I simply review the science not the fiction often seen in news reports. Having smoked for over 35yrs. and then
vaping for the last 2 1/2 I have a good idea. No tightness in the chest and irritated passage ways and the nasty burning taste you would get at times.
There are a number of other things from breathing in all that crap in comparison to PG(Propylene Glycol) used in any number of consumer goods like with food additives on top of already having been in use in Immediate Asthmatic inhalers since the 1950s and used commercially to clean out ventilation systems for heating and air in hospitals where nothing harmful can be pumped in!
Recent articles point to nicotine helping with Parkinson's Disease and chronic depression compared to pumping prescription meds into someone or Chantrix! Yet even the hazards of second hand smoke were blown way out of proportion so Big Pharma could cash in on all that $$$$$$$ from selling patches, gums, loaded with chemicals like Hydrochloric acid(want to inhaled stomach acid?) Nicorette QuickMist compare to PG, VG(Vegetable Glycerin natural extract), flavorings natural and artificial, and options for nicotine.
For those of us here at ECF who once had smoked for decades it doesn't take much to know how each of us feels once a good period of time passed by being smoke free.