Characterization of Endotoxin and Mouse Allergen Exposures in Mouse Facilities and Research Laboratories

Objectives: Researchers and technicians who use mice in research are exposed to complex mixtures containing mouse allergen, endotoxin and particulates from animals, bedding and feed. The particle characteristics of these different exposures, and whether they are encountered together or separately, are important to better understand their adjuvant and allergic effects. Endotoxin and mouse allergen are derived from the same animal source, but have different physicochemical attributes. It is not known if airborne exposures to these agents are correlated in the laboratory animal workplace. Methods: Side-by-side personal and area samples for airborne endotoxin (52), mouse allergen (46) and total particulates (43) were obtained in the animal facility and laboratories of amedical research institution. Animal handlers and researchers reported time spent on work tasks with mice, symptoms upon exposure to mice and mouse sensitization was determined by skin test or RAST. Results: Mean airborne endotoxin exposure was highest during mouse experiments in the animal facility at 960 pg m3, peaked at 3125 pg m3, and ranged from 46 to 678 pg m3 with work in mouse rooms and research labs. Mouse allergen concentrations were highest durin