So when he awakes recovered on the table... um....
Because Jor El got rid of the toxic atmosphere.
Also, since Earth air gives sensory powers, why weren't the Kryptonians on the ship shown to be experiencing that issue when Lois was escaping? Oh right, internal consistency.
No, earth air doesn't give sensory powers. The sun gives powers. The masks block sensory powers.
The only wacky bit is why the Kryptonians need he masks in the first place.