While it beggars belief that they could find willing guinea pigs, researchers in Holland have confirmed that inhaling diesel exhaust fumes impairs the brain’s processing ability.

The study, which was conducted at the Zuyd University in the Netherlands, involved participants inhaling diesel engine exhaust fumes similar to those breathed in by roadside or garage workers during 30 minutes.

Their minds displayed stress responses recorded on an electroencephalograph, whilst controls breathing clean air registered normal brain activity.