Increased JUUL Emissions from Initial Puffs after Removing and Reinserting Pod.

Standard laboratory electronic cigarette (ECIG) puffing protocols that do not consider user behaviors, such as removing and resinserting a pod, may underestimate emissions. This study compared JUUL emissions from four 10-puff bout procedures. We generated ECIG aerosol in a chamber using a JUUL device and measured concentrations of particulate matter ≤2.5 μm in diameter (PM 2.5 ). The JUUL pod was removed and reinserted 0 times, 1 time, 4 times, and 9 times in experiments 1-4, respectively. Mean real-time PM 2.5 concentration was 65.06 μg/m 3 (SD = 99.53) for experiment 1, 375.50 μg/m 3 (SD = 346.45) for experiment 2, 501.94 μg/m 3 (SD = 450.00) for experiment 3, and 834.69 μg/m 3 (SD = 578.34) for experiment 4. In this study, removing and reinserting a JUUL pod resulted in greater PM 2.5 concentrations compared to puffing protocols in which the JUUL pod was not removed and reinserted. ECIGs should be examined and evaluated based on ECIG users' real-world behaviors.