Protect care homes with trees, new study says

A new study from the University of Surrey finds that the presence of trees between  care homes and heavy traffic can mitigate the impact of air pollutions possible to shield residents from air pollution.

Previous studies have focused on the distance between the care homes and the road – with one determining they should be should be at least 152m from major roads – but this research is the first to bring trees into the equation.

The researchers argue that simply extending the distance to the road it not practical in the city, instead it is important to take into account the trade-off between transportation convenience, urban design, and air quality the care homes.

Professor Prashant Kumar, Director of Surrey’s Global Centre for Clean Air Research (GCARE), said: ‘Older adults in care settings can be especially vulnerable to poor quality air. Our study confirms that building care homes next to busy roads without adequate tree planting can significantly increase their exposure to deadly fine particle pollution.

‘We hope planners will be able to use our findings to make sure care homes are built in safer locations – striking the right balance between the convenience of urban living and better air quality.’

Researchers studied three care homes in the Chinese city of Nanjing that had 105m, 40m and 10m wide spaces of dense trees between the road and the care home gate. In all cases, beyond the trees was a similar type of heavily trafficked road and the trees themselves were primarily magnolia.

They found that the amount of pollution inside the care home decreased exponentially, the further it was from the road.

Huaiwen Wu, a researcher at GCARE, said: ‘Our study gives so many useful insights into where to build new care homes.

‘For instance, there was a significant relationship between outdoor and indoor pollution. This tells us that bedrooms should be kept on the far side of the building where possible.’

Professor Shi-Jie Cao, Visiting Professor at GCARE and Professor at the Southeast University, China, said: ‘We also saw how pollution was highest during rush hour. Concentrations were higher during spells of lighter winds, and during colder seasons when more people are heating their homes.

‘As such, care homes near busy roads could keep their windows closed more during those periods – then open them afterwards to mitigate the accumulation of emissions.’