Short-term Associations between Fine and Coarse Particulate Matter and Hospitalizations in Southern Europe: Results from the MED-PARTICLES Project

Background: Evidence on the short-term effects of fine and coarse particles on morbidity in Europe is scarce and inconsistent.Objectives: We aimed to estimate the association between daily concentrations of fine and coarse particles with hospitalizations for cardiovascular and respiratory conditions in eight Southern European cities, within the MED-PARTICLES project.Methods: City-specific Poisson models were fitted to estimate associations of daily concentrations of particulate matter with aerodynamic diameter ≤ 2.5 μm (PM_2.5), ≤ 10 μm (PM₁₀), and their difference (PM_2.5–10) with daily counts of emergency hospitalizations for cardiovascular and respiratory diseases. We derived pooled estimates from random-effects meta-analysis and evaluated the robustness of results to co-pollutant exposure adjustment and model specification. Pooled concentration–response curves were estimated using a meta-smoothing approach.Results: We found significant associations between all PM fractions and cardiovascular admissions. Increases of 10 μg/m³ in PM_2.5, 6.3 μg/m³ in PM_2.5–10, and 14.4 μg/m³ in PM₁₀ (lag 0–1 days) were associated with increases in cardiovascular admissions of 0.51% (95% CI: 0.12, 0.90%), 0.46% (95% CI: 0.10, 0.82%), and 0.53% (95% CI: 0.06, 1.00%), respectively. Stronger associations were estimated for respiratory hospitalizations, ranging from 1.15% (95% CI: 0.21, 2.11%) for PM₁₀ to 1.36% (95% CI: 0.23, 2.49) for PM_2.5 (lag 0–5 days).Conclusions: PM_2.5 and PM_2.5–10 were positively associated with cardiovascular and respiratory admissions in eight Mediterranean cities. Information on the short-term effects of different PM fractions on morbidity in Southern Europe will be useful to inform European policies on air quality standards.Citation: Stafoggia M, Samoli E, Alessandrini E, Cadum E, Ostro B, Berti G, Faustini A, Jacquemin B, Linares C, Pascal M, Randi G, Ranzi A, Stivanello E, Forastiere F, the MED-PARTICLES Study Group. 2013. Short-term associations between fine and coarse particulate matter and hospitalizations in Southern Europe: results from the MED-PARTICLES project. Environ Health Perspect 121:1026–1033; http://dx.doi.org/10.1289/ehp.1206151     

Short-term Exposure to Particulate Matter Constituents and Mortality in a National Study of U.S. Urban Communities

Background: Although the association between PM_2.5 mass and mortality has been extensively studied, few national-level analyses have estimated mortality effects of PM_2.5 chemical constituents. Epidemiologic studies have reported that estimated effects of PM_2.5 on mortality vary spatially and seasonally. We hypothesized that associations between PM_2.5 constituents and mortality would not vary spatially or seasonally if variation in chemical composition contributes to variation in estimated PM_2.5 mortality effects.Objectives: We aimed to provide the first national, season-specific, and region-specific associations between mortality and PM_2.5 constituents.Methods: We estimated short-term associations between nonaccidental mortality and PM_2.5 constituents across 72 urban U.S. communities from 2000 to 2005. Using U.S. Environmental Protection Agency (EPA) Chemical Speciation Network data, we analyzed seven constituents that together compose 79–85% of PM_2.5 mass: organic carbon matter (OCM), elemental carbon (EC), silicon, sodium ion, nitrate, ammonium, and sulfate. We applied Poisson time-series regression models, controlling for time and weather, to estimate mortality effects.Results: Interquartile range increases in OCM, EC, silicon, and sodium ion were associated with estimated increases in mortality of 0.39% [95% posterior interval (PI): 0.08, 0.70%], 0.22% (95% PI: 0.00, 0.44), 0.17% (95% PI: 0.03, 0.30), and 0.16% (95% PI: 0.00, 0.32), respectively, based on single-pollutant models. We did not find evidence that associations between mortality and PM_2.5 or PM_2.5 constituents differed by season or region.Conclusions: Our findings indicate that some constituents of PM_2.5 may be more toxic than others and, therefore, regulating PM total mass alone may not be sufficient to protect human health.Citation: Krall JR, Anderson GB, Dominici F, Bell ML, Peng RD. 2013. Short-term exposure to particulate matter constituents and mortality in a national study of U.S. urban communities. Environ Health Perspect 121:1148–1153; http://dx.doi.org/10.1289/ehp.1206185     

Prospective Study of Ambient Particulate Matter Exposure and Risk of Pulmonary Embolism in the Nurses’ Health Study Cohort

Background

Pulmonary embolism (PE) is the most serious manifestation of venous thromboembolism and a leading cause of sudden death. Several studies have suggested associations of venous thromboembolism with short-term particulate matter (PM) exposure; evidence on long-term PM and traffic exposure is mixed.

Objectives

We examined the association of long-term exposure to PM_2.5, PM_2.5–10, and PM₁₀ (PM with diameter of ≤ 2.5, 2.5–10, and ≤ 10 μm) and distance to roadways with overall incident PE and with PE subtypes in a cohort of U.S. women.

Methods

The study included 115,745 women from the Nurses’ Health Study, followed from 1992 through 2008. Incident PE cases were self-reported biennially. Nonidiopathic PE were cases for which the medical record revealed an underlying health condition related to PE (i.e., surgery, trauma, or malignancy); idiopathic PE were cases with no such history. We used spatiotemporal models combining spatial smoothing and geographic covariates to quantify exposure at residential addresses, and Cox proportional hazards models to calculate hazard ratios (HR) and 95% confidence intervals (CIs).

Results

PM_2.5 averaged over 1 month (HR = 1.22; 95% CI: 1.04, 1.44) or 12 months (HR = 1.17; 95% CI: 0.93, 1.48) was associated with incident PE, after adjusting for known risk factors and PM_2.5–10. Equivalent analyses restricted to PE subtypes showed a positive association for PM_2.5 with nonidiopathic PE, but not with idiopathic PE. We did not find evidence of an association between distance to roadways and PE risk.

Conclusions

We provide evidence that PM in the prior 1 and 12 months is associated with PE risk. Our results also suggest that women with underlying health conditions may be more susceptible to PE after PM exposure.

Citation

Pun VC, Hart JE, Kabrhel C, Camargo CA Jr, Baccarelli AA, Laden F. 2015. Prospective study of ambient particulate matter exposure and risk of pulmonary embolism in the Nurses’ Health Study cohort. Environ Health Perspect 123:1265–1270; http://dx.doi.org/10.1289/ehp.1408927     

Carotid Intima-Media Thickness and Long-Term Exposure to Traffic-Related Air Pollution in Middle-Aged Residents of Taiwan: A Cross-Sectional Study

Background

Associations between long-term exposure to air pollution and carotid intima-media thickness (CIMT) have inconsistent findings.

Objectives

In this study we aimed to evaluate association between 1-year average exposure to traffic-related air pollution and CIMT in middle-aged adults in Asia.

Methods

CIMT was measured in Taipei, Taiwan, between 2009 and 2011 in 689 volunteers 35–65 years of age who were recruited as the control subjects of an acute coronary heart disease cohort study. We applied land-use regression models developed by the European Study of Cohorts for Air Pollution Effects (ESCAPE) to estimate each subject’s 1-year average exposure to traffic-related air pollutants with particulate matter diameters ≤ 10 μm (PM₁₀) and ≤ 2.5 μm (PM_2.5) and the absorbance levels of PM_2.5 (PM_2.5abs), nitrogen dioxide (NO₂), and nitrogen oxides (NO_x) in the urban environment.

Results

One-year average air pollution exposures were 44.21 ± 4.19 μg/m³ for PM₁₀, 27.34 ± 5.12 μg/m³ for PM_2.5, and (1.97 ± 0.36) × 10^–5/m for PM_2.5abs. Multivariate regression analyses showed average percentage increases in maximum left CIMT of 4.23% (95% CI: 0.32, 8.13) per 1.0 × 10^–5/m increase in PM_2.5abs; 3.72% (95% CI: 0.32, 7.11) per 10-μg/m³ increase in PM₁₀; 2.81% (95% CI: 0.32, 5.31) per 20-μg/m³ increase in NO₂; and 0.74% (95% CI: 0.08, 1.41) per 10-μg/m³ increase in NO_x. The associations were not evident for right CIMT, and PM_2.5 mass concentration was not associated with the outcomes.

Conclusions

Long-term exposures to traffic-related air pollution of PM_2.5abs, PM₁₀, NO₂, and NO_x were positively associated with subclinical atherosclerosis in middle-aged adults.

Citation

Su TC, Hwang JJ, Shen YC, Chan CC. 2015. Carotid intima–media thickness and long-term exposure to traffic-related air pollution in middle-aged residents of Taiwan: a cross-sectional study. Environ Health Perspect 123:773–778; http://dx.doi.org/10.1289/ehp.1408553     

Performance of Multi-City Land Use Regression Models for Nitrogen Dioxide and Fine Particles

Background: Land use regression (LUR) models have been developed mostly to explain intraurban variations in air pollution based on often small local monitoring campaigns. Transferability of LUR models from city to city has been investigated, but little is known about the performance of models based on large numbers of monitoring sites covering a large area.Objectives: We aimed to develop European and regional LUR models and to examine their transferability to areas not used for model development.Methods: We evaluated LUR models for nitrogen dioxide (NO₂) and particulate matter (PM; PM_2.5, PM_2.5 absorbance) by combining standardized measurement data from 17 (PM) and 23 (NO₂) ESCAPE (European Study of Cohorts for Air Pollution Effects) study areas across 14 European countries for PM and NO₂. Models were evaluated with cross-validation (CV) and hold-out validation (HV). We investigated the transferability of the models by successively excluding each study area from model building.Results: The European model explained 56% of the concentration variability across all sites for NO₂, 86% for PM_2.5, and 70% for PM_2.5 absorbance. The HV R²s were only slightly lower than the model R² (NO₂, 54%; PM_2.5, 80%; PM_2.5 absorbance, 70%). The European NO₂, PM_2.5, and PM_2.5 absorbance models explained a median of 59%, 48%, and 70% of within-area variability in individual areas. The transferred models predicted a modest-to-large fraction of variability in areas that were excluded from model building (median R²: NO₂, 59%; PM_2.5, 42%; PM_2.5 absorbance, 67%).Conclusions: Using a large data set from 23 European study areas, we were able to develop LUR models for NO₂ and PM metrics that predicted measurements made at independent sites and areas reasonably well. This finding is useful for assessing exposure in health studies conducted in areas where no measurements were conducted.Citation: Wang M, Beelen R, Bellander T, Birk M, Cesaroni G, Cirach M, Cyrys J, de Hoogh K, Declercq C, Dimakopoulou K, Eeftens M, Eriksen KT, Forastiere F, Galassi C, Grivas G, Heinrich J, Hoffmann B, Ineichen A, Korek M, Lanki T, Lindley S, Modig L, Mölter A, Nafstad P, Nieuwenhuijsen MJ, Nystad W, Olsson D, Raaschou-Nielsen O, Ragettli M, Ranzi A, Stempfelet M, Sugiri D, Tsai MY, Udvardy O, Varró MJ, Vienneau D, Weinmayr G, Wolf K, Yli-Tuomi T, Hoek G, Brunekreef B. 2014. Performance of multi-city land use regression models for nitrogen dioxide and fine particles. Environ Health Perspect 122:843–849; http://dx.doi.org/10.1289/ehp.1307271     

Air Pollution Exposures During Adulthood and Risk of Endometriosis in the Nurses’ Health Study II

Background: Particulate matter and proximity to large roadways may promote disease mechanisms, including systemic inflammation, hormonal alteration, and vascular proliferation, that may contribute to the development and severity of endometriosis.Objective: Our goal was to determine the association of air pollution exposures during adulthood, including distance to road, particulate matter < 2.5 μm, between 2.5 and 10 μm, and < 10 μm, (PM_2.5, PM_10–2.5, PM₁₀), and timing of exposure with risk of endometriosis in the Nurses’ Health Study II.Methods: Proximity to major roadways and outdoor levels of PM_2.5, PM_10–2.5, and PM₁₀ were determined for all residential addresses from 1993 to 2007. Multivariable-adjusted time-varying Cox proportional hazard models were used to estimate the relation between these air pollution exposures and endometriosis risk.Results: Among 84,060 women, 2,486 incident cases of surgically confirmed endometriosis were identified over 710,230 person-years of follow-up. There was no evidence of an association between endometriosis risk and distance to road or exposure to PM_2.5, PM_10–2.5, or PM₁₀ averaged over follow-up or during the previous 2- or 4-year period.Conclusions: Traffic and air pollution exposures during adulthood were not associated with incident endometriosis in this cohort of women.Citation: Mahalingaiah S, Hart JE, Laden F, Aschengrau A, Missmer SA. 2014. Air pollution exposures during adulthood and risk of endometriosis in the Nurses’ Health Study II. Environ Health Perspect 122:58–64; http://dx.doi.org/10.1289/ehp.1306627     

Associations between Long-Term Air Pollutant Exposures and Blood Pressure in Elderly Residents of Taipei City: A Cross-Sectional Study

Background

Limited information is available regarding long-term effects of air pollution on blood pressure (BP) and hypertension.

Objective

We studied whether 1-year exposures to particulate matter (PM) and nitrogen oxides (NO_x) were correlated with BP and hypertension in the elderly.

Methods

We analyzed cross-sectional data from 27,752 Taipei City residents > 65 years of age who participated in a health examination program in 2009. Land-use regression models were used to estimate participants’ 1-year exposures to particulate matter with aerodynamic diameter ≤ 10 μm (PM₁₀), coarse particles (PM_2.5–10), fine particles (≤ 2.5 μm; PM_2.5), PM_2.5 absorbance, NO_x, and nitrogen dioxide (NO₂). Generalized linear regressions and logistic regressions were used to examine the association between air pollution and BP and hypertension, respectively.

Results

Diastolic BP was associated with 1-year exposures to air pollution, with estimates of 0.73 [95% confidence interval (CI): 0.44, 1.03], 0.46 (95% CI: 0.30, 0.63), 0.62 (95% CI: 0.24, 0.99), 0.34 (95% CI: 0.19, 0.50), and 0.65 (95% CI: 0.44, 0.85) mmHg for PM₁₀ (10 μg/m³), PM_2.5–10 (5 μg/m³), PM_2.5 absorbance (10^–5/m), NO_x (20 μg/m³), and NO₂ (10 μg/m³), respectively. PM_2.5 was not associated with diastolic BP, and none of the air pollutants was associated with systolic BP. Associations of diastolic BP with PM₁₀ and PM_2.5 absorbance were stronger among participants with hypertension, diabetes, or a body mass index ≥ 25 kg/m² than among participants without these conditions. One-year air pollution exposures were not associated with hypertension.

Conclusions

One-year exposures to PM₁₀, PM_2.5–10, PM_2.5 absorbance, and NO_x were associated with higher diastolic BP in elderly residents of Taipei.

Citation

Chen SY, Wu CF, Lee JH, Hoffmann B, Peters A, Brunekreef B, Chu DC, Chan CC. 2015. Associations between long-term air pollutant exposures and blood pressure in elderly residents of Taipei City: a cross-sectional study. Environ Health Perspect 123:779–784; http://dx.doi.org/10.1289/ehp.1408771     

Air Pollution and Atherosclerosis: A Cross-Sectional Analysis of Four European Cohort Studies in the ESCAPE Study

Background:

In four European cohorts, we investigated the cross-sectional association between long-term exposure to air pollution and intima-media thickness of the common carotid artery (CIMT), a preclinical marker of atherosclerosis.

Methods:

Individually assigned levels of nitrogen dioxide, nitrogen oxides, particulate matter ≤ 2.5 μm (PM_2.5), absorbance of PM_2.5 (PM_2.5abs), PM₁₀, PM_coarse, and two indicators of residential proximity to highly trafficked roads were obtained under a standard exposure protocol (European Study of Cohorts for Air Pollution Effects—ESCAPE study) in the Stockholm area (Sweden), the Ausburg and Ruhr area (Germany), and the Girona area (Spain). We used linear regression and meta-analyses to examine the association between long-term exposure to air pollution and CIMT.

Results:

The meta-analysis with 9,183 individuals resulted in an estimated increase in CIMT (geometric mean) of 0.72% (95% CI: –0.65%, 2.10%) per 5-μg/m³ increase in PM_2.5 and 0.42% (95% CI: –0.46%, 1.30%) per 10^–5/m increase in PM_2.5abs. Living in proximity to high traffic was also positively but not significantly associated with CIMT. Meta-analytic estimates for other pollutants were inconsistent. Results were similar across different adjustment sets and sensitivity analyses. In an extended meta-analysis for PM_2.5 with three other previously published studies, a 0.78% (95% CI: –0.18%, 1.75%) increase in CIMT was estimated for a 5-μg/m³ contrast in PM_2.5.

Conclusions:

Using a standardized exposure and analytical protocol in four European cohorts, we found that cross-sectional associations between CIMT and the eight ESCAPE markers of long-term residential air pollution exposure did not reach statistical significance. The additional meta-analysis of CIMT and PM_2.5 across all published studies also was positive but not significant.

Citation:

Perez L, Wolf K, Hennig F, Penell J, Basagaña X, Foraster M, Aguilera I, Agis D, Beelen R, Brunekreef B, Cyrys J, Fuks KB, Adam M, Baldassarre D, Cirach M, Elosua R, Dratva J, Hampel R, Koenig W, Marrugat J, de Faire U, Pershagen G, Probst-Hensch NM, de Nazelle A, Nieuwenhuijsen MJ, Rathmann W, Rivera M, Seissler J, Schindler C, Thiery J, Hoffmann B, Peters A, Künzli N. 2015. Air pollution and atherosclerosis: a cross-sectional analysis of four European cohort studies in the ESCAPE Study. Environ Health Perspect 123:597–605; http://dx.doi.org/10.1289/ehp.1307711     

Air Pollution Exposure and Abnormal Glucose Tolerance during Pregnancy: The Project Viva Cohort

Background: Exposure to fine particulate matter (PM with diameter ≤ 2.5 μm; PM_2.5) has been linked to type 2 diabetes mellitus, but associations with hyperglycemia in pregnancy have not been well studied.Methods: We studied Boston, Massachusetts–area pregnant women without known diabetes. We identified impaired glucose tolerance (IGT) and gestational diabetes mellitus (GDM) during pregnancy from clinical glucose tolerance tests at median 28.1 weeks gestation. We used residential addresses to estimate second-trimester PM_2.5 and black carbon exposure via a central monitoring site and spatiotemporal models. We estimated residential traffic density and roadway proximity as surrogates for exposure to traffic-related air pollution. We performed multinomial logistic regression analyses adjusted for sociodemographic covariates, and used multiple imputation to account for missing data.Results: Of 2,093 women, 65 (3%) had IGT and 118 (6%) had GDM. Second-trimester spatiotemporal exposures ranged from 8.5 to 15.9 μg/m³ for PM_2.5 and from 0.1 to 1.7 μg/m³ for black carbon. Traffic density was 0–30,860 vehicles/day × length of road (kilometers) within 100 m; 281 (13%) women lived ≤ 200 m from a major road. The prevalence of IGT was elevated in the highest (vs. lowest) quartile of exposure to spatiotemporal PM_2.5 [odds ratio (OR) = 2.63; 95% CI: 1.15, 6.01] and traffic density (OR = 2.66; 95% CI: 1.24, 5.71). IGT also was positively associated with other exposure measures, although associations were not statistically significant. No pollutant exposures were positively associated with GDM.Conclusions: Greater exposure to PM_2.5 and other traffic-related pollutants during pregnancy was associated with IGT but not GDM. Air pollution may contribute to abnormal glycemia in pregnancy.Citation: Fleisch AF, Gold DR, Rifas-Shiman SL, Koutrakis P, Schwartz JD, Kloog I, Melly S, Coull BA, Zanobetti A, Gillman MW, Oken E. 2014. Air pollution exposure and abnormal glucose tolerance during pregnancy: the Project Viva Cohort. Environ Health Perspect 122:378–383; http://dx.doi.org/10.1289/ehp.1307065     

Air Pollution and Percent Emphysema Identified by Computed Tomography in the Multi-Ethnic Study of Atherosclerosis

Background: Air pollution is linked to low lung function and to respiratory events, yet little is known of associations with lung structure.Objectives: We examined associations of particulate matter (PM_2.5, PM₁₀) and nitrogen oxides (NO_x) with percent emphysema-like lung on computed tomography (CT).Methods: The Multi-Ethnic Study of Atherosclerosis (MESA) recruited participants (45–84 years of age) in six U.S. states. Percent emphysema was defined as lung regions < –910 Hounsfield Units on cardiac CT scans acquired following a highly standardized protocol. Spirometry was also conducted on a subset. Individual-level 1- and 20-year average air pollution exposures were estimated using spatiotemporal models that included cohort-specific measurements. Multivariable regression was conducted to adjust for traditional risk factors and study location.Results: Among 6,515 participants, we found evidence of an association between percent emphysema and long-term pollution concentrations in an analysis leveraging between-city exposure contrasts. Higher concentrations of PM_2.5 (5 μg/m³) and NO_x (25 ppb) over the previous year were associated with 0.6 (95% CI: 0.1, 1.2%) and 0.5 (95% CI: 0.1, 0.9%) higher average percent emphysema, respectively. However, after adjustment for study site the associations were –0.6% (95% CI: –1.5, 0.3%) for PM_2.5 and –0.5% (95% CI: –1.1, 0.02%) for NO_x. Lower lung function measures (FEV₁ and FVC) were associated with higher PM_2.5 and NO_x levels in 3,791 participants before and after adjustment for study site, though most associations were not statistically significant.Conclusions: Associations between ambient air pollution and percentage of emphysema-like lung were inconclusive in this cross-sectional study, thus longitudinal analyses may better clarify these associations with percent emphysema.Citation: Adar SD, Kaufman JD, Diez-Roux AV, Hoffman EA, D’Souza J, Stukovsky KH, Rich SS, Rotter JI, Guo X, Raffel LJ, Sampson PD, Oron AP, Raghunathan T, Barr RG. 2015. Air pollution and percent emphysema identified by computed tomography in the Multi-Ethnic Study of Atherosclerosis. Environ Health Perspect 123:144–151; http://dx.doi.org/10.1289/ehp.1307951     

Retinal Microvascular Responses to Short-Term Changes in Particulate Air Pollution in Healthy Adults

Background: Microcirculation plays an important role in the physiology of cardiovascular health. Air pollution is an independent risk factor for the development and progression of cardiovascular diseases, but the number of studies on the relation between air pollution and the microcirculation is limited.Objectives: We examined the relationship between short-term changes in air pollution and microvascular changes.Methods: We measured retinal microvasculature using fundus image analysis in a panel of 84 healthy adults (52% female), 22–63 years of age, during January–May 2012. Blood vessels were measured as central retinal arteriolar/venular equivalent (CRAE/CRVE), with a median of 2 measurements (range, 1–3). We used monitoring data on particulate air pollution (PM₁₀) and black carbon (BC). Mixed-effect models were used to estimate associations between CRAE/CRVE and exposure to PM₁₀ and BC using various exposure windows.Results: CRAE and CRVE were associated with PM₁₀ and BC concentrations, averaged over the 24 hr before the retinal examinations. Each 10-µg/m³ increase in PM₁₀ was associated with a 0.93-µm decrease (95% CI: –1.42, –0.45; p = 0.0003) in CRAE and a 0.86-µm decrease (95% CI: –1.42, –0.30; p = 0.004) in CRVE after adjusting for individual characteristics and time varying conditions such as ambient temperature. Each 1-µg/m³ increase in BC was associated with a 1.84-µm decrease (95% CI: –3.18, –0.51; p < 0.001) in CRAE.Conclusions: Our findings suggest that the retinal microvasculature responds to short-term changes in air pollution levels. These results support a mechanistic pathway through which air pollution can act as a trigger of cardiovascular events at least in part through effects on the microvasculature.Citation: Louwies T, Int Panis L, Kicinski M, De Boever P, Nawrot TS. 2013. Retinal microvascular responses to short-term changes in particulate air pollution in healthy adults. Environ Health Perspect 121:1011–1016; http://dx.doi.org/10.1289/ehp.1205721     

Associations of Pregnancy Outcomes and PM2.5 in a National Canadian Study

Background

Numerous studies have examined associations between air pollution and pregnancy outcomes, but most have been restricted to urban populations living near monitors.

Objectives

We examined the association between pregnancy outcomes and fine particulate matter in a large national study including urban and rural areas.

Methods

Analyses were based on approximately 3 million singleton live births in Canada between 1999 and 2008. Exposures to PM_2.5 (particles of median aerodynamic diameter ≤ 2.5 μm) were assigned by mapping the mother’s postal code to a monthly surface based on a national land use regression model that incorporated observations from fixed-site monitoring stations and satellite-derived estimates of PM_2.5. Generalized estimating equations were used to examine the association between PM_2.5 and preterm birth (gestational age < 37 weeks), term low birth weight (< 2,500 g), small for gestational age (SGA; < 10th percentile of birth weight for gestational age), and term birth weight, adjusting for individual covariates and neighborhood socioeconomic status (SES).

Results

In fully adjusted models, a 10-μg/m³ increase in PM_2.5 over the entire pregnancy was associated with SGA (odds ratio = 1.04; 95% CI 1.01, 1.07) and reduced term birth weight (–20.5 g; 95% CI –24.7, –16.4). Associations varied across subgroups based on maternal place of birth and period (1999–2003 vs. 2004–2008).

Conclusions

This study, based on approximately 3 million births across Canada and employing PM_2.5 estimates from a national spatiotemporal model, provides further evidence linking PM_2.5 and pregnancy outcomes.

Citation

Stieb DM, Chen L, Beckerman BS, Jerrett M, Crouse DL, Omariba DW, Peters PA, van Donkelaar A, Martin RV, Burnett RT, Gilbert NL, Tjepkema M, Liu S, Dugandzic RM. 2016. Associations of pregnancy outcomes and PM_2.5 in a National Canadian Study. Environ Health Perspect 124:243–249; http://dx.doi.org/10.1289/ehp.1408995     

Associations between Traffic Noise,Particulate Air Pollution,Hypertension, and Isolated Systolic Hypertension in Adults: The KORA Study

Background: Studies on the association between traffic noise and cardiovascular diseases have rarely considered air pollution as a covariate in the analyses. Isolated systolic hypertension has not yet been in the focus of epidemiological noise research.Methods: The association between traffic noise (road and rail) and the prevalence of hypertension was assessed in two study populations with a total of 4,166 participants 25–74 years of age. Traffic noise (weighted day–night average noise level; L_DN) at the facade of the dwellings was derived from noise maps. Annual average PM_2.5 mass concentrations at residential addresses were estimated by land-use regression. Hypertension was assessed by blood pressure readings, self-reported doctor-diagnosed hypertension, and antihypertensive drug intake.Results: In the Greater Augsburg, Germany, study population, traffic noise and air pollution were not associated with hypertension. In the City of Augsburg population (n = 1,893), where the exposure assessment was more detailed, the adjusted odds ratio (OR) for a 10-dB(A) increase in noise was 1.16 (95% CI: 1.00, 1.35), and 1.11 (95% CI: 0.94, 1.30) after additional adjustment for PM_2.5. The adjusted OR for a 1-μg/m³ increase in PM_2.5 was 1.15 (95% CI: 1.02, 1.30), and 1.11 (95% CI: 0.98, 1.27) after additional adjustment for noise. For isolated systolic hypertension, the fully adjusted OR for noise was 1.43 (95% CI: 1.10, 1.86) and for PM_2.5 was 1.08 (95% CI: 0.87, 1.34).Conclusions: Traffic noise and PM_2.5 were both associated with a higher prevalence of hypertension. Mutually adjusted associations with hypertension were positive but no longer statistically significant.Citation: Babisch W, Wolf K, Petz M, Heinrich J, Cyrys J, Peters A. 2014. Associations between traffic noise, particulate air pollution, hypertension, and isolated systolic hypertension in adults: the KORA Study. Environ Health Perspect 122:492–498; http://dx.doi.org/10.1289/ehp.1306981     

Sources of Fine Particulate Matter and Risk of Preterm Birth in Connecticut, 2000–2006: A Longitudinal Study

Background: Previous studies have examined fine particulate matter (≤ 2.5 μm; PM_2.5) and preterm birth, but there is a dearth of longitudinal studies on this topic and a paucity of studies that have investigated specific sources of this exposure.Objectives: Our aim was to assess whether anthropogenic sources are associated with risk of preterm birth, comparing successive pregnancies to the same woman.Methods: Birth certificates were used to select women who had vaginal singleton live births at least twice in Connecticut during 2000–2006 (n = 23,123 women, n = 48,208 births). We procured 4,085 daily samples of PM_2.5 on Teflon filters from the Connecticut Department of Environmental Protection for six cities in Connecticut. Filters were analyzed for chemical composition, and Positive Matrix Factorization was used to determine contributions of PM_2.5 sources. Risk estimates were calculated with conditional logistic regression, matching pregnancies to the same women.Results: Odds ratios of preterm birth per interquartile range increase in whole pregnancy exposure to dust, motor vehicle emissions, oil combustion, and regional sulfur PM_2.5 sources were 1.01 (95% CI: 0.93, 1.09), 1.01 (95% CI: 0.92, 1.10), 1.00 (95% CI: 0.89, 1.12), and 1.09 (95% CI: 0.97, 1.22), respectively.Conclusion: This was the first study of PM_2.5 sources and preterm birth, and the first matched analysis, that better addresses individual-level confounding potentially inherent in all past studies. There was insufficient evidence to suggest that sources were statistically significantly associated with preterm birth. However, elevated central estimates and previously observed associations with mass concentration motivate the need for further research. Future studies would benefit from high source exposure settings and longitudinal study designs, such as that adopted in this study.Citation: Pereira G, Bell ML, Lee HJ, Koutrakis P, Belanger K. 2014. Sources of fine particulate matter and risk of preterm birth in Connecticut, 2000–2006: a longitudinal study. Environ Health Perspect 122:1117–1122; http://dx.doi.org/10.1289/ehp.1307741     

Elemental Constituents of Particulate Matter and Newborn’s Size in Eight European Cohorts

Background

The health effects of suspended particulate matter (PM) may depend on its chemical composition. Associations between maternal exposure to chemical constituents of PM and newborn’s size have been little examined.

Objective

We aimed to investigate the associations of exposure to elemental constituents of PM with term low birth weight (LBW; weight < 2,500 g among births after 37 weeks of gestation), mean birth weight, and head circumference, relying on standardized fine-scale exposure assessment and with extensive control for potential confounders.

Methods

We pooled data from eight European cohorts comprising 34,923 singleton births in 1994–2008. Annual average concentrations of elemental constituents of PM ≤ 2.5 and ≤ 10 μm (PM_2.5 and PM₁₀) at maternal home addresses during pregnancy were estimated using land-use regression models. Adjusted associations between each birth measurement and concentrations of eight elements (copper, iron, potassium, nickel, sulfur, silicon, vanadium, and zinc) were calculated using random-effects regression on pooled data.

Results

A 200-ng/m³ increase in sulfur in PM_2.5 was associated with an increased risk of LBW (adjusted odds ratio = 1.36; 95% confidence interval: 1.17, 1.58). Increased nickel and zinc in PM_2.5 concentrations were also associated with an increased risk of LBW. Head circumference was reduced at higher exposure to all elements except potassium. All associations with sulfur were most robust to adjustment for PM_2.5 mass concentration. All results were similar for PM₁₀.

Conclusion

Sulfur, reflecting secondary combustion particles in this study, may adversely affect LBW and head circumference, independently of particle mass.

Citation

Pedersen M, Gehring U, Beelen R, Wang M, Giorgis-Allemand L, Andersen AM, Basagaña X, Bernard C, Cirach M, Forastiere F, de Hoogh K, Gražulevičienė R, Gruzieva O, Hoek G, Jedynska A, Klümper C, Kooter IM, Krämer U, Kukkonen J, Porta D, Postma DS, Raaschou-Nielsen O, van Rossem L, Sunyer J, Sørensen M, Tsai MY, Vrijkotte TG, Wilhelm M, Nieuwenhuijsen MJ, Pershagen G, Brunekreef B, Kogevinas M, Slama R. 2016. Elemental constituents of particulate matter and newborn’s size in eight European cohorts. Environ Health Perspect 124:141–150; http://dx.doi.org/10.1289/ehp.1409546     

Long-term Exposure to PM10 and NO2 in Association with Lung Volume and Airway Resistance in the MAAS Birth Cohort

Background: Findings from previous studies on the effects of air pollution exposure on lung function during childhood have been inconsistent. A common limitation has been the quality of exposure data used, and few studies have modeled exposure longitudinally throughout early life.Objectives: We sought to study the long-term effects of exposure to particulate matter with an aerodynamic diameter ≤ 10 μm (PM₁₀) and to nitrogen dioxide (NO₂) on specific airway resistance (sR_aw) and forced expiratory volume in 1 sec (FEV₁) before and after bronchodilator treatment. Subjects were from the Manchester Asthma and Allergy Study (MAAS) birth cohort (n = 1,185).Methods: Spirometry was performed during clinic visits at ages 3, 5, 8, and 11 years. Individual-level PM₁₀ and NO₂ exposures were estimated from birth to 11 years of age through a microenvironmental exposure model. Longitudinal and cross-sectional associations were estimated using generalized estimating equations and multivariable linear regression models.Results: Lifetime exposure to PM₁₀ and NO₂ was associated with significantly less growth in FEV₁ (percent predicted) over time, both before (–1.37%; 95% CI: –2.52, –0.23 for a 1-unit increase in PM₁₀ and –0.83%; 95% CI: –1.39, –0.28 for a 1-unit increase in NO₂) and after bronchodilator treatment (–3.59%; 95% CI: –5.36, –1.83 and –1.20%; 95% CI: –1.97, –0.43, respectively). We found no association between lifetime exposure and sR_aw over time. Cross-sectional analyses of detailed exposure estimates for the summer and winter before 11 years of age and lung function at 11 years indicated no significant associations.Conclusions: Long-term PM₁₀ and NO₂ exposures were associated with small but statistically significant reductions in lung volume growth in children of elementary-school age.Citation: Mölter A, Agius RM, de Vocht F, Lindley S, Gerrard W, Lowe L, Belgrave D, Custovic A, Simpson A. 2013. Long-term exposure to PM₁₀ and NO₂ in association with lung volume and airway resistance in the MAAS birth cohort. Environ Health Perspect 121:1232–1238. http://dx.doi.org/10.1289/ehp.1205961     

Long-Term Exposure to Concentrated Ambient PM2.5 Increases Mouse Blood Pressure through Abnormal Activation of the Sympathetic Nervous System: A Role for Hypothalamic Inflammation

Background: Exposure to particulate matter ≤ 2.5 μm in diameter (PM_2.5) increases blood pressure (BP) in humans and animal models. Abnormal activation of the sympathetic nervous system may have a role in the acute BP response to PM_2.5 exposure. The mechanisms responsible for sympathetic nervous system activation and its role in chronic sustenance of hypertension in response to PM_2.5 exposure are currently unknown.Objectives: We investigated whether central nervous system inflammation may be implicated in chronic PM_2.5 exposure-induced increases in BP and sympathetic nervous system activation.Methods: C57BL/6J mice were exposed to concentrated ambient PM_2.5 (CAPs) for 6 months, and we analyzed BP using radioactive telemetric transmitters. We assessed sympathetic tone by measuring low-frequency BP variability (LF-BPV) and urinary norepinephrine excretion. We also tested the effects of acute pharmacologic inhibitors of the sympathetic nervous system and parasympathetic nervous system.Results: Long-term CAPs exposure significantly increased basal BP, paralleled by increases in LF-BPV and urinary norepinephrine excretion. The increased basal BP was attenuated by the centrally acting α_2a agonist guanfacine, suggesting a role of increased sympathetic tone in CAPs exposure–induced hypertension. The increase in sympathetic tone was accompanied by an inflammatory response in the arcuate nucleus of the hypothalamus, evidenced by increased expression of pro-inflammatory genes and inhibitor kappaB kinase (IKK)/nuclear factor–kappaB (NF-κB) pathway activation.Conclusion: Long-term CAPs exposure increases BP through sympathetic nervous system activation, which may involve hypothalamic inflammation.Citation: Ying Z, Xu X, Bai Y, Zhong J, Chen M, Liang Y, Zhao J, Liu D, Morishita M, Sun Q, Spino C, Brook RD, Harkema JR, Rajagopalan S. 2014. Long-term exposure to concentrated ambient PM_2.5 increases mouse blood pressure through abnormal activation of the sympathetic nervous system: a role for hypothalamic inflammation. Environ Health Perspect 122:79–86; http://dx.doi.org/10.1289/ehp.1307151     

Differential Effects of Source-Specific Particulate Matter on Emergency Hospitalizations for Ischemic Heart Disease in Hong Kong

Background: Ischemic heart disease (IHD) is a major public health concern. Although many epidemiologic studies have reported evidence of adverse effects of particulate matter (PM) mass on IHD, significant knowledge gaps remain regarding the potential impacts of different PM sources. Much the same as PM size, PM sources may influence toxicological characteristics.Objectives: We identified contributing sources to PM₁₀ mass and estimated the acute effects of PM₁₀ sources on daily emergency IHD hospitalizations in Hong Kong.Methods: We analyzed the concentration data of 19 PM₁₀ chemical components measured between 2001 and 2007 by positive matrix factorization to apportion PM₁₀ mass, and used generalized additive models to estimate associations of interquartile range (IQR) increases in PM₁₀ exposures with IHD hospitalization for different lag periods (up to 5 days), adjusted for potential confounders.Results: We identified 8 PM₁₀ sources: vehicle exhaust, soil/road dust, regional combustion, residual oil, fresh sea salt, aged sea salt, secondary nitrate, and secondary sulfate. Vehicle exhaust, secondary nitrate, and secondary sulfate contributed more than half of the PM₁₀ mass. Although associations with IQR increases in 2-day moving averages (lag₀₁) were statistically significant for most sources based on single-source models, only PM₁₀ from vehicle exhaust [1.87% (95% CI: 0.66, 3.10); IQR = 4.9 μg/m³], secondary nitrate [2.28% (95% CI: 1.15, 3.42); IQR = 8.6 μg/m³], and aged sea salt [1.19% (95% CI: 0.04, 2.36); IQR = 5.9 μg/m³] were significantly associated with IHD hospitalizations in the multisource model. Analysis using chemical components provided similar findings.Conclusion: Emergency IHD hospitalization was significantly linked with PM₁₀ from vehicle exhaust, nitrate-rich secondary PM, and sea salt–related PM. Findings may help prioritize toxicological research and guide future monitoring and emission-control polices.Citation: Pun VC, Yu IT, Ho KF, Qiu H, Sun Z, Tian L. 2014. Differential effects of source-specific particulate matter on emergency hospitalizations for ischemic heart disease in Hong Kong. Environ Health Perspect 122:391–396; http://dx.doi.org/10.1289/ehp.1307213     

Household Cooking with Solid Fuels Contributes to Ambient PM2.5 Air Pollution and the Burden of Disease

Background: Approximately 2.8 billion people cook with solid fuels. Research has focused on the health impacts of indoor exposure to fine particulate pollution. Here, for the 2010 Global Burden of Disease project (GBD 2010), we evaluated the impact of household cooking with solid fuels on regional population-weighted ambient PM_2.5 (particulate matter ≤ 2.5 μm) pollution (APM_2.5).Objectives: We estimated the proportion and concentrations of APM_2.5 attributable to household cooking with solid fuels (PM_2.5-cook) for the years 1990, 2005, and 2010 in 170 countries, and associated ill health.Methods: We used an energy supply–driven emissions model (GAINS; Greenhouse Gas and Air Pollution Interactions and Synergies) and source-receptor model (TM5-FASST) to estimate the proportion of APM_2.5 produced by households and the proportion of household PM_2.5 emissions from cooking with solid fuels. We estimated health effects using GBD 2010 data on ill health from APM_2.5 exposure.Results: In 2010, household cooking with solid fuels accounted for 12% of APM_2.5 globally, varying from 0% of APM_2.5 in five higher-income regions to 37% (2.8 μg/m³ of 6.9 μg/m³ total) in southern sub-Saharan Africa. PM_2.5-cook constituted > 10% of APM_2.5 in seven regions housing 4.4 billion people. South Asia showed the highest regional concentration of APM_2.5 from household cooking (8.6 μg/m³). On the basis of GBD 2010, we estimate that exposure to APM_2.5 from cooking with solid fuels caused the loss of 370,000 lives and 9.9 million disability-adjusted life years globally in 2010.Conclusions: PM_2.5 emissions from household cooking constitute an important portion of APM_2.5 concentrations in many places, including India and China. Efforts to improve ambient air quality will be hindered if household cooking conditions are not addressed.Citation: Chafe ZA, Brauer M, Klimont Z, Van Dingenen R, Mehta S, Rao S, Riahi K, Dentener F, Smith KR. 2014. Household cooking with solid fuels contributes to ambient PM_2.5 air pollution and the burden of disease. Environ Health Perspect 122:1314–1320; http://dx.doi.org/10.1289/ehp.1206340