A new study says that children who live near tree-lined streets have a reduced risk of developing asthma.
Researchers indicated that children who live in streets with trees running parallel have lower rates of asthma, reports British Medical Journal.
The findings of the research are based on rates of asthma among kids aged between 4 to 5 years and hospital admissions for the disease in children up to 15 years of age, from 42 health service districts of New York City, USA.
Between 1980 and 2000, the rates of childhood asthma in US rocketed to almost 50 percent, with high rates mainly in poor urban communities. Particularly in New York City, this respiratory disorder is the major cause for children under 15 to get admitted to hospitals.
The researchers then compared the medical data with city data depending on the number of trees in each area, sources of pollution, racial and ethnic make-up, and population density.
An average of 613 street trees per square kilometre and almost 9 percent of kids were found to have asthma in the City. Almost a one-fourth decrease in asthma rates in the same age group was observed for every standard deviation increase in tree density, i.e. 343 trees per square kilometre.
A similar pattern was observed even when the researchers considered all the factors likely to influence the results, like sources of pollution, levels of affluence, and population density.
However, when they took other governing factors into account, they found that tree density did not influence admissions to hospital for asthma among older children.
The authors warned that the results do not indicate that the number of trees in any city is directly related to asthma rates among individuals.
In fact, the authors have said that the trees may eventually help in limiting the asthma rates by pushing children towards playing outdoors more or by improving air quality.
Besides, they added that New York City is looking forward to plant 1 million extra trees by 2017, which may offer an ultimate chance to know the exact influence of tree density on asthma,
The study is published ahead of print in the Journal of Epidemiology and Community Health.