D’Alessandro et al. (A-47) wished to know if preexisting airway hyperresponsiveness (HR)

predisposes subjects to a more severe outcome following exposure to chlorine. Subjects were healthy volunteers between the ages of 18 and 50 years who were classified as with and without HR.

The following are the FEV1 and specific airway resistance (Sraw) measurements taken on the subjects before and after exposure to appropriately diluted chlorine gas:

Hyperreactive Subjects Pre-Exposure Post-Exposure Subject FEV1 Sraw FEV1 Sraw 1 3.0 5.80 1.8 21.4 2 4.1 9.56 3.7 12.5 3 3.4 7.84 3.0 14.3 4 3.3 6.41 3.0 10.9 5 3.3 9.12 3.0 17.1 Normal Subjects Pre-Exposure Post-Exposure Subject FEV1 Sraw FEV1 Sraw 1 4.3 5.52 4.2 8.70 2 3.9 6.43 3.7 6.94 3 3.6 5.67 3.3 10.00 4 3.6 3.77 3.5 4.54 5 5.1 5.53 4.9 7.37 Source: Data provided courtesy of Dr. Paul Blanc.