Clean air cures asthma

A new study by researchers at the University of Exeter has found that people living in polluted urban areas are less likely to be hospitalized with asthma when there are many trees in their neighborhood. A study on the impact of urban greenery on asthma suggests that improvements in respiratory health can be achieved by expanding green space in highly polluted urban areas.
The study identified more than six hundred thousand and fifty severe asthma attacks over a fifteen year period. Emergency hospitalizations were compared across 26,000 city blocks in England. In the most polluted urban areas, trees were particularly associated with fewer asthma exacerbations. In relatively unpolluted urban areas, trees had no such impact. In a typical urban area with high levels of background air pollution, about fifteen microprograms of fine particles (PM2.5) per cubic meter or a nitrogen dioxide concentration of about thirty-three microprograms per cubic meter, an additional three hundred trees per square kilometer were associated with a reduction in asthma exacerbations of about fifty cases per hundred thousand inhabitants over a 15-year study period. The findings could have important public health implications, as tree planting can play a role in reducing exposure to air pollution. Over 5.4 million people receive treatment for asthma in the UK, with an annual medical cost of around £1 billion. 18% of adults report asthma within the previous twelve months, and a quarter of 13-14 year olds report symptoms. Asthma causes over a thousand deaths a year. The study found that trees and green spaces were associated with fewer people hospitalized for asthma. Trees are known to remove air pollutants that can trigger asthma attacks, but in some situations they can also cause localized accumulations of particles, preventing them from being dispersed by wind. Vegetation can also produce allergenic pollen, which aggravates asthma. However, urban vegetation does far more good than harm, the authors say. However, the effects were not the same everywhere. Green spaces and gardens have been associated with reduced asthma hospitalizations at lower pollutant levels, but not in the most polluted urban areas. The opposite was true for trees. It is possible that grass pollen becomes more allergenic when combined with air pollutants, so that the benefits of green space decrease as pollution increases. In contrast, trees can effectively remove pollutants from the air, and this may explain why they seem to be most beneficial when airborne concentrations of harmful substances are high.
The scientists conclude that the impacts of various types of vegetation – green spaces, gardens and thickets of trees – are characterized by both very high and very low levels of air pollution, and are especially important for public health policy and urban planning. It is also known that the interaction between pollen and air pollution, as well as the effects on health and asthma, is very complex, and this study confirms that more research is needed in this area.

event_note March 16, 2022

account_box Kroll

Leave a Reply

Your email address will not be published. Required fields are marked *