Japan radiation update - Bupa

Japan radiation update

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Japan radiation update

12 April 2011

1 Main developments

Upgrading of incident severity

Japanese authorities increased the severity of the nuclear incident in Japan from five (‘accident with wider consequences’) to seven on the seven-point International Nuclear Event Scale (INES) on 12 April 2011. A score of seven means the event is a ‘major accident’. However, despite the jump in severity score, the situation in Japan has not deteriorated and the levels of radiation being released are no higher than at other times since the tsunami. In mid-March, the authorities initially scored the incident at five on the scale as a temporary measure. The upgrade comes after Japanese authorities made new estimates on the total amount of radiation released into the environment. The disaster at the Chernobyl nuclear power plant in Ukraine 25 years ago is the only other nuclear incident in history to have scored seven on the scale. Estimates suggest that the amount of radiation released so far in the Japanese disaster is considerably less than that released during the Chernobyl accident.

Expansion of the evacuation zone

As of 12 April 2011, Japanese authorities have expanded the 20km evacuation zone surrounding the Fukushima Daiichi plant to include five towns. Weather and geographical conditions mean that these towns are experiencing high levels of radiation. Although the radiation levels in these areas are not immediately harmful to health, they may pose a danger if people continue to live there for an extended period of time. Residents will be evacuated over the coming month. Japanese authorities are also warning people living in the voluntary evacuation zone – a belt of land 20 to 30km from the plant – to be prepared to evacuate themselves in an emergency. People who cannot evacuate without help are being advised to leave now. This includes children, elderly people and pregnant women. Schools in this 10km belt are now closed.

2 Key points

Situation

A magnitude 9.0 earthquake off the coast of Japan on 11 March caused a tsunami that severely damaged several nuclear reactors in the north-east of the country. The worst affected reactor is at the Fukushima Daiichi power station. Radiation has leaked out of the plant and into the surrounding environment. Radioactive iodine has been found in at least seven prefectures of the country, radioactive caesium has been found in at least six prefectures and small amounts of radioactive plutonium have been found in soil up to 1km from the plant. Levels of radiation in the Fukushima area are falling but the situation will remain unstable until engineers have brought the reactors under control.

Radiation-affected areas

Japanese authorities have evacuated people living within a 20km radius of the Fukushima Daiichi plant. They have also advised people living within a radius of 20 to 30km of the plant to voluntarily evacuate the area. Those who choose to stay in this 10km-belt have been told to stay indoors. As a precautionary measure, Australian authorities have advised that Australians living within an 80km zone from the plant should evacuate the area.

Health risks

Exposure to high doses of radiation can cause radiation sickness and even death. At lower doses, radiation can cause an increased risk of cardiovascular disease and cancer, particularly thyroid cancer from radioactive iodine. Children and young adults have a higher risk of developing thyroid cancer after iodine radiation exposure than adults. The extra disease risk caused by radiation depends on the size of dose, length of time someone is exposed to it and the part of the body affected.

Who is at risk?

People directly involved in the repair work at the plant have the highest risk to their health from the radiation. An accident at a nuclear power plant is unlikely to expose the general population to radiation at the high dose that causes radiation sickness. Those living near the Fukushima power station and affected area have a higher risk to their health from the radiation than people living in other parts of the country.

Extent of contamination

People are always exposed to small levels of radiation emitted from cosmic rays and radioactive materials that occur naturally in soil. This is called background radiation. As a result of the current nuclear event in Japan, people living outside the 20km exclusion zone will not have been exposed to harmful levels of radiation at this time. Officials have found levels of radiation that are higher than usual in samples of air and tap water collected from other areas of the country, including the capital Tokyo. Although these levels are higher than usual background radiation, it does not mean that they are harmful if people are exposed to them for weeks or months.

Food and drink

Currently, the World Health Organization (WHO) advises that levels of radiation in tap water across Japan do not pose an immediate risk to health. Levels in water may vary in different areas and fluctuate day to day, so it is important to take advice from local authorities in Japan. Japanese authorities have found radioactivity above the regulatory standard in milk, spinach and other vegetables grown near the plant.

Since this situation emerged in Japan, Food Standards Australian New Zealand (FSANZ) has advised the Australian Quarantine and Inspection Service (AQIS) to test some foods from 13 Japanese prefectures before the products can be released for sale in Australia. These foods include fresh and dried fruit and vegetables, milk products, seafood and seaweed from five prefectures (Fukushima, Gunma, Ibaraki, Tochigi and Chiba) while frozen and dried vegetables from a further eight prefectures will also be tested. The tests ensure levels of radiation-emitting radionuclides in these foods are below internationally accepted safe limits. However, the risk currently posed by Japanese foods in Australia is negligible as Australia imports very little food from Japan and imports are limited to a small range of specialty products such as seaweed-based products and sauces.

3 Prevention measures

Potassium iodide tablets can offer some protection against radioactive iodine but not other radioactive substances. If the level of radioactive iodine rises and becomes potentially harmful to health, authorities may advise people to take potassium iodide tablets. TheAustralian Radiation Protection and Nuclear Safety Agency (ARPANSA) and Australia’s Chief Medical Officer advises that iodine tablets are only required when exposed to substantial radiation doses from radioactive iodine. While the Australian Government has sent potassium iodide tablets to the Embassy in Tokyo with additional supplies available if required. However, as radiation levels outside the 80km exclusion zone are low, there is no benefit of taking these pills at this time for those returning from Japan or those in Japan outside the Exclusion Zone. Using them unnecessarily may cause shortages in an emergency.

In the event of a significant release of radiation containing high levels of radioactive iodine, Japanese public health and emergency management officials may advise people in a specified area to take potassium iodide. If this instance, one tablet should be taken one to two hours before or after the exposure. The treatment is less effective if taken later than this, but it can still work up to six hours after exposure. The pills are safe to take during pregnancy and for breastfeeding mothers.

Potassium iodide tablets cannot protect people from radioactive caesium or plutonium so it is important to follow local advice if levels of these types of radiation rise. In the future, local authorities may advise people to take shelter inside a building to reduce exposure to radiation. A rise in radiation outside the exclusion zone is only likely in a worst-case scenario. Current predictions suggest that even in a worst-case scenario potassium iodide tablets and shelter will be sufficient to protect people from the likely levels of radiation.

4 Travel advice

There are currently no international travel restrictions on visiting Japan, but the WHO is advising against all but essential travel to the areas of the country affected by the tsunami. Because of the limitation on essential services, infrastructure damage, aftershocks and continuing uncertainty about the status of the Fukushima Nuclear Power Plan, the Australian Department of Foreign Affairs and Trade (DFAT) has advised Australians living in Tokyo, areas surrounding Tokyo and Honshu north of Tokyo to consider leaving the area unless their presence is essential. Australians are also advised not to travel to these areas. Foreign nationals from other countries should seek advice from their relevant embassy or consulate.

5 Where to get help

Emergency contact numbers in Japan are as follows:

  • Police 110
  • Fire and Ambulance 119
  • The Tokyo English Lifeline (Tel: +813 5774 0992) provides advice and counselling in English.

In Tokyo, you can obtain consular assistance from the following:

Australian Embassy Tokyo
2-1-14 Mita, Minato-ku
TOKYO 108 8361
Telephone (81 3) 5232 4111
Facsimile (81 3) 5232 4057
Web: http://www.australia.or.jp/en/consular/
Email address: auscitzreg.tokyo@dfat.gov.au

In a consular emergency if you are unable to contact the Embassy you can contact the 24-hour Consular Emergency Centre on +61 2 6261 3305 or 1300 555 135 within Australia.

6 Further information

Websites for the latest information

The situation is constantly changing and further Bupa updates will follow. Please check the websites below for the latest WHO and country-specific information most relevant to you.

Global:

Japan:

Australia:

UK:

USA:

7 Sources

Updated sources 14/4/11