Study on Pathogenesis and Prevention of Pneumoconiosis Due to "Sendo" Dusts.
Ueda-A; Futatsuka-M; Nomura-S
Proceedings of the VII International Congress of Rural Medicine, Salt Lake City, Utah, September 17-21, International Association of Agricultural Medicine 1978 Sep:81-83
Pneumoconiosis due to exposure to sendo dust in Japanese workers engaged in the production of tatami woven mats was studied. Workers who cut, smear, dry, and store the rush during the reaping process in July were exposed to the sun and dense concentrated dusts of sendo dyeing soil. The process of smearing rushes into the sendo to keep the color in the mat is called dorozome. Over 100 milligrams/cubic meter of dust was measured during this process. Of the airborne dust particles, 78 percent were under 5 micrometers in diameter. The sendo contains quartz (14808607), clay and other minerals, with 20 to 30 percent free silica. In a health survey conducted among rush farmers, 44 cases of slight fibrosis was noted in 326 subjects, and 37 cases of suspected pneumoconiosis were identified. An experimental study was also made of fibrogenicity occurring in lung tissue of rats exposed to sendo dusts through intratracheal infusion of 3.5 percent and 10 percent suspensions. After 3 to 6 months following injection histological changes were noted in lung tissue which suggested that rush farmers' pneumoconiosis resulted from long term inhalation of sendo dusts. The authors suggest there is a real need for dust control procedures for these workers including legal steps and the substitution of other materials for the sendo.
NIOSH-Grant; Airborne-particles; Airborne-dusts; Dust-inhalation; Laboratory-animals; Pulmonary-system-disorders; Agricultural-workers; Mineral-dusts; Silica-dusts;
Prev Med & Environmental Hlth University of Iowa Inst/agric Med & Environ Hlth Iowa Oakdale, Iowa 52319
Asthma and Chronic Obstructive Pulmonary Disease; Disease and Injury; Pulmonary-system-disorders;
Proceedings of the VII International Congress of Rural Medicine, Salt Lake City, Utah, September 17-21, International Association of Agricultural Medicine
University of Iowa, Iowa City, Iowa