Asked by: Lucas Moore, Swansea
They don’t absorb it, but pollution particles do get stuck to the bark and trapped in the hairs on the leaves. A 2011 study estimated that every year, trees in Greater London remove 850 to 2,000 tonnes of PM10 pollution particles, which are the type considered harmful to humans.
Plane trees do emit isoprene though, which combines with nitrous oxide in car exhaust emissions to produce harmful ozone. Luckily, this only reaches dangerous levels in temperatures above 30°C, which are rare in the UK.