- Exposure to e-cigarette vapor condensate (ECVC) leads to dose-dependent cell death, inflammatory response, inhibited phagocytosis in alveolar macrophages (AMs).
- Vaping and nicotine contributed independently to harm.
- Authors: “We caution against the widely held opinion that e-cigarettes are safe.”
Why this matters
- Though touted as a smoking-cessation aid, vaping's long-term safety is unclear.
- Many studies assess nonvaporized e-cigarette liquid (ECL), but vaping process alters composition.
- Authors devised a way to generate and study ECVC.
- Viabilities of AMs exposed to ECVC and unvaped ECL, vs untreated controls (UTCs):
- ECVC 0.8% volume/volume (v/v): 18.2% viable (interquartile range [IQR], 15.7%-19.5%; P<.001 nicotine-free ecvc viable p>
- ECL 2.5% v/v: 78.8% viable; nicotine-free ECL, 84.6% viable;
- All effects were dose-dependent.
- Increased apoptosis, necrosis;
- Increased multiplied reactive oxygen species release 50-fold;
- Increased IL-6, TNF-α, matrix metalloprotease 9;
- Reduced phagocytosis by 30%.
- Researchers assessed viability of AMs from never-smokers after 24-hour exposure to regular, nicotine-free ECVC and regular, nicotine-free ECL.
- ECVC simulates vaped ECL.
- Funding: Medical Research Council (UK); British Lung Foundation.
- In vitro study reflecting acute exposure only.
- Flavors not assessed.
- Real-life nicotine dosage during vaping varies widely.