Fig. 1

Exposure and analysis timeline. Gray boxes mark control exposures to HEPA-filtered air for six hours per day, including four successive BL (BL) days. Black boxes with gray borders indicate PEPs exposures preceded and followed by 30-min clean air exposures. White boxes indicate post-exposure sampling periods, with striped boxes marking 20-min stress tests at 2 days, 5 weeks, and 10 weeks after cessation of inhalation exposures. Empty boxes mark urine collection periods before and after stress test at 10 weeks post-PEPs. Stars indicate period during which physiologic endpoints were analyzed, including left ventricular pressure (LVP), heart rate variability (HRV), electrocardiogram morphology (ECG), baroreflex slope (BRS), and ventricular arrhythmia. For more details, see Methods