The near-infrared reflectance spectroscopy (NIRS) method of analysis, as applied to cotton dust, offers an independent method for searching for byssinosis causatives. We report here a test of the hypothesis that the acute pulmonary response from subjects exposed to cotton dust is a linear function of the composition of unsieved dust as measured by near-infrared reflectance spectroscopy (NIRS). A linear relationship was found between delta FEV1 (the forced expiratory volume in 1 second) and unsieved cotton dust captured by the Hi-Vol dust sampler. Of the various agents proposed over the years as the byssinosis causative agent, at least three of them (gram-negative bacteria and their endotoxins, and tannins) were present in the unsieved dust at concentrations exceeding the NIRS sensitivity level and may account for the observed relationship. No association was found between the pulmonary effects and cotton compositional analysis by NIRS. NIR reflectance spectra of cotton and cotton dust, in air and in nonabsorbing carbon tetrachloride, reveal similar absorption bands of different intensity.
Joseph G. Montalvo, Sherman E. Faught, and Steven M. Buco, "Relation of the Acute Pulmonary Response to Cotton Dust and Dust Compositional Analysis by Near-Infrared Reflectance Spectroscopy. Part II: Unsieved Dust," Appl. Spectrosc. 42, 433-442 (1988)