Tree cover reduces risks of childhood asthma
a recent study has found that children residing in areas with more trees are less likely to suffer from asthma. Trees may prevent asthma because they bring about a difference in the local air quality, say Colombia University researchers. The study comes in the backdrop of a rising number of asthma cases among children in the us. Between 1980 and 2000, there was a 50 per cent jump in the number of asthma cases in children.
The situation is particularly true for children living in poor urban communities. "Changes to the indoor and outdoor environments in which children are growing up could be increasing their risk of developing asthma,' says Gina Lovasi and lead author of the study. Other trends such as lack of exercise and gaining weight more rapidly could also contribute to the increasing prevalence of asthma, she adds.
For the study, the researchers obtained data of asthma cases from the records of the New York City Department of Health. They also collated data on population density and socio-demographic characteristics. Proximity of residential areas to sources of pollution such as power plants was also considered. They found that for every increase of 343 trees per square km, there was a 29 per cent lower chance of asthma among children aged four to five years old.
The researchers, however, warn that trees are also a source of pollen that can aggravate allergy-related asthma. "It is important to understand that trees may not actually prevent young children from getting asthma. What we found was simply that young children were less likely to have asthma. Further studies need to confirm this,' said Lovasi.
The study was published online on May 1 in the Journal of Epidemiology and Community Health.