Fires are a logical aftermath of certain events, especially tornadoes and thunderstorms. A Fire Containment Unit seems like a nice addition to the game.
Regarding a Pollution Containment Unit, I don't think that is necessary, however, just like in Zoo Tycoon, certain areas could get too polluted and dirty due to guests not having the possibility to properly get rid of their waste (lack of dustbins). Maybe players could send out the rangers to empty dustbins. Nobody really wants to wander a zoo/theme park when one has to watch out to not slip on a banana peel or whatever lying on the ground.