A possible quadrupling in the number of diesel trains passing through Toronto's west end has some residents in an uproar.

Public consultations begin this week concerning a plan to expand and increase the number of trains using the Georgetown rail corridor from Bathurst Street through the Parkdale and Weston neighbourhoods.

The regional transportation agency Metrolinx wants to add new tracks to carry more GO trains to Brampton and Georgetown plus the proposed high-speed rail link to Pearson Airport.

But even before the public meetings get underway, people living near the rail lines are raising concerns about the potential effect on their neighbourhoods.

"This is a project with incredible potential but some of the facets of the project are threatening to our neighbourhood," said Eli Malinsky who lives a block from the rail lines. He's concerned about the long-term projections for traffic along the tracks.

"[There will be ] 400-500 trains daily coming through the city, through residential neighbourhoods, that are spewing toxic diesel in communities," said Malinsky.

He said he'd be willing to accept increased traffic if the trains were pulled by electric engines — and if there were more stations so people in the neighbourhood could ride the trains — but right now that's not part of the plan.

Brian Peltier, the project manager for Metrolinx says more stops would slow the trains down too much.

"Although there is a plan to electrify the corridor, right at the moment there isn't funding available for that and it's quite a significant cost," he said.

Peltier says the expansion has been needed for many years.

"This project has been studied since at least back in the 1980s and we do need to get on with expanding the GO capacity in this corridor," he said.

The assessment of the project's environmental impact is expected to take six months.