Sir,

I note that the Planning Application for Commercial Development adjoining Dixton Roundabout has been delayed to await the air quality assessment for the site.

I agree that there is an urgent need to improve the air quality in proximity to the A40, especially in relation to households close to this very busy road, with 36,000 vehicles passing Monmouth every day.

However it would appear that there are no major funds available to undertake substantial alterations to the A40, or even less likely, to re-route it away from the town.

I would like to take this opportunity to highlight the 'big air pollution experiment' featured on the BBC TV programme 'Trust me I'm a Doctor' on 28th October 2013.

Dr Michael Mosley and surgeon Gabriel Weston helped test a new pollution filter developed by Professor Barbara Maher of the University of Lancaster: silver birch trees.

They set up a row of 24 young silver birch trees in tubs along the pavement of the busy A9 in Lancaster. Behind the trees were four terraced houses, and next to them four identical terraced houses without silver birches between them and the traffic.

At the end of the fortnight's experiment the results were astounding; particulate pollution in the four houses with trees was 50-60 per cent lower than in those without.

Electron microscope images of the leaves of silver birch trees show why they are so good - they are covered in tiny hairs and ridges which help trap the pollution particles. Their sparse structure also keeps the air circulating and flowing past the leaves to filter it effectively.

Rain washes the pollution off the leaves and the cycle is repeated.

At our meeting on 26th Marc, we discussed this successful experiment and it was suggested that planting rows of silver birch trees between the town and the A40 would provide an effective barrier to particulate pollution.

Grahame Thomas,

(Chairman,

Monmouth Civic Society)