does cigarette smoke contain formaldehyde Content of toxic components of cigarette, vs cigarette butts: A comprehensive systematic review How does smoking cause cancer?

Tobacco smoking significantly increased risk for cancers of the lung, larynx, liver, oesophagus, bladder, pancreas, head and neck, stomach, colorectum, kidney, gallbladder, and cancers of unknown primary site

There are over 4000 chemicals involved in the smoke of a lit cigarette (Tobacco: Behind the Smoke)

Moreover, the smell of smoke clings to clothing and fabric, reinforcing the habit and making it harder for smokers to quit

79 There is even evidence that prenatal and postnatal second-hand smoke contributes to insulin resistance in children

It was reported that active smoking correlated with augmented numbers of DC/LC lineage and caused a dramatic increase in the number of LCs in human alveolar parenchyma [95]