Tobacco smoke is a lightly charged aerosol in which the individual particles carry only a few elementary charge. The aerosol as a whole is neutral. While some of the electronic charge may be acquired from the burning process the number of electronic charges per particle found in the tobacco smoke indicates most of the charge is acquired through collision with atmospheric ions. There are probably particles present in cigarette smoke which are too small to be observed by any of the techniques reported here or elsewhere. These small particles, which must be present at very high number concentrations are intimately associated with the mechanism of formation of the cigarette. The measured size of smoke particles is dependent upon both the age and degree of dilution of the smoke. Thus, it is rather difficult to compare reported values for size of cigarette smoke particles unless the age and degree of dilution at the time of measurements are known.

(Full article published with kind permission from "Tobacco International")