Fukushima Daiichi worker dies of acute leukemia; radioactive cesium contamination found over wide area

In an article entitled "Radioactive Cesium Found in Wide Areas Around Japan Fukushima Plant," Fox Business reports that a 40 year old Tokyo Electric Power (Tepco) worker has died of acute leukemia after having worked at Fukushima Daiichi for 7 days and being exposed to 0.5 millisieverts (50 millirem) of radioactivity, according to the company. Tepco denies any relationship between the worker's death and his radioactive exposures at Fukushima Daiichi.

The article also reports wide ranging radioactive cesium contamination. Of 2,200 locations checked within a 100 kilometer (62 mile) radius of the melted, shattered atomic reactors, 33 tested positive for Cesium-137 contamination "in excess of 1.48 million becquerels per square meter, the level set by the Soviet Union for forced resettlement after the 1986 Chernobyl disaster. Another 132 locations had combined amount of cesium 137/134 over 555,000 becquerels per square meter, the level at which the Soviet authorities called for voluntary evacuation and imposed a ban on farming."

A becquerel is defined as one radioactive disintegration per second. Cesium-137 has a half-life of around 30 years, meaning it has a long-lasting hazardous persistence of 300 to 600 years. Cesium-134 has a half-life of just two years, but this means during its 20 to 40 year persistence, it is intensely radioactive. The human body mistakes radioactive cesium for potassium. It lodges in muscle tissue.

The Mainichi Daily News and Kyodo News Service report some more detail on the worker's death, such as claims by Tepco that the worker's radiation exposure at Fukushima Daiichi is only one-tenth what is usually associated with a workplace related death, and that acute leukemia's latency period is at least a year long. However, Tepco admitted it did not know the worker's history prior to his arrival at Fukushima Daiichi in August. 

The Mainichi Daily News also reported more detail on the radioactive cesium contamination map published by the federal Ministry of Education, Culture, Sports, Science and Technology (MEXT) alluded to above, including the names of the towns with radioactivity levels in excess of Soviet habitation bans downwind of Chernobyl. The unlucky Japanese towns are: Okuma (which hosts part of the Fukushima Daiichi nuclear power plant, and is contaminated at a level ten times worse than the Soviet habitation ban), Minamisoma, Tomioka, Futaba, Namie, and Iitate. In addition, the federal Ministry of Agriculture, Forestry, and Fisheries (MAFF) has documented 13 Fukushima Prefecture municipalities -- including Iitate, Soma and Minamisoma -- where radioactivity measurements exceed 5,000 becquerels per kilogram of soil, "which is the limit over which rice planting is forbidden."