A trial has begun in the capital to reduce levels of pollutants in the air by spraying roads with a dust suppressant that causes dangerous particulates to stick to the road surface.

Transport for London (TFL) is to run the trials, which hope to reduce pollutant levels by up to 20 per cent, at two central London locations including the Victoria Embankment and Euston Road, which have been identified as having high levels of particulate matter associated with engine emissions.

The suppressant, a solution of calcium magnesium acetate, prevents pollutants being recirculated in the air. London is at danger of breaching EU legal limits for particulate matter at some central locations.