Environmental and Occupational Health Surveillance Program, New Jersey Department of Health, 135 East State Street, P.O. Box 369, Trenton, NJ 08625, USA.
Robert Wood Johnson University Hospital, Center for Environmental Prediction, Rutgers University, 14 College Farm Road Room 243, New Brunswick, NJ 08901, USA.
Environ Res. 2014 Jul;132:421-9. doi: 10.1016/j.envres.2014.03.035. Epub 2014 May 21.
Asthma is one of the most common chronic diseases among school-aged children in the United States. Environmental respiratory irritants exacerbate asthma among children. Understanding the impact of a variety of known and biologically plausible environmental irritants and triggers among children in New Jersey - ozone, fine particulate matter (PM2.5), tree pollen, weed pollen, grass pollen and ragweed - would allow for informed public health interventions.
Time-stratified case-crossover design was used to study the transient impact of ozone, PM2.5 and pollen on the acute onset of pediatric asthma. Daily emergency department visits were obtained for children aged 3-17 years with a primary diagnosis of asthma during the warm season (April through September), 2004-2007 (inclusive). Bi-directional control sampling was used to select two control periods for each case for a total of 65,562 inclusion days. Since the period of exposure prior to emergency department visit may be the most clinically relevant, lag exposures were investigated (same day (lag0), 1, 2, 3, 4, and 5 as well as 3-day and 5-day moving averages). Multivariable conditional logistic regression controlling for holiday, school-in-session indicator, and 3-day moving average for temperature and relative humidity was used to examine the associations. Odds ratios are based on interquartile range (IQR) increases or 10 unit increases when IQR ranges were narrow. Single-pollutant models as well as multipollutant models were examined. Stratification on gender, race, ethnicity and socioeconomic status was explored.
The associations with ozone and PM2.5 were strongest on the same day (lag0) of the emergency department visit (RR IQR=1.05, 95% CI 1.04-1.06) and (RR IQR=1.03, 95% CI 1.02-1.04), respectively, with a decreasing lag effect. Tree and weed pollen were associated with pediatric ED visits; the largest magnitudes of association was with the 5-day average (RR IQR=1.23, 95% CI 1.21-1.25) and (RR 10=1.13, 95% CI 1.12-1.14), respectively. Grass pollen was only minimally associated with the outcome while ragweed had a negative association.
The ambient air pollutant ozone is associated with increases in pediatric emergency department asthma visits during the warm weather season. The different pollen types showed different associations with the outcome. High levels of tree pollen appear to be an important risk factor in asthma exacerbations.
哮喘是美国学龄儿童中最常见的慢性疾病之一。环境呼吸刺激物会使儿童的哮喘恶化。了解新泽西州各种已知和合理的生物环境刺激物和诱因（臭氧、细颗粒物[PM2.5]、树花粉、杂草花粉、草花粉和豚草花粉）对儿童的影响，可以进行明智的公共卫生干预。
采用时间分层病例交叉设计研究臭氧、PM2.5 和花粉对儿科哮喘急性发作的瞬时影响。2004 年至 2007 年（含）期间，获取了 3-17 岁患有哮喘主要诊断的儿童在温暖季节（4 月至 9 月）的每日急诊就诊情况。双向控制采样用于为每个病例选择两个对照期，总计纳入 65562 天。由于急诊就诊前的暴露期可能是最具临床意义的，因此研究了滞后暴露（当天[lag0]、1、2、3、4 以及 5 天和 3 天和 5 天移动平均值）。使用多变量条件逻辑回归控制假期、在校指示以及温度和相对湿度的 3 天移动平均值，以检查相关性。比值比基于四分位距（IQR）增加或 IQR 范围较窄时的 10 个单位增加。检查了单污染物模型和多污染物模型。探索了性别、种族、民族和社会经济地位的分层。
臭氧和 PM2.5 与急诊就诊当天（lag0）的关联最强（RR IQR=1.05，95%CI 1.04-1.06）和（RR IQR=1.03，95%CI 1.02-1.04），滞后效应逐渐减弱。树木花粉和杂草花粉与儿科 ED 就诊相关；与 5 天平均（RR IQR=1.23，95%CI 1.21-1.25）和（RR 10=1.13，95%CI 1.12-1.14）相关的关联幅度最大。草花粉与结果仅有轻微关联，豚草花粉则呈负相关。
在温暖季节，环境空气污染物臭氧与儿科急诊哮喘就诊次数增加有关。不同的花粉类型与结果的关联不同。高水平的树木花粉似乎是哮喘恶化的一个重要危险因素。
