Temporal variations of 137Cs concentrations in the surface seawater and marine organisms collected from the Japanese coast during the 1980's

The surface seawater and marine organisms were collected on the Japanese coast and analyzed for their 137Cs concentrations during the 1980's. The 137Cs concentrations in surface seawater decreased almost exponentially with time and the 137Cs removal rate constant was estimated to be 0.0445 y-1. The 137Cs concentrations in marine organisms also decreased almost exponentially with time. The environmental half-lives of 137Cs in muscle and viscera of fish, crustacea, and seaweed were estimated from the measured decreases of 137Cs concentrations. (author)