[Effects in the rat of a weak dose of acrolein inhaled continuously]

The results of an experiment on 173 S. P. F. rats inhaling 0.55 ppm of acrolein, compared to 173 control rats, are reported. In what concerns the respiratory apparatus, this dose of acrolein affects its defense mechanisms, leading to a greater susceptibility to the airborne Salmonella enteritidis infection, compared to the control group. These phenomena disappear spontaneously when intoxication is prolonged more than three weeks. On the contrary, the general toxic action, manifesting itself through diminished weight growth and under-nourishment, compared to control group, lasts as long as intoxication and disappears only after acrolein inhalation has stopped. These results are discussed.