Application of Metal Ferrocyanide-anion Exchange Resin to the Enhancement of Elimination of 137Cs from Human Body

Abstract

In order to accelerate the elimination of internally deposited 137Cs from the human body, we noticed the effectiveness of ferrocyanides of transition metals used for concentrating radiocesium from fission product mixtures. Prussian blue which is an iron ferrocyanide powder, has been employed in eliminating 13'Cs from rat and man.Our chemistry group developed various ferrocyanide metals firmly bound in an anion exchange resin, and found that "nickel ferrocyanide-anion exchange resin" (NiFC)R was most stable in a wide range of hydrogen ion concentration and had a larger adsorbability for cesium than ferrocyanide salt. Several experiments were carried out on the effect of (NiFC)R and (FeFC)R (iron ferrocyanide-anion exchange resin) upon acute and chronic intake of la7Cs by rats and mice. Both "ferrocyanide-resins" were very effective in eliminating la7Cs, but (NiFC)R showed a slightly better efficiency.Long term toxicity studies were made using rats as a preliminary step to human application of (NiFC)R. The (NiFC)R mixed with foods was given to the rats for about 150 days, and then the rats were sacrificed for histo-pathological examination. No change was observed between the control group and those fed with (NiFC)R.From the result of these experiments, we decided to use (NiFC)R for two adult human males. The first experiment was performed as follows: 50 nCi of carrier-free 137Cs was ingested and 1 g, 0.5 g and 0.5 g of (NiFC)R was given at 10 min, 4 hr and 8 hr respectively after 137Cs ingestion. Excretion of la7Cs after 24 hr was about 40% of the ingested dose in comparison with about 5% without (NiFC)R dosing. The second experiment was as follows: 200 nCi of carrierfree 137Cs was ingested and then 0.5 g of (NiFC)R was given four times per day from the 2 1st to the 29th day following 137Cs ingestion. Excretion rates, as measured from the whole body retention curves, were about twice that during the period in which no (NiFC)R was given. Moreover, no side effects were observed for the two subjects.Thus, we may conclude that (NiFC)R can be successfully used to enhance the elimination of I3jrCs from the body.

Bioavailability of iron and cyanide from oral potassium ferric hexacyanoferrate(II) in humans

“…It is well known that the intestinal absorption of radiocaesium can be inhibited very efficiently by simultaneous oral administration of ferric hexacyanoferrate(II) compounds (HCF) in animals and humans (Nigrovic 1965;Giese and Hantzsch 1970;Seletskaya and Borisov 1973;Nielsen et al 1988a). In addition, the elimination of already absorbed caesium can be accelerated by HCF treatment (Havlicek et al 1967;Madshus and Strrmme 1968;Iinuma et al 1971) because hexacyanoferrate(II) compounds tightly adsorb caesium in the intestine and thus block its entero-enteral circulation. Besides Cs ions, HCF compounds have a high affinity for thallium(I) and HCF (specific activity: 59Fe, 0.35 kBq/mg; 14C, 15.3 kBq/mg) were prepared from 59FEC13 and laC-labelled potassium ferrocyanide as described earlier (Nielsen et al 1987.…”

Comparison of Absorbents and Drugs for Internal Decorporation of Radiocesium: Advances of Polyvinyl Alcohol Hydrogel Microsphere Preparations Containing Magnetite and Prussian Blue

“…After binding with the carrier to prevent dissolution of the constituent in the GI tract, 24) these ferrocyanides were examined for decorporation of radiocesium in livestocks in the 1970s. 25,26) Currently, ferrocyanide is applied for the removal of radiocesium from animals 27) or the environment 28,29) by binding with insoluble carriers. Unfortunately, the recent trends of emphasizing the adverse effects 30,31) or allergenic effects 32) of the transition metals have hampered their medical application.…”

Efficacy of Nickel Ferrocyanide-anion Exchange Resin for Reducing Egg Contamination with137Cs in Laying Japanese Quails

“…Caesium-137 reaches humans through successive foodchains (Pendleton andHanson 1958, Shannon, McClellan, Watson andBustad 1965) and is absorbed almost completely through the gastrointestinal wall (Hood and Comar 1953, Weeks and Oakley 1955, Moore and Comar 1962 . Elimination of 117 Cs has been attempted using various agents, among which Prussian blue (Nigrovic 1965, Richmond andBunde 1966), several metal ferrocyanides (Matsusaka, Inaba, Ichikawa, Enomoto, Watari and linuma 1971), and nickel ferrocyanide-anion exchange resin (Iinuma, Izawa, Watari, Enomoto, Matsusaka, Inaba, Kasuga and Nagai 1971) were efficient in eliminating 137 Cs via faeces in experimental animals and humans .…”