I think taosists suggesting possibly has some gravity. Anyone I have spoken to is finding it very hard to believe that this is the cause of thier difficulties. CO2 possibly, rather than CO.
It would be interesting to see if someone (perhaps from dca) could talk to the hospital about this. (could the abulance have had a leaky exhaust on the way to the hospital

). Just because CO appeared on the hospitals tests, doesnt mean its direct evidence of the cause of thier illness.
The blasting fumes thing just doesnt seem to add up to me, if there was a draught blowing from the quarry face and into long rake, and supposing *enough* fumes did get carried along (the volume of air in long rake is pretty vast, its hardly a small pokey place) then surely they'd carry on moving and pressumably up the chimney like shaft.
There is an active stream way in the bottom, and its possible that this is giving off some sort of gas.
I think DCA ought to act on this in some way to clear up any doubt to prevent any issues with access to the place.
