Survey of effects of variety and growing location of cotton on cardroom dust composition.

Electrostatically precipitated respirable dusts from six major U.S. varieties and growing areas were analyzed. From 81-95% by weight, was under 15 micronm diameter. Composition was affected more by growing location than by variety. Dusts contained 16-28% ash, 8-9% moisture, and 62-76% organic matter, including 16-31% protein and 2-12% cellulose. Inorganic composition reflected soil type and minerals. Major elements were silicon, calcium, potassium, phosphorus, magnesium, and aluminum. Infrared spectra of dusts resembled proteins, but water extract spectra did not. Possible implications concerning byssinosis are discussed.