A study in Australia has revealed the risk of premature death from smoking is much more severe than previously thought for both light and heavy smokers.
The study found two thirds of deaths in current smokers can be attributed to tobacco use; the international rule of thumb is that half of all smoker deaths are directly caused by tobacco.
Professor Emily Banks from the Australian National University who led the study, says it followed 200,000 people over four years.
She says the study found people who are current smokers were three times more likely to die than people who had never smoked.
As well, their life expectancy within that four-year period was diminished by 10 years compared with those who had never smoked.