People are increasingly being warned about the dangers of diesel pollution, but how much are we actually exposed to? Tim Johns tried to find out.
Waiting for my train one day, standing on the concourse, it occurred to me that there seemed to be rather a lot of fumes coming from the idling diesel engines.
How much diesel pollution was I breathing in?
I decided to undertake an experiment for The Jeremy Vine Show on BBC Radio 2 to find out how much I was being exposed to on a daily basis, in different locations and on different modes of transport.