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 many different constituents of the dust. Endotoxins, from gram-negative bacteria, have for a long time been considered as important nonimmunogenic, nonallergenic inflammatory constituents responsible for systemic and respiratory effects in a wide range of agricultural industries. Other constituents with a similar mode of action have been identified, such as β(1→3)-glucans 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 settings, such as in indoor and outdoor exposures, are being evaluated for their potential effects on humans.