Experimental studies of long-term aerosol inhalation. An inhalation apparatus for long-term exposure with concentration regulation facilities (author's transl)

Abstract

A "multipurpose" inhalation system for long-term experiments was developed to study health effects of the exposure to various kinds of aerosols appearing in general working environments as well as in the ambient atmosphere. In order to carry out a continuous inhalation study on animals for their life-span, at least two essential conditions should continuously be fulfilled. (1) Steady maintenance of the appropriate sanitary conditions for the animals placed in the inhalation box. (2) Constant feeding of aerosol at an appropriately regulated concentration level. The developed system described in the present paper has been proved to be satisfactory from the above viewpoints. This inhalation system was applied to an experimental study attempting to simulate the polluted lungs in the urban dwellers. Heavy oil combustion products were chosen as the inhalation material, which were made to be inhaled by the male rats of SD-JCL strain for their life-span. The present report is mainly concerned with the construction of the inhalation system including a newly devised regulation facility of the aerosol concentration. Operating characteristics and actual data obtained are described. Details of the exposure conditions and pathological findings obtained will be described in the succeeding reports.