ORGANIC DUST EXPOSURE FROM COMPOST HANDLING - RESPONSE OF AN ANIMAL-MODEL

The objective of this investigation was to elucidate the pulmonary responses of an animal model to dust generated from leaf/wood compost which had caused a severe case of acute respiratory illness in an individual. Guinea pigs were exposed for 4 hr to 30 mg/m3 of aerosolized leaf/wood compost dust. Inhalation resulted in significant cellular activation and changes in pulmonary mechanics. Maximal elevation in breathing rate (up 36%) was observed 12-18 hr postexposure. Similarly, maximal granulocyte infiltration (up 1,600%) and activation of alveolar macrophages (up 65%) occurred 18 hr postexposure. In contrast, maximal airway obstruction (up 120%) occurred immediately after exposure and returned toward normal (up 53%) by 18 hr postexposure. In several respects, the airway obstruction and pulmonary inflammation described in the animal model were comparable to the human response to compost dust. Therefore, this animal model may be useful in predicting the potential respiratory hazard associated with exposure to various organic dusts. (C) 1993 Wiley-Liss, Inc.