Toxic Fumes Are Leaking Into Airplanes, Sickening Crews and Passengers

Wall Street Journal article on toxicity of contaminated bleed air:

So it drags on and on in a regulatory morass. Note how the airlines defend themselves with “we follow all the regulations”

I wonder how much it would cost these days to just take fresh air from the outside and compress it separately for use in the cabin? I suppose the compressor could still end up with leaks.