Small Plants and Their Medical Problems - The Furniture Industry: Respiratory Health Effects of Isocyanates.
NIOSH 1980 Jun:53-55
The effect of exposure to toluene-diisocyanate (584849) (TDI) was investigated by a 5 year longitudinal study conducted in a factory that began manufacturing TDI when the study was initiated. The airborne concentration of TDI was measured using a tape cassette that monitored its vapor for 8 hours. About 5 percent of the population became intolerant to TDI. Some of these workers were smokers, some had an atopic history, some had positive skin sensitivity test results, some developed symptoms shortly after the exposure, and some several months later. Inhalation challenge was performed with TDI doses from 0.005 to 0.02 parts per million. The susceptible workers either had an immediate decline in ventilatory capacity (VC) with prompt reversibility followed by a late response, or there was a gradual decrease in VC. A dose response relationship was observed in three workers. The radioallergosorbent test (RAST) indicated that immunoglobulin-E antibodies were not present in a significant quantity. The stimulation of cells with isoproterenol (7683592) in the presence of TDI failed to release cyclic-adenosine- monophosphate (cAMP). TDI at certain concentrations acted as a partial agonist on lymphocytes to stimulate the release of cAMP; at lower concentrations it could block its release. The annual declines in forced expiratory volume in 1 second, forced expiratory volume (FEV) percent, and FEV midflow were significantly related to TDI dose after controlling for smoking and atopy. Those in higher exposure groups had a significantly greater decline. The prevalence of bronchitis and dyspnea increased more in the high exposure group than in the low groups, but the differences were not statistically significant. Neither atopy nor smoking helped to identify persons who might be at risk of TDI sensitivity. The evidence indicated that some people had clinical evidence of sensitization without a positive reaction to inhalation provocative testing.
NIOSH-Contract; Contract-210-79-0009; Bronchial-asthma; Occupational-respiratory-disease; Respiratory-irritants; Respiratory-hypersensitivity; Physiological-response; Isocyanates; Health-hazards; Physiological-testing; Organic-chemicals;
Occupational Safety and Health Symposia 1979, NIOSH, U.S. Department of Health and Human Services, Cincinnati, Ohio, DHHS (NIOSH) Publication No. 80-139