Residential greenspace and childhood asthma: An intra-city study

Interest in assessing the effects of exposure to greenspace on human health has been increasing due to rapid urbaniza-tion, and rising trends of physical inactivity and air pollution. However, findings on the link between greenspace and child respiratory health, especially asthma, are inconsistent. We investigated the association between greenspace sur-rounding residential addresses and asthma in children. A city-wide cross-sectional study was conducted, involving 16,605 children aged 3-12 years, in Shanghai, China. Data on asthma symptoms and covariates were collected from validated self-reported questionnaires. Residential greenspace was measured using satellite-derived normalized differ-ence vegetation index (NDVI) and enhanced vegetation index (EVI). Information on ambient temperature and partic-ulate matter with dynamic diameter <1 mu m (PM1) and 2.5 mu m (PM2.5) was also collected from satellite data. Logistic regression models were performed to assess the associations of greenspace exposure with childhood asthma as well as the effect modification by covariates. The prevalence of current asthma in children was 4.8 % in this study. An in-terquartile range increase in mean NDVI from 2016 to 2018 was associated with decreased odds of asthma in 2019 at 500 m, and 250 m resolutions (0.82, 95 % confidence interval (CI): 0.74 to 0.93; and 0.82, 95 % CI: 0.72 to 0.94, re-spectively) after adjustment for covariates. The greenspace-asthma association was modified by ambient temperature and residential area. Sensitivity analyses using various models and EVI exposure showed the robustness of the results.

Automated summary

The interest in assessing the effects of exposure to greenspace on human health, especially asthma in children, has been increasing due to urbanization, physical inactivity, and air pollution. This study conducted a city-wide cross-sectional study in Shanghai, China, involving 16,605 children to investigate the association between residential greenspace and asthma. The study found that an increase in greenspace was associated with a decreased odds of asthma, and the association was modified by ambient temperature and residential area.