Figure 1

ECG changes recorded during pre-specified 5 minute segments. Mean ± SE change from pre-exposure baseline in heart rate (A), pNN50 (B), rMSSD (C), and HF (D) in subjects exposed to elemental carbon UFP (solid boxes) and filtered air (open circles), during and at specified time intervals after exposure. The insets show actual baseline values. P-value is for mixed models main effect of exposure.