Nuclear explosions used to test new types of nuclear weapons cause pollution of the environment by radioactive materials, cause leukaemia, stimulate further rounds in the nuclear armaments race, encourage emulation of such developments by previously non-nuclear countries, and increase international tension.
The Threshold Treaty or USA-USSR Treaty on the Limitation of Underground Nuclear Weapon Tests limited testing to below the 150 kiloton yield level. This accord went into effect in 1976. The USA announced 14 underground tests in 1983 alone, but officially admitted through its Department of Energy, that it only announced the larger tests. Tests with 5 kiloton yield or less are kept secret. The figures for tests in 1980, 1981 and 1982 respectively are 14, 16 and 18 for the USA and 21, 21 and 21 for the USSR. USSR figures are obtained from seismic detectors outside the country, as all testing is secret.