Bronchial reactivity among cotton workers in relation to dust and endotoxin exposure.

Bronchial reactivity was measured before work among non-smoking female and male workers from carding, spinning, warping and weaving areas in a cotton mill. Airport baggage loaders were used as controls. The amount of dust and endotoxin was measured at the different workplaces. Statistically significant decreases in FEV1 were found between groups of cotton workers at different work sites after administration of the highest accumulated methacholine dose used (1.25 mg). A relationship was found between decreases in FEV1 after methacholine challenge and airborne endotoxin levels but not for dust.