129I Present in Animal Thyroid and Fresh Water in Argentina

A. E. NEGRI; J. O. FERNÁNDEZ NIELLO; A. ARAZI; A. WALLNER; P. F. F. CARNELLI; E. DE BARBARÁ; J. M. FIGUEIRA; L. FIMIANI; D. MARTÍNEZ HEIMANN; G. V. MARTÍ

Vancouver

Conferencia; International Nuclear Physics Conference 2010; 2010

The 129I radioisotope (half-life: 15.7 Ma), produced mainly by nuclear reprocessing plants, have been extendely used as oceanic tracer, and as nuclear-activity monitor as well in the northern hemisphere. However, there is up to now very scarce information (from different matrixes and different decades) of the South-American subcontinent. At the TANDAR Laboratory we have started a research program aiming to the use of 129I as environmental tracer in Argentina. The 129I, coming either by water or by atmospheric fallout over pasture fields, is naturally concentrated by grazing cattle in their thyroids glands. Hence, bovine thyroids and fresh water samples coming from all over Argentina were chemically processed in order to extract the ontained iodine. These samples were analyzed by Accelerated Mass Spectrometry, at VERA facility, to determine the concentration of 129I relative to the stable 127I. The concentration of iodine was established by means of Inductively-Coupled-Plasma Mass Spectrometry or Gas Chromatography. Preliminary results present 129I/127I ratios in the range from 10^-9 to 10^-11 compatible with previous measurements made of samples from the southern hemisphere.