Researchers calculated the number of days that each of the 196 inner-city children involved in the study suffered from asthma symptoms and worked out the distance between the child's home and the nearest green space.
Kids who lived next to a park averaged five days with symptoms over two weeks. For every 1,000 feet between their home and a park, children had symptoms one extra day.
Strongest effect for older kids
Experts say the research, which is set to be presented Sept. 11 at a European Respiratory Society meeting in Milan, Italy, shows the importance of parks in cities for children’s health.
Lead study author Kelli DePriest, a public health nurse, says the positive effect of living near a park appears to be strongest for children aged six years and older.
This might be because older children “have more freedom to choose where they want to go compared to younger children” and are more likely to go to the park on their own, DePriest said.
"Living in a city environment increases the risk of childhood asthma, and factors associated with city-living -- such as air pollution -- are also known to contribute to high rates of poorly controlled asthma," she said in a news release.
Encourages physical activity
Green spaces may be beneficial to kids with severe asthma because they promote physical activity and help to lower pollution, DePriest explained. Previous studies have suggested that symptoms of childhood asthma can be alleviated by exercise.
"These results are important because they provide further support for the benefits of city parks, and they suggest that the right building policies can improve children's health."
The findings “will also help health care providers to take a more holistic view of their patients by understanding how access to green space might affect health," she added.
DePriest says she hopes to expand upon the study’s findings by analyzing the relationship between children’s asthma symptoms and other forms of green space, such as backyards and gardens.