The commercially available roof tile is already estimated to have removed the equivalent of 500,000 car miles worth of nitrogen oxides from the air since its launch four years ago.

Manufacturer Marley Eternit developed the groundbreaking EcoLogic tile, which is coated with a sun activated ‘pollution-eating’ chemical.

This removes nitrogen oxide gases from the air, blamed for encouraging Ozone formation and triggering asthma and other respiratory infections among the very young and the elderly.

Dr Andrew McKnight, head of research and development at Marley Eternit, said: “A roof fitted with EcoLogic tiles can absorb the equivalent of 100,000 car miles worth of NOx emissions over its lifetime.

“As such it has already been used by some local authorities seeking to take positive steps to improve air quality.”

He said that Greater London, Glasgow and North East Scotland were failing to comply with European hourly targets for minimum concentrations of NOx.

“While the emission of these pollutants is in decline as combustion has become cleaner, NOx still represents a significant challenge for the UK.

The UK failed to meet its NO₂ target for 2010 and the government submitted plans to the EU this September to extend the deadline until 2015.

Furthermore parts of 40 out of the 43 UK zones didn’t achieve full compliance with the annual NO₂ limit.

The external coating on Ecologic tiles contains titanium dioxide which reacts with nitrogen oxides in the air to convert them to nitric acid, which is then neutralised to form calcium nitrate, a liquid fertiliser for the garden.

Based on Marley Eternit’s Ludlow Major concrete tile, EcoLogic tiles have a brown granular textured surface to blend with many architectural styles.

McKnight adds: “The EcoLogic tile is attracting a lot of attention because not only does it offer a high environmental rating, containing 50% recycled materials, but it actively improves the environment, making it a genuine solution to the needs of our customers.

“Ecologic tiles have removed over 500,000 car mile equivalents of NOx since their release, and with more tiles being installed by the week, this figure is only going to grow.”