A new European study has found that people exposed to several harmful environmental factors at the same time were more likely to develop asthma.
These environmental factors include air pollution, limited access to green space, dense urban development (such as areas covered in concrete), and exposure to artificial light at night.
The study conducted as part of a major EU project known as EXPANSE and was led by researchers from Karolinska Institutet in Sweden.
The team examined data from 14 cohorts across Europe to see how different aspects of the urban environment such as air pollution, city design, and temperature, affect the chances of developing asthma.
Out of over 349,000 people in the study, they found around 7,400 new cases of asthma, from birth to people over 70 years old.
It was seen that adults living in areas with high levels of particulate matter and NO2 had a higher chance of developing asthma but the research also showed that air pollution alone doesn’t tell the whole story.
With the exception of the above example, when environmental exposures were looked at individually, the links to asthma weren’t always strong. However, when other factors were introduced, such as a lack of green space, the links became much clearer.
Both children and adults were found to be more likely to develop asthma if they lived in places with a lot of buildings and very little green space.
When all the environmental factors were combined into a single risk score, a clear link was identified: the higher the environmental risk, the higher the chance of getting asthma. They estimated that about one in nine asthma cases could be linked to living in areas with poor environmental conditions.
Zhebin Yu, first author and assistant professor at the Institute of Environmental Medicine at Karolinska Institutet said: ‘Previous studies have typically calculated the risk of one environmental factor at a time. We have combined several environmental factors and described how they together affect the risk of developing asthma. This provides a better picture of environmental risks, as life in a city usually involves exposure to several environmental risk factors at the same time.’
The study also found that women were more sensitive to environmental risks than men. Another finding was that people who had lived at the same address for a long time showed stronger links between their environment and asthma.
The team point out that because conditions don’t look the same everywhere – some cities may suffer more from pollution, while others may lack greenery or have high levels of artificial light at night – solutions need to be adapted to each local context, and urban planning should aim to reduce pollution, protect green spaces, and avoid overly built-up areas.
Erik Melén, professor at the Department of Clinical Research and Education, Södersjukhuset added: ‘This is useful for politicians and others involved in urban planning. The method makes it possible to identify risk areas in existing urban areas, but it can also be used when planning future urban environments.’
The full research can be read here.
Leave a Reply