Radioactive carbon from nuclear weapon tests

Interest in bomb produced 14C was a result of the series of tests (337 MT) by the Soviet Union in high northern latitudes during 1961 and 1962. Besides 14C dating, the current changes in 14C level became one of the main research fields. By the end of 1963 a chain of sampling stations was established between Svalbard and Dakar for measuring 14C in the atmosphere. This chain was later extended to include Ethiopia, Tchad and Madagascar. Norwegian Air Force planes from Oerland collected samples at levels up to 40,000 feet. A programme for collecting samples from the ocean surface was performed by Fred Olsen and Wilh. Wilhelmsen Lines in the Atlantic, Pacific and Indian Oceans. The 14C increase in the human body was also directly observed by measurement of hair and blood. France and China have continued minor tests in the atmosphere, and the increasing number of nuclear power reactors has also been a source of 14C production. Consequently the decrease in 14C concentration in the atmosphere and human body has been less than earlier predicted. Bomb produced 14C introduced in the human body is mainly of genetic importance. The total genetic dose received in a period of 40 years is calculated tobe about 10 millirad, which is 1-2% of that received from natural sources. (JIW)