THE USE of fog, generated by ultrasonic nebulizers, has become increasingly popular for the treatment of infants and children with a variety of pulmonary diseases. Recent studies in this laboratory have shown that while dogs tolerate exposure to ultrasonic aerosols for short periods of time (six hours),1 continuous exposure to aerosols generated from either distilled water or particularly from physiologic saline solution for 72 hours can result in severe pulmonary pathological findings.2
In order to further test the relative toxicity of chronic exposure to various solutions in nebulized form, the mouse, an animal noted for its susceptibility to changes in environment, was selected for the following experiments.
Methods
We divided 800 CBA white mice, averaging 22.6 gm in weight, into eight groups of 100 mice each for mortality studies.Aluminum chambers 2 × 3 × 2 feet with plexiglass windows were constructed for exposing these animals to aerosols