The relationships between neighborhood greenness and respiratory health depends on geographic regionThis study examined the effect of living in green or grey (non-natural built-up infrastructure) urban spaces on incidence of childhood wheezing, asthma, and bronchitis. The study involved 2472 children living in two different biogeographic regions in Spain. The two study areas have distinct climates and vegetation patterns: one (the Euro-Siberian area) with an Atlantic climate and high water availability and the other (the Mediterranean area) with a predominantly dry climate.
Data included parent-report information about their child’s wheezing, asthma, and bronchitis status at two points in time -- at age 1 and age 4. Data on green space exposure included both general outdoor greenness of the living environment and residential proximity to green spaces. Proximity implies access, which surrounding greenness does not. Residential surrounding greyness included industrial, commercial and transport land-use areas.
Overall analysis found no statistically significant associations between exposure to residential surrounding greenness, residential proximity to green spaces and residential surrounding greyness in relation to any of the respiratory or allergy-related health outcomes investigated. However, when analyzed by region, this research found associations between children’s respiratory health and green space exposure. Higher residential surrounding greenness and proximity to green spaces were associated with a lower risk of wheezing up to the age of 4 years in the Euro-Siberian region. Exposure to moderate (but not higher) residential surrounding greenness was associated with an increased risk for asthma among children growing up in this region. Higher residential surrounding greenness was not associated with a lower risk of wheezing in the Mediterranean region. Residential proximity to green spaces also lowered the risk of doctor-diagnosed bronchitis among children in the Mediterranean region. For children in the Euro-Siberian region, higher residential surrounding greenness was linked with decreased bronchitis after adjusting for air pollution exposure. Children growing up in the Mediterranean region with higher exposure to residential surrounding greyness had an increased risk of both bronchitis and wheezing.
These findings suggest that living near green spaces may reduce or increase the risk of childhood respiratory ailments, depending on geographic region. Various hypotheses were offered for this effect, however, the authors indicated the need for more research focusing on region-specific characteristics at a finer scale.
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