Abstract
Numerous studies have demonstrated that exposure to ambient ozone (O3) could have adverse effects on children’s respiratory health. However, previous studies mainly focused on asthma and wheezing. Evidence for allergic rhinitis and bronchitic symptoms (e.g., persistent cough and phlegm) associated with O3 is limited, and results from existing studies are inconsistent. This study included a total of 59,754 children from the seven northeastern cities study (SNEC), who were aged 2 to 17 years and from 94 kindergarten, elementary and middle schools. Information on doctor-diagnosed allergic rhinitis (AR), persistent cough, and persistent phlegm was collected during 2012–2013 using a standardized questionnaire developed by the American Thoracic Society (ATS). Information for potential confounders was also collected via questionnaire. Individuals’ exposure to ambient ozone (O3) during the four years before the investigation was estimated using a satellite-based random forest model. A higher level of O3 was significantly associated with increased risk of AR and bronchitic symptoms. After controlling for potential confounders, the OR (95% CI) were 1.13 (1.07–1.18), 1.10 (1.06–1.16), and 1.12 (1.05–1.20) for AR, persistent cough, and persistent phlegm, respectively, associated with each interquartile range (IQR) rise in O3 concentration. Interaction analyses showed stronger adverse effects of O3 on AR in children aged 7–17 years than those aged 2–6 years, while the adverse association of O3 with cough was more prominent in females and children aged 7–12 years than in males and children aged 2–6 and 13–17 years. This study showed that long-term exposure to ambient O3 was significantly associated with higher risk of AR and bronchitic symptoms in children, and the association varies across age and gender. Our findings contribute additional evidence for the importance of controlling O3 pollution and protecting children from O3 exposure.
Highlights
Ozone (O3 ) is one of the most serious air pollutants [1,2] that has adverse respiratory and cardiovascular effects [3,4]
We aim to evaluate the association of long-term exposure to ambient O3 with allergic rhinitis (AR)
We examined the associations between exposure to ambient O3 pollution and respiratory health of children in Northeast China
Summary
Ozone (O3 ) is one of the most serious air pollutants [1,2] that has adverse respiratory and cardiovascular effects [3,4]. O3 can reach the distal regions of human lungs due to its low water solubility and may have more adverse effects on lung function than other pollutants [5]. Previous studies suggest that the hazards of O3 include deep penetration, bronchial and bronchiolar injury, and tissue hypoxia [6], which are associated with higher risk of diseases such as allergic rhinitis (AR), and respiratory symptoms such as cough, wheezing, or phlegm, and decreased lung function [7]. The prevalence of allergic diseases in Chinese children has increased dramatically in recent decades. Respiratory health in early life may have lifelong impacts on lung health and life expectancy [12,13]
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