In 1992, Guillemin became part of Meselson's investigation into another Cold War controversy, the 1979 outbreak of anthrax in Sverdlovsk, a closed Soviet city in the Ural Mountains. The Soviet government claimed the cause was infected meat. Guillemin's interviews with the families of victims (64 people were recorded as dying) resulted in an epidemiological map showing the source to be an air-borne release of anthrax spores from a military facility where, in violation of the 1972 Biological Weapons Convention, the testing of anthrax weapons had been in process. In 1994, the results of this research were published in "Science" and in 1999 her book on this research was published ("Anthrax: The Investigation of a Deadly Outbreak", U of California Press).