And Prof Hugh Coe, head of school of Atmospheric Composition at the University of Manchester, said levels of pollution would be 'substantial' on the M60.
"If you happen to live next to the Simister roundabout or you happen to be in Wythenshawe very close to the main junction that's going to have a major impact.
"Or if you live somewhere like Ashton, again you are going to be impacted."
He said the biggest impact would be on those driving their cars - which act as a 'bubble' trapping the nitrogen dioxide and particulates.
Smart Motorways, he said, would have a positive effect by reducing speeds, and therefore emissions but he recommends that drivers switch on the recirculating air system and close front vents to reduce breathing in harmful air.
So what more could be done?
Prof Coe says barriers - tall wooden fences for example - on motorways near homes could help by 'diluting' pollution, adding: "Where you have have a built-up area next to the motorway and exposure is high a barrier will push air over the top and mix it with clean air."