模造真珠製造作業の労働衛生学的実態 : とくに四塩化エタン取扱い作業を中心として

Abstract

A report is made, from the standpoint of occupational health, on the work manufacturing artificial pearls with special reference to the work using tetrachloroethane as a solvent. 1) A hundred and twenty seven workers (socalled coating workers using several kinds of solvents) chosen from 33 factories were examined on their health by screening tests in November, 1960. In about 10% of the workers examined were observed lowering of specific gravity of whole blood and a decrease in white cell count respectively, in 23% positive result in the urobilinogen test, and in 24% subjective symptoms of the digestive system. 2) Medical examinations were conducted on the workers in the three factories (A, B and C) using tetrachloroethane with air analysis of the working environment in July, 1960 and in November, 1961. In the first survey in 1960, air analysis showed the concentration of tetrachloroethane as high as 75 to 225 p.p.m. Of 18 workers examined, there observed such clinical findings as lowering of specific gravity of whole blood (67%), a decrease in red cell count (44%), relative lymphocytosis (83%), positive result in the urobilinogen test (39%). Since the first survey, the two factories (A and C) had abondaned the use of tetrachloroethane on their own initiative, while the one (B) still used. In the second survey in 1961, air analysis showed 20 p.p.m. in factory B. The results of medical examinations in the second survey in 1961, as compared with those in the first survey in 1960, remarkable improvement was observed in the two factories (A and C) as shown in Table 5. This has revealed that the best way to prevent industrial poisoning is the elimination of the sources of hazards.