大气臭氧短期监测指标与健康年轻人肺功能和气道炎症的关联

目的 探讨不同监测指标下,大气臭氧(ozone,O₃)短期暴露与健康年轻人肺功能和气道炎症的关联。方法 采用定组研究设计,招募97名健康年轻大学生为研究对象,于2017年12月至2018年6月对每位研究对象进行3次随访调查,每次随访期间对研究对象的肺功能和呼出气一氧化氮(fractional exhaled nitric oxide,FeNO)进行测量;空气污染物浓度数据由距研究对象居住区最近的北京市环境监测站获得,气象数据来自中国气象数据网。采用线性混合效应模型分析不同监测指标下,大气O₃短期暴露与健康年轻人肺功能和气道炎症的关联。结果 研究期间大气O₃日1 h最大浓度(daily 1-h maximum concentration of O₃,O₃-1 h max)、日最大8 h平均浓度(daily maximum 8-h average concentration of O₃,O₃-8 h max)和24 h平均浓度(24-h average concentration of O₃,O₃-24 h avg)的P₅₀(P₂₅,P₇₅)分别为102.5(76.8,163.0) μg/m³、91.1(68.3,154.3) μg/m³和61.6(36.9,81.7) μg/m³。效应估计结果显示,不同监测指标下,大气O₃与第1秒用力呼气容积(forced expiratory volume in the first second,FEV₁)呈显著负相关,与FeNO呈显著正相关。O₃-1 h max的6 d滑动平均值每增加一个四分位数间距(interquartile range,IQR=71.5 μg/m³)与FEV₁降低 6.2%(95%CI: -11.8%,-0.5%)和FeNO升高63.3%(95%CI: 13.8%,134.3%)有关。O₃-8 h max的7 d滑动平均值每增加一个四分位数间距(IQR=62.0 μg/m³)与FEV₁降低6.2%(95%CI: -11.6%,-0.7%)和FeNO升高75.5%(95%CI: 19.3,158.0%)有关。O₃-24 h avg的5 d滑动平均值每增加一个四分位数间距(IQR=32.9 μg/m³)与FEV₁降低3.7%(95%CI: -7.1%,-0.2%)和FeNO升高25.3%(95%CI: 3.6%,51.6%)有关。没有观察到不同监测指标下O₃与最大呼气流量(peak expiratory flow,PEF)变化的显著关联。 结论 大气O₃的短期暴露与健康年轻人的肺功能降低和气道炎症增加有关,且日1 h最大浓度指标更能灵敏反映O₃的呼吸效应。

Monitoring metrics for short-term exposure to ambient ozone and pulmonary function and airway inflammation in healthy young adults

Objective: To assess the associations of different monitoring metrics for short-term exposure to ambient ozone (O₃) with pulmonary function and airway inflammation in healthy young adults.Methods: A total of 97 healthy young college students were recruited and followed in a panel study conducted from December 2017 to June 2018. Each participant underwent 3 follow-up visits, and lung function and fractional exhaled nitric oxide (FeNO) were measured at each visit. Ambient air pollutant concentrations were obtained from the environment monitoring station of Beijing closest to the participant residences, and meteorological data were collected from China Meteorological Data Service Center. Linear mixed-effect models were applied to assess the associations between different monitoring metrics for ambient O₃ short-term exposure with pulmonary function or airway inflammation in the healthy young adults.Results: During the study period, the P₅₀ (P₂₅, P₇₅) values for ambient O₃ concentration expressed as daily 1-hour maximum (O₃-1 h max), daily maximum 8-hour average (O₃-8 h max) and 24-hour average (O₃-24 h avg) were 102.5 (76.8, 163.0) μg/m³, 91.1 (68.3, 154.3) μg/m³ and 61.6 (36.9, 81.7) μg/m³, respectively. The different monitoring metrics for short-term exposure to ambient O₃ were significantly associated with reduced forced expiratory volume in the first second (FEV₁) and increased FeNO. An interquartile range (IQR) increase in 6-d moving average of O₃-1 h max (IQR=71.5 μg/m³) was associated with a 6.2% (95%CI: -11.8%, -0.5%) decrease in FEV₁ and a 63.3% (95%CI: 13.8%, 134.3%) increase in FeNO. An IQR increase in 7-d moving average of O₃-8 h max (IQR=62.0 μg/m³) was associated with a 6.2% (95%CI: -11.6%, -0.7%) decrease in FEV₁and a 75.5% (95%CI: 19.3%, 158.0%) increase in FeNO. An IQR increase in 5-d moving average of O₃-24 h avg (IQR=32.9 μg/m³) was associated with a 3.7% (95%CI: -7.1%, -0.2%) decrease in FEV₁and a 25.3% (95%CI: 3.6%, 51.6%) increase in FeNO. There was no significant association between the three monitoring metrics for O₃ exposure and peak expiratory flow (PEF).Conclusion: Short-term exposure to ambient O₃ was associated with decreased lung function and increased airway inflammation among the healthy young adults, and daily 1-hour maximum was more sensitively to the respiratory effects of O₃.