Radiation Exposure Q&A

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Q&A concerning radiation from the Fukushima Daiichi Nuclear Power Plant damaged during the 2011 Tohoku Earthquake

 

Q1. Will airborne radioactive material reach Mie Prefecture?

A1. Airborne radioactive material behaves similarly to pollen. This means that it can become suspended in the air, but will move according to wind patterns, and cannot drift against the wind. Because the westerly winds over Japan blow from west to east, it is highly unlikely that radioactive material from the Fukushima Daiichi Nuclear Power Plant will reach Mie.

 

Q2. Is it necessary to wear masks and/or protective clothing when going outside?

A2. At this time, there is no indication that airborne radioactive material will reach Mie Prefecture. Even if airborne radioactive material were to reach Mie, such measures are not expected to be necessary.

 

For more information about radiation monitoring in Mie, please visit:

http://www.pref.mie.lg.jp/KOHO/HP/tohoku/data/index.htm

 

Q3. Is exposure to rain water dangerous?

A3. At this time, there is no indication that airborne radioactive material will reach Mie Prefecture. Even if airborne radioactive material were to reach Mie, exposure to rain water is not expected to be hazardous.

 

Q4. How does radiation affect the human body?

A4. Small amounts of radiation will not cause illness. However, increasingly high levels of exposure can have probabilistic effects and deterministic effects on the body, such as genetic abnormalities, nausea, cell damage, etc.

 

Example of a probabilistic effect: Receiving 100 mSv (milli seiverts) in a single dose increases an individual’s risk of developing cancer by 0.5%.

 

Example of a deterministic effect: At exposures of 200 mSv and higher, individuals begin to develop health issues.

 

 

Q5. What is the difference between radioactive material, radioactivity, and radiation?
A5. ”Radioactive material” is defined as material that possesses the quality of “radioactivity,” which is in turn defined as the quality of releasing radiation. The Japanese terms for “radioactive material” (放射性物質- houshasei busshitsu) and “radioactivity” (放射能- houshanou) are used interchangeably in Japan. “Radiation” (e.g. gamma rays), like visible light, is a form of energy. [The radiation emitted by certain substances is particularly high in energy, and can cause damage to the human body.]

 

Q6. Is it safe to consume agricultural produce from Fukushima?

A6. All produce from Fukushima undergoes screening for any radioactive material. Any produce that does not meet the required standards is not distributed to consumers; therefore, there is no risk in consuming produce from Fukushima. Thoroughly washing produce that has been distributed is also effective.

 

 

Q7. Is it safe to consume seafood from Fukushima Bay?

A7. All seafood caught in Fukushima Bay undergoes screening for any radioactive material. Any seafood that does not meet the required standards is not distributed to consumers; therefore, there is no risk in consuming seafood caught off the shores of Fukushima.

 

Source: Food Safety Edition 0317, Volume 3,　03/17/11.　Notification from the Director of the Ministry of Health, Labour and Welfare, Pharmaceutical and Food Safety Bureau’s Food Safety Division.

 

 

 

Q8.How far should one move away from the plant to ensure their safety and how is time spent in an area related to exposure?

A8. As a photon, radiation behaves similarly to light. The concentration of radiation in an area is inversely proportional to the square of the distance from the radiation source (i.e. if the distance from the plant is doubled, the amount of radiation drops to a quarter of the original amount from the previous area) The radiation levels cited by the media represent the amount of exposure that an individual would receive if they stayed in the same area for one hour. (mSv per hour) In other words, an individual’s exposure depends on both the strength of radiation at the source and the amount of time spent in an area.

The radioactive material released from the plant can be suspended in the atmosphere and carried by wind. However, as long as the wind continues to blow from the West, it is likely that airborne radioactive material will be carried out to the Pacific Ocean.