[Intrapulmonary deposition of submicron-size particles].

Inhalation studies of ultrafine aerosol particles are described. Chambers with controlled atmospheres have been built, in which known volumes of clear air and aerosol particles are introduced. By means of an electrical mobility analyzer the size distribution of the aerosol in the chamber determined down to a mean diameter of 0,01 micron. Such aerosol is inhaled by the subject and exhaled into an identical chamber, previously filled with clean air. The size distribution of the resulting aerosol is determined with the same measuring system. The particle number distributions of inhaled and exhaled particles are then suitably correlated and compared. In this paper data are reported based on the retention of cigarette smoke referred to male subjects in the age group from 24 to 44 years old. These results are compared with the experimental data which appeared most recently in the medical literature. A standardization is proposed of the experimental conditions for measurements of intrapulmonary deposition of inhaled particles. This is because of the importance that the results of such studies might have in the field of prevention and industrial hygiene, in particular in the nuclear field.