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/m3) 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.
Statistics from Altmetric.com
Competing interests: None.
Funding: The main funding sources of the study were the European Union (ENV4-CT97-0568), the Academy of Finland (53307) and the National Technology Fund (40715/01). In addition, the corresponding author received personal grants from the Helsingin Sanomat Foundation and the Finnish Cultural Foundation.
Ethics approval: The study protocol was approved by the ethics committee of the National Public Health Institute.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.