how chewing tobacco effects What are the first signs of mouth cancer from tobacco? | Roswell Park Comprehensive Cancer Center Effects of Chewing Tobacco –

Study outcomes and follow-up The primary endpoint of this study was pneumonia hospitalization, which was identified on the basis of the ICD-10 codes of J10.0, J11.0, and J12 to J18 administered for hospital admission

Dirt & hair

Add to this that vapour doesn't smell or stain like smoke and many e-cig users start to vape inside

That means over their smoking lifetime, they take in more of toxic chemicals and tar from cigarettes

However, caution is required in interpreting these results, as this perceivable benefit was accompanied with a significant elevation in liver enzymes, thus establishing these apparently beneficial changes as a mere reflection of the toxic damage of electronic cigarette liquid on the liver.94 Recently, electronic cigarettes have been proposed as a possible interfering factor in the splenocardiac axis, a signalling network involving the brain, autonomic nervous system and hematopoietic tissues

doi:10.1086/508458 416