Pollution of Lake Karachay

[2] In 1968, following a drought in the region, the wind carried 185 PBq (5 MCi) of radioactive dust away from the dried bed of the lake, irradiating half a million people.

When Russian president Boris Yeltsin signed a 1992 decree opening the area, Western scientists were able to gain access.

The sediment of the lake bed is estimated to be composed almost entirely of high level radioactive waste deposits to a depth of roughly 11 feet (3.4 m).

[7] After a drought caused water levels to drop, revealing contaminated silt, which was then wind blown, further polluting surrounding areas, it was decided to completely fill in the lake.

[9] The Techa River, which provides water to nearby areas, was contaminated, and about 65% of local residents fell ill with radiation sickness.