Abstract
The present paper is described the rusults obtained by investigation of houry variations of air-borne dusts concentration and bacterial counts indoors and outdoors and the differences at the places, using several estimation methods. The concentration of air-borne dusts and bacterial counts indoors depend upon the artificial factors in the room and the atmosphere. The magnitude of houry variations of the concentrations of the air-borne dusts are often larger than that of those seasonal variations and regional differences on the average. No significant differences are not found between the dust counts determined indoors and outdoors using the Roken dust sampler. Therefore, it is known that these values chiefly depend upon air-borne particulates owing to the air pollution, and is not intensely affected by artificial pollution in the rooms. On the otherhand, the values of dusts and bacterial counts by means of electrostatic dust sampler and bacterial sampler are intensely affected by artificial pollution in the rooms, and these values indoors generally do not have relation to the values outdoors.
