5.Environmental Radiation
Radiation has always been around us.
Can we eliminate radiation?
We can't.
Because there has always been radiation around us in nature and in our bodies.
Radiation received from nature
External exposure
exposure to radiation from outside the body.
2.1mSv per year
( in Japan's case)
Internal exposure
Radiation received from inside the body.
Natural radioactive materials in the body and food
7000Bq
Radioactive materials in the body
For a Japanese person weighing 60 kg
potassium 40
carbon 14
rubidium 87
tritium,
lead and polonium
4,000Bq
2,500Bq
500Bq
100Bq
20Bq
sum total
Approx7,000Bq
Amount of radioactive material (potassium 40) in food
Potassium is found in most foods.
Dried kelp 2,000
Dried shiitake
mushroom 700
Potato chips 400
Raw seaweed 50
Spinach 200
Fish 100
Beef 100
Milk 50
Bread 30
Rice 30
Beer 10
Unit: Bq / kg (becquerel / kilogram)
In addition to environmental radiation, we're also exposed to radiation in medicine.
Radiation exposure around you
There is no physical difference between natural and man-made radiation, such as alpha, beta, and gamma radiation, and there is no difference in their effects on the body.
There is also no difference in the effects of exposure to the same dose of external and internal radiation.
So there is a surprisingly large amount of radiation around us.
Radiation is also very common in nature.
Here's the point!
Radiation has always been present in nature, such as in the air and earth, and in food.
We receive small amounts of radiation every day from nature,about 2.1 mSv per year in Japan.