WEDNESDAY, April 30 (HealthDay News) -- Young children who live
in neighborhoods with lots of trees have lower rates of asthma than
children who reside in areas with fewer trees, a new study
finds.
Researchers looked at asthma rates among children aged 4 to 5,
and asthma-related hospital admissions for children up to age 15,
in 42 service districts of New York City. Asthma is the leading
cause of hospital admission among children aged 15 and younger in
the city.
The researchers compared the medical data to information about
the number of trees in each of the districts, along with sources of
pollution, population density, and racial and ethnic
composition.
Nine percent of the young children in the study had asthma, and
the city had an average of 613 trees per square kilometer. Asthma
rates decreased by almost one-quarter for every standard deviation
increase in tree density, equivalent to 343 trees per square
kilometer, the study found. This pattern held true even after the
researchers factored in sources of pollution, socioeconomic status
and population density.
However, there was no association between tree density and
asthma-related admissions to hospital among older children.
The results don't mean that tree density in a neighborhood is
directly related to asthma rates among children, said the
researchers, who added that trees may help reduce asthma rates by
encouraging children to play outdoors more or by improving air
quality.
The study was published online in the
Journal of Epidemiology and Community Health.
The researchers noted that New York City is planning to plant 1
million extra trees by 2017, which could provide an opportunity to
study exactly what impact tree density may have on asthma.
More information
The American Lung Association has more about
childhood asthma.
