Sir - I read with interest the letter (March 14) from Bruce Heagerty about air pollution in Oxford and its negative impact on health.

Four years ago last month, my partner and long-standing Green city councillor Mike Woodin was diagnosed with lung cancer (he died five months later). He was asked by the consultant oncologist if he'd ever smoked (he hadn't), worked down a mine (!) or been exposed to asbestos (not to our knowledge).

He was not asked, however, if he'd spent most of his adult life living and working in Oxford, a city where air pollution levels on a number of the main arterial routes regularly breach World Health Organisation safety guidelines. Clearly, a link has already been made between exposure to airborne particulates and lung cancer.

A direct link between air pollution and cancer might be harder to prove. But it's certainly a point worth pondering.

Deborah Glass Woodin, South Oxford