“ An alloy of iron and iridescent meteoric metal, also known as shadesteel. Weapons forged of this metal cause gangreneous infections almost instantly and sometimes the victims becomes a shambling zombie after death. The material is very vulnerable to fresh water which will cause it to corrode and eventually melt in a period of hours to days.”
“ As they travel they notice a horrible rotten smell. As they travel it gets stronger and stronger forcing them to cover their noses and mouth less they choke on the horrible smell. Stream full of dead fish. Spawning trout die in mass quantities after they spawn littering areas with dead fish dying and deteriorating in the sun.”
“ 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.”