Koenig J Q, Pierson W E, Covert D S, Marshall S G, Morgan M S, van Belle G
Department of Environmental Health, University of Washington, Seattle.
Res Rep Health Eff Inst. 1988 Jan(14):5-24.
The aim of this project was to investigate whether or not well characterized groups of healthy adolescents and adolescents with asthma differed in their sensitivity to ozone and nitrogen dioxide at near ambient concentrations of these pollutants. The project was divided into three phases. In each phase, ten healthy and ten asthmatic adolescents were exposed via a mouthpiece to three different atmospheres (filtered air, ozone, and nitrogen dioxide, at either 0.12 or 0.18 ppm) on separate days at least one week apart. During Phase I, subjects at rest inhaled the test atmospheres at 0.12 ppm for two 30-minute periods. The following pulmonary functional values were measured before, during, and after exposure: peak flow, total respiratory resistance, thoracic gas volume at functional residual capacity, maximal flow at 50 and 75 percent of expired vital capacity (performed with both room air and a helium-oxygen mixture), and forced expiratory volume in one second. Pulmonary function was not consistently altered in either the asthmatic or the healthy nonasthmatic adolescents as a result of the exposures. As a result, the study was repeated with the addition of ten minutes of exercise to the 30-minute rest exposure period (Phase II). In Phase II, small but significant increases in total respiratory resistance to all test atmospheres were seen after exposure at 0.12 ppm during exercise in both healthy and asthmatic adolescents. However, the increase in resistance between the groups of subjects was not statistically different. On the basis of these results, Phase III was conducted at higher concentrations of the pollutants (0.18 ppm). In Phase III, statistically significant changes were seen in average total respiratory resistance values in both healthy and asthmatic adolescents exposed to 0.18 ppm ozone while exercising. Again, the difference between the groups was not significant. Small decreases in average forced expiratory volume were found in healthy subjects exposed to ozone and filtered air. After exposure to nitrogen dioxide there was a 3 percent decrease in the forced expiratory volume in one second in asthmatic subjects. This change was not significant. It is concluded that there were no differences in pulmonary function responses between asymptomatic, allergic asthmatic adolescents and healthy adolescents exposed to either ozone or nitrogen dioxide under the conditions of these studies. However, an increase in total respiratory resistance was observed in both asthmatic and healthy adolescent subjects after their exercise exposure to 0.18 ppm ozone.(ABSTRACT TRUNCATED AT 400 WORDS)
该项目的目的是研究特征明确的健康青少年群体与哮喘青少年群体在接近环境浓度的臭氧和二氧化氮环境中，对这两种污染物的敏感性是否存在差异。该项目分为三个阶段。在每个阶段，10名健康青少年和10名哮喘青少年通过咬嘴在至少相隔一周的不同日期分别暴露于三种不同的环境（过滤空气、0.12 ppm或0.18 ppm的臭氧和二氧化氮）中。在第一阶段，休息状态下的受试者以0.12 ppm的浓度吸入测试环境气体，每次30分钟，共两次。在暴露前、暴露期间和暴露后测量以下肺功能值：峰值流量、总呼吸阻力、功能残气量时的胸腔气体容积、呼出肺活量50%和75%时的最大流量（分别在室内空气和氦氧混合气条件下进行）以及一秒用力呼气量。暴露后，哮喘青少年和健康非哮喘青少年的肺功能均未出现持续改变。因此，在30分钟的休息暴露期基础上增加10分钟运动，重复该研究（第二阶段）。在第二阶段，健康青少年和哮喘青少年在运动时暴露于0.12 ppm的测试环境气体后，总呼吸阻力均出现了虽小但显著的增加。然而，两组受试者之间阻力的增加在统计学上并无差异。基于这些结果，在更高的污染物浓度（0.18 ppm）下进行了第三阶段研究。在第三阶段，健康青少年和哮喘青少年在运动时暴露于0.18 ppm臭氧后，平均总呼吸阻力值出现了统计学上的显著变化。同样，两组之间的差异并不显著。暴露于臭氧和过滤空气的健康受试者一秒用力呼气量出现了小幅下降。哮喘受试者暴露于二氧化氮后，一秒用力呼气量下降了３%。这一变化并不显著。得出的结论是，在这些研究条件下，无症状的过敏性哮喘青少年和暴露于臭氧或二氧化氮的健康青少年在肺功能反应方面没有差异。然而，哮喘青少年和健康青少年在运动后暴露于0.18 ppm臭氧时，总呼吸阻力均出现了增加。（摘要截选至400字）
