哮喘联盟

   摘要
   背景：众所周知，空气污染物可使哮喘进一步加重，但是它与儿童新发哮喘之间的关系尚不明了。
   目的：本研究旨在评估儿童哮喘发病与出生时和随时间推移室外空气污染物暴露之间的关系。
   方法：本研究为开放性队列研究，纳入对象来源于医疗管理数据库中出生于加拿大魁北克省的儿童。新发哮喘的定义是为期两年内出院诊断为哮喘或者经两名医生均诊断为哮喘。估算1999-2010年出生的所有儿童住处每年的臭氧水平(O3)，以及1996-2006年出生于蒙特利尔岛的儿童住处的二氧化氮(NO2)水平。PM2.5浓度则通过10平方公里分辨率的卫星计算得出，并覆盖全省居住区域(1996-2011)。运用Cox模型评估出生时及随时间推移污染物暴露的风险比(HRs)。并对二手烟暴露进行间接校正。
   结果：本研究跟踪观察了1,183,865例儿童（7,752,083 病人-年），其中162,752例患有哮喘。对性别、物质与社会剥夺校正后，出生时NO2、O3、PM2.5暴露的四分位数间距分别增加5.45 ppb、3.22 ppb、6.50 μg/m3，则HR值分别为1.04 (95% CI: 1.02-1.05)、1.11 (95% CI: 1.10-1.12) 及1.31 (95% CI: 1.28-1.33)。运用Cox模型计算随时间推移O3和PM2.5对哮喘发病的影响，结果与出生时类似，但是NO2的影响略大(HR = 1.07; 95% CI: 1.05-1.09)。
   结论：儿童哮喘的发病与居住地PM2.5、O3 和NO2暴露有关。
 

（杨冬 审校）
Environ Health Perspect. 2016 Jan 5. [Epub ahead of print]


 

Childhood Exposure to Ambient Air Pollutants and the Onset of Asthma: An Administrative Cohort Study in Québec.
 

Tétreault LF1,2, Doucet M, Gamache P, Fournier M, Brand A, Kosatsky T, Smargiassi A.
 

Abstract
BACKGROUND:While it is well established that air pollutants can exacerbate asthma, the link with new asthma onset in children is less clear.
OBJECTIVE:We assessed the association between the onset of childhood asthma with both time of birth and time-varying exposures to outdoor air pollutants.
METHOD:An open cohort of children born in the province of Québec, Canada was created using linked medico-administrative databases. New cases of asthma were defined as one hospital discharge with a diagnosis of asthma or two physician claims for asthma within a two year period. Annual ozone levels (O3) were estimated at the child's residence for all births 1999-2010, and nitrogen dioxide (NO2) levels during 1996-2006 were estimated for births on the Montreal Island. Satellite based concentrations of fine particles (PM2.5) were estimated at a 10 km by 10 km resolution and assigned to residential postal codes throughout the province (1996-2011). Hazard ratios (HRs) were assessed with Cox models for the exposure at the birth address and for the time-dependent exposure. We performed an indirect adjustment for second hand smoke (SHS).
RESULTS:We followed 1,183,865 children (7,752,083 person-years) of whom 162,752 became asthmatic. After controlling for sex, material and social deprivation, HRs for an interquartile range increase in exposure at the birth address to NO2 (5.45 ppb), O3 (3.22 ppb), and PM2.5 (6.50 μg/m3) were 1.04 (CI 95% 1.02,1.05), 1.11 (CI 95% 1.10,1.12) and 1.31 (CI 95% 1.28,1.33), respectively. Effects of O3 and PM2.5 estimated with time-varying Cox models were similar to those estimated using exposure at birth, while the effect of NO2 was slightly stronger (HR = 1.07; 95% CI: 1.05, 1.09).
CONCLUSIONS:Asthma onset in children appears to be associated with residential exposure to PM2.5, O3 and NO2.
 

Environ Health Perspect. 2016 Jan 5. [Epub ahead of print]