Breathing masks

Although I won't argue with your point I think there is more to be considered i.e. at the time of the introduction of the '73 stock we were resignalling the Picc which involved dropping all the old cables from the runs into balata straps slung below to make way for the new cabling. This was a filthy job which disturbed the tunnel dust on a nightly basis for many months in the late 1970s so the trains were then able to whip up all the dust into clouds.

It was a site to behold as the first train came roaring into the platform following one of our cable dropping shifts pushing a cloud ahead of it and depositing fine black specs upon everything in its path and immediate surroundings.

Back in those days we were also resignalling the Northern line and the part of the Bakerloo that was to become the Jubilee. I used to come out of the tunnel at Baker Street black to my skin after a night down the hole pulling lead despite wearing overalls and also being wrapped in rag in an attempt to prevent the dust penetration as was custom and practice for many signal installation staff at the time. Of course the Northern had the added problem of anti-noise baffles in the tunnels made of asbestos sheet which disintegrated over time into fine dust. On the Victoria line just about everything was lined or coated with asbestos including all the cables which are still there of course though they are coated to mitigate breaking down into dangerous particles. Much work has been undertaken by RACU and its successors over the last two decades to eliminate the asbestos hazard but there can be no guarantees though regular monitoring of air samples is undertaken to ensure the maintenance of safe levels.