Schelegle Edward S, Morales Christopher A, Walby William F, Marion Susan, Allen Roblee P
Department of Anatomy, Physiology, and Cell Biology, University of California Davis School of Veterinary Medicine, Davis, California 95616, USA.
Am J Respir Crit Care Med. 2009 Aug 1;180(3):265-72. doi: 10.1164/rccm.200809-1484OC. Epub 2009 May 15.
Identification of the minimal ozone (O(3)) concentration and/or dose that induces measurable lung function decrements in humans is considered in the risk assessment leading to establishing an appropriate National Ambient Air Quality Standard for O(3) that protects public health.
To identify and/or predict the minimal mean O(3) concentration that produces a decrement in FEV(1) and symptoms in healthy individuals completing 6.6-hour exposure protocols.
Pulmonary function and subjective symptoms were measured in 31 healthy adults (18-25 yr, male and female, nonsmokers) who completed five 6.6-hour chamber exposures: filtered air and four variable hourly patterns with mean O(3) concentrations of 60, 70, 80, and 87 parts per billion (ppb).
Compared with filtered air, statistically significant decrements in FEV(1) and increases in total subjective symptoms scores (P < 0.05) were measured after exposure to mean concentrations of 70, 80, and 87 ppb O(3). The mean percent change in FEV(1) (+/-standard error) at the end of each protocol was 0.80 +/- 0.90, -2.72 +/- 1.48, -5.34 +/- 1.42, -7.02 +/- 1.60, and -11.42 +/- 2.20% for exposure to filtered air and 60, 70, 80, and 87 ppb O(3), respectively.
Inhalation of 70 ppb O(3) for 6.6 hours, a concentration below the current 8-hour National Ambient Air Quality Standard of 75 ppb, is sufficient to induce statistically significant decrements in FEV(1) in healthy young adults.
在风险评估中，需确定能导致人类肺功能出现可测量下降的最低臭氧（O₃）浓度和/或剂量，这有助于制定适当的国家臭氧环境空气质量标准以保护公众健康。
识别和/或预测在完成6.6小时暴露方案的健康个体中，导致第一秒用力呼气容积（FEV₁）下降和出现症状的最低平均臭氧浓度。
对31名健康成年人（年龄18 - 25岁，男女不限，非吸烟者）进行肺功能和主观症状测量，他们完成了五次6.6小时的舱内暴露：过滤空气以及四种每小时浓度可变的模式，平均臭氧浓度分别为60、70、80和87十亿分比（ppb）。
与过滤空气相比（P < 0.05），暴露于平均浓度为70、80和87 ppb的臭氧后，FEV₁出现了具有统计学意义的下降，总主观症状评分增加。在每个方案结束时，暴露于过滤空气、60、70、80和87 ppb臭氧时，FEV₁的平均变化百分比（±标准误差）分别为0.80 ± 0.90%、 - 2.72 ± 1.48%、 - 5.34 ± 1.42%、 - 7.02 ± 1.60%和 - 11.42 ± 2.20%。
对于健康的年轻人，吸入70 ppb的臭氧6.6小时（该浓度低于当前8小时国家环境空气质量标准75 ppb）足以导致FEV₁出现具有统计学意义的下降。
