Radioactive Cesium in baby food - Fukushima

It is reported that radioactive Cesium (probably 137Cs) is found in milk powder (baby food) to the level of 30.8 Bq/kg. The limit set by the Japan’s Health Ministry is 200 Bq/kg. In terms of mass, the permissible amount works out to be 6.2 x 10-11 (ten to the power minus 11)g per kg of the milk food, i.e., about hundred times lower than one-billionth of a gram)!

Since, the SI unit to express the amount of radioactivity is Becquerel (Bq) is a very small unit, the numbers look big. In terms of the classical unit of Curie, the permissible amount of 200 Bq/kg works out to be just over 5 nanoCurie/kg (nano = 10-9 (ten to the power minus nine);means one-billionth).

Radioactive Cesium (137Cs/134Cs) and Strontium (89Sr/90Sr) are the radioactive elements found in the environment following any reactor accidents.

Since radioactivity measurement systems are so much advanced that we are able to detect and measure such low levels which were earlier treated as below detectable limits (BDL)!