The swiftest and most effective way to damage them—by inhaling generous quantities of toxic cigarette smoke. While anyone born in the era of color television already knows that cigarettes are poison in a stick, you may not know exactly how they damage your lungs.
It turns out that there is no single answer. Although it’s tempting to talk about cigarette smoke as though it’s a single thing, it’s actually a lethal brew of more than 4,000 lung-scarring chemicals, with nearly 100 known carcinogens (cancer-causing agents) in the mix. The following figure highlights some of the nasty substances you’ll encounter in cigarette smoke, and links them to the industrial products they’re more often associated with.
While cigarette smoke is hard on your lungs, its most popular ingredient— nicotine—is a disaster for the rest of your body. It’s particularly hard on your heart, as it increases your heart rate while constricting your arteries, leading to higher blood pressure and hardening of the arteries. That’s why smoking is so tightly associated with heart disease. The brutal truth is this: Every cigarette you smoke inches you closer to a coronary disaster.
Because human lungs are somewhat overbuilt with capacity to spare, smokers don’t suffer the most damaging effects of cigarette smoke for some time. However, it doesn’t take many packs of puffing to coat the lungs with a rich assortment of tars. If you’re a regular smoker, you’ll have no trouble picking out your lungs in the picture below, which is featured on cigarette warning labels in several countries.
Incidentally, even though the average cigarette contains about 10 milligrams of nicotine, the most a smoker can get from burning it is a couple of milligrams. This is rather fortunate—if you could inject all the nicotine from a pack of cigarettes directly into your veins, you’d be dead in a matter of minutes.
Source of Information : Oreilly - Your Body Missing Manual