University Michigan, Ann Arbor, Michigan, USA.
Occupational and Environmental Health, University of KwaZulu-Natal, Durban, South Africa
Thorax. 2019 Nov;74(11):1055-1062. doi: 10.1136/thoraxjnl-2017-211458. Epub 2019 Sep 18.
Acute pollutant-related lung function changes among children varies across pollutants and lag periods. We examined whether short-term air pollutant fluctuations were related to daily lung function among a panel of children and whether these effects are modified by airway hyperresponsiveness, location and asthma severity.
Students from randomly selected grade 4 classrooms at seven primary schools in Durban, participated, together with asthmatic children from grades 3-6 (n=423). The schools were from high pollutant exposed communities (south) and compared with schools from communities with lower levels of pollution (north), with similar socioeconomic profiles. Interviews, spirometry and methacholine challenge testing were conducted. Bihourly lung function measurements were performed over a 3-week period in four phases. During all schooldays, students blew into their personal digital monitors every 1.5-2 hours. Nitrogen dioxide (NO), nitrogen oxide (NO), sulphur dioxide and particulate matter (<10 μm diameter) (PM) were measured at each school. Generalised estimating equations assessed lag effects, using single-pollutant (single or distributed lags) models.
FEV declines ranged from 13 to 18 mL per unit increase in IQR for NO and 14-23 mL for NO. Among the 5-day average models, a 20 mL and 30 mL greater drop in FEV per IQR for NO and NO, respectively, among those with airway hyperresponsiveness compared with those without. Effects were seen among those with normal airways.
This first panel study in sub-Saharan Africa, showed significant declines in lung function, in response to NO and NO with effects modified by airway hyperresponsiveness or persistent asthma.
儿童的急性污染物相关肺功能变化因污染物和滞后时间而异。我们研究了短期空气污染物波动是否与儿童的日常肺功能有关，以及这些影响是否因气道高反应性、位置和哮喘严重程度而改变。
来自德班七所小学随机选择的四年级教室的学生，以及来自 3-6 年级的哮喘儿童（n=423）参与了研究。这些学校位于高污染暴露社区（南部），并与污染水平较低的社区（北部）的学校进行了比较，这些社区具有相似的社会经济状况。进行了访谈、肺活量测定和乙酰甲胆碱挑战测试。在四周的四个阶段中，每 1.5-2 小时对学生进行两小时的肺功能测量。在每个学校测量二氧化氮（NO）、氮氧化物（NO）、二氧化硫和粒径小于 10μm 的颗粒物（PM）。使用单污染物（单一或分布滞后）模型，通过广义估计方程评估滞后效应。
FEV 下降范围为 IQR 中每单位增加 13-18mL 的 NO 和 14-23mL 的 NO。在 5 天平均模型中，与无气道高反应性者相比，气道高反应性者的 NO 和 NO 的 IQR 每增加 20 和 30ml，FEV 分别下降 20 和 30ml。在正常气道者中也观察到了这些影响。
这是撒哈拉以南非洲的第一项面板研究，表明肺功能明显下降，与 NO 和 NO 有关，并且气道高反应性或持续性哮喘会改变这些影响。
