Vaping is significantly less harmful than smoking for lung health, but it is not harmless. The 2019 EVALI outbreak was caused by illegal THC cartridges (not nicotine vapes), while long-term COPD data remains inconclusive due to short study timelines. Flavoring chemicals like diacetyl and cinnamaldehyde pose known lung irritation risks, and heavy metal exposure from coil degradation is an active area of research.