Respiratory symptoms and low tar cigarette smoking--a longitudinal study on young people.

Longitudinal data on the effect of low tar cigarette smoking on respiratory symptoms was collected from a sample of Finnish young people born in 1966, by mailed questionnaires in 1979, 1983 and 1985. Cough was 3 to 6 times more common than expected after starting smoking low tar brands (1-10 mg tar). The increase in cough was the same as with those who started middle tar cigarette smoking (11-18 mg). Before starting smoking, the low tar cigarette smokers did not report more symptoms than the middle tar or nonsmokers. After a few years smoking cough and phlegm were 2 to 3 times more common in the low tar cigarette smokers than in the non-smokers but on the same level as in the middle tar cigarette smokers. Tar yield was not a significant predictor of symptoms in logistic regression analysis.