Tagged: trees

More Trees in Urban Spaces Linked to Less Childhood Asthma

A recent post from The Nature of Cities discusses a case study in Cities and Biodiversity Outlook: Action and Policy, 2012. The study reports that increasing trends in childhood asthma rates are correlated with the density of urban street trees. The report says:

“Rates of childhood asthma in the USA increased by 50 percent between 1980 and 2000, with the highest rates reported in poor urban communities. In New York City, where asthma is the leading cause of hospitalization among children under age 15, researchers at Columbia University studied the correlation between numbers of trees on residential streets and incidences of childhood asthma. They found that as the number of trees rose, the prevalence of childhood asthma tended to fall, even after data were adjusted for sociodemographics, population density, and proximity to pollution sources. How might trees reduce the risk for asthma? One explanation is that they help remove pollutants from the air. Another is that trees may be more abundant in neighborhoods that are well maintained in other ways, leading to lower exposure to allergens that trigger asthma. Yet another is that leafy neighborhoods encourage children to play outdoors, where they are exposed to microorganisms that help their immune systems develop properly. Further studies will provide a clearer picture of whether street trees really do make for healthier children. New York City is currently in the midst of planting a million new trees by 2017.”