Children living in areas with more street trees have lower prevalence of asthma

Poor urban areas in America experience a significantly higher prevalence of childhood asthma. However, little is known regarding the geographical variation in the prevalence of asthma within cities. This study investigated the prevalence of asthma in children in New York City compared with street tree density. Even after adjusting for potentially confounding variables (e.g. proximity to pollution sources), results demonstrated a significant negative association between street tree density and asthma rates. More specifically, an increase of 1 standard deviation in tree density resulted in a 29% decrease in the prevalence of asthma. The study’s findings suggest that street trees may play a role in preventing early childhood asthma. The authors suggest a tree planting initiative to more conclusively determine how street tree density affects the occurrence of asthma.