Smoking began as a ritual among Native American tribes and was introduced to widespread American society by the Spanish. Smoking is now common among men and 1 in 3 women also smoke. Smoking reduces life expectancy, as each cigarette decreases life by 6-8 minutes and over 70% of smoker deaths are caused by smoking. Most people who start smoking between ages 15-20 will become heavy smokers. The negative health effects of smoking include increased risk of cancer, impacts on pregnancy, skin, respiratory, digestive, nervous and cardiovascular systems.