Organic dusts: Beyond endotoxin

Organic dust is defined as dust that originates from plant or animal matter . Organic-dust-associated respiratory effects can potentially be due to man y different constituents of the dust. Endotoxins, from gram-negative bacter ia, have for a long time been considered as important nonimmunogenic, nonal lergenic inflammatory constituents responsible for systemic and respiratory effects in a wide range of agricultural industries. Other constituents wit h a similar mode of action have been identified, such as beta(1-->3)-glucan s from molds and peptidoglycans predominantly from gram-positive bacteria, although their toxicology and epidemiology are still to be established. At the same time, exposures to these agents other than in occupational setting s, such as in indoor and outdoor exposures, are being evaluated for their p otential effects on humans.