Spreading of occupational allergens: laboratory animal allergens on hair-covering caps and in mattress dust of laboratory animal workers

Background: Family members of laboratory animal workers are at risk of developing allergy to laboratory animals. Little is known about the spreading of laboratory animal allergens outside the animal facilities. Objective: To assess the presence of laboratory animal allergens in dust collected from mattresses of laboratory animal workers and unexposed controls. Methods: Mouse and rat urinary proteins were measured in samples of mattress dust collected by laboratory animal workers and unexposed controls. In addition, rat and mouse allergens were determined in extracts of hair-covering caps, used during laboratory animal work, to estimate spreading of allergen through dust captured on hair. Allergen concentrations on hair caps were compared with exposure measured by personal airborne dust sampling. Results: Levels of rat urinary allergens (RUA) and mouse urinary allergens (MUA) and mouse urinary protein (MUP) 8, a specific pheromone-binding mouse allergen, were significantly higher in mattress samples of laboratory animal workers than in those of controls. Hair-covering caps used in animal facilities harboured large amounts of RUA and MUA, which correlated significantly with exposure measured by the personal sampling technique in the animal facility. Conclusions: Occupational laboratory animal allergens are detectable in mattress dust of laboratory animal workers. Transfer of allergens via uncovered hair of animal workers is likely contributing to this phenomenon. This study stresses the importance of using hair caps to prevent spreading of occupational allergens.