Berhane Kiros, Chang Chih-Chieh, McConnell Rob, Gauderman W James, Avol Edward, Rapapport Ed, Urman Robert, Lurmann Fred, Gilliland Frank
Department of Preventive Medicine, University of Southern California, Los Angeles, California.
Sonoma Technology Inc, Petaluma, California.
JAMA. 2016 Apr 12;315(14):1491-501. doi: 10.1001/jama.2016.3444.
Childhood bronchitic symptoms are significant public and clinical health problems that produce a substantial burden of disease. Ambient air pollutants are important determinants of bronchitis occurrence.
To determine whether improvements in ambient air quality in Southern California were associated with reductions in bronchitic symptoms in children.
DESIGN, SETTING, AND PARTICIPANTS: A longitudinal study involving 4602 children (age range, 5-18 years) from 3 cohorts was conducted during the 1993-2001, 1996-2004, and 2003-2012 years in 8 Southern California communities. A multilevel logistic model was used to estimate the association of changes in pollution levels with bronchitic symptoms.
Average concentrations of nitrogen dioxide, ozone, particulate matter with an aerodynamic diameter of less than 10 µm (PM10) and less than 2.5 µm (PM2.5).
Annual age-specific prevalence of bronchitic symptoms during the previous 12 months based on the parent's or child's report of a daily cough for 3 months in a row, congestion or phlegm other than when accompanied by a cold, or bronchitis.
The 3 cohorts included a total of 4602 children (mean age at baseline, 8.0 years; 2268 girls [49.3%]; 2081 Hispanic white [45.2%]) who had data from 2 or more annual questionnaires. Among these children, 892 (19.4%) had asthma at age 10 years. For nitrogen dioxide, the odds ratio (OR) for bronchitic symptoms among children with asthma at age 10 years was 0.79 (95% CI, 0.67-0.94) for a median reduction of 4.9 ppb, with absolute decrease in prevalence of 10.1%. For ozone, the OR was 0.66 (95% CI, 0.50-0.86) for a median reduction of 3.6 ppb, with an absolute decrease in prevalence of 16.3%. For PM10, the OR was 0.61 (95% CI, 0.48-0.78) for a median reduction of 5.8 µg/m3, with an absolute decrease in prevalence of 18.7%. For PM2.5, the OR was 0.68 (95% CI, 0.53-0.86) for a median reduction of 6.8 µg/m3, with absolute decrease in prevalence of 15.4%. Among children without asthma (n = 3710), the ORs were 0.84 (95% CI, 0.76-0.92) for nitrogen dioxide; 0.85 (95% CI, 0.74-0.97) for ozone, 0.80 (95% CI, 0.70-0.92) for PM10, and 0.79 (95% CI, 0.69-0.91) for PM2.5; with absolute decrease in prevalence of 1.8% for nitrogen dioxide, 1.7% for ozone, 2.2% for PM10, and 2.3% for PM2.5. The associations were similar or slightly stronger at age 15 years.
Decreases in ambient pollution levels were associated with statistically significant decreases in bronchitic symptoms in children. Although the study design does not establish causality, the findings support potential benefit of air pollution reduction on asthma control.
儿童支气管炎症状是重大的公共卫生和临床健康问题，会产生巨大的疾病负担。环境空气污染物是支气管炎发生的重要决定因素。
确定南加州环境空气质量的改善是否与儿童支气管炎症状的减少相关。
设计、地点和参与者：在1993 - 2001年、1996 - 2004年和2003 - 2012年期间，对来自南加州8个社区3个队列的4602名儿童（年龄范围5 - 18岁）进行了一项纵向研究。使用多水平逻辑模型来估计污染水平变化与支气管炎症状之间的关联。
二氧化氮、臭氧、空气动力学直径小于10微米（PM10）和小于2.5微米（PM2.5）的颗粒物的平均浓度。
根据父母或儿童报告的连续3个月每日咳嗽、除感冒时的鼻塞或咳痰或支气管炎情况，得出前12个月特定年龄的支气管炎症状年患病率。
这3个队列共有4602名儿童（基线时平均年龄8.0岁；2268名女孩[49.3%]；2081名西班牙裔白人[45.2%]），他们有来自2份或更多年度问卷的数据。在这些儿童中，892名（19.4%）在10岁时患有哮喘。对于二氧化氮，10岁哮喘儿童中支气管炎症状的比值比（OR）为0.79（95%置信区间，0.67 - 0.94），中位数降低4.9 ppb，患病率绝对下降10.1%。对于臭氧，OR为0.66（95%置信区间，0.50 - 0.86），中位数降低3.6 ppb，患病率绝对下降16.3%。对于PM10，OR为0.61（95%置信区间，0.48 - 0.78），中位数降低5.8微克/立方米，患病率绝对下降18.7%。对于PM2.5，OR为0.68（95%置信区间，0.53 - 0.86），中位数降低6.8微克/立方米，患病率绝对下降15.4%。在无哮喘儿童（n = 3710）中，二氧化氮的OR为0.84（95%置信区间，0.76 - 0.92）；臭氧为0.85（95%置信区间，0.74 - 0.97），PM10为0.80（95%置信区间，0.70 - 0.92），PM2.5为0.79（95%置信区间，0.69 - 0.91）；二氧化氮患病率绝对下降1.8%，臭氧为1.7%，PM10为2.2%，PM2.5为2.3%。在年龄为15岁时，这些关联相似或略强。
环境污染水平的降低与儿童支气管炎症状在统计学上的显著减少相关。尽管该研究设计未确立因果关系，但研究结果支持减少空气污染对哮喘控制的潜在益处。
