Inhalation toxicity studies on cigarette smoke II. Tobacco smoke inhalation dosimetry studies on small laboratory animals.

A newly developed exposure system has been used to carry out smoke dosimetry studies on rats, mice, hamsters and guinea pigs. In all species, smoke total particulate matter (TPM) deposited in significant amounts in the lower respiratory system (LRS) at dose levels ranging from 0.515 to 1.710 mg TPM/g respiratory tissue. Nasal deposition of smoke particulates did occur in all of the species examined. The significance of these dosimetry data in relation to the conduct of long-term comparative inhalation toxicity studies with tobacco smoke is discussed.