A new study suggests that the lungs may react to vaping more quickly than previously thought, with damage potentially occurring within days of exposure. Published in JCI Insight by researchers at National Jewish Health, the findings are based on pre-clinical models and indicate that even short-term exposure to e-cigarette aerosol can initiate damage in the deepest and most delicate regions of the lungs. The study focused on the distal lung, where gas exchange between air and blood occurs. Human lung cells and tissue fragments were exposed to e-cigarette aerosol, revealing that within less than 24 hours, the protective barrier of the tissue became more permeable. Cellular stress increased, cell repair slowed, and cell death progressed. Irina Petrache, pulmonologist and head of the Division of Pulmonology, Intensive Care, and Sleep Medicine at National Jewish Health, explained that the results suggest even short-term exposure to vaping can initiate damage in the deepest and most delicate regions of the lungs. In another part of the study, golden Syrian hamsters inhaled the aerosol for five days under conditions corresponding to occasional exposure. Ten days after stopping, the animals appeared clinically normal, with no weight loss or obvious symptoms. However, their lungs still showed markers of cellular stress and programmed cell death. The activity of hundreds of genes was noted, though specific details were not provided in the summary. The scientific alert must, however, be confirmed in humans.