Dissolution and Volatilization of Dieldrin from Moth-proofed Wool Fabrics : An Attempt to Evaluate Harmfulness of Textile Treating Agents for Consumers

Abstract

Five kinds of wool fabrics treated with dieldrin emulsion in the laboratory under reflux or at 40° and those on the market were used for the experiments. The amount of dieldrin dissolved in perspiration or saliva increased with increasing total dieldrin concentration (A) in fabrics, and also with the mild treating condition, at 40°. Ease of dissolution of dieldrin into both body fluids varied with the kind of fabrics and decreased in the order of carpet, blanket, flannel, and doeskin. This also indicates the order of harmfulness by dermal and oral exposure. Volatilization of dieldrin obeyed the first-order kinetics under the adopted condition, at 40°, 50% relative humidity. Through the kinetic treatment, the total volatilizable dieldrin (a) in fabrics, volatilization rate constant (k) and half-life of a (t1/2a), were obtained. The ratio of a/A decreased with the kind of fabrics in the order of blanket, carpet, flannel, doeskin and tuxedo cloth, while t1/2a decreased in the order of blanket, carpet, doeskin, tuxedo cloth, flannel. Harmfulness by respiratory exposure to dieldrin volatilized from fabrics should be evaluated with two factors, volatilized amount and prolonging time which are represented by ka/A and t1/2a, respectively. The order evaluated in this manner was as follows : carpet=blanket»flannel>doeskin=tuxedo cloth. From these results, care should be taken in using carpets and blankets moth-proofed with dieldrin, compared with others, because they are treated in a mild condition with dieldrin to effect its easy dissolution and volatilization, and in addition these large products containing a large amount of dieldrin are used daily.