The use of hexacyanoferrates in different forms to reduce radiocaesium contamination of animal products in Russia

Hexacyanoferrates have been identified as highly effective radiocaesium bin ders which effectively reduce radiocaesium uptake and transfer to milk and meat. In Russia a hexacyanoferrate called ferrocyn has been produced for us e as a countermeasure. In 1989-1992, experiments were undertaken in Russia to study the effectiveness of four different ferrocyn materials as Cs-137 b inders, their potential toxicity, effect on production rates of cow milk, e ffect on animal health and ease of implementation in routine agricultural p ractice. Four different ferrocyn delivery forms have been used: 98% pure po wder, sustained release rumen boli (15% ferrocyn), salt licks (10% ferrocyn ) and sawdust with 10% ferrocyn adsorbed (bifege). In initial experiments w ith different cows, sheep and pigs these four ferrocyn materials were effec tive in reducing radiocaesium transfer to animal products. Daily administra tion of ferrocyn powder at a rate of 3-5 g per cow reduced Cs-137 transfer by up to 90% in milk. One single administration of three boli per cow (cont aining 30 g ferrocyn per boli) reduced 137Cs transfer by 50-75% for a perio d of 2 months. Salt licks containing 10% ferrocyn (0.22 kg ferrocyn per 2.2 kg briquette provided once) reduced transfer of 137Cs UP to twofold for up to 10 days whilst bifege, given at a rate of 30-60 g day(-1) (3-6 g day(-1 ) ferrocyn), reduced Cs-137 transfer by 90-95%. However, large-scale applic ation of these ferrocyn materials on collective and private farms in agricu ltural trials in 1994 resulted in a lower effectiveness. Therefore, in 1996 a comparative assessment of the application of the four ferrocyn forms was made under carefully controlled conditions; The results fully validated th e previous experimental data, and showed the importance of meeting recommen ded procedures for treatment, particularly when hexacyanoferrates are admin istered on a day-to-day basis. (C) 1998 Elsevier Science B.V. All rights re served.