Resurrection of Evil changed?

[Arbitard1171]

do any of you remember the part where you had to put on a suit and go through the toxic waste area? well you actually don't put on a mask or anything now...guess he's immume to toxic waste.

here's an old pic of the area: http://www.mobygames.com/images/shots/l/108602-doom3-resurrection-of-evil-windows-screenshot-toxic-tunnels.jpg