The past two decades have witnessed dramatic changes in public health governance and international cooperation on the Chernobyl Nuclear Power Plant accident, especially after the end of the Cold War. The World Health Organization (WHO) has committed itself deeply to the public health issues around Chernobyl and has participated in various health projects such as health monitoring and cancer screening. WHO has also been engaged in research activities such as the Chernobyl Tissue Bank, in close collaboration with the Ministries of Health in Belarus, Russia, and Ukraine. In addition to the official report of the Chernobyl Forum "Health Expert Groups" in 2005, the task of WHO is to not only analyze and clarify the global burden of Chernobyl-related illness, but also to promote the well-being of the local residents who suffered chronic low-level radiation exposure from radiation fallout.