Inhalation toxicity studies on cigarette smoke III. Tobacco smoke inhalation dosimetry study on rats.

Smoke inhalation dosimetry studies have been carried out on rats, using a new exposure system. A range of cigarettes, tobacco types and smoke concentrations was used. Penetration of smoke into the lungs was clearly demonstrated, and loads of total particulate matter (TPM) of up 1 mg were detected in the lower respiratory system of rats. The mass of TPM deposited was affected by the smoke concentration during exposure. Deposition of TPM in the head of the rat was low in relation to total respiratory system deposition. A pattern of predominantly lung deposition was achieved under the conditions used for this series of experiments. This pattern was not affected by changes in smoke dilution level, cigarette or tobacco type.