Influence of residential location on asthma symptoms in children: A cross-sectional study in Shanghai, China

Introduction: Rapid industrialization and environmental and lifestyle modifications in China have led to the prevalence of asthma in children showing an increasing trend. However, few studies have assessed the influence of residential geographic location on asthma symptoms in this population. We aimed to explore the influence of residential location on asthma symptoms of children in Shanghai, China.Methods: This cross-sectional study included 114 children with physician-diagnosed asthma. The inclusion criteria included an age <18 years and reported wheezing or asthma medication use over the previous 12 months. We excluded children with other respiratory diseases (e.g., pneumonia and laryngeal edema); severe diseases, disabilities, and mental illnesses; or undiagnosed asthma (with symptoms suggestive of asthma, yet having not been diagnosed with asthma by a physician). We evaluated asthma symptoms by assessing the number of asthma exacerbations in the previous 12 months, number of maximum symptom days, spirometry outcomes, respiratory resistance at 5 Hz, and fractional exhaled nitric oxide. Spatial analysis techniques of geographic information systems were used to assess the distance from the residence to major roadways.Results: Approximately 66.7% of children reside in close proximity to urban expressways. The number of asthma exacerbations in the past 12 months increased if the children lived close to a national highway. Asthma symptom days was high in children living in Jiading District. Residential location was not significantly associated with spirometry outcomes, total specific airway resistance, and fractional exhaled nitric oxide.Conclusions: Residential location was associated with more severe asthma symptoms. To better prevent and control asthma symptom exacerbations, the construction of physical barriers around high-risk roads and areas, avoidance of smoking exposure from neighbors in the same building, and weight control are potential strategies; older children should be seriously considered. The traffic volume and flow effects should be further explored.