Vibration disorder in casting plant

Vibration disorder in casting plant

by KAWAMOTO Hiroyuki
Kanagawa OSHC

The automobile industry has been a leading export industry in Japan. Toyota and Nissan are big names, well known around the world. Another, Isuzu Motors Ltd., is one of the most important truck manufacturers in Japan.

As other companies do, this company has been transferring its production sites overseas and diversifying its procurements. This globalizing strategy is putting many of its subcontracting companies on the brink of closure. Some companies are trying to survive by dismissing employees, while others have closed down. One way or another, many employees end up losing their work, and often with their health damaged by hazardous working conditions.

We present here the case of three victims of a vibration disorder, who were dismissed because their company-subcontractors for Isuzu Motors Ltd-closed down.

They had been working for Sogo Unyu, an in-house subcontracting company of Jidosha Imono, a casting company, which was, in turn, a subcontracting company for Isuzu Motors Ltd. The automobile manufacturer reduced their procurements from Jidosha Imono, which resulted in the shutdown of Sogo Unyu. In December, 1995, the company fired all of its employees, among whom were three vibration disorder victims, Masayoshi Tsuchidate (67), Yositsugu Endo (63) and Masamitsu Kobayashi (43).

They had been engaged in cast finishing operations, including hammering and grinding with machines, which generated intolerable noise and dust. Additionally they had been working in a factory where the temperature exceeded 50KC during summer. "Some 2000 workers came and left during these several years, although our company required only 7 employees," says Kobashi. Their company was a typical 3D workplace (i.e. dirty, dangerous and difficult).

Vibration disorder victims have traditionally been reported among forestry workers, construction workers, and miners who use vibrating machines. There have been few cases reported among manufacturing workers. The fact that our victims are included among so few cases illustrates the poor environment in which they had been working.

This scarcity of vibration disorder cases in the manufacturing industry is probably explained by another factor: few doctors can identify occupational factors hidden behind the apparent symptoms. Our victims did not receive the relevant diagnosis until they happened to visit Dr. Ryuta Saito, who specializes in occupational diseases. Several years ago Mr. Tsuchidate happened to see Dr. Saito's clinic advertised at a railway station, and visited him. Dr. Saito, one of the organizing members of Kanagawa OSHC, diagnosed him as suffering from vibration disease and informed us of Mr. Tsuchidate's case. Mr. Tsuchidate, however, gave up his claim for official certification as an occupational disease victim at that time, fearing that his company would harass or perhaps fire him. Previously he had been fired after being diagnosed as suffering from pneumoconiosis. Several years after his first diagnosis as a vibration disease victim, he was dismissed, and then finally decided to seek certification of his illness as occupationally induced.

He visited our office again to discuss his case, along with another six dismissed coworkers. They joined a local labor union to urge their company as well as Jidosha Imono and Isuzu Ltd. to nullify their dismissal and reinstate them. Their efforts--backed by the union--led to compensation payments by the companies, although they could not secure alternative employment. In addition, late in 1996, Mr. Tsuchidate and two other workers filed an application with the Labor Standards Inspection Office (LSIO) for insurance benefits for their vibration disease. In October 1997, the LSIO certified them as official victims of work-related vibration disease. They continue to receive treatment under the government labor insurance scheme. They also plan to claim liability--in some ways at least--of the companies which had neglected to improve their working environment, causing their health to be damaged.


Japan Occupational Safety and Health Resource Center (JOSHRC)
Z Bldg. 5F, 7-10-1 Kameido, Koto-ku, Tokyo 136-0071, Japan
FAX: 81-3-3636-3881