Endotoxins in the working and general environment

Endotoxins, cell-wall fragments of gram-negative bacteria, are found in var ious work environments and first measurements have been made in general ind oor environments. Endotoxins cause an inflammatory response of the respiratory tract. The res ponse is mediated by the proinflammatory cytokines IL-l, IL-6, IL-8, and TN F-alpha and gives rise to general symptoms (fever, headache, malaise), resp iratory symptoms (tightness of chest, dry cough), and lung function decreme nts. In the work environment endotoxins have been identified in all environ ments which produce similar symptoms. The qualitative results of experiment al and epidemiological studies agree well. The related question whether end otoxins are the biologically active component of organic dust cannot yet be answered because of the gap between the concentration of lipopolysaccharid es and of endotoxins necessary to induce the same quantitative effect. Diff erent possible explanations are discussed. Endotoxins are also found in the general environment, especially indoors. Their health relevance needs to b e assessed in more detail, especially in subjects with bronchial hyperreact ivity.