Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California, USA.
Environ Health Perspect. 2010 Oct;118(10):1497-502. doi: 10.1289/ehp.0901292. Epub 2010 Jun 22.
Although studies have demonstrated that air pollution is associated with exacerbation of asthma symptoms in children with asthma, little is known about the susceptibility of subgroups, particularly those with atopy.
This study was designed to evaluate our a priori hypothesis that identifiable subgroups of asthmatic children are more likely to wheeze with exposure to ambient air pollution.
A cohort of 315 children with asthma, 6-11 years of age, was recruited for longitudinal follow-up in Fresno, California (USA). During the baseline visit, children were administered a respiratory symptom questionnaire and allergen skin-prick test. Three times a year, participants completed 14-day panels during which they answered symptom questions twice daily. Ambient air quality data from a central monitoring station were used to assign exposures to the following pollutants: particulate matter ≤ 2.5 μm in aerodynamic diameter, particulate matter between 2.5 and 10 μm in aerodynamic diameter (PM10-2.5), elemental carbon, nitrogen dioxide (NO2), nitrate, and O3.
For the group as a whole, wheeze was significantly associated with short-term exposures to NO2 [odds ratio (OR) = 1.10 for 8.7-ppb increase; 95% confidence interval (CI), 1.02-1.20] and PM10-2.5 (OR = 1.11 for 14.7-μg/m3 increase; 95% CI, 1.01-1.22). The association with wheeze was stronger for these two pollutants in children who were skin-test positive to cat or common fungi and in boys with mild intermittent asthma.
A pollutant associated with traffic emissions, NO2, and a pollutant with bioactive constituents, PM10-2.5, were associated with increased risk of wheeze in asthmatic children living in Fresno, California. Children with atopy to cat or common fungi and boys with mild intermittent asthma were the subgroups for which we observed the largest associations.
尽管已有研究表明，空气污染与哮喘患儿的哮喘症状恶化有关，但对于亚组人群（尤其是特应性人群）的易感性知之甚少。
本研究旨在验证我们的假设，即可识别的哮喘患儿亚组在接触环境空气污染时更有可能出现喘息。
我们招募了 315 名 6-11 岁的哮喘患儿参加加利福尼亚州弗雷斯诺的纵向随访。在基线访视时，对儿童进行了呼吸症状问卷和过敏原皮肤点刺试验。每年三次，参与者完成 14 天的面板，在此期间他们每天回答两次症状问题。使用来自中心监测站的环境空气质量数据来分配以下污染物的暴露值：空气动力学直径≤2.5μm 的颗粒物、空气动力学直径在 2.5 到 10μm 之间的颗粒物（PM10-2.5）、元素碳、二氧化氮（NO2）、硝酸盐和臭氧。
对于整个组，喘息与短期暴露于 NO2[比值比（OR）=1.10（增加 8.7-ppb）；95%置信区间（CI），1.02-1.20]和 PM10-2.5（OR=1.11（增加 14.7-μg/m3）；95%CI，1.01-1.22]显著相关。对于皮肤试验阳性的猫或常见真菌的儿童和轻度间歇性哮喘的男孩，这两种污染物与喘息的相关性更强。
与交通排放有关的污染物二氧化氮（NO2）和具有生物活性成分的污染物 PM10-2.5 与加利福尼亚州弗雷斯诺居住的哮喘儿童喘息风险增加有关。对猫或常见真菌过敏的儿童和轻度间歇性哮喘的男孩是我们观察到相关性最大的亚组。
