Abstract
The detection methods for 129I now prevailing are based roughly on two different principles: one is the direct method such as the liquid scintillation method and X-ray detection method by use of the intrinsic Ge detector and the other is neutron activation method.
The detection limit of the direct method is about 1dpm of 129I, while that of the neutron activation method, though it changes with the irradiation conditions, can reach the level of 10-4 to 10-6dpm.
A lot of data have been reported by means of those methods on the environmental materials such as water, milk, soils, vegetation and thyroid of animals and human-beings.
In this review, the level of 129I in the environment is briefly stated first, and then the individual detection methods and the pretreatments required for each measurement are referred.
