Health consequences of smoking 1-4 cigarettes per day -- Bjartveit and Tverdal 14 (5): 315 -- Tobacco Control

Health consequences of smoking 1-4 cigarettes per day -- Bjartveit and Tverdal 14 (5): 315 -- Tobacco Control
Conclusions
In both sexes, smoking 1–4 cigarettes per day was significantly associated with higher risk of dying from ischaemic heart disease and from all causes, and from lung cancer in women. Accordingly, five cigarettes per day is not a threshold value for daily cigarette consumption that must be exceeded before serious health consequences occur. /.../