Why did Vozrozhdenya Island raise environmental concerns after the Aral Sea receded?

Vozrozhdenya Island became a significant environmental concern because the recession of the Aral Sea caused the island to connect to the mainland, transforming it into a peninsula. This increased accessibility posed a major public health risk because the island had served as a secret Soviet Union testing ground for biological weapons during the Cold War.1

The site was used for experiments involving agents such as tularemia and bubonic plague. Furthermore, hundreds of tons of live anthrax bacteria were buried on the island during the 1980s. The discovery of still-living anthrax spores in 1999 necessitated a cleanup operation by a team from the United States in 2002 to mitigate the potential for contamination and disease outbreaks.1