Abstract:
Background
Studies on the association between greenness exposure and allergic rhinitis (AR) in children are mostly conducted in developed countries, and the conclusion is not consistent.
Objective
Using street view data to explore the association between greenness exposure and allergic rhinitis (AR) prevalence in Chinese children.
Methods
A cross-sectional study was conducted among 40868 children aged 2-17 years in three cities of Northeast China from 2012 to 2013, which consisted of 20886 (51.1%) boys and 19982 (48.9%) girls. The information of AR prevalence was obtained through questionnaire. Based on downloaded street view images from Tencent Maps, a green view index (GVI) of green vegetation (trees and grass) within 800 m and 1000 m buffer of the participants' schools was calculated by using artificial intelligence, and it was used as a surrogate of the greenness exposure. A mixed-effect logistic regression model was used to estimate the odds ratio (OR) of AR prevalence in children for per increase of inter-quartile range (IQR) of GVI. In addition, according to ambient PM2.5 concentration, the participants were divided into a low PM2.5 exposure group (≤56.23 μg·m−3) and a high exposure group (>56.23 μg·m−3) to investigate whether PM2.5 was a modifier on the association between GVI and AR.
Results
The average age of the subjects was (10.40±3.68) years and 3 963 (9.7%) subjects reported diagnosed AR. Within 800 m buffer, an IQR increase in GVI for trees (IQR=0.031,OR=0.85, 95%CI: 0.81-0.90) and overall greenness (IQR=0.029, OR=0.86, 95%CI: 0.81-0.90) was associated with lower adjusted odds ratio of AR. The interaction between PM2.5 and GVI was statistically significant (P< 0.1), that is, the negative associations of trees and overall greenness with AR were observed only at low PM2.5 exposure levels. The sensitivity analysis results of GVI within 1000 m buffer was consistent with that within 800 m buffer.
Conclusion
Exposure to green vegetation, especially trees, may be associated with decreased risks of AR in children, and such associations may be more obvious in areas with a low PM2.5concentration.