Of the few microorganisms that have been studied, all underwent rapid changes in the areas heavily contaminated by Chernobyl. Organisms such as tuberculosis bacilli; hepatitis, herpes, and tobacco mosaic viruses; cytomegalovirus; and soil micromycetes and bacteria were activated in various ways. The ultimate long-term consequences for the Chernobyl microbiologic biota may be worse than what we know today. Compared to humans and other mammals, the profound changes that take place among these small live organisms with rapid reproductive turnover do not bode well for the health and survival of other species.