If I have already developed so many risk factors with smoking, would there be any good if I now quit as I have already harmed my body?
Yes, indeed it would be helpful. If you quit tobacco, your body detoxifies itself many of your body functions will get improved.
Third Hand Smoking
Third hand smoke is the residue from tobacco smoke that clings virtually on all surfaces, clothes and accessories such as belts, shoes, rings, chain, watch etc. long after a cigarette is smoked. Anyone entering the room or wherever the smoker goes after smoking other individuals come in contact and inhale the same. Third hand smoking leads to impotence in men. Children are the main victims of this third hand smoke. The study conducted by World Health organisation (WHO) on third hand cigarette smoke estimates that children ingest 0.25 mg/day of dust which may contain cigarette toxins. The toxins include neurotoxins, which affects nervous system and other compounds that can delay development of certain milestones in the babies.