Sulphur caves should be poisonous and have a new effect

The Sulphur caves should be more poisonous, or at least the air or vicinity around them, perhaps the Sulphur blocks themselves. as Sulphur gas can be very poisonous to breathe in, just like with the pools in also being deadly, the there should be a chance or chances to get some new affect that could be determinantal to exploring the area, if not properly equipped to handle particular affect.