Concentration and emission of airborne contaminants in a laboratory animal facility housing rabbits.
ABSTRACT Characterization of animal housing conditions can determine the frequency of bedding and cage changes, which are not standardized from facility to facility. Rabbits produce noticeable odors, and their excreta can scald and stain cages. Our facility wanted to document measurable airborne contaminants in a laboratory rabbit room in which excreta pans were changed weekly and cages changed biweekly. Contaminants included particulate, endotoxin, ammonia, carbon dioxide, and a rabbit salivary protein as a marker for rabbit allergen. Concentrations were measured daily over a 2-wk period in a laboratory animal facility to determine whether they increased over time and on days considered to be the dirtiest. Except for ammonia, concentrations of all airborne contaminants did not differ between clean and dirty days. Concentrations were lower than occupational health exposure guidelines for all contaminants studied, including ammonia. After measurement of concentration, a model was applied to calculate mean emission factors in this rabbit room. Examples of emission factor utilization to determine airborne contaminant concentration in rabbit rooms under various environmental conditions and housing densities are provided.
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ABSTRACT: Urine of rats and mice is the main source of allergenic proteins that can enter the respiratory tract of laboratory animal care workers. Little is known about the levels and determinants of these exposures in the United States. We investigated the relationship between activities in animal facilities and levels of personal exposure to allergen by collecting personal breathing zone dust samples from 7 caretakers during full workdays for 1 wk. Mice and rat urinary allergens in inhalable dust were quantified via immunoassay. The activities of the sampled workers were observed, and the methods of preventing exposure to allergens were recorded. Mouse urinary allergen was detected in 20 of 39 measurements, yielding a geometric mean of 0.8 ng/m(3) with a maximum of 24 ng/m(3). Washing and cleaning cages and the number of mice handled daily were the most important determinants of personal exposure to mouse urinary allergen, as identified by using multiple linear regressions that explained 51% of total variance. Personal exposures to mouse urinary allergen were associated with day-to-day variation of tasks rather than characteristics of workers. Where potential for personal exposure is the highest, protective measures (N95 masks and cage dumping stations) appeared to be used, as is appropriate. Rat urinary allergen was detected in 4 of 39 measurements; detectable concentrations were between 0.8 and 39 ng/m(3). Only persons who handled rats were exposed to rat urinary allergen. The current findings are valuable for establishing exposure levels against which comparisons of improvement or deterioration of personal exposures can be made.Journal of the American Association for Laboratory Animal Science: JAALAS 01/2012; 51(5):554-60. · 0.73 Impact Factor