においの強度と濃度の間の相関に関する考察(第9報) : 野外調査成績に及ぼすバックグラウンド臭及び臭気サンプリング時間の影響

Abstract

Odor emanating from a kraft mill has been considered a public nuisance and, up till now, a variety of odor control techniques have been developed. The present paper deals with the interpretation for the results of field studies around a kraft mill, in particular reference to (1) the impact of the background upon the intensity dermined olfactorily during a field study, and (2) the relation between the cocentration of odor while sampling and the intensity measured concurrently. The findings are as follows. As for (1), it was ascertained that the odor of background is due to hydrogen sulfide at the concentration of 0.3 to 0.4 ppb. Taking into account the conditions, correction was applied to the results of field studies, with the outcome that it is definitely effective, though not sufficient. In passing, remark was made on the use of some types of gas masks for field studies. Concerning (2), it was pointed out that there holds Eq. (4) in text between the average of the intensities measured in the course of a field study and the intensity calculated, through the Weber-Fechner's formula, from the average of the concentrations determined by gaschromatography. In light of the relation, sampling should be accomplished within a time as short as possible. The general conclusion to be drawn from these considerations is that, for better understanding of the results of field studies obtained, it is necessary to get further information besides the above.