As this blog has reported both in English and Japanese, the official number for the air radiation level in Tokyo is measured at only one location in Shinjuku, on top of the building about 18 meters from the ground.
However, there are many unofficial numbers, i.e. measured by concerned citizens and residents at the level where most people live and work - 1 meter above the ground.
Here is a Japanese site, "Environmental radiation monitoring by volunteers who are engaged in radiation and nuclear science". The site name says it all.
Looking at the numbers in different locations in Tokyo (PDF file for download), the radiation level varies significantly. To measure only at the Shinjuku location and tell the residents in Tokyo that the radiation level in Tokyo is back to normal range is highly misleading.
Here's some numbers from the "Environmental radiation monitoring" latest PDF file that exceed the "official" number (0.0629 microgray/hour, or microsievert/hour, 5/17/11)
Nishi-Shinjuku, Shinjuku-ku: 0.124 microsievert/hour, 100 cm above the side walk, 5/10/11
Kyobashi, Chuo-ku: 0.071 microsievert/hour, 100 cm above concrete, 5/10/11
Hongo, Bunkyo-ku: 0.14 microsievert/hour, 100 cm above asphalt, 5/10/11
Kanamachi, Katsushika-ku: 0.359 microsievert/hour, 100 cm above sand, 5/10/11
Shimo-Shakujii, Nerima-ku: 0.074 microsievert/hour, 100 cm above dirt, 5/6/11
Yoyogi, Shibuya-ku: 0.114 microsievert/hour, 100 cm above asphalt, 5/10/11
Nihonbashi Nakasu, Chuo-ku: 0.111 microsievert/hour, 100 cm above asphalt, 5/10/11
Kitano-maru Park, Chiyoda-ku: 0.085 microsievert/hour, 100 cm above dirt, 5/10/11
Fuchu City: 0.091 microsievert/hour, 100 cm above asphalt, 5/10/11
The number in Kanamachi, 0.359 microsievert/hour, would translate to more than 3 millisieverts per year. (8.61 microsieverts per day x 365 = 3.142 millisieverts per year)