wero a ere 4 Meath ait itor ak sat A AVAL bine seetwraith . cece ee -je during the treatment. The personnel go through an installation for neasuring ingested gamma radiation before and about 2% hours after each experiment during which the radlo-lodine is sprayed, no activity of the thyroid gland has bean detected in these persons. Sampi ing Grass: Hand-mowing or use of a motorized cutter, sccording to the type of experiment and the surface to be sampled, with removal of a surface greater than or equal to 1 a’, Milk: Milking twice daily (8 and 18 hrs), which is present practice on the farm. Treatment and Measurement of the Samples Grass: The harvest is weighed, then an aliquot is oven dried to determine the quantity of dry grass material per unit of surface, We introduce 500 g of fresh material into a hermetic flask (3 2), special for gamma spectrometry, and add 10 al of formaldehyde to stop any fermentation, Milk: Production from each milking is measured; we take 3 i liters, to which we add 10 ml of formaldehyde as preserving &gent. Measurement by sulitichannel gamma spectrometry is done as soon as possible, for the reasons given above. Results | | Contamination of the Grass Direct retention: the measurement of I/°) in the air saapled part (mowed or cut) has let us calculate the percentage of the atomized 1251 directly retained in this part of the plant. The results obtained are showm in Table I. oe .

Select target paragraph3