Effects of toluene inhalation on pulmonary host defenses of mice

The potential hazards of exposure to vapor-phase toluene on pulmonary host defenses were evaluated. Mice exposed to concentrations ranging from 2.5–500 ppm, including the threshold limit value level of 100 ppm, exhibited increased susceptibility to respiratory infection with Streptococcus woepidemicus. The no-measurable-effect level for single, as well as for 5 exposures was 1 ppm. Significantly decreased pulmonary bactericidal activity was observed after single exposures to 500, 250, 100 and 2.5 ppm toluene, and after 5 daily 3-h exposures to 1.0 ppm of toluene. A 20-exposure study with toluene at 1 ppm produced no changes in either of the 2 assays.