A major rail expansion project that will bring train service to Pearson Airport and the suburbs has been given the green light from Ontario’s environment minister.

The $875-million Metrolinx plan was approved Monday, but it’s been slapped with 18 conditions including a requirement to use clean diesel technology that’s still in the works.

The technology is designed to cut back on particulate produced by locomotive exhausts by 90 per cent and nitrogen oxides by 80 per cent.

Residents and health officials have expressed concern about the pollution produced by diesel locomotives running along the rail corridor.

Environment Minister John Gerretsen told the Globe and Mail that he’s confident locomotive manufacturers can meet the green standard by 2015, when the proposed rail link is scheduled to be completed.