A study of half a million adults concludes that quitting smoking lowers your risk of dying from lung cancer by 70 percent, researchers say.

The George Institute for International Health reported that the Asia-Pacific Cohort Studies Collaboration also found that the risk of dying from lung cancer was about 20 times higher among female smokers than among men.

"If interventions only focus on prevention, then 160 million current smokers will die before 2050, with the vast majority of deaths occurring in China," warned lead researcher Rachel Huxley, director of The George Institute's nutrition and lifestyle program. "There are huge numbers of lives to be saved through campaigns to alert current smokers to the dangers of their habit. Effective action in Asia would help to head off a significant part of the projected one billion deaths from smoking that will otherwise occur around the world this century."

The study was published online in the American Journal of Epidemiology.