Pulmonary deposition of aerosols in individual and group caged rats

There has long been a need to define differences in the amount of aerosol inhaled by group caged rodents as compared to the theoretically ideal individually caged rodent. Therefore, an experiment was designed and conducted to gain insight into this problem. Three groups of animals were evaluated for the degree of pulmonary deposition following a single six hour exposure to a 3 mu aerosol of dodecyl alcohol. One group contained individually caged rats, while the other two groups contained rats caged either in groups of three or seven. Analyzing lungs and trachea for the dodecyl alcohol indicated 25.6 micrograms/g, 27.1 microbrams/g, and 23.1 micrograms/g for rats caged individually, in threes, or in sevens, respectively. There was no statistically significant difference between the amount of dodecyl alcohol found in group caged rat lungs as compared to individually caged rats. Thus group housing does not appear to reduce the amount of aerosol inhaled by rats during a six hour whole body exposure.