Association of multiple environmental exposures with rhinitis and asthma symptoms in preschool children: Identifying...

The concept "one airway, one disease" for childhood rhinitis and asthma has been challenged in recent years. This study aimed to evaluate associations of environmental exposures with alone and co-morbid symptoms of rhinitis and asthma and identify critical risk factor.

5828 children aged 3-6 years in Shanghai were surveyed in 2019. Rhinitis and wheezing symptoms in the past 12 months were collected using questionnaire. 11 outdoor environment exposure factors were assessed by high-resolution spatial-temporal model based on residences. Logistic regression and random forest were applied to evaluate and rank the association of environmental exposure with rhinitis and wheezing symptoms.

The proportions of children with rhinitis alone, wheezing & rhinitis, and wheezing alone were 37.2 %, 4.6 %, and 2.6 %, respectively. Regression modeling of two exposure factors adjusted for each other showed that PM_1, PM_2.5 and nighttime light(NTL) remained the robust significant associations with rhinitis alone, whereas NO₂ had the robust significant association with wheezing & rhinitis and wheezing alone. Random forest ranking analysis further corroborated the most significant environmental exposure for rhinitis alone was PM₁, and for wheezing symptoms (both wheezing & rhinitis and wheezing alone) was NO₂. Significant additive and multiplicative interactions were examined between indoor dampness and PM₁ exposure on rhinitis alone.

Children's current rhinitis alone was more susceptible to ambient PM₁ and PM_2.5, while asthmatic wheezing symptom, either with or without rhinitis, was more susceptible to NO₂. Co-exposure to indoor dampness and PM₁ exposure had synergistic effects on rhinitis alone.