The study by the UK Green Wall Centre in Staffordshire looked at this green wall at New Street station, Birmingham.

It found ‘promising potential for removal of atmospheric PM (PM₁, PM_2.5 and PM₁₀). The researchers noted that careful species selection is crucial to optimize living walls as PM filters. ‘Smaller-leaved species, hairy leaf surfaces and [waxy leaves] enhance the PM capture potential of living wall-plants.’

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