(WHDH) – Some MBTA Commuter Rail engineers are getting sick on the job and ending up in the hospital.

7NEWS has confirmed four incidents where engineers have been overcome by fumes in their cabs since last month.

A source familiar with the investigation tells 7NEWS that the engineers suffered flu-like symptoms, including headaches and vomiting. And Keolis, the company that runs the Commuter Rail, still hasn’t identified the exact cause.

The first engineer got sick on June 12. There have been three additional episodes since then, most recently on July 10. According to a 7NEWS source, all of those engineers were driving older-model trains at the time.

Keolis said it’s working hard to figure out why this is happening. Right now, the company’s focus is on the air compressor systems, which vent air through the engineer’s cab.

Keolis declined to address the issue on camera, but provided 7NEWS with the following statement:

“Safety is our number one priority for our passengers and our employees. When the first employee reported these symptoms, Keolis management, union officials, senior engineers and independent outside analysts immediately began a review to determine the cause and resolve it as quickly as possible. This review is ongoing and has already helped to isolate the issue.”

The trains in which the drivers fell ill are still being used right now. But Keolis is closely monitoring them, and cleaning each one twice a day.

“These initial corrective actions have helped to address the issue in the short term while our cross-functional team determines a long-term solution,” the company said. “The specific locomotives and control cars impacted represent a very small percent of the overall fleet.”

No Commuter Rail passengers have reported feeling sick, and Keolis noted that the systems in question do not vent any air through passenger areas.

7NEWS reached out to the Brotherhood of Locomotive Engineers and Trainmen, the union that represents Commuter Rail engineers. But neither the national office nor Local Division 57, based in Boston, returned multiple messages seeking comment.

(Copyright (c) 2024 Sunbeam Television. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)

Join our Newsletter for the latest news right to your inbox