Hourly variation in fine particle exposure is associated with transiently increased risk of ST segment depression. Issue 11 (4th June 2008)

• Record Type: Journal Article
• Authors: Lanki, T; Hoek, G; Timonen, K L; Peters, A; Tiittanen, P; Vanninen, E; Pekkanen, J
• Is Part Of: Occupational and environmental medicine. Volume 65:Issue 11(2008)
• Page Start: 782
• Page End: 786
• Publication Date: 2008-06-04
• Subjects: Medicine, Industrial -- Periodicals; Environmental health -- Periodicals; 616.980305
• DOI: 10.1136/oem.2007.037531
• Languages: English
• ISSNs: 1351-0711

Abstract

Abstract : Objectives: To evaluate whether hourly changes in fine particle (PM2.5, diameter<2.5 µm) exposure or outdoor particle concentrations are associated with rapid ischaemic responses. Methods: 41 non-smoking elderly people with coronary heart disease were followed up with biweekly clinic visits in Helsinki, Finland. The occurrence of ST segment depressions >0.1 mV was recorded during submaximal exercise tests. Hourly variations in personal PM2.5 exposure and outdoor levels of PM2.5 and ultrafine particles (<0.1 µm) were recorded for 24 h before a clinic visit. Associations between particulate air pollution and ST segment depressions were evaluated using logistic regression. Results: Both personal and outdoor PM2.5 concentrations, but not outdoor ultrafine particle counts, were associated with ST segment depressions. The odds ratio (per 10 µg/m 3 ) for personal PM2.5 concentration during the hour preceding a clinic visit was 3.26 (95% CI 1.07 to 9.99) and for 4 h average outdoor PM2.5 it was 2.47 (95% CI 1.05 to 5.85). Conclusions: Even very short-term elevations in fine particle exposure might increase the risk of myocardial ischaemia. The precise mechanism is still unknown but could involve changes in autonomic nervous control of the heart.