On the long-term behaviour of 110mAg in the soil-plant system and its transfer from feed to pig

The long-term transfer of radiosilver from soil to pasture grass was investigated over 5 years on an undisturbed pasture using stable silver (109Ag) isotope as a tracer. The silver content of all the samples was determined by neutron activation analysis. The temporal change of the Ag+ uptake into forage was negligible mainly due to the low mobility of silver in the soil (orthi-humic-gleysol). The mean grass/soil concentration factor levelled out at 1.3±0.5x10-2 during the 59-month observation period. In a 30-day feeding experiment with pigs, 110mAg was used to determine distribution and retention. The internal distribution of 110mAg showed the liver to be the most contaminated tissue. The highest 110mAg retention was found in the brain. The biological half-lives obtained for the liver and the brain were 35 and 136 days, respectively