http://www.bbc.com/news/health-37849000

Smoking 'causes hundreds of DNA changes'

many people in the world always smoke everyday.  they know what the impact with their body and they do not care about it because smoking could make them feel enjoy. sometimes cancer can develop into their body and it can make their life shorten than human who not smoke. maybe if you smoke you can feel enjoy in your life but you never known that smoke is very dangerous for human. not for who is smoking but for someone who live or sit near the smoker. It could make them sick or infection inflamed of lung. If you near a baby and you smoke it can make the baby sick and slurp the smoke, it is not good for the baby.

after that if you decided to stop smoke it is better for you, but you have carry on what you have did before because after you decided to stop smoking it would not make you feel better 100 percent. because some people who decided to stop smoking have cancer because they were an active smoker.

The study, in the journal Science, was carried out by an international group, including the Wellcome Trust Sanger Institute in Cambridgeshire and the Los Alamos National Laboratory in New Mexico.
The analysis shows a direct link between the number of cigarettes smoked in a lifetime and the number of mutations in tumour DNA.
The authors found that, on average, smoking a packet of cigarettes a day led to:

• 150 mutations in each lung cell every year

• 97 in the larynx or voice box

• 23 in the mouth

• 18 in the bladder

• six in the liver

so if you a smoker please stop it because you never known what happen with your body in the future. please take care of your self. it better to help yourself without torture yourself.