Association between residential green space and development of allergic rhinitis up to 12 years of age: a population-based birth cohort study

Abstract

Background: Exposure to residential green spaces has been reported to have a positive impact on both physical and mental health as well as on wellbeing. However, evidence on potential association between urban green spaces and development of allergic rhinitis is limited and inconsistent.

Aim: We aimed to evaluate potential association between early-life exposure to green spaces in a cold climate and development of allergic rhinitis up to 12 years of age.

Methods: A longitudinal study was performed consisting of 2330 participants from the Espoo Cohort (1991-2011), which included originally 2568 children delivered between 1984 and 1990 in Espoo, Finland. Green space was assessed using the mean Normalized Difference Vegetation Index (NDVI) within 300 m of the participant's residence during pregnancy and the first 2 years after birth. Potential associations were estimated applying Poisson regression and expressed as risk ratios (RRs) and 95% confidence intervals (95% CI).

Results: Living in neighborhoods surrounded by more vegetation during the first 2 years after birth was associated with a significantly lower risk of allergic rhinitis up to 12 years of age [RR (95% CI) = 0.26 (0.08; 0.86)]. Although no significant association was found between exposure to NDVI during pregnancy and allergic rhinitis, a trend was observed between higher exposure to NDVI and a lower risk of childhood allergic rhinitis [RR (95% CI) = 0.47 (0.09; 2.22)].

Conclusions: Our results suggest that early-life exposure to green spaces in a cold climate may have a protective effect on the development of allergic rhinitis among children up to 12 years of age.