WHENEVER I visit another city I am struck by how much pollution the buses emit in comparison to our wonderful clean emission buses in Oxford. In the light of your excellent article on air pollution fatalities we are certainly blessed to have these zero particulate buses.

However, more needs to be done as our air quality is still unacceptable. A recent study found that vehicle PM2.5 particulates age the brain by three years. These ultra-fine particles dissolve into the bloodstream and inflame the arteries and lungs.

The city council urgently needs to incorporate licensed taxis and mini cabs into the low emission zone to comply with EU air quality directives.

Their diesel particulates are especially harmful and leave a very nasty choking smell in the clean air. Oxford lies in a basin that traps stagnant polluted air. Oxford councillors are doing a great job with lowering carbon emissions that are thought to affect the climate; they now need to focus on lowering vehicle particulate emissions that are medically proven to harm health.

SUSAN THOMAS Magdalen Road Oxford