About the radioactivity and the unit Becquerel

There was Tohoku Kanto Great Earthquake on March 11, 2011. The radioactive substance leaked in the first nuclear accident in Fukushima Japan, and the remaining radioactivity was detected in food. The amount of this radioactivity is a unit named Becquerel. Did the question what it was Becquerel and one.

Radioactivity and radiation

The radioactivity is an ability that the radioactive substance puts out the radiation. There are Becquerel [Bq] and a curie for the unit. The material that has the ability to put out the radiation is called a radioactive substance.

The radioactivity (radioactive substance) puts it out, and the radiation is an electromagnetic radiation and corpuscular rays not visible. The unit of sievert is used to show the exposed dose to the living body in this.

Note might the confusion of these and use in a recent report though the radioactivity and the radiation are quite different.

Becquerel (Bq) is an amount of the radioactivity.

Becquerel is a unit that shows the amount of the radioactivity. The amount of the radioactivity that collapses one atomic nucleus a second and is put out is assumed one Becquerel. If ten atomic nuclei a second collapse and the radiation is put out, it becomes ten Becquerel. It is a similar one to hertz [Hz] of the frequency of the exchange because it is a number of one second.

The remaining radioactivity of food and the intake have been limited.

To prevent effects of atomic radiation by taking food and water including the radioactive substance to the inside of the body, Becquerel is handled as a unit of the safety standard of food. The limitation of the intake is a hit by food 1kg and as follows.

For radioactive iodine 131

Drinking water and milk---300[Bq/kg],  vegetable---2,000[Bq/kg]

For radioactive cesium 137

Drinking water and milk---200[Bq/kg],  vegetable, grain, meat, egg, and fish---500[Bq/kg]