Heike Luttmann-Gibson

Association of Air Pollution with Increased Incidence of Ventricular Tachyarrhythmias Recorded by Implanted Cardioverter Defibrillators

Epidemiologic studies have demonstrated a consistent link between sudden cardiac deaths and particulate air pollution. We used implanted cardioverter defibrillator (ICD) records of ventricular tachyarrhythmias to assess the role of air pollution as a trigger of these potentially life-threatening events. The study cohort consisted of 203 cardiac patients with ICD devices in the Boston metropolitan area who were followed for an average of 3.1 years between 1995 and 2002. Fine particle mass and gaseous air pollution plus temperature and relative humidity were measured on almost all days, and black carbon, sulfate, and particle number on a subset of days. Date, time, and intracardiac electrograms of ICD-detected arrhythmias were downloaded at the patients’ regular follow-up visits (about every 3 months). Ventricular tachyarrhythmias were identified by electrophysiologist review. Risk of ventricular arrhythmias associated with air pollution was estimated with logistic regression, adjusting for season, temperature, relative humidity, day of the week, patient, and a recent prior arrhythmia. We found increased risks of ventricular arrhythmias associated with 2-day mean exposure for all air pollutants considered, although these associations were not statistically significant. We found statistically significant associations between air pollution and ventricular arrhythmias for episodes within 3 days of a previous arrhythmia. The associations of ventricular tachyarrhythmias with fine particle mass, carbon monoxide, nitrogen dioxide, and black carbon suggest a link with motor vehicle pollutants. The associations with sulfate suggest a link with stationary fossil fuel combustion sources.

Parental smoking and children’s respiratory health: independent effects of prenatal and postnatal exposure

Objectives: Adverse effects have been reported of prenatal and/or postnatal passive exposure to smoking on children’s health. Uncertainties remain about the relative importance of smoking at different periods in the child’s life. We investigate this in a pooled analysis, on 53 879 children from 12 cross-sectional studies—components of the PATY study (Pollution And The Young). Methods: Effects were estimated, within each study, of three exposures: mother smoked during pregnancy, parental smoking in the first two years, current parental smoking. Outcomes were: wheeze, asthma, “woken by wheeze”, bronchitis, nocturnal cough, morning cough, “sensitivity to inhaled allergens” and hay fever. Logistic regressions were used, controlling for individual risk factors and study area. Heterogeneity between study-specific results, and mean effects (allowing for heterogeneity) were estimated using meta-analytical tools. Results: There was strong evidence linking parental smoking to wheeze, asthma, bronchitis and nocturnal cough, with mean odds ratios all around 1.15, with independent effects of prenatal and postnatal exposures for most associations. Conclusions: Adverse effects of both pre- and postnatal parental smoking on children’s respiratory health were confirmed. Asthma was most strongly associated with maternal smoking during pregnancy, but postnatal exposure showed independent associations with a range of other respiratory symptoms. All tobacco smoke exposure has serious consequences for children’s respiratory health and needs to be reduced urgently.

Increased Risk of Paroxysmal Atrial Fibrillation Episodes Associated with Acute Increases in Ambient Air Pollution

Objectives: We reported previously that 24-hr moving average ambient air pollution concentrations were positively associated with ventricular arrhythmias detected by implantable cardioverter defibrillators (ICDs). ICDs also detect paroxysmal atrial fibrillation episodes (PAF) that result in rapid ventricular rates. In this same cohort of ICD patients, we assessed the association between ambient air pollution and episodes of PAF. Design: We performed a case–crossover study. Participants: Patients who lived in the Boston, Massachusetts, metropolitan area and who had ICDs implanted between June 1995 and December 1999 (n = 203) were followed until July 2002. Evaluations/Measurements: We used conditional logistic regression to explore the association between community air pollution and 91 electrophysiologist-confirmed episodes of PAF among 29 subjects. Results: We found a statistically significant positive association between episodes of PAF and increased ozone concentration (22 ppb) in the hour before the arrhythmia (odds ratio = 2.08; 95% confidence interval = 1.22, 3.54; p = 0.001). The risk estimate for a longer (24-hr) moving average was smaller, thus suggesting an immediate effect. Positive but not statistically significant risks were associated with fine particles, nitrogen dioxide, and black carbon. Conclusions: Increased ambient O3 pollution was associated with increased risk of episodes of rapid ventricular response due to PAF, thereby suggesting that community air pollution may be a precipitant of these events.

Opposing Effects of Particle Pollution, Ozone, and Ambient Temperature on Arterial Blood Pressure

Background: Diabetes increases the risk of hypertension and orthostatic hypotension and raises the risk of cardiovascular death during heat waves and high pollution episodes. Objective: We examined whether short-term exposures to air pollution (fine particles, ozone) and heat resulted in perturbation of arterial blood pressure (BP) in persons with type 2 diabetes mellitus (T2DM). Methods: We conducted a panel study in 70 subjects with T2DM, measuring BP by automated oscillometric sphygmomanometer and pulse wave analysis every 2 weeks on up to five occasions (355 repeated measures). Hourly central site measurements of fine particles, ozone, and meteorology were conducted. We applied linear mixed models with random participant intercepts to investigate the association of fine particles, ozone, and ambient temperature with systolic, diastolic, and mean arterial BP in a multipollutant model, controlling for season, meteorological variables, and subject characteristics. Results: An interquartile increase in ambient fine particle mass [particulate matter (PM) with an aerodynamic diameter of ≤ 2.5 μm (PM2.5)] and in the traffic component black carbon in the previous 5 days (3.54 and 0.25 μg/m3, respectively) predicted increases of 1.4 mmHg [95% confidence interval (CI): 0.0, 2.9 mmHg] and 2.2 mmHg (95% CI: 0.4, 4.0 mmHg) in systolic BP (SBP) at the population geometric mean, respectively. In contrast, an interquartile increase in the 5-day mean of ozone (13.3 ppb) was associated with a 5.2 mmHg (95% CI: –8.6, –1.8 mmHg) decrease in SBP. Higher temperatures were associated with a marginal decrease in BP. Conclusions: In subjects with T2DM, PM was associated with increased BP, and ozone was associated with decreased BP. These effects may be clinically important in patients with already compromised autoregulatory function.

Exposure to indoor mould and children’s respiratory health in the PATY study

Background: Living in a damp or mouldy home reportedly damages children’s respiratory health, yet mould appears not to be a prominent risk factor in the public’s perception. Analyses of data on over 58 000 children from the Pollution and the Young (PATY) study are presented. In this collaboration, researchers from 12 cross-sectional studies pooled their data to assess the effects of air quality on a spectrum of children’s respiratory disorders. Method: Original studies were conducted in Russia, North America and 10 countries in Eastern and Western Europe. Pooled analyses were restricted to children aged 6–12 years. Associations between visible mould reported in the household and a spectrum of eight respiratory and allergic symptoms were estimated within each study. Logistic regressions were used, controlling for individual risk factors and for study area. Heterogeneity between study-specific results and mean effects (allowing for heterogeneity) were estimated using meta-analysis. Results: Visible mould was reported by 13.9% of respondents in Russia, increasing to 39.1% in North America. Positive associations between exposure to mould and children’s respiratory health were seen with considerable consistency across studies and across outcomes. Confounder-adjusted combined ORs ranged from 1.30 (95% CI 1.22 to 1.39) for “nocturnal cough” to 1.50 (1.31 to 1.73) for “morning cough”. Evidence of stronger effects in more crowded households was statistically significant for only asthma and sensitivity to inhaled allergens. No consistent interactions between mould and age, sex or parental smoking were found. Conclusion: Indoor mould exposure was consistently associated with adverse respiratory health outcomes in children living in these diverse countries.

Short-term effects of air pollution on heart rate variability in senior adults in Steubenville, Ohio.

Objective: We examined the association between ambient air pollution levels and heart rate variability (HRV) in a panel study of 32 subjects. Methods: We used linear mixed models to analyze the effects of fine particles (PM2.5), sulfate (SO42−), elemental carbon (EC), and gases on log-transformed standard deviation of normal RR intervals (SDNN), mean square of differences between adjacent RR intervals (r-MSSD), and high- and low-frequency power (HF, LF). Results: An interquartile range (IQR) increase of 5.1 &mgr;g/m3 in SO42− on the previous day was associated with a decrease of −3.3% SDNN (95% confidence = −6.0% to −0.5%), −5.6% r-MSSD (−10.7% to −0.2%), and −10.3% HF (−19.5% to −0.1%). Associations with total PM2.5 were similar. HRV was not associated with EC, NO2, SO2, or O3. Conclusion: In addition to traffic-related particles, elevated levels of sulfate particles may also adversely affect autonomic function.

Acute exposure to air pollution triggers atrial fibrillation.

OBJECTIVES This study sought to evaluate the association of air pollution with the onset of atrial fibrillation (AF). BACKGROUND Air pollution in general and more specifically particulate matter has been associated with cardiovascular events. Although ventricular arrhythmias are traditionally thought to convey the increased cardiovascular risk, AF may also contribute. METHODS Patients with dual chamber implantable cardioverter-defibrillators (ICDs) were enrolled and followed prospectively. The association of AF onset with air quality including ambient particulate matter <2.5 μm aerodynamic diameter (PM2.5), black carbon, sulfate, particle number, NO2, SO2, and O3 in the 24 h prior to the arrhythmia was examined utilizing a case-crossover analysis. In sensitivity analyses, associations with air pollution between 2 and 48 h prior to the AF were examined. RESULTS Of 176 patients followed for an average of 1.9 years, 49 patients had 328 episodes of AF lasting ≥ 30 s. Positive but nonsignificant associations were found for PM2.5 in the prior 24 h, but stronger associations were found with shorter exposure windows. The odds of AF increased by 26% (95% confidence interval: 8% to 47%) for each 6.0 μg/m(3) increase in PM2.5 in the 2 h prior to the event (p = 0.004). The odds of AF were highest at the upper quartile of mean PM2.5. CONCLUSIONS PM was associated with increased odds of AF onset within hours following exposure in patients with known cardiac disease. Air pollution is an acute trigger of AF, likely contributing to the pollution-associated adverse cardiac outcomes observed in epidemiological studies.

PM10, and children's respiratory symptoms and lung function in the PATY study

Studies of the impact of long-term exposure to outdoor air pollution on the prevalence of respiratory symptoms and lung function in children have yielded mixed results, partly related to differences in study design, exposure assessment, confounder selection and data analysis. We assembled respiratory health and exposure data for >45,000 children from comparable cross-sectional studies in 12 countries. 11 respiratory symptoms were selected, for which comparable questions were asked. Spirometry was performed in about half of the children. Exposure to air pollution was mainly characterised by annual average concentrations of particulate matter with a 50% cut-off aerodynamic diameter of 10 &mgr;m (PM10) measured at fixed sites within the study areas. Positive associations were found between the average PM10 concentration and the prevalence of phlegm (OR per 10 &mgr;g·m−3 1.15, 95% CI 1.02–1.30), hay fever (OR 1.20, 95% CI 0.99–1.46), bronchitis (OR 1.08, 95% CI 0.98–1.19), morning cough (OR 1.15, 95% CI 1.02–1.29) and nocturnal cough (OR 1.13, 95% CI 0.98–1.29). There were no associations with diagnosed asthma or asthma symptoms. PM10 was not associated with lung function across all studies combined. Our study adds to the evidence that long-term exposure to outdoor air pollution, characterised by the concentration of PM10, is associated with increased respiratory symptoms.

Parental education and children's respiratory and allergic symptoms in the Pollution and the Young (PATY) study

Inequalities in health between socio-economic groups are a major public health concern. The current authors studied associations between parental socio-economic status (SES) and childrens respiratory and allergic symptoms in 13 diverse countries, including the Russian Federation, North America (Canada and the USA), and countries across Eastern and Western Europe. Data of 57,000 children aged 6–12 yrs, originating from eight cross-sectional studies, were analysed. SES was defined by parental education. Respiratory and allergic symptoms were defined by parental questionnaire reports. Multiple logistic regressions showed that low parental education was associated with a decreased risk of inhalant allergy and itchy rash in school children. Furthermore, low parental education was associated with an increased prevalence of wheeze and nocturnal dry cough. No clear association was found between parental education and prevalence of doctor-diagnosed asthma and bronchitis. Part of the difference between socio-economic groups with regard to their childrens symptoms was explained by established risk factors, such as parental allergy, smoking during pregnancy, pet ownership, crowding, mould/moisture in the home, use of gas for cooking, and air pollution (particulate matter with a diameter of <10 µm). However, differences remained after adjusting for these variables. Childrens health was associated with parental education. The association could not fully be explained by established risk factors.

Systemic inflammation, heart rate variability and air pollution in a cohort of senior adults

Objectives Short-term elevation of ambient particulate air pollution has been associated with autonomic dysfunction and increased systemic inflammation, but the interconnections between these pathways are not well understood. We examined the association between inflammation and autonomic dysfunction and effect modification of inflammation on the association between air pollution and heart rate variability (HRV) in elderly subjects. Methods 25 elderly subjects in Steubenville, Ohio, were followed up to 24 times with repeated 30-min ECG Holter monitoring (545 observations). C-reactive protein (CRP), fibrinogen, interleukin-6 (IL-6), soluble inter-cellular adhesion molecule 1 (sICAM-1), and white blood cell and platelet counts were measured in peripheral blood samples collected in the first month of the study. Increased systemic inflammation was defined for subjects within the upper 20% of the distribution for each marker. A central ambient monitoring station provided daily fine particle (PM2.5) and sulphate (SO42−) data. Linear mixed models were used to identify associations between inflammatory markers and HRV and to assess effect modification of the association between air pollution and HRV due to inflammatory status. Results A 5.8 mg/l elevation in CRP was associated with decreases of between −8% and –33% for time and frequency domain HRV outcomes. A 5.1 μg/m3 increase in SO42− on the day before the health assessment was associated with a decrease of −6.7% in the SD of normal RR intervals (SDNN) (95% CI −11.8% to −1.3%) in subjects with elevated CRP, but not in subjects with lower CRP (p value interaction=0.04), with similar findings for PM2.5. Conclusions Increased systemic inflammation is associated with autonomic dysfunction in the elderly. Air pollution effects on reduced SDNN are stronger in subjects with elevated systemic inflammation.