Pulmonary function and symptoms in herbal tea workers.

INTERNATIONAl. CONFERENCE ON BYSSINOSIS 81S study may have been due to the differences in dust concentrations for the different cottons. An accurate adjustment for these differences cannot be made because only two closely spaced points on the doseresponse curve for standard cotton dust were obtained, and it may not be accurate to assume a similar slope for the dose-response to closed boll cotton dust even if the slope for standard cotton dust were known precisely. However, using a simple extrapolation based on the observed dose-response slope for standard cotton dust, response to SCBI and LCBR cotton dusts remained significantly lower than the response to standard cotton dust. The same adjustment applied to the response to rayon, results in a larger decline in FEy, than observed with standard cotton exposure. Whether bract removal is important in reducing the biologic activity of closed boll cotton cannot be determined from this study. Likewise, although the correlation of endotoxin content and pulmonary function response was not significant, the inhaled dose of endotoxin may not be accurately reflected in measurements on random bulk samples. Analysis of airborne endotoxin from this and future studies may allow more definite conclusions to be made. Finally, whether the acute pulmonary function response to a six-hour exposure in nonbyssinotic subjects is a valid predictor of the potential of a given type of cotton dust to produce byssinosis or permanent pulmonary impairment after long-term exposure can only be determined from carefully controlled prospective studies. However, short-term exposure studies seem to be useful and safe in rapidly estimating the relative effectiveness of various experimental treatments in decreasing the biologic activity of cotton dust.