System 1986 (DS86)
|In the late 1970s, scientists from the
United States noticed differences between the T65D
doses, extensively used in the study of radiation
hazards among atomic-bomb (A-bomb) survivors, and the theoretical
dose estimates. Therefore, a US-Japan joint study was initiated
to reassess various factors related to the A-bomb explosions
that determine actual doses of ionizing radiation. The new
dosimetry system, Dosimetry System 1986, was established
in March 1986. DS86 permits the calculating of exposures
received by various organs (referred to as organ
doses) on the basis of individual exposure-history information, something that
could not be done with the T65D system. Using DS86, the dose-response relationships
of the various effects resulting from A-bomb radiation exposure were reassessed.
refinement of DS86, ultimately replaced by DS02, was continued over several years.
A total dose (in gray)
of gamma and neutron radiations is assigned to an individual. See the Table,
which shows the free-in-air dose (kerma)
of gamma rays.