- The DOST-PNRI continues to closely monitor the situation at the Fukushima Daiichi Nuclear Power Plant. The condition in the plant remains very serious but is slowly getting better.
- Gamma dose rates are measured daily in all 47 prefectures. As of 11 May 2011, the only notable values are those from Fukushima prefecture, where gamma dose rates were 1.7 µSv/h and Ibaraki prefecture, where gamma dose rates were 0.10 µSv/h. In all other prefectures, reported gamma dose rates were below 0.1 µSv/h with a general decreasing trend.
- Iodine-131, Cesium-134 and Cesium-137 were not detected in seawater at the sampling points of Japan’s Ministry of Education, Culture, Sports, Science and Technology (MEXT) beyond 30 km from the Fukushima plant.
- As of 11 May 2011, the PNRI had analyzed 42 food samples imported from Japan. These had activities lower than 3 Bq/kg of Cesium-137 and Cesium-134 and were almost at the limit of detection. The WHO Codex Alimentarius Commission recommended limit for international trade is 1000 Bq/kg for total radioactivity in food.
- The Comprehensive Nuclear Test Ban Treaty Organization (CTBTO) air monitoring station in the Philippines being serviced by the DOST-PNRI detected the following radioactivity concentrations (in table and graph):
|
Day |
Iodine-131 |
Cesium-134 |
Cesium-137 |
|
March 23 |
33 |
4.2 |
5.7 |
|
March 24 |
480 |
92 |
120 |
|
March 25 |
54 |
6.3 |
7.7 |
|
March 26 |
20 |
0.7 |
0.7 |
|
March 27 |
47 |
2.6 |
3.1 |
|
March 28 |
93 |
4.4 |
5.3 |
|
March 29 |
130 |
4.6 |
5.3 |
|
March 30 |
210 |
1.7 |
1.6 |
|
March 31 |
31 |
Not detected |
0.7 |
|
April 1 |
57 |
4.3 |
5.7 |
|
April 2 |
61 |
9.9 |
12 |
|
April 3 |
160 |
86 |
100 |
|
April 4 |
79 |
53 |
79 |
|
April 5 |
51 |
18 |
20 |
|
April 6 |
21 |
8.7 |
11 |
|
April 7 |
12 |
4.2 |
4.6 |
|
April 8 |
73 |
23 |
28 |
|
April 9 |
95 |
22 |
25 |
|
April 10 |
140 |
21 |
26 |
|
April 11 |
80 |
16 |
20 |
|
April 12 |
53 |
8.1 |
11 |
|
April 13 |
45 |
13 |
17 |
|
April 14 |
30 |
17 |
21 |
|
April 15 |
26 |
16 |
21 |
|
April 16 |
23 |
22 |
28 |
|
April 17 |
21 |
17 |
21 |
|
April 18 |
15 |
9.4 |
14 |
|
April 19 |
12 |
5.7 |
7.2 |
|
April 20 |
7.5 |
9.8 |
12 |
|
April 21 |
5.3 |
6.4 |
7.8 |
|
April 22 |
6.2 |
4.8 |
5.9 |
|
April 23 |
6.9 |
3.1 |
6.9 |
|
April 24 |
5.5 |
2.2 |
3.8 |
|
April 25 |
4.6 |
2.8 |
2.5 |
|
April 26 |
1.4 |
0.64 |
Not detected |
|
April 27 |
1.1 |
Not detected |
Not detected |
|
April 28 |
1.6 |
Not detected |
Not detected |
|
April 29 |
Not detected |
Not detected |
Not detected |
|
April 30 |
Not detected |
Not detected |
Not detected |
|
May 1 |
1.5 |
Not detected |
Not detected |
|
May 2 |
Not detected |
Not detected |
Not detected |
|
May 3 |
Not detected |
Not detected |
Not detected |
|
May 4 |
Not detected |
Not detected |
Not detected |
|
May 5 |
Not detected |
Not detected |
Not detected |
|
May 6 |
0.84 |
Not detected |
Not detected |
|
May 7 |
Not detected |
Not detected |
Not detected |
|
May 8 |
Not detected |
Not detected |
Not detected |
|
May 9 |
Not detected |
Not detected |
Not detected |
- The peak values on March 24 correspond to a dose of 131 nanosieverts in a year; sleeping next to someone for 8 hours a day for one year gives a dose of 20,000 nanosieverts because of the natural radioactivity present in the body.
- Activity Concentration of Topsoil Samples taken from PNRI grounds and other sites:
|
DATE COLLECTED d |
SITE |
ACTIVITY CONCENTRATION, Bq/kg |
||
|
Iodine-131 |
Cesium-134 |
Cesium-137 |
||
|
March 28 |
PNRI |
Not detected |
Not detected |
0.064 b |
|
March 28 |
PNRI |
Not detected |
Not detected |
0.175 b |
|
April 1 |
Gattaran, Cagayan |
Not detected |
Not detected |
Not detected |
|
April 4 |
Tuguegarao, Cagayan |
Not detected |
Not detected |
0.867 b |
|
April 5 |
La Mesa Dam |
Not detected |
Not detected |
Not detected |
|
April 5 |
La Mesa Dam |
Not detected |
Not detected |
0.500 b |
|
April 8 |
Site 1, Tanay, Rizal |
Not detected |
Not detected |
Not detected |
|
April 8 |
Site 2, Tanay, Rizal |
Not detected |
Not detected |
Not detected
|
