オゾンと喫煙単独および両者暴露後のアセチルコリン吸入に対する人の気道反応性への影響

抄録

We studied the bronchial reactivity of 6 healthy human subjects (3 nonsmokers and 3 smokers) to inhaled acetylcholine after 2-hour exposure to 0.3ppm ozone (O₃), smoking cigarettes alone, 0.3ppm O₃ with smoking, and 0.5ppm O₃. Most subjects showed significant decrease of specific airway conductance (Gaw/Vtg) after these exposures in comparison with control measurements. The decrease of Gaw/Vtg after smoking was similar to O₃ exposure and not enhanced by addition of O₃. The decrease of Gaw/Vtg after 0.5ppm O₃ seemed to be greater than 0.3ppm O₃ in nonsmokers.
Five of 6 subjects showed a tendency for Gaw/Vtg to decrease with each concentration of acetylcholine in comparison with controls, which indicated increased bronchial reactivity, but these 5 did not show the enhanced effect by a combination of O₃ and smoking together.
Although the mechanism of the increased reactivity after exposure to O₃ at concentrations observed in the urban atmosphere is not clear, this problem should be investigated in particular in association with the pathogenesis of asthma.