The radioactive pollutions in environment caused by the accident of atomic power plants in Fukushima,
Japan, is still serious and rapid measures to the severe problem is required. It is well known that various biomass have
adsorption ability for toxic metal ions from aqueous media. We have evaluated the adsorption ability of the bark of
Cryptomeria japonica and Chamaecyparis obtusa, and their hybrid materials with hydrophilic polymers, for
cesium, strontium, and other heavy metal ions. As the results, these materials are useful as adsorbents for a water
and soil purification system.