哮喘发病率与环境空气污染：住宅交通相关空气污染的影响修饰。

Asthma morbidity and ambient air pollution: effect modification by residential traffic-related air pollution.

机构信息

From the aDepartment of Epidemiology, School of Medicine, University of California, Irvine, Irvine, CA; bProgram in Public Health, College of Health Sciences, University of California, Irvine, Irvine, CA; cDepartment of Statistics, School of Information and Computer Sciences, University of California, Irvine, Irvine, CA; and dDivision of Pulmonary Medicine, Children's Hospital of Orange County, Orange, CA.

出版信息

Epidemiology. 2014 Jan;25(1):48-57. doi: 10.1097/EDE.0000000000000016.

DOI:10.1097/EDE.0000000000000016

PMID:24240657

Abstract

BACKGROUND

Ambient air pollution has been associated with asthma-related hospital admissions and emergency department visits (hospital encounters). We hypothesized that higher individual exposure to residential traffic-related air pollutants would enhance these associations.

METHODS

We studied 11,390 asthma-related hospital encounters among 7492 subjects 0-18 years of age living in Orange County, California. Ambient exposures were measured at regional air monitoring stations. Seasonal average traffic-related exposures (PM2.5, ultrafine particles, NOx, and CO) were estimated near subjects' geocoded residences for 6-month warm and cool seasonal periods, using dispersion models based on local traffic within 500 m radii. Associations were tested in case-crossover conditional logistic regression models adjusted for temperature and humidity. We assessed effect modification by seasonal residential traffic-related air pollution exposures above and below median dispersion-modeled exposures. Secondary analyses considered effect modification by traffic exposures within race/ethnicity and insurance group strata.

RESULTS

Asthma morbidity was positively associated with daily ambient O3 and PM2.5 in warm seasons and with CO, NOx, and PM2.5 in cool seasons. Associations with CO, NOx, and PM2.5 were stronger among subjects living at residences with above-median traffic-related exposures, especially in cool seasons. Secondary analyses showed no consistent differences in association, and 95% confidence intervals were wide, indicating a lack of precision for estimating these highly stratified associations.

CONCLUSIONS

Associations of asthma with ambient air pollution were enhanced among subjects living in homes with high traffic-related air pollution. This may be because of increased susceptibility (greater asthma severity) or increased vulnerability (meteorologic amplification of local vs. correlated ambient exposures).

摘要

背景

环境空气污染与哮喘相关的住院和急诊就诊（医院就诊）有关。我们假设，个体对住宅交通相关空气污染物的暴露水平越高，这些关联就会越强。

方法

我们研究了加利福尼亚州奥兰治县 7492 名 0-18 岁哮喘患者的 11390 例哮喘相关住院就诊情况。在环境监测站测量了环境暴露情况。使用基于 500 米半径内局部交通的扩散模型，估算了每个季节的平均交通相关暴露（PM2.5、超细颗粒、NOx 和 CO），以受试者经地理编码的住所为中心，适用于 6 个月的温暖和凉爽季节。使用基于温度和湿度的病例交叉条件逻辑回归模型调整后，检验了关联。我们评估了季节性住宅交通相关空气污染暴露高于和低于中值分散模型暴露的效应修饰。二次分析考虑了交通暴露在种族/族裔和保险组分层内的效应修饰。

结果

在温暖季节，哮喘发病率与每日环境 O3 和 PM2.5 呈正相关，在凉爽季节与 CO、NOx 和 PM2.5 呈正相关。在居住地交通相关暴露高于中位数的受试者中，CO、NOx 和 PM2.5 的相关性更强，尤其是在凉爽季节。二次分析表明，关联没有一致的差异，95%置信区间较宽，表明这些高度分层关联的估计精度较低。