Department of Epidemiology and Healthcare Research, Kyoto University School of Public Health, Yoshidakonoe-cho, Sakyo-ku, Kyoto, Japan.
Environ Health. 2011 Mar 10;10:15. doi: 10.1186/1476-069X-10-15.
Little information is available on the possible association between hourly short-term air pollution and peak expiratory flow (PEF) in asthmatic children.
PEF was measured twice daily, from October through December, 2000, in 17 children aged 8 to 15 years hospitalized with severe asthma. A total of 1198 PEF measurements were made at 7 a.m. and 1175 at 7 p.m. Measurements were conducted immediately prior to medication under the guidance of trained nurses. PEF changes were estimated in 10-μg/m3 increments of particulate matter with a 50% cut-off aerodynamic diameter of ≤2.5 μm (PM2.5), with adjustment for sex, age, height, and temperature. Lagged-hour exposures of up to 24 hours were examined.
Increased 24-hour mean concentration of PM2.5 was associated with a decrease in both morning and evening PEF (-3.0 l/minute; 95%CI: -4.6, -1.4 and -4.4 l/minute; 95%CI: -7.1, -1.7, respectively). In addition, hourly concentrations of PM2.5 and PEF showed a significant association between some lags of PM2.5 and PEF. Effect size was almost -3 l/minute in both morning and evening PEF for an hourly PM2.5 concentration of 10 μg/m3 in several lags. Even after adjustment for other air pollutants, some of the significant associations with PEF remained.
Among hospitalized children with severe asthma, increased hourly concentration of PM2.5 was associated with a decrease in PEF.
关于小时短期空气污染与哮喘儿童呼气峰值流量（PEF）之间可能存在的关联，相关信息较少。
2000 年 10 月至 12 月，对 17 名年龄在 8 至 15 岁因严重哮喘住院的儿童，每日早晚两次测量 PEF。每天早上 7 点测量 1198 次，晚上 7 点测量 1175 次。在经过培训的护士的指导下，每次测量前均服药。根据性别、年龄、身高和温度，对颗粒物（PM2.5）浓度每增加 10μg/m3（PM2.5 空气动力学直径为 50%的截止值≤2.5μm）的 PEF 变化进行了估计。还检查了长达 24 小时的滞后小时暴露。
24 小时平均 PM2.5 浓度升高与早晚 PEF 降低均有关（分别为-3.0 l/min；95%CI：-4.6，-1.4 和-4.4 l/min；95%CI：-7.1，-1.7）。此外，PM2.5 和 PEF 的小时浓度之间也显示出 PM2.5 和 PEF 之间一些滞后的显著关联。在几个滞后时段中，PM2.5 浓度每增加 10μg/m3，早晚 PEF 的效应大小几乎为-3 l/min。即使在调整了其他空气污染物后，PEF 仍与一些具有显著相关性的污染物有关联。
在患有严重哮喘的住院儿童中，PM2.5 小时浓度的增加与 PEF 的降低有关。
