著者

樋端 規邦 石川 長英 山田 信也

出版者

公益社団法人日本産業衛生学会

雑誌

産業医学 (ISSN:00471879)

巻号頁・発行日

vol.33, no.2, 1991-03-20

著者

井上 俊 竹内 康浩 竹内 寿和子 山田 信也 鈴木 秀吉 松下 敏夫 宮垣 仁実 前田 勝義 松本 忠雄

出版者

社団法人 日本産業衛生学会

雑誌

産業医学 (ISSN:00471879)

巻号頁・発行日

vol.12, no.3, pp.73-84, 1970-03-20 (Released:2008-04-14)

参考文献数

17

被引用文献数

1 2

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In 1967 there occurred many polyneuropathy cases in household vinyl sandal manufacturers at F-disrict in Mie prefecture. In this district among 3, 210 people (788 families) most of them engaged in vinyl sandal manufacture (as of Oct, 1967). Ninety three patients suffering from polyneuropathy were found by our survey. Out of these 93 patients those suffering from sensory polyneuropathy were 53, from sensorimotor polyneuropathy 32 and from sensorimotor polyneuropathy with muscle atrophy 8 (cf. Tab. 1). The work conditions and the factors contributing to the intoxication's were investigated, and the method of prevention was suggested. The results are as follows. (1) The patients occurred in 1961 at first and the number of them increased rapidly from 1965 and showed a peak in 1967 (cf. Tab. 2). This increase was in parallel with the amount of adhesives containing "n-Hexane" used in this district (cf. Tab. 3, 4). Outbreak of many patients in winter and spring may due to poor ventilation in winter. (2) The causative substance was considered to be "n-Hexane". But "n-Hexane" on sale contains 2-methylpentane, 3-methylpentane, n-hexane, and methylcyclopentane, and the quantity of n-hexane in "n-Hexane" is about 60% (cf. Fig. 6). (3) The work conditions of the vinyl sandal manufacturers among whom many cases of "n-Hexane" intoxication occurred were as follows. 1) The work was primitive household manufacture and living rooms were used as the working place (cf. Fig. 1, 3). 2) As adhesives containing a large quantity of highly volatile "n-Hexane" were used in narrow rooms, the concentration of "n-Hexane" vapor became high and reached about 500-2500 ppm in the work room. The vapor concentrations were especially high in winter because of closed windows. (cf. Fig. 7, 8, 9). 3) Since the workers (subcontractors) were paid by the number of manufacturedgoods, their working period was unrestrictedly long and some worked for 14 hours per day (cf. Fig. 10). 4) The work intensity was high and some starched 3, 000 times per day. It seems that the more the times of starching, the heavier the degree of symptoms (cf. Fig. 11). 5) As the adhesives were used with hand brushes, the vapor concentrations were high at the site near the noses of the workers, so that they inhaled the organic solvent vapor at high concentrations. 6) As the organic solvents vapor ignite easily, the work rooms were not heated and they were working at quite low temperatures in winter (cf. Tab. 5). 7) The workers were not instructed as to the toxicity and the handling method of the organic solvents. 8) Usual health supervision was not performed at all. (4) The chief cause of the occurrence of intoxications was that a large amount of the organic solvents was used under very poor work conditions as above mentioned combined with neglected supervision. Moreover, that which gave impetus to the occurrence of the intoxication was that the easily drying adhesives containing a large quantity of "n-Hexane" were used in order to increase the number of the manufactured goods, because the pay per one of the goods was not increased for these several years in spite of the recent inflation. (5) As the urgent measure for the prevention, though instruction on the toxicity and the handling method of the organic solvents, improvement of the ventilation and the working methods, guidance by the health center and so on were made, these are only certain aspects of measures for the prevention. The danger of the intoxication may not be perfectly removed without the fundamental reform in the work conditions.

著者

山田 信也

出版者

社団法人 日本産業衛生学会

雑誌

産業医学 (ISSN:00471879)

巻号頁・発行日

vol.9, no.8, pp.651-659, 1967-08-20 (Released:2008-04-14)

参考文献数

11

被引用文献数

3 4

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(1) 17 cases of intoxication polyneuritis occurred in 17 workers exposed to n-hexane vapour in recent years, from 1960 to 1962, in Japan. (2) 6 cases of those occurred in 3 small polyethylene laminating plants. In these plans, in the first process, gravure printed cellophane sheet was smeared with n-hexane solution containing 5% organic titan, tetra isopropyl titan or tetra buthyl titan. Solvent n-hexane was vapourized with warm air and n-hexane vapour contaminated the air of the workroom. Organic titan, remained on the printed surfarce of cellophane sheet, was rapidly hydrolized with water in the air to titan oxide. In the second process, fused polyethylene was painted thinly on this surface. Titan oxide on this surface accelerated adhesion of polyethylene with cellophane, and cellophane sheet was laminated fast with polyethylene. This laminated sheet had the character of clear printed colour and water-proof, and was used widely as packing materials of foods, confectionery and others. Concentration of n-hexane vapour in the air around the machine in the first process was 1000∼2500 ppm. N-hexane used in these plants contained impurties, i.e. methyl pentane (16%) methyl cyclopentane (20%). Titan was not detected in the air. Working time was 10∼12 hours and workers became drausy in half or one hour and went outdoor to inspire fresh air for 10 to 15 minutes. (3) 11 cases of those occurred in a great pharmaceutical plant. In this plant, 95% n-hexane was used as a remover of grease on the surface of tablets. Tablets in wire netting were immersed for 5 minutes in n-hexane within the immersion box, and tablets in wire netting were dried on the shelf. N-hexane vapourized from the surface of the tablets and the immersion box. Concentration of n-hexane vapour was 1000 ppm around the immersion box and 500 ppm at the center of the workroom. Workers stayed in this room for 8 hours except for the noon recess. (4) In all cases symptoms of intoxican began with the same subjective complaints. The first complaint was fatigue in all cases and loss of appetite in some cases, followed by paresthesia in distal parts of the extremities, weakness, and difficulty in walking. Symptoms and signs advanced during the exposure and this progress was arrested finally three months after removing from the exposure, and the symptoms gradually improved throughout the period between six and thiry months. This characteristic process of development and improvement of symptoms was not such as usually seen in common polyneuritis. All diagnosis of these cases by clinical and hygienic examinations was intoxication polyneuritis of the mixed form. (5) In the first case, n-hexane, impurities in n-hexane and organic titan were suspected of the causes of intoxication. But in the second case, the cause was only n-hexane. N-hexane causes undoubtedly intoxication polyneuritis in man. One of my co-workers, Miyagaki proved experimentally the occurrence of intoxication neuritis due to n-hexane in rats. (6) Till now, n-hexane was regarded as of lowtoxic solvent owing to its low toxicity on the hematopoiesis and the liver function. But the present result showed that toxicity of n-hexane on the peripheral neuron was not insignificant.