Aerosolized cotton dust was evaluate for anti-log cancer properties using a mouse model in support of reported epidemiological evidence. C57 BL/6J mice were injected in a lateral tail vein with Lewis lung carcinoma (1,1,/2) and exposed to cotton or inert dust cellulose dust. All mice were treated for one hour a day/seven days a week, using a Pitt # 3 generator. Cotton dust exposed mice had significantly reduced pulmonary tumor involvement when compared to non-treated and inert dust controls. These results support epidemiological evidence that cotton lust inhibits lung cancer. It is hypothesized that contaminating endotoxin in the aerosolized cotton dust, inhibits metastases of the tumor through immunological mechanisms.