New Insights Into Pollution and the Cardiovascular System

Abstract

Figure.Odds ratio of ischemic stroke onset for US Environmental Protection Agency categories (good and moderate) of mean ambient fine particulate matter air pollution (PM 2.5 ) levels in the 24 hours preceding stroke onset. Error bars indicate 95% confidence interval. Reproduced from Wellenius et al 5 with permission from the publisher. The increased risk was greatest within 12 to 14 hours of exposure. Update, 2010 to 2012: Cardiac Arrhythmia, Arrhythmia Precursors, and PollutionEvidence continues to be mixed for associations between pollution and documented cardiac arrhythmias or electrophysiological changes such as repolarization abnormalities that may increase the risk of arrhythmias. Even more so than studies of stroke, ascertainment of the timing of the onset of the outcome and the specific electrophysiological nature of the outcome can be challenging to ascertain without personal monitoring, which is absent in studies of administrative data sets, which often report null findings. 6 In their recent review, Link and Dockery 7 concluded that "the incremental risk of air pollution in triggering arrhythmias… is greatest for patients with underlying cardiac disease." A London study examined associations of 11 pollutants with activation of implanted cardioverter-defibrillators, finding mostly weak associations with the elevation of a number of secondary regional pollutants, the strongest of which was the nontraffic particle component sulfate. 8 Increases in premature ventricular counts, atrial fibrillation/flutter, and its precedent, P-wave complexity, were associated with increased PM 2.5 in the previous 1 to 2 hours in a Pennsylvania study of 105 middle-aged healthy nonsmokers with 24-hour ECG and personal particle monitoring.9,10 Ghio et al 11 presented a case report of new-onset atrial fibrillation that occurred 20 minutes into a controlled exposure to concentrated ambient particles and resolved within 2 hours with no sequella. In studies of vulnerable populations who have personal electrophysiological monitoring, ozone has also been considered a risk factor for arrhythmias. An increase in the maximum ozone level predicted increases in bradycardia and apnea in high-risk infants on home monitors. 12Controlled human exposure to 1-hour exposures of diesel exhaust did not influence heart rhythm or variability in a UK study.13 Increased spatial dispersion of myocardial repolarization, but not T-wave alternans, was seen after controlled human exposures to concentrated ambient particles, ozone, or a combination of the 2 exposures.14 Increases in long-term estimated residential PM 2.5 predicted increased odds of QT prolongation without overt ventricular abnormalities in the Multi-Ethnic Study of Atherosclerosis (MESA). 15 Two recent studies (the Table) also suggest acute effects of O 3 on repolarization abnormalities in sensitive subjects. 16,17 Update, 2010 to 2012: Cardiovascular Effects of the Coarse (PM 10-2.5 ) or Ultrafine (<0.1 μm) Fractions of PM 10 Findings on cardiovascular health effects of coarse or ultr...

Air Quality, Stroke, and Coronary Events

“…For stroke, the HR is approximately 2.0 for smoking, 1.5 for atrial fibrillation, and 1.4 for diabetes mellitus (34). These risk factors, however, are only present for subgroups of the population.…”

“…The American Heart Association (AHA) has produced a comprehensive statement describing the marked effect of air pollution (1,34). The AHA recommends that practicing physicians should educate pa-…”

Air Pollution, Climate, and Heart Disease

“…Several reviews of these studies, including 2 American Heart Association scientific statements, describe the scientific findings and conclude that air pollution poses a risk to heart health. [1][2][3][4] You can help protect your health and the health of your family, neighbors, and community from risk caused by air pollution, including the risk to your cardiovascular health. The Environmental Protection Agency (EPA), American Heart Association, American Stroke Association, and American College of Cardiology have published a concise leaflet on "Heart Disease, Stroke and Outdoor Air Pollution" that is available online (www.epa.gov/airnow/ heart_flyer-1-28-10-final.pdf).…”

“…4 Especially if air conditioning is not available, very hot weather is dangerous for those with heart disease, the elderly, and persons e412 Circulation…”

Environmental triggers of acute myocardial infarction: results of a nationwide multiple-factorial population study

“…the association between air pollution and near-term risk of myocardial infarction remains controversial. Some studies have shown an association, while other studies have found either no association or an association only for selected pollutants 3,9,30 . In a recent meta-analysis the most important pollutant was PM 2.5 with an RR of 1.02 (95% CI, 1.01-1.02) for every 10 µg/m 3 increase, which is in line with our findings 9 .…”