Airway Diseases Due to Organic Dust Exposure

Exposure to organic dust can occur in various occupational settings, particularly in the agricultural environment. Organic dust exposures have been shown to induce not only acute airway disease such as asthma or asthma-like syndromes, but chronic exposure also give rise to chronic airflow obstruction. Such exposures may cause various acute and chronic airway inflammatory diseases. Exposures in these environments are complex and are marked by a number of airborne bioaerosol contaminants including complex mixtures of organic dust, particulates, skin debris, feather, insect parts, aerosolized feed, animal respiratory secretions, excreta, bacteria, and fungi. The abundance and wide variety of gram-negative and gram-positive microbial components and fungal components in the organic dusts are likely responsible for the pathogenesis of the organic dust associated airway inflammatory diseases. The authors discuss the effect of such settings, exposures, and agents that include crop farming and grain dust, animal farming (cattle, pigs) as well cotton and other textile dusts causing byssinosis. Acute airway inflammatory reactions following exposure to organic dust environments with participation of innate and adaptive immunity have been demonstrated in healthy subjects and also in those with lung disease. The chronic effects, including the risk of developing COPD and asthma-COPD overlap, are also considered. Prevention strategy is mainly aimed at reducing exposure by improving ventilation of facilities.