Table 1.

Constituents of ENDS Aerosol [19]

Serial number	Aerosol component	Health risk	Reference
1.	Ultrafine particles	Asthma, vasoconstriction leading to cardiovascular problems	[20, 21]
2.	Benzene, formaldehyde, acetaldehyde, toluene, cadmium, lead, and nickel	Carcinogen, reproductive toxin	[22, 23]
3.	Propylene glycol	Irritant of the eyes, throat and airways, long-term exposure leads to asthma	[24, 25]
4.	Propylene oxide	Carcinogen	[26]
5.	Diethylene glycol	renal and neurologic toxicity	[27]
6.	Diacetyl and acetyl propionyl (sweet flavorings)	bronchiolitis obliterans	[28, 29]
7.	Carbonyls	Cardiovascular toxicity	[30]
8.	Copper nanoparticles	DNA fragmentation, mitochondrial stress	[31]