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Urban Greenness: Inverse Association with Asthma

Ann Allergy Asthma Immunol; 2019 Mar; Eldeirawi, et al

Results of a recent study suggest inverse associations of urban greenness with respiratory outcomes, especially in children exposed to environmental tobacco smoke (ETS). Researchers evaluated based on parent-reported data on 1,915 Mexican American children. They calculated residential surrounding greenness (RSG) using the normalized difference vegetation index based on satellite imagery within buffers of 100, 250, and 500 meters of each child's residence. Multivariable multilevel mixed-effect logistic regression was used to estimate adjusted odds ratios (aORs) for the effect of a 1-interquartile range increase in greenness. They found:

  • In adjusted analyses, a protective effect of greenness within 100 meters was observed for lifetime wheezing (aOR, 0.82).
  • ETS exposure modified the association of RSG with lifetime asthma and current dry cough at night.
  • For all buffer distances, increased greenness was associated with lower odds of lifetime asthma among children with current ETS exposure (100 meters: aOR, 0.43; 250 meters: aOR, 0.39; 500 meters: aOR, 0.48) and lower odds of current dry cough at night among children with perinatal ETS exposure (100 meters: aOR, 0.53; 250 meters: aOR, 0.55; 500 meters: aOR, 0.55).

Eldeirawi K, Kunzweiler C, Zenk S, et al. Associations of urban greenness with asthma and respiratory symptoms in Mexican American children. Ann Allergy Asthma Immunol. 2019;122(3):289–295. doi:10.1016/j.anai.2018.12.009.