Humans need to consume food that is untainted by the virus (known colloquially as dome grown) if they are not to be changed by the virus into something quite different.
In addition to climatic reasons, the traditionally sparse population of the tropics has greatly aided research in the area, as the landscape is largely untainted by mankind and machinery.
It's wild and totally alien, but it offers something rather precious nowadays: the chance for raw adventure as yet untainted by multitudinous tour operators.
The spill acted like a flush, and when the fish came back a few years later, they were reportedly untainted and thriving, although the toxic smell still remained.
The doctrine applies to evidence initially discovered during, or as a consequence of, an unlawful search, but later obtained independently from activities untainted by the initial illegality.