The Soviets started experimenting with nuclear technology in 1943, and first tested a nuclear weapon in August 1949. Many of the fission based devices left behind radioactive isotopes which have contaminated air, water and soil in the areas immediately surrounding, downwind and downstream of the blast site. According to the records that the Russian government released in 1991, the Soviet Union tested 969 nuclear devices between 1949 and 1990.[54]:1 Soviet scientists conducted the tests with little regard for environmental and public health consequences. The detrimental effects that the toxic waste generated by weapons testing and processing of radioactive materials are still felt to this day. Even decades later, the risk of developing various types of cancer, especially that of the thyroid and the lungs, continues to be elevated far above national averages for people in affected areas.[55]:1385 Iodine-131, a radioactive isotope that is a major byproduct of fission-based weapons, is retained in the thyroid gland, and so poisoning of this kind is commonplace in impacted populations.[55]:1386

The Soviets set off 214 nuclear bombs in the open air between 1949 and 1962, the year the United Nations banned atmospheric tests worldwide.[54]:6 The billions of radioactive particles released into the air exposed countless people to extremely mutagenic and carcinogenic materials, resulting in a myriad of deleterious genetic maladies and deformities. The majority of these tests took place at the Semipalatinsk Test Site, or STS, located in northeast Kazakhstan.[54]:61 The testing at STS alone exposed hundreds of thousands of Kazakh citizens to the harmful effects, and the site continues to be one of the most highly irradiated places on the planet.[56]:A167 When the earliest tests were being conducted, even the scientists had only a poor understanding of the medium- and long-term effects of radiation exposure. In fact, the STS was chosen as the primary site for open-air testing precisely because the Soviets were curious about the potential for lasting harm that their weapons held.[55]:1389

Contamination of air and soil due to atmospheric testing is only part of a wider issue. Water contamination due to improper disposal of spent uranium and decay of sunken nuclear-powered submarines is a major problem in the Kola Peninsula in northwest Russia. Although the Russian government states that the radioactive power cores are stable, various scientists have come forth with serious concerns about the 32,000 spent nuclear fuel elements that remain in the sunken vessels.[56]:A166 There have been no major incidents other than the explosion and sinking of a nuclear-powered submarine in August 2000, but many international scientists are still uneasy at the prospect of the hulls eroding, releasing uranium into the sea and causing considerable contamination.[56]:A166 Although the submarines pose an environmental risk, they have yet to cause serious harm to public health. However, water contamination in the area of the Mayak test site, especially at Lake Karachay, is extreme, and has gotten to the point where radioactive byproducts have found their way into drinking water supplies. It has been an area of concern since the early 1950s, when the Soviets began disposing of tens of millions of cubic meters of radioactive waste by pumping it into the small lake.[56]:A165 Half a century later, in the 1990s, there are still hundreds of millions of curies of waste in the Lake, and at points contamination has been so severe that a mere half-hour of exposure to certain regions would deliver a dose of radiation sufficient to kill 50% of humans.[56]:A165 Although the area immediately surrounding the lake is devoid of population, the lake has the potential to dry up in times of drought. Most significantly, in 1967, it dried up and winds carried radioactive dust over thousands of square kilometers, exposing at least 500,000 citizens to a range of health risks.[56]:A165 To control dust, Soviet scientists piled concrete on top of the lake. Although this was effective in helping mediate the amount of dust, the weight of the concrete pushed radioactive materials into closer contact with standing underground groundwater.[56]:A166 It is difficult to gauge the overall health and environmental effects of the water contamination at Lake Karachay because figures on civilian exposure are unavailable, making it hard to show causation between elevated cancer rates and radioactive pollution specifically from the lake.

Contemporary efforts to manage radioactive contamination in the former Soviet Union are few and far between. Public awareness of the past and present dangers, as well as the Russian government's investment in current cleanup efforts, are likely dampened by the lack of media attention STS and other sites have gotten in comparison to isolated nuclear incidents such as Hiroshima, Nagasaki, Chernobyl and Three-Mile Island.[57] The domestic government's investment in cleanup measures seems to be driven by economic concerns rather than care for public health. The most significant political legislation in this area is a bill agreeing to turn the already contaminated former weapons complex Mayak into an international radioactive waste dump, accepting cash from other countries in exchange for taking their radioactive byproducts of nuclear industry.[56]:A167 Although the bill stipulates that the revenue go towards decontaminating other test sites such as Semipalatinsk and the Kola Peninsula, experts doubt whether this will actually happen given the current political and economic climate in Russia.[56]:A168