I became aware of it because of the work of the Fluffers. The Wikipedia article only mentions the occupational hazards of their work in passing (but they were •only• women)
https://en.wikipedia.org/wiki/Fluffer_(London_Underground)
The Pathé film of their work is here
https://youtu.be/J4yT_PyZH14?si=WsW3e8ogRCvxErPC