We Stan Characters With Arcs

Eukaryotic cell gang!! We love women in STEM.

So I have a theory as to what the cloud is in Dead Money. I've been researching others opinions and everyone I've seen as been summed up "created by some experiment" or "chemical weapons". But I don't think that's the case. I think it's something already existent.

Let's start off with the characteristics of the cloud.

Corrosive

Blood red

Seen as a vapor, but also as residue

Toxic to inhale

Symptoms from coming in contact including: trouble breathing, burns, death

Smells like copper/metallic

This sounds to me like bromine. Bromine is a naturally occurring halogen with the atomic number 35 on the periodic table. It is highly corrosive and at room temperature, is a liquid that gives off blood red fumes. Due to the location of the Sierra Madre, we can assume that it is well above room temperature which explains why we may see more cloud as a gas than liquid, and explains why we can find residue to scrape up. Now why would it be there in the first place?

Common uses of bromine include:

Water treatment

HVAC refrigerant

Fire retardants

Preservatives

Well drilling and precious metal mining

Which could explain why it was first discovered in ventilation, as it is one of the most common refrigerants in HVAC. Now you may argue that it was still part of an experiment, but we never find evidence that they made the chemical. At the Z-43 Innovative Toxins Plant in the Old World Blues DLC, they're studying chemicals toxic to humans. Perhaps one of the studies was to see what prolonged exposure to bromine would do.

Another thing mentioned about the cloud, is how it seems to have preserved the area. Bromine is used as a food preservative. BVO or Brominated Vegetable Oil is used to preserve processed foods and beverages, though due to bromines toxic nature, is banned from use in several countries.

Would I breathe fresh air