(UPDATE from Security Tokyo on April 29, 2012:
Cs-134: 86 becquerels/kg
Cs-137: 128 becquerels/kg
Total: 214 becquerels/kg
Margin of error (Cs-137): 5 becquerels/kg
The number is below the provisional safety limit of 500 becquerels/kg that was in effect till April 1 this year, and would be above the new safety limit of 100 becquerels/kg if the testing method for green tea remained the same.
Well it didn't. Starting April 1, 2012, you only test green tea after it's brewed, and test the liquid. If that tests less than 10 becquerels/kg, it is supposed to be "safe" as far as the regulation goes.
But Security Tokyo, a private entity that has been conducting the very precise, professional measuring of radioactive materials using the calibrated germanium semiconductor detector, is testing the green tea ("Sayama-cha") made in Tokyo last year the old way - measuring the dry leaves.
From Security Tokyo's tweet (4/28/2012):
Sayama-cha made in Tokyo: we're detecting 210 becquerels/kg of radioactive cesium. We are still measuring. The tea was being sold at a supermarket in Tokyo. We haven't tested the tea after it is brewed.
Judging from the limited result from Shizuoka Prefecture last year*, the brewed tea may have between 1% to 1.3% of radioactive cesium detected in the dry leaves. In this case, 2 to 3 becquerels/kg, totally "safe".
*For your information, here's the result in Shizuoka from last year. Unit is becquerels/kg:
Tea (dry leaves) Brewed tea (brewed tea/dry tea leaves)
614 5.8 （0.94%）
602 7.8 （1.30%）
604 7.8 （1.29%）
581 7.6 （1.31%）
654 7.3 （1.12%）
The testing method to be used from this year on would in effect result in relaxing the safety limit for green tea IF the testing method remained the same. Now, green tea with up to 1,000 becquerels/kg of radioactive cesium in dry leaves may "safely" pass the test (brewed tea with 10 becquerels/kg of cesium or less). It seems Shizuoka Prefecture and Saitama Prefecture (main growing region for Sayama-tea) will only announce the results of brewed tea this year.