Coal seam fracking

What you are not told by the big companies is that after fracking the coal seams become sterile unable to be mined. Yes the rock strata is broken and the mining of the coal is impossible because the roof can not be held up because of the fracking. I personally would not like to mine coal after fracking. It would like digging under a pile of gravel be it big pieces of gravel. Then there is the chemical poisoning that one would have to deal with in the air system. Radon is given off during mining but add to that all the other chemicals forced into the coal seam.