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Numerical values and units to know

Basic Knowledge on Radiation

3.Numerical values and units to know

Typical values related to radiation and radioactive materials

Are food and drinks safe?

男の子
博士

Let me explain about the threshold of radioactive materials in food and some of the typical radiation dose rate values in everyday life.

Numerical values and units relevant to food

Bq

Becquerel

Units used for radioactive materials in food

general foods

100Bq/kg

魚
食パン
野菜

Strict standards

The safe limit of additional radiation dose is set at 1mSV or less per year for all ages and genders.

Milk

50Bq/kg

Milk

Stricter standards

Due to the high intake of milk by children, milk is governed by a stricter standard, which limits the allowed radiation dose to half of "general foods".

Infant foods

50Bq/kg

Infant foods

Stricter standards

Since children are considered to be more vulnerable than adults. Baby food is governed by a stricter standard, which limits the allowed radiation dose to half of "general foods".

drinking water

10Bq/kg

drinking water

Even stricter standards

Products that are consumed in high quantity by everyone and cannot be substituted follow the most strict of standards.

博士

Food is expressed in units of becquerels.
Everything for sale has to meet strict standards.

So food products and tap water are safe!

男の子

Numbers and units related to radiation around us

Sv

Sievert

Units used for effects on the body

Radiation around us

2.1mSv/y

Amount of radiation received from nature in a year

The amount of radiation received from nature in a year.

For more information, see "5. Environmental Radiation."

1mSv/y

Annual additional radiation dose

This is the limit set for radiation exposure in a year in addition to natural and medical radiation.

0.23mSv/h

Additional radiation dose per hour

Additional radiation dose 1 millisievert per year, converted to per hour, plus the natural radiation dose.

Values and units with health effects

Sv

Sievert

Units used for physical effects

Approximate Health Effects

100mSv

A guideline to determine effect on human health

It has not been scientifically determined whether 100 millisieverts or fewer has an effect on the body.

Details are explained in "6. Effects on the human body."

博士

Radiation is also found in nature.
We regulate it to make sure we receive as little radiation as possible.

When using Sv, make sure to check the units and see if it's in years or hours.

男の子

Here's the point!

Three numbers and units related to food

100Bq/kg
50Bq/kg10Bq/kg

Unit: becquerel/kilogram

Three numbers and units related to familiar radiation

2.1mSv/y1mSv/y0.23mSv/h

Units: millisievert/year, millisievert/hour

Values and units relevant to health effects

100msv

Unit: millisievert

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