[Particle Size in the Smoke Produced by Six Different Types of Cigarette]

Introduction: For several decades a more peripheral distribution of the broncho-pulmonary pathologies related to tobacco has been observed.

Methods: The aim of this study is to examine whether changes in the particle size of cigarette smoke as the result of new manufacturing technologies could play a part in the observed epidemiologic changes through a more distal disposition of smoke particles in the airways. Using a smoking machine and a low pressure electrostatic impactor we measured the particle size of the smoke from six different types of cigarette, representing old and new manufacturing techniques. The effect of a filter was assessed by a size analyser measuring the electrical mobility of the particles.

Results: The results show a difference in particle size between the primary smoke inhaled by the smoker, S1 (0.27 +/- 0.03 microm.) and the secondary smoke, S2 inhaled by passive smokers (0.09 +/- 0.01 microm). There is no difference in particle size between the 6 different types of cigarette. Filters dilute the smoke without altering particle size.

Conclusion: The recent alterations in the distribution of tobacco related pathologies cannot be explained by changes in particle size in cigarette smoke. The explanation has to sought elsewhere.