哮喘联盟

    先前的研究已经证实空气污染和哮喘加重的关系。但目前对碳元素(EC)的效应及其与温度对儿童哮喘发病增加的联系和在重工业或相对污染较轻的都市地区，这些联系随季节如何变化了解甚少。圣路易斯环保署测定了2001年6月1日至2003年5月31日之间的EC、臭氧(O3),二氧化硫(SO2)及所有氮氧化物(NOx)的含量。获得了圣路易斯27所医院281,763名急诊哮喘患儿的ICD-9信息。以Poisson广义估计方程分析了EC和急诊儿科哮喘患者、季节变化、周末暴露、变态原、其他可加重哮喘的污染物之间的关系，暴露与就诊之间间隔1天。评价了EC与温度、EC与周末比工作日暴露之间的关系。对11-17岁患者，EC与温度之间在夏、冬季存在相互作用效应。在夏季平均季节温度下（华氏温度86.5），EC增加0.10 mug/m3可致11-17岁哮喘急诊患者人数增加9.45% (95%CI = 1.02,1.17)，患病风险随温度升高而增加。在冬季平均季节温度下(华氏温度43.3)，EC增加0.10 mug/m3可致11-17岁哮喘急诊患者人数增加2.80% (95%CI = 1.01-1.05)，患病风险随温度降低而增加。夏季气温最高时和冬季气温最低时，11-17岁青少年中每日哮喘急诊患者人数与EC增加水平相关。

（林江涛 审校）
Mohr LB, et al. J Asthma. 2008 Dec;45(10):936-43.

Influence of season and temperature on the relationship of elemental carbon air pollution to pediatric asthma emergency room visits.

Previous studies have demonstrated an association between air pollution and asthma exacerbation. Less understood is the effect of elemental carbon (EC), and the interaction of EC with temperature, on increases in pediatric asthma emergency department visits and how these relationships change across the seasons in a metropolitan area with several industries and relatively low air pollution. Measurements of EC, ozone (O(3)), sulfur dioxide (SO(2)), and total oxides of nitrogen (NO(x)) were available from the St. Louis EPA Supersite for June 1, 2001 to May 31, 2003. We obtained ICD-9 information on 281,763 pediatric ED visits from 27 hospitals in the St. Louis, MO metropolitan area. The relationship between EC and pediatric asthma ED visits, controlling for season, weekend exposure, allergens, and other pollutants known to exacerbate asthma, was assessed using Poisson generalized estimating equations using a 1-day lag between exposure and ED visit. We evaluated the interaction of EC and temperature and EC and weekend vs. weekday exposure. An interaction effect existed between EC and temperature for 11-17-year-olds during the summer and winter seasons. During the summer, a 0.10 mug/m(3) increase in EC resulted in a 9.45% increase in asthma ED visits among 11-17-year-olds (95%CI = 1.02,1.17) at the median seasonal temperature (86.5 degrees F). This risk increased with increasing temperature. During the winter, a 0.10 mug/m(3) increase in EC resulted in 2.80% increase in asthma ED visits among 11-17-year-olds (95%CI = 1.01,1.05) at the median seasonal temperature (43.3 degrees F). This risk increased with decreasing temperature. Among 11-17-year-olds, daily number of asthma ED visits is associated with increased levels of EC at higher temperatures in the summer and lower temperatures in the winter.