School of Psychology and Public Health, La Trobe University, Melbourne, Vic., Australia.
School of Medicine, Western Sydney University, Sydney, NSW, Australia.
Clin Exp Allergy. 2018 Nov;48(11):1421-1428. doi: 10.1111/cea.13225. Epub 2018 Aug 10.
Pollen is an important aeroallergen that triggers asthma exacerbations in children, but we know little about the impact of different pollen types in cities with varying climatic conditions and pollen seasons.
We aimed to assess the role of ambient level of different types of pollen on a large time series of child and adolescent asthma hospitalizations in Sydney, Australia.
Childhood asthma hospitalization and the daily ambient pollen concentrations of different species were collected in South-West Sydney. With a bidirectional case-crossover design, we fitted conditional logistic regression models to measure the associations between instantaneous and up to 3 days lagged effects of pollen concentrations on asthma hospitalizations after controlling for potential confounders and testing for interactions.
A total of 2098 children, more boys (59.7%) and 2-5 years old (62.6%), were hospitalized due to asthma. The geometric mean concentration of Cupressus, 7.88 [5.02] grains/m , was the highest during the study period. The increase from 75th to 90th percentile of grass (OR = 1.037, 95% CI 1.005-1.070), weed other than Plantago species (OR = 1.053, 95% CI 1.009-1.098) and unclassified pollen (OR = 1.034, 95% CI 1.010-1.058) were significantly associated with the odds of asthma hospitalizations. Boys were at greater risk of asthma exacerbations associated with grass (OR = 1.046, 95% CI 1.003-1.090) and unclassified pollen (OR = 1.041, 95% CI 1.010-1.073). There was evidence of effect modification by age groups for Cupressus, conifer, total tree and total pollen.
Although boys are more vulnerable to grass pollen, weed, and other pollen are also important triggers of asthma exacerbations in all children and adolescents. These findings are important for urban green space planning and the development of pollen monitoring systems for families with children at risk of asthma exacerbations during peak pollen seasons.
花粉是引发儿童哮喘发作的重要气传过敏原，但我们对于不同气候条件和花粉季节的城市中不同花粉类型的影响知之甚少。
我们旨在评估大气中不同类型花粉水平对澳大利亚悉尼大量儿童和青少年哮喘住院时间序列的影响。
在西南悉尼收集儿童哮喘住院和不同物种的每日环境花粉浓度。采用双向病例交叉设计，我们拟合条件逻辑回归模型，以衡量花粉浓度对哮喘住院的即时和最多 3 天滞后影响与潜在混杂因素的关系，并检验交互作用。
共有 2098 名儿童（59.7%为男孩，62.6%为 2-5 岁）因哮喘住院。研究期间，柏科花粉的几何平均浓度最高，为 7.88[5.02]粒/m³。草（OR=1.037，95%CI 1.005-1.070）、非车前草属杂草（OR=1.053，95%CI 1.009-1.098）和未分类花粉（OR=1.034，95%CI 1.010-1.058）的第 75 百分位数至第 90 百分位数的增加与哮喘住院的几率显著相关。男孩患哮喘的风险更高，与草（OR=1.046，95%CI 1.003-1.090）和未分类花粉（OR=1.041，95%CI 1.010-1.073）相关。柏树、针叶树、总树和总花粉的影响存在年龄组的修饰作用。
尽管男孩更容易受到草花粉的影响，但杂草和其他花粉也是所有儿童和青少年哮喘恶化的重要触发因素。这些发现对于城市绿地规划和花粉监测系统的开发很重要，以便在花粉高峰期为有哮喘恶化风险的家庭提供服务。
