the project objectives were the development of a system to be used for exposing small laboratory animals to the respirable fraction of cotton dust found in a cotton mill, and testing an animal model of byssinosis which could be used to study the development of the disease in humans. the final report contained 10 published papers of the research at various stages of completion. a description of the cotton dust exposure system optimization techniques and measurements of the resulting improvements were noted in these articles. the final system developed used a large, modified, pitt-3 cotton generator to expose up to 10 animals simultaneously to cotton dust in a wahman stainless steel chamber. the acoustical powered generator, which was developed for the project to resuspend cotton dust has been very useful in resuspending other agricultural dusts. the development of an animal model for byssinosis involved verifying results of other investigators, developing and testing several new methods to evaluate pulmonary function in guinea pigs following acute cotton dust exposures, and modification of the cotton dust response using drug mediators