According to the Chicago Tribune, Metra's own air tests show pollution problems are worse previously disclosed. The development comes after the Tribune obtained new public documents from Metra.
The findings apparently show alarming pollution levels that contradict the rail system's public response to the original Tribune probe.
A summary of tests Metra conducted shows the highest levels of lung-damaging soot inside Metra's stainless steel cars were in outbound trains. At times, levels were hundreds of times above what is normally found on urban streets.
Metra's testing summary shows the worst pollution generally was on trains leaving the south platform at Union Station. The highest soot levels on a single route were on a train leaving the Ogilvie Transportation Center. Higher-than-normal levels also were detected on outbound trains from the LaSalle Street Station.
Metra's air quality tests show that the car immediately behind the locomotive had the higest level of diesel soot. Pollution levels decreased the further away from the engine.
"You can smell the fumes when you're in the terminal. You can smell it when you're waiting on the train. You can smell it when the train is on the way and you're waiting for the doors to open," one commuter told ABC7 Chicago Monday.
"I am going to my train over at the Metra. I end up getting on the second car. That's typical of what I do, except that there is a train that's emitting right next to our train. That smoke goes right into the second car, and it's like, trapped," another commuter said.
Metra's chief mechanical officer repeatedly downplayed the test results during board meetings Friday and I January saying, "Everything is very, very low."
In January, Metra announced it was installing more efficient air filters on its train cars.
The transit company also said it planned to switch to cleaner fuel and was upgrading many of its trains with technology that automatically shuts down the engines at the downtown stations.