France’s first ever pollution-absorbent plant wall was unveiled this week at the railway station of Lyons Perrache. The 400 square meter wall, built by Canevaflor, is designed to filter out air pollution generated by the station’s parking lot. Plant walls were popularised in France by Patrick Blanc, who developed the concept of the vertical garden, notably at the Musée du Quai Branly in Paris. But the pollution-absorbing wall is a new innovation. Dirty air is sucked up – using energy from solar panels – into tiny tubes embedded in the wall and the air is first filtered by the plants before being shunted into the earth where it is metabolised by micro-organisms such as bacteria and mushrooms. The wall comprises 19 different plant species, selected for their ability to soak up heavy metals. For instance the “cornus” absorbs copper, “stachys” absorbs nickel and “arabis” absorbs cadium, lead and copper. The installation, which cost 213,000 euros, will also provide cooling and noise insulation for the building. It is expected to consume 12 times less water than a traditional plant wall. City authorities in Lyons have said that they are considering installing green roofs and facades throughout the city in order to achieve energy savings.