Lei Jian, Sun Qinghua, Chen Renjie, Zhu Yixiang, Zhou Lu, Xue Xiaowei, Fang Jianlong, Du Yanjun, Wang Yanwen, Li Tiantian, Kan Haidong
School of Public Health, Key Lab of Public Health Safety of the Ministry of Education, National Health Commission Key Lab of Health Technology Assessment, Fudan University, Shanghai, China.
Department of Occupational and Environmental Health, Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, China.
JAMA Pediatr. 2025 Feb 1;179(2):122-128. doi: 10.1001/jamapediatrics.2024.5049.
Particulate matter exposure has been linked to impaired respiratory health in children, but the respiratory benefits of air purification have not been fully elucidated.
To assess the respiratory health outcomes among children exposed to multisetting air purification vs sham purification.
DESIGN, SETTING, AND PARTICIPANTS: This cluster randomized, double-blind, crossover trial was conducted among healthy school-aged children (10-12 years) in China from April to December 2021. Data were analyzed from December 2021 to July 2024.
A multisetting (both in classrooms and bedrooms) air purification intervention compared with sham purification in a 2-stage intervention with more than 2 months (76 days) for each period and a washout period (88 days) to estimate the respiratory benefits of air purification.
The primary outcomes were pulmonary function, airway inflammation markers, and metabolites in exhaled breath condensate (EBC) before and after the air purification intervention. Linear mixed-effects models were used to estimate the respiratory benefits of children related to air purification. Differential metabolites in EBC were identified using metabolomics analysis to explore their possible mediation roles.
A total of 79 children (38 male [48%]; mean [SD] age, 10.3 [0.5] years) were included in the statistical analyses. During the study period, the mean (SD) concentration of outdoor fine particulate matter (PM2.5) at the school site was 32.53 (24.06) μg/m3. The time-weighted personal PM2.5 concentration decreased by 45.14% during the true air purification period (mean [SD], 21.49 [8.72] μg/m3) compared with the sham air purification period (mean [SD], 39.17 [14.25] μg/m3). Air purification improved forced expiratory volume in 1 second by 8.04% (95% CI, 2.15%-13.93%), peak expiratory flow by 16.52% (95% CI, 2.76%-30.28%), forced vital capacity (FVC) by 5.73% (95% CI, 0.48%-10.98%), forced expiratory flow at 25% to 75% of FVC by 17.22% (95% CI, 3.78%-30.67%), maximal expiratory flow at 75% of FVC by 14.60% (95% CI, 0.35%-28.85%), maximal expiratory flow at 50% of FVC by 17.86% (95% CI, 3.65%-32.06%), and maximal expiratory flow at 25% of FVC by 18.22% (95% CI, 1.73%-34.70%). Fractional exhaled nitric oxide in the true air purification group decreased by 22.38% (95% CI, 2.27%-42.48%). Several metabolites in EBC (eg, L-tyrosine and β-alanine) were identified to mediate the effect of air purification on respiratory health.
This randomized clinical trial provides robust and holistic evidence that indoor air purification notably improved pulmonary health in children, highlighting the importance of intensified indoor air purification in regions with high air pollution levels.
ClinicalTrials.gov Identifier: NCT04835337.
接触颗粒物与儿童呼吸系统健康受损有关，但空气净化对呼吸系统的益处尚未完全阐明。
评估接触多场景空气净化与假净化的儿童的呼吸系统健康结局。
设计、地点和参与者：这项整群随机、双盲、交叉试验于2021年4月至12月在中国健康学龄儿童（10 - 12岁）中进行。数据于2021年12月至2024年7月进行分析。
一种多场景（包括教室和卧室）空气净化干预与假净化进行比较，采用两阶段干预，每个阶段超过2个月（76天），并有一个洗脱期（88天），以评估空气净化对呼吸系统的益处。
主要结局是空气净化干预前后的肺功能、气道炎症标志物和呼出气冷凝物（EBC）中的代谢物。使用线性混合效应模型来估计与空气净化相关的儿童呼吸系统益处。通过代谢组学分析确定EBC中的差异代谢物，以探索它们可能的中介作用。
共有79名儿童（38名男性[48%]；平均[标准差]年龄，10.3[0.5]岁）纳入统计分析。在研究期间，学校场地室外细颗粒物（PM2.5）的平均（标准差）浓度为32.53（24.06）μg/m³。与假空气净化期（平均[标准差]，39.17[14.25]μg/m³）相比，在真正空气净化期个人PM2.5的时间加权浓度降低了45.14%。空气净化使1秒用力呼气容积提高了8.04%（95%置信区间，2.15% - 13.93%），呼气峰值流速提高了16.52%（95%置信区间，2.76% - 30.28%），用力肺活量（FVC）提高了5.73%（95%置信区间，0.48% - 10.98%），FVC的25%至75%时的用力呼气流量提高了17.22%（95%置信区间，3.78% - 30.67%），FVC的75%时的最大呼气流量提高了14.60%（95%置信区间，0.35% - 28.85%），FVC的50%时的最大呼气流量提高了17.86%（95%置信区间，3.65% - 32.06%）以及FVC的25%时的最大呼气流量提高了18.22%（95%置信区间，1.73% - 34.70%）。真正空气净化组的呼出一氧化氮分数降低了22.38%（95%置信区间，2.27% - 42.48%）。EBC中的几种代谢物（如L - 酪氨酸和β - 丙氨酸）被确定为介导空气净化对呼吸系统健康的影响。
这项随机临床试验提供了有力且全面的证据，表明室内空气净化显著改善了儿童的肺部健康，凸显了在空气污染水平高的地区加强室内空气净化的重要性。
ClinicalTrials.gov标识符：NCT04835337。
