Oh, for goodness sake, first of all "If Mexico set up colonies in the United States, I'm pretty sure they'd be kicked out." That's a fallacy! I'm sure if aliens landed in a wasteland and when someone came to investigate stressed they came in peace and offered gifts that its a different scenario. Furthermore, I'm ignoring the entirety of the post you just made and not abiding by it.
But, to play along with your idea, do some research on Dallol. Its a volcanic anomaly site surrounded by acidic hot springs, mountains of sulfur and salt, with small gas geysers and pools of acid separated by salt forming ridges between them. The name in Ethiopian literally means disintegrated. That might explain your two illnesses.
But I'm not abiding by the concept that we are deathly to people and ignoring any further major implications you make because you're just
trolling
me at this point.