STUDIES ON PATHOGENESIS AND PREVENTION OF PNEUMOCONIOSIS DUE TO “SENDO”
10.2185/jjrm.27.112
- VernacularTitle:染土じん肺の本態とその予防に関する衛生学的研究
- Author:
Atsushi UEDA
- Publication Type:Journal Article
- From:Journal of the Japanese Association of Rural Medicine
1978;27(2):112-133
- CountryJapan
- Language:Japanese
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Abstract:
The “tatami” mat production is one of the most important farming in Japan. It is all year domestic labor, being consisted of rush cultivating and “tatami” mat weaving process. From the industrial health point of view the working process have several problems.
1. Rush harvesting process
Rush is reaped for 3 weeks in July. The process, cutting, smearing, drying and storing, is hard physical work and energy consumption was estimated 3500-4500 kcal. per day. The workers are exposed to the scorching heat of the sun and the average value of WBGT-index of the working times a day was culculated 29.3°C. The process requires 5-10 co-workers per each household. The reaped rush bundles are carried hand in hand with each workers from the field to the storing room.
The workers are exposed to dense concentrated dusts of “sendo” used for “dorozome”, smearing rushes into mud in order to keep it's color unfaded. Especially, in the process of drying to storing, for 1-3 hours per day, over 100mg/m3 of dusts was observed. And average values of the working space was 44mg/m3 for male and 41mg/m3 for female during 7: 00-18: 00. Seventy eight percent of particles of the floating dusts in the working space were under 5μ in diameter. The “sendo” is clayey dust mixed with quartz, chlorite, kaolin, sericite and other minerals and contains 20-30% of free silica.
2. “Tatami” mat weaving process
The stored rushes are weaved into “tatami” mat domestically for all seasons. It contains the process of sorting length of rushes and weaving. The intensity of works are relatively low, but it's compulsory working times are very long.
The workers are exposed chronically for long-term to low dencity (1-5mg/m3) of “sendo” dusts through the process. And occasionally, the workers are exposed to relatively dense concentrated dust (15-25mg/m3) in the storing process. Seventy five to eighty five percent of the floating dusts were under 5μ in diameter.
