Comparison of the guinea pig's physiological and cellular response to the respirable fraction of untreated, heat treated, microwave irradiated and ethylene oxide treated DB 1/88 bulk cotton dust

A study was conducted to determine whether bulk cotton dust could be treated in order to reduce the biological activity of the respirable fraction of the dust. Four groups of guinea-pigs were exposed to respirable DB 1/88 bulk cotton dust aerosol which had been untreated, heat treated (to 190 degrees-C for 2 hours), microwave irradiated (for 3 minutes at 700 watts and a frequency of 2450 megahertz), and ethylene-oxide treated (for 48 hours) and a control group which was held in a chamber with filtered air. Animals exposed to the respirable fraction of untreated DB 1.88 bulk dust had the greatest breathing rate response while the minimum breathing rate response occurred in the group of animals exposed to the respirable fraction of heat treated DB 1.88 bulk cotton dust. Lymphocyte and granulocyte infiltration was greatest in animals exposed to the respirable fraction of the untreated DB 1.88 bulk cotton dust and the smallest in animals exposed to the respirable fraction of heated DB 1.88 bulk cotton dust. The results indicated that treating bulk cotton dust to alter bacteria viability and bacteria byproducts was effective in reducing the response of the guinea-pig model to the respirable dust