【正文】 disease by more than 22 times.
　　Women who smoke increase this risk by nearly 12 times.
　　Lung cancer is a difficult cancer to treat long term survival rates are poor.
　　Smoking also increases the risk of oral, uterine, liver, kidney, bladder, stomach, and cervical cancers, and leukaemia.
　　Another health problem associated with tobacco is emphysema, which, when bined with chronic bronchitis, produces chronic obstructive pulmonary disease.
　　he lung damage which causes emphysema is irreversible, and makes it extremely difficult to breathe.
　　Harm to children
　　Smoking in pregnancy greatly increases the risk of miscarriage, is associated with lower birthweight babies, and inhibited child development.
　　Smoking by parents following the birth is linked to sudden infant death syndrome, or cot death, and higher rates of infant respiratory illness, such as bronchitis, colds, and pneumonia.
　　Nicotine, an ingredient of tobacco, is listed as an addictive substance by the US authorities.
　　Although the health risks of smoking are culmulative, giving up can yield health benefits regardless of the age of the patient, or the length of time they have been smoking.
　　By 2020, the WHO expects the worldwide death toll to reach 10 million, causing % of all deaths in developed countries.
　　There are believed to be billion smokers in the world, 800 million of them in developing coun