM2.5 and risk of hospitalization among COVID-19 individuals was present in each wave of the pandemic. Models of non-linear exposure–response suggested increased risk at PM2.5 concentrations below the national standard 12 µg/m3. Formal effect modification analyses suggested higher risk of hospitalization associated with PM2.5 in Black people compared to White people (p = 0.045), and in those living in socioeconomically disadvantaged neighborhoods (p < 0.001). ConclusionsExposure to higher levels of PM2.5 was associated with increased risk of hospitalization among COVID-19 infected individuals. The risk was evident at PM2.5 levels below the regulatory standards. The analysis identified those of Black race and those living in disadvantaged neighborhoods as population groups that may be more susceptible to the untoward effect of PM2.5 on risk of hospitalization in the setting of COVID-19.

Ambient Fine Particulate Matter Air Pollution and Risk of Weight Gain and Obesity in United States Veterans: An Observational Cohort Study.

Background:Experimental evidence and studies of children and adolescents suggest that ambient fine particulate matter [particulate matter in aerodynamic diameter ()] air pollution may be obesogenic, but the relationship between and the risk of body weight gain and obesity in adults is uncertain.Objectives:Our goal was to characterize the association between and the risks of weight gain and obesity.Methods:We followed 3,902,440 U.S. Veterans from 2010 to 2018 (median 8.1 y, interquartile range: 7.3–8.4) and assigned time-updated exposures by linking geocoded residential street addresses with satellite-based estimates of surface-level mass (at resolution). Associations with were estimated using Cox proportional hazards models for incident obesity [body mass index (] and a increase in weight relative to baseline and linear mixed models for associations with intra-individual changes in BMI and weight.Results:A higher average annual concentration was associated with risk of incident obesity [; (95% CI: 1.06, 1.11)] and the risk of a () increase in weight [ (95% CI: 1.06, 1.08)] and with higher intra-individual changes in BMI [ (95% CI: 0.139, 0.142)] and weight [ (95% CI: 0.955, 0.981)]. Nonlinear exposure–response models indicated associations at concentrations below the national standard of . As expected, a negative exposure control (ambient air sodium) was not associated with obesity or weight gain. Associations were consistent in direction and magnitude across sensitivity analyses that included alternative outcomes and exposures assigned at different spatial resolutions.Discussion: air pollution was associated with the risk of obesity and weight gain in a large predominantly male cohort of U.S. Veterans. Discussions about health effects of should include its association with obesity, and deliberations about the epidemiology of obesity should consider its association with . Investigation in other cohorts will deepen our understanding of the relationship between and weight gain and obesity. https://doi.org/10.1289/EHP7944

The global and national burden of chronic kidney disease attributable to ambient fine particulate matter air pollution: a modelling study

IntroductionWe aimed to integrate all available epidemiological evidence to characterise an exposure–response model of ambient fine particulate matter (PM2.5) and the risk of chronic kidney disease (CKD) across the spectrum...

Association of residential air pollution, noise, and greenspace with initial ischemic stroke severity.

Background and PurposeA number of environmental risk factors of acute ischemic stroke have been identified, but few studies have evaluated the influence of the outdoor environment on stroke severity. We assessed the association of residential ambient fine particulate matter air pollution (PM2.5), noise, and surrounding greenspace with initial stroke severity. MethodsWe obtained data on patients hospitalized with acute ischemic stroke from a hospital-based prospective stroke register (2005–2014) in Barcelona. We estimated residential PM2.5 based on an established land use regression model, greenspace as the average satellite-based Normalized Difference Vegetation Index (NDVI) within a 300 m buffer of the residence, and daily (Lday), evening (Levening), night (Lnight) and average noise (Lden) level at the street nearest to the residential address using municipal noise models. Stroke severity was assessed at the time of hospital presentation using the National Institute of Health Stroke Scale (NIHSS).We used logistic regression and binomial models to evaluate the associations of PM2.5, greenspace, and noise with initial stroke severity adjusting for potential confounders. ResultsAmong 2761 patients, higher residential surrounding greenspace was associated with lower risk of severe stroke (OR for NIHSS>5, 0.75; 95% CI: 0.60–0.95), while, living in areas with higher Lden was associated with a higher risk of severe stroke (OR, 1.30; 95% CI: 1.02–1.65). PM2.5 was not associated with initial stroke severity. ConclusionsIn an urban setting, surrounding greenspace and traffic noise at home are associated with initial stroke severity, suggesting an important influence of the built environment on the global burden of ischemic stroke.

Estimates of the 2016 global burden of kidney disease attributable to ambient fine particulate matter air pollution

ObjectiveTo quantitate the 2016 global and national burden of chronic kidney disease (CKD) attributable to ambient fine particulate matter air pollution ≤ 2.5 μm in aerodynamic diameter (PM2.5).DesignWe used the...

Effect of Ambient Fine Particulate Matter Air Pollution and Colder Outdoor Temperatures on High-Density Lipoprotein Function

Fine particulate matter (PM2.5) air pollution and environmental temperatures influence cardiovascular morbidity and mortality. Recent evidence suggests that several air pollutants can promote dyslipidemia; however, the impact of ambient PM2.5 and temperature on high-density lipoprotein (HDL) function remains unclear. We hypothesized that daily exposures to higher levels of ambient PM2.5 and colder outdoor temperatures would impair HDL functionality. Lipoproteins, serum cholesterol efflux capacity (CEC), and HDL oxidation markers were measured twice in 50 healthy adults (age 32.1 ± 9.6 years) living in southeast Michigan and associated with ambient and personal-level exposures using mixed models. Although previous 7-day mean outdoor temperature (4.4 ± 9.8°C) and PM2.5 levels (9.1 ± 1.8 µg/m3) were low, higher ambient PM2.5 exposures (per 10 µg/m3) were associated with significant increases in the total cholesterol-to-HDL-C ratio (rolling average lag days 1 and 2) as well as reductions in CEC by -1.93% (lag day 5, p = 0.022) and -1.62% (lag day 6, p = 0.032). Colder outdoor temperatures (per 10°C) were also associated with decreases in CEC from -0.62 to -0.63% (rolling average lag days 5 and 7, p = 0.027 and 0.028). Previous 24-hour personal-level PM2.5 and temperature exposures did not impact outcomes, nor were any exposures associated with changes in HDL-oxidation metrics. In conclusion, we provide the first evidence that ambient PM2.5 (even at low levels) and outdoor temperatures may influence serum CEC, a critical antiatherosclerotic HDL function.

Impact of ambient fine particulate matter air pollution on health behaviors: a longitudinal study of university students in Beijing, China

ObjectivesPoor air quality has become a national public health concern in China. This study examines the impact of ambient fine particulate matter (PM2.5) air pollution on health behaviors among college students in Beijing, China. Study designProspective cohort study. MethodsHealth surveys were repeatedly administered among 12,000 newly admitted students at Tsinghua University during 2012–2015 over their freshman year. Linear individual fixed-effect regressions were performed to estimate the impacts of ambient PM2.5 concentration on health behaviors among survey participants, adjusting for various time-variant individual characteristics and environmental measures. ResultsAmbient PM2.5 concentration was found to be negatively associated with time spent on walking, vigorous physical activity and sedentary behavior in the last week, but positively associated with time spent on nighttime/daytime sleep among survey participants. An increase in the ambient PM2.5 concentration by one standard deviation (36.5 μg/m³) was associated with a reduction in weekly total minutes of walking by 7.3 (95% confidence interval [CI] = 5.3–9.4), a reduction in weekly total minutes of vigorous physical activity by 10.1 (95% CI = 8.5–11.7), a reduction in daily average hours of sedentary behavior by 0.06 (95% CI = 0.02–0.10) but an increase in daily average hours of nighttime/daytime sleep by 1.07 (95% CI = 1.04–1.11). ConclusionsAmbient PM2.5 air pollution was inversely associated with physical activity level but positively associated with sleep duration among college students. Future studies are warranted to replicate study findings in other Chinese cities and universities, and policy interventions are urgently called to reduce air pollution level in China's urban areas.

Ambient coarse particulate pollution and mortality in three Chinese cities: Association and attributable mortality burden

The short-term mortality effects of ambient fine particulate matter air pollution have been widely investigated in China. However, the associations between day-to-day variation in ambient coarse particles pollution (PMc) and mortality, as well as the corresponding mortality burden, remain understudied. We estimated the short-term PMc-mortality association in three Chinese cities of the Pearl River Delta (PRD) region during the period of 2013–16. The city-specific association was first estimated using generalized additive models and then combined to obtain the overall effect estimates. We further estimated PMc related attributable fraction and attributable mortality. Our study found a significant association between PMc and mortality. Each 10μg/m3 increase of a current day's PMc was associated with a 1.37% (95% CI: 0.55%, 2.22%) increase in total mortality, a 1.63% increase (95% CI: 0.31%, 2.98%) in cardiovascular mortality, and a 0.97% increase (95% CI: −0.17%, 2.13%) in respiratory mortality in the three cities. We estimated that 0.37% (95% CI: 0.14%, 0.61%) and 2.72% (95% CI: 1.03%, 4.50%) of total mortalities were attributable to PMc by using China's standards and WHO's air quality guidelines as references—corresponding to 1394 (95% CI: 528, 2291) and 10,305 (95% CI: 3884, 17,000) attributable premature mortalities in the three cities, respectively. This study suggests that ambient coarse particulate pollution might be one important risk factor of total, cardiovascular, and respiratory mortality, as well as account for substantial mortality burdens in the three Chinese cities of the PRD.

Ambient Fine Particulate Matter Air Pollution and Physical Activity: A Longitudinal Study of University Retirees in Beijing, China.

We examined the longitudinal relationship between ambient fine particulate matter (PM2.5) air pollution and physical activity-related health behaviors among university retirees in Beijing, China. Annual health surveys of retirees were conducted at Tsinghua University during 2011-2016. We conducted linear individual fixed-effect regression analyses to estimate the impact of ambient PM2.5 concentration on physical activity-related health behaviors among survey participants, adjusting for various time-variant individual characteristics and environmental measures. An increase in ambient PM2.5 concentration by one standard deviation (56.6 μg/m³) was associated with a reduction in weekly total hours of walking by 4.69 (95% confidence interval=1.30-8.08), a reduction in leisure-time Physical Activity Scale for the Elderly (PASE) score by 71.16 (28.91-113.41), and a reduction in total PASE score by 110.67 (59.25-162.08). An increase in ambient PM2.5 concentration by one standard deviation was associated with an increase in daily average hours of nighttime/daytime sleeping by 1.75 (1.24-2.26). The impact of ambient PM2.5 concentration on weekly hours of walking tended to be greater among men than among women. Air pollution significantly discouraged Chinese older adults from engaging in daily physical activities. Policy interventions are needed to reduce air pollution in China's urban areas.

PM2.5 AIR POLLUTION, EDUCATIONAL ATTAINMENT, AND COGNITIVE FUNCTION AMONG OLDER U.S. ADULTS

AbstractThis study examines whether the association between air pollution and cognitive function among older adults differs by educational attainment. Data on 13,389 adults over age 50 are from the 2004 Health and Retirement Study and were linked to 2004 annual average concentrations of ambient fine particulate matter air pollution (PM). Multilevel linear regression models were used to examine the association of PM concentrations and individual-level education on cognitive function. Higher concentrations of PM were associated with lower scores on cognitive function, but the association was stronger among individuals with lower educational attainment. These findings were robust to the inclusion of a variety of individual demographic, socioeconomic, and health factors as well as neighborhood-level education and income. The findings suggest the cognitive harms of pollution exposure may be offset by educational attainment, and that older adults with low educational attainment may be particularly vulnerable to air pollution.

Short-term associations of fine particulate matter components and emergency hospital admissions among a privately insured population in Greater Houston

A number of time-series studies have associated PM2.5 (particulate matter with aerodynamic diameter less than 2.5 μm) mass and components with various health outcomes. No studies have yet examined the associations between PM2.5 components and hospital admissions among a privately insured population. We estimated the short-term associations between exposure to PM2.5 mass and components and emergency hospital admissions for all-cause and cause-specific diseases in Greater Houston, Texas, during 2008–2013 using Blue Cross Blue Shield Texas claims data. A total of 90,085 emergency hospital admissions were included in this study, with an average of 34 ± 10 admissions per day. We selected 20 PM2.5 components from the U.S. Environmental Protection Agency's Chemical Speciation Network site located in Houston, and then applied Poisson regression models to assess the short-term effects of PM2.5 mass and species on emergency hospital admissions. Effects were estimated without adjustment for other airborne pollutants. PM2.5 mass was not statistically significantly associated with increased all-cause emergency hospital admissions and selected cause-specific admissions. For selected PM2.5 species, we found interquartile range increases in arsenic (0.001 μg/m3) and copper (0.017 μg/m3) were significantly (P < 0.05) associated with increased admissions for stroke, (5.98% [95% confidence interval (CI): 0.73, 11.50%]) and pneumonia (4.07% [95% CI: 0.37, 7.90%]), respectively. Seasonal analysis showed weak variation among PM2.5 mass and components, except that nickel significantly increased all-cause emergency hospital admissions (2.16% [95% CI: 0.21, 4.14%]) during the warm season. Our findings suggest that hospital admissions in the privately insured population are slightly affected by ambient fine particulate matter air pollution.

Mortality burden of ambient fine particulate air pollution in six Chinese cities: Results from the Pearl River Delta study

BackgroundEpidemiological studies have reported significant association between ambient fine particulate matter air pollution (PM2.5) and mortality, however, few studies have investigated the relationship of mortality with PM2.5 and associated mortality burden in China, especially in a multicity setting. MethodsWe investigated the PM2.5-mortality association in six cities of the Pearl River Delta region from 2013 to 2015. We used generalized additive Poisson models incorporating penalized smoothing splines to control for temporal trend, temperature, and relative humidity. We applied meta-analyses using random-effects models to pool the effect estimates in the six cities. We also examined these associations in stratified analyses by sex, age group, education level and location of death. We further estimated the mortality burden (attributable fraction and attributable mortality) due to ambient PM2.5 exposures. ResultsDuring the study period, a total of 316,305 deaths were recorded in the study area. The analysis revealed a significant association between PM2.5 and mortality. Specifically, a 10μg/m3 increase in 4-day averaged (lag03) PM2.5 concentration corresponded to a 1.76% (95% confidence interval (CI): 1.47%, 2.06%) increase in total mortality, 2.19% (95% CI: 1.80%, 2.59%) in cardiovascular mortality, and 1.68% (95% CI: 1.00%, 2.37%) in respiratory mortality. The results were generally robust to model specifications and adjustment of gaseous air pollutants. We estimated that 0.56% (95% CI: 0.47%, 0.66%) and 3.79% (95% CI: 3.14%, 4.45%) of all-cause mortalities were attributable to PM2.5 using China's and WHO's air quality standards as the reference, corresponding to 1661 (95% CI: 1379, 1946) and 11,176 (95% CI: 9261, 13,120) attributable premature mortalities, respectively. ConclusionThis analysis adds to the growing body of evidence linking PM2.5 with daily mortality, and mortality burdens, particularly in one Chinese region with high levels of air pollution.

Interactions Between Cigarette Smoking And Ambient PM2.5 For Cardiovascular Mortality In The Cancer Prevention Study-II

Introduction: Associations between long-term exposure to ambient fine particulate matter air pollution (PM2.5) and cardiovascular mortality are clearly established in the literature. However, further work is needed to investigate possible joint effects of PM2.5 and cigarette smoking for the disease. We recently reported a greater-than-additive relationship between PM2.5 and cigarette smoking for lung cancer mortality in the American Cancer Society Cancer Prevention Study-II (CPS-II) and extend this work to mortality from circulatory diseases here. Methods: Included in this analysis were 429,406 current or never cigarette smokers among whom 32,354 died of circulatory disease during 22 years of follow-up (1982-2004). We estimated PM2.5 concentrations from a national hybrid land use-kriging interpolation model for the years 1999-2004. We fit Cox proportional hazards regression models to estimate mortality associations and interactions on both the additive and multiplicative scales. Results: The hazard ratio (HR) (95% confidence interval (CI)) for high vs. low PM2.5 exposure (according to the 75th and 25th percentile) was 1.10 (95% CI 1.07-1.13) in never smokers. The HR for cigarette smoking was 1.89 (95% CI 1.82-1.96) in those with low PM2.5. The HR for both high PM2.5 and cigarette smoking was 2.10 (95% CI 2.02-2.17). There was a significant relative excess risk due to interaction (RERI) of 0.11 (95% CI 0.03-0.19) observed. There was a stronger RERI for mortality from dysrhythmias, heart failure, cardiac arrest more specifically (RERI = 0.20, 95% CI 0.01-0.40). Results using an additive hazards model will also be presented. Conclusions: There was some evidence for a small additive interaction between PM2.5 and cigarette smoking for circulatory mortality.

Ambient fine particulate matter air pollution and leisure-time physical inactivity among US adults

ObjectivesThere is mounting evidence documenting the adverse health effects of short- and long-term exposure to ambient fine particulate matter (PM2.5) air pollution, but population-based evidence linking PM2.5 and health behaviour remains lacking. This study examined the relationship between ambient PM2.5 air pollution and leisure-time physical inactivity among US adults 18 years of age and above. Study designRetrospective data analysis. MethodsParticipant-level data (n = 2,381,292) from the Behavioral Risk Factor Surveillance System 2003–2011 surveys were linked with Wide-ranging Online Data for Epidemiologic Research air quality data by participants' residential county and interview month/year. Multilevel logistic regressions were performed to examine the effect of ambient PM2.5 air pollution on participants' leisure-time physical inactivity, accounting for various individual and county-level characteristics. Regressions were estimated on the overall sample and subsamples stratified by sex, age cohort, race/ethnicity and body weight status. ResultsOne unit (μg/m3) increase in county monthly average PM2.5 concentration was found to be associated with an increase in the odds of physical inactivity by 0.46% (95% confidence interval = 0.34%–0.59%). The effect was similar between the sexes but to some extent (although not always statistically significant) larger for younger adults, Hispanics, and overweight/obese individuals compared with older adults, non-Hispanic whites or African Americans, and normal weight individuals, respectively. ConclusionsAmbient PM2.5 air pollution is found to be associated with a modest but measurable increase in individuals' leisure-time physical inactivity, and the relationship tends to differ across population subgroups.