it is detremental, causes an average dec of life expectancy by 10yrs compared to non-smokers and smokers have an abg of -7.5yrs taken off their lifes (idk i know its weird facts but thats what she said in the lecture)
it also majorly increases risk of
Cancer
CVD
COPD
overall it not be good
smoking = inc COPD
Transtheoretical model of behavioural change