Urban particulate pollution reduction by four species of green roof vegetation in a UK city

► Green roofs act as passive filters of airbourne particulate matter. ► Species differences in particle capture efficiency were observed. ► Morphological reasons for differences in particle capture efficiency were posited. ► Spatial differences in leaf SIRM were observed in relation to PM10 sources. ► 0.24 tonnes of PM10 a year could be removed from Manchester city centre.