This study evaluated the potential of a simple method for determining the deposition fraction of cigarette smoke in the respiratory system of volunteer smokers, using optical tar measurements of inhaled and exhaled smoke.  Optical tar is the mass of the cigarette smoke as estimated using puff airflow and light obscuration measurements.

The optical tar measurements of both inhaled and exhaled smoke were well correlated to aerosol measurements of particle volume/mass equivalent.  Calculated deposition fractions by optical tar, aerosol measurement of particle volume/mass equivalent and chemical analysis of solanesol in inhaled and exhaled smoke were similar, implying that optical tar may be a convenient method to estimate deposition fraction, although this technique would not account for smoke lost from the mouth prior to inhalation, and could affect the volunteer’s puffing and inhalation behaviour.