http://www.bmj.com/content/360/bmj.j5855
ref - https://www.reddit.com/r/science/comments/7sv8vb/smoking_only_about_one_cigarette_per_day_carries/
origin - https://www.pipiscrew.com/2018/01/low-cigarette-consumption-and-risk-of-coronary-heart-disease-and-stroke/ low-cigarette-consumption-and-risk-of-coronary-heart-disease-and-stroke