Toxic samples

Toxic samples is a paper note in Fallout: New Vegas add on Dead Money. It can be found Inside of Ennis's locker in the Puesta del Sol switching station.

Background
The toxins the group collected was a residue most likely created by The Villa's power generators which were, much like the rest of The Villa, hastily constructed. These toxins created both the cloud and, somewhat indirectly, the ghost people.