Iodine 131 is measured from dired sludge and incineration ash at purification center of Shizuoka prefecture.
About incineration ash, the iodine 131 level is increasing from 11/11/2011.
Incineration ash
Nakashima purification center Bq/kg
| Sample taken | Iodine | Cesium |
| 3/1/2012 | 107 | 317 |
| 2/2/2012 | 80 | 159 |
| 1/5/2012 | 18 | 209 |
| 12/9/2011 | 59 | 260 |
| 11/11/2011 | 19 | 273 |
| 10/14/2011 | ND | 352 |
| 9/15/2011 | ND | 411 |
| 8/18/2011 | ND | 304 |
| 7/21/2011 | ND | 439 |
| 6/20/2011 | ND | 731 |
| 5/27/2011 | ND | 631 |
Dried sludge
Johoku purification center
| Sample taken | Iodine | Cesium |
| 3/1/2012 | 18 | ND |
| 2/2/2012 | 140 | ND |
| 1/5/2012 | 58 | ND |
| 12/9/2011 | 190 | ND |
| 11/11/2011 | 26 | ND |
| 10/14/2011 | 114 | ND |
| 9/15/2011 | ND | ND |
| 8/22/2011 | 85 | ND |
| 7/21/2011 | 50 | ND |
| 6/20/2011 | 148 | 36.7 |
| 5/27/2011 | 12.2 | 16.2 |
Nakajima purification center
| Sample taken | Iodine | Cesium |
| 3/1/2012 | 72 | ND |
| 2/2/2012 | 50 | ND |
| 1/5/2012 | ND | ND |
| 12/9/2011 | 51 | ND |
| 11/11/2011 | 28 | ND |
| 10/14/2011 | 32 | ND |
| 9/15/2011 | ND | ND |
| 8/22/2011 | 70 | ND |
| 7/21/2011 | 33 | 87 |
| 6/20/2011 | 26.3 | ND |
| 6/13/2011 | 29.0 | 22.1 |