Removal of radiocesium using cation exchange resin

Cation exchange resins (calcium polystyrene sulfonate, Ca-resin and sodium polystyrene sulfonate, Na-resin) have been used as agents to improve hyperkerlemia. For removing ¹³⁷Cs from the human body, the adsorption ability of the resin for ¹³⁷Cs was examined and evaluated. Resin (0.03 g) and ¹³⁷Cs (ca.1 kBq) were introduced into 3 mL of water, the Japanese Pharmacopoeia 1st fluid for a dissolution test (pH 1.2) and 2nd fluid (pH 6.8), respectively, and shaken. After 1-3 hours, the ¹³⁷Cs adsorption (%) of Na-resin was 99 % in water, 60 % in a pH 1.2 fluid and, 66 % in a pH 6.8 fluid. By adding potassium, the ¹³⁷Cs adsorption (%) of Ca-resin was reduced. However, the ¹³⁷Cs adsorption (%) of Na-resin was almost unchanged. These results show that both resins have adsorption ability for ¹³⁷Cs in the stomach and the intestines. Therefore, the proposed method will be an effective means in the case of a radiological emergency due to ¹³⁷Cs.