Gram-negative bacterial endotoxins in airborne dusts from washed and unwashed cottons

Gram-negative bacteria possess lipopolysaccharide-protein complexes termed endotoxins as an integral portion of their cell walls. These biologically active substances elicit profound effects both in vitro and in vivo. Organic dusts from many occupational environments contain measureable amounts of gram-negative bacteria and their endotoxins. In particular, cottons and cotton dusts contain these materials, and research is directed to elucidate the association between endotoxins and the acute and chronic respiratory effects of inhaling cotton dusts. It is the purpose of this paper to describe an experimental process which removes endotoxins from cotton by washing prior to processing the baled cottons. The studies show that water washing is a reliable method for removing endotoxins, and pulmonary function studies correlate well with endotoxin levels in the air. Quantification of airborne endotoxins provides a good indicator of cleanliness and toxocity of the cotton dusts. However, the differential toxicities of different endotoxins must be considered and evaluated further.