Figure 3.

After-exposure antioxidants increase survival of Cl₂-exposed mice returned to room air. Mice were exposed to 600 ppm of Cl₂ for 45 minutes and returned to room air. Each data point shows the number of mice that were alive at the indicated time after Cl₂ exposure. The experimental group (gray line, solid circles; n = 18) received intramuscular injections of ascorbate (2 mg) and deferoxamine (0.3 mg) in saline starting at 1 hour after exposure and every 12 hours thereafter up to 60 hours after exposure. They also received aerosols of ascorbate (150 mg/ml) and deferoxamine (0.3577 mg/ml) at 1.5, 24, and 48 hours after exposure in sterile water, as described in the online supplement. The control group (black line, solid squares; n = 18) received vehicle (saline for intramuscular injections; sterile water for aerosols) instead of antioxidants using identical protocols. A total of 14 mice were alive at 72 hours after exposure in the antioxidant group, and 4 in the saline group, respectively. Data points were fitted with Kaplan-Meier survival curves and compared with the log-rank test (P = 0.0007).