Ozone Exposure and Asthma Attack in Children.

Background: Increasing evidence indicated that ozone (O) exposure could trigger asthma attacks in children. However, the effect of O at low concentrations is uncertain.

Purpose: This study aimed to explore the effects of O exposure at low concentrations on asthma attacks in children.

Methods: A total of 3,475 children with asthma attacks from the First Affiliated Hospital of Xiamen University were available for the analyses. Air pollution data and meteorological data in Xiamen during 2016-2019 were also collected. A case-crossover design and conditional logistic regression models were conducted to evaluate the association between asthma attacks and outdoor air pollution with lag structures (from lag 0 to lag 6) in both single and multi-pollutant models. Furthermore, we estimated the influence of various levels of O exposure on an asthma attack in three groups categorized by maximum daily 8-h sliding average ozone (O-8 h) (O-8 h ≥ 100 μg/m, O-8 h: 80-99 μg/m, O-8 h < 80 μg/m).

Results: For both single-pollutant models and multi-pollutant models, when O-8 h was higher than 80 μg/m, O exposure was increased the risk of acute asthma attacks on each day of lag. The effect of O on children with asthma was significant when O concentration was higher than 100 μg/m.

Conclusion: O concentration above 80 μg/m contributed to an increased risk of asthma attacks in children.