“ A small, primitive village has yet to discover fire, which is a good thing because there are highly flammable (but not otherwise dangerous) gasses in the air. The heroes, blissful in their ignorance, don't know that and think it a wonderful idea to show the locals open flame.”
“ '...The people of the Dalaben Fens have a custom heretical to our superior Zodashan faith, in which they place their dead upon the grass roofs of their stilt-houses. It is said that they do this because they used to bury their dead before the great Judgement, in which their home became the swamp which it is today.'-Sir Edrosh Metorva, 'The Barbarian Lands of the East, Volume X.'”
“ Mining in a certain area turns all exposed skin (maybe just parts that are actively disturbing the chemicals that cause the reaction) of the those doing the mining to a dark blue color. Will wear off taking as many years/days spent in the mine. ... meeting a party of blue-skinned humans armed with pick-axes etc. Strange disease? Demon offspring? Curse? If they meet only one ex-worker, they will very carefully listen to any stories he says, no matter if drunken or insane, or just makes up to get a beer.”