Contamination levels and variation of Cs-137 in tea plant leaves from
1986-1992 were determined over the coast line of the Eastern Black Sea
region in Turkey. The decrease of Cs-137 radionuclide concentration i
n tea plant leaves may be described by a double exponential function w
ith 94.8% activity lost with a T-eff of 125 d and 5.2% activity lost w
ith a T-eff of 1,114 d.