The Chernobyl Meltdown happened on this day in 1986.
On 26 April 1986 at 01:23:40 a.m. (UTC+3) reactor number four at the Chernobyl Nuclear Power Plant located in the Soviet Union near Pripyat in Ukraine exploded. Further explosions and the resulting fire sent a plume of highly radioactive fallout into the atmosphere and over an extensive geographical area. Nearly thirty to forty times more fallout was released than Hiroshima. The plume drifted over parts of the western Soviet Union, Eastern Europe, Western Europe, Northern Europe, and eastern North America. Large areas in Ukraine, Belarus, and Russia were badly contaminated, resulting in the evacuation and resettlement of over 336,000 people. According to official post-Soviet data, about 60% of the radioactive fallout landed in Belarus. *
From the UN’s Chernobyl site:
Recent research has shown that people in the Chernobyl region still lack the information they need to lead healthy, productive lives. Information itself is not in short supply; what is missing are creative ways of disseminating information in a way that induces people to change their behavior. Moreover, propagation of healthy lifestyles is at least as important as providing information on living safely with low-dose radiation. To improve the population’s mental health and ease fears, community activists will be mobilized to deliver truthful and reassuring messages to dispel the misconceptions surrounding Chernobyl. *