Activation of the autonomic nervous system and blood coagulation in association with an air pollution episode

Air pollution has been associated with increases in hospital admissions for cardiovascular diseases. This article aims to identify subgroups of indivi duals who exhibit early biological responses consistent with the health eff ects of ambient air pollution. Resting heart ra res have been recorded in a cohort of 2681 men and women aged 25-64 yr who participated in the MONICA Augsburg survey during the winter 1984/1985 and in a reexamination during t he winter 1987/1988. Increases in heart rate of 1.8 beats per minute (bpm) (95% confidence interval: 0.7 to 2.8 bpm) were observed during the air poll ution episode compared to nonepisode days, adjusted for potential cardiovas cular risk factors and meteorological parameters. Among persons whose plasm a viscosity was above the 90th percentile, heart rates increased 5.1 bpm (9 5% confidence interval: 2.1 to 8.2 bpm) during the air pollution episode. P ersons with normal values of plasma viscosity only had an increase of 1.4 b pm (95% confidence interval: 0.3 to 2.5 bpm) during the air pollution episo de. Subjects with increased plasma viscosity showed a more pronounced accel eration in heart rate at rest, pointing toward a modification of the autono mic control of the heart during an air pollution episode.