Our lungs are simply not meant to breathe in smoke from an e-cig. Whether the smoke is from a black market product or a legal product makes no difference. Dense smoke in the lungs irritates the alveoli and the bronchioles. The mucus tissue gets inflamed and oxygen transfer is reduced. This in turn causes a cascading effect of poorer quality blood, poorer quality tissues, a higher risk of stroke etc. E-Cigs are also marketed to youth that are very impressionable. Their lungs are affected more than adults.