某造船工場,Thinner使用塗装作業場における作業員の尿中馬尿酸,メチル馬尿酸量について : Thinner中毒第8報,有機溶剤中毒第12報

Abstract

We measured, during a week, the urinary hippuric acid (H.A.) and m-and p-methyl hippuric acid (M.H.A) of workers exposed to thinner containing toluene and m-and p-xylene in their routine spraying or painting work in a ship-building yard, and also, during a month, total amount of H.A. and M.H.A. Average toluene and xylene inhaled were calculated from the chart indicating relationship between toluene density and urinary H.A., or m-and p-xylene density and urinary M.H.A. described previously. The following results were obtained. 1) The concentration of the urinary H.A. varied in parallel with M.H.A. The mole ratio of toluene to m-and p-xylene in the thinner on the 13th of March was similar to that of urinary H.A. to M.H.A. in the workers using the thinner. As to the evaporation ration of the thinner, the ratio of toluene to m-and p-xylene in the air is thought to be different. Therefore, determination of the ratio of H.A. to M.H.A. appears to be suitable to know the ratio of toluene and m-and p-xylene inhaled. 2) We could calculate the average toluene and m-and p-xylene density inhaled respectively and also sum of them from urinary H.A. and M.H.A., We could check the day when workers were thought to be exposed to over 200 p.p.m. of toluene plus xylene concentration. 3) We also succeeded in checking the day exposure of workers to 200 p.p.m. of toluene plus xylene using the following equation. (H.A.conc. in working time, (mg/ml)) / (H.A.conc. exposed to 200 p.p.m. of toluene, (5.74 mg/ml )) + (M.H.A.conc. in working time, (mg/ml)) / (M.H.A.conc. exposed to 200 p.p.m. of xylene, (4.56 mg/ml)) ⪌1……………(1) or simply, (H.A. + M.H.A.conc. (mg/ml)) / (5.15 mg/ml)⪌1……………(2) Equation (2) was useful in the case in which sum of H.A. and M.H.A. concentration had been measured by simple paperchromatography with buthanol-acetic acid-water as a developing solvent. (4) Daily urinary H.A. and M.H.A. concentrations varied distinctly, depending on the kinds and duration of work. Therefore, determination of the average concentrations of toluene and xylene or of urinary H.A. and M.H.A. during a week or a month is necessary.