Japan Travel Guidelines

We have been asked many times if it is safe to travel to Japan or if it is safe to travel with children to Japan.
Safety depends on the radiation levels in the area you plan to visit, what you consume, and the risk factors for the people traveling.

General radiation levels have reduced in the decade since the accident. Some aspects still pose a health risk to the public. Insoluble cesium-bearing microparticles typically referred to as “microparticles” are microscopic pieces of melted reactor fuel. Many of these are small enough to inhale, are highly radioactive, and can lodge in the lungs. Due to its insoluble nature, the body cannot easily expel these materials, creating a long-term highly localized internal radiation exposure. These have been found in the regions that were originally subjected to fallout from the reactor meltdowns. They tend to concentrate in ditches, gutters, places where water or dirt collects. They have been found as far away as Tokyo. Activities that kick up dirt or involve walking in areas likely to be contaminated pose a higher risk. High winds and typhoons are also a concern for suspension into the air and the redeposition of these microparticles. Industrial grade N95 masks may be sufficient to reduce the risk of inhaling microparticles during lower-risk activities.

For newer food testing data we suggest independent testing done by Iwaki Mother’s Radiation Lab. Their data has been more relevant than some of the government-sponsored data and they test samples brought in by the public. Their data in English can be found here.

Foods that are at the highest risk for potential contamination are wild vegetables, wild mushrooms, deer, boar, and bottom feeder-type fish from the areas closest to the disaster site. The findings in Japan are similar to the findings after Chernobyl. These high-risk foods are still heavily contaminated in the Chernobyl fallout regions of Europe.

Risk Factors:
Radiation impacts children and pregnant women much more than it does men. Women who are not pregnant in general fall somewhere between the risk for children and men. More caution should be taken based on the person’s risk factor.

Determining Radiation Levels:
There are a number of resources that will show the current environmental radiation in cities across Japan.  They are normally in microsieverts per hour or uSv/h. The pre-accident background levels in Japan are in millisieverts per year or mSv/year. We will explain how to interpret the two so you can understand any radiation increase in an area you plan to visit.
* millisieverts are 1000 microsieverts. 

Example using Osaka:
Osaka .05 usv/h to .119 uSv/h
source – http://japan.failedrobot.com/

Natural background annual radiation for Osaka about 1 mSv/year
source – http://www.jaea.go.jp/04/ztokai/kankyo_e/kaisetsu/expln_1.html

One year is 8765.8 hours
1 year = 8 765.81277 hours

.05 usv/h x 8765.8 = 438.29 usv/year
438 microSv/year equals 0.05 microSv/h.
0.119 microSv/h equals 1042 microSv/y or roughly 1 mSv/year which represents the natural background level. So the current levels in Osaka are at about normal background levels indicating no additional radiation contamination.

An example for Tokyo:
Current readings on May 9, 2012, showed a radiation level of between .05 uSv/h and .261 uSv/h and the natural background radiation around Tokyo was .99 mSv/year
.05 uSv/h x 8765.8 = 438.29 uSv/year or roughly, slightly less than .5 mSv/year. This is less than background levels.
.261 uSv/h x 8765.8 = 2287.87 uSv/year or 2.2 mSv/year roughly just over double the pre-disaster background level in Tokyo but this is the higher end of the varied readings around Tokyo. There are of course higher levels being found in “hot spots” where radiation collects in the environment.

Background radiation levels in Japan (pre-accident)

Live radiation readings taken in May 2012 show the “per hour” reading in various areas.

Consumption Safety:
The environment is one risk factor for potential contamination, the other is what you consume. Eating or drinking substances contaminated with radioactive substances will cause internal exposure, something that can be worse than external exposure from the environment. Even in an area of little or no environmental contamination, food can be a risk factor. As with any modern culture, food is shipped from various places or co-mingled with food from many sources. Knowing the source of what you are eating, sticking to things lower on the food chain and food of better quality can help lower risk.

You can find out more about food contamination in Japan by the area grown with this convenient search tool
This map (below) shows amounts of food contamination over the government limits in areas of Japan in May 2012
This chart shows food contamination levels in a spreadsheet for early 2012.

Some suggestions for safer food consumption:

  • Try to know where your food came from. Imports, food from the far south and west are less likely to be contaminated.
  • Try to find food that has been tested, some producers and retailers are testing and showing results to prove the food is safe.
  • Produce is frequently labeled with the production location, these have been faked by some unscrupulous sellers in rare instances, using a food source you trust or that tests lower your risk.
  • Aeon grocery stores and many food coops are testing food and only accepting no contamination products.
  • In situations where you can’t research food like restaurants, looking for quality can help lower the risk.
  • It is commonly assumed that low-quality foods are more likely to have questionable ingredients in them.
  • Highly processed foods, things like convenience store prepackaged foods have been mentioned as possible risks.
  • Seafood from the Sea of Japan tends to be less likely to be contaminated, as is Lake Biwa.
  • Seafood from the eastern Pacific holds more risk of being contaminated.
  • Eating lower on the food chain and from safer areas will help lower risk.
  • Formula and baby foods could be brought from home to sidestep the risk issue.
  • Distilled water would be preferable to tap water, distillation removes potential contaminants.
  • Reverse osmosis water also would have most contaminants removed.

Both are typically available as bottled water in most countries.

Places where contamination can concentrate:

  • Water puddles
  • Street gutters
  • Under downspouts
  • Places where wind concentrates or funnels consistently

Practicing good hygiene and housekeeping habits can also lower exposure if you plan to be in a contaminated area. Leave shoes outside or in an entryway to keep contaminated dirt out of inside spaces. Wash your hands before eating or putting anything into your mouth with your hands. If conditions are dry and very windy a nonwoven pollen mask can be worn to block contaminated dust and dirt from being breathed in. A simple N95 dust mask is suggested by various groups in Japan as being sufficient to block contaminated dust and dirt that can be blown around. If you plan to be in an area with some contamination packing a few of these may be of use. They also block pollen.

Find out more about radiation protection measures you can take to lower exposure from this handy guide from The Coalition For Independent Investigation

Distillation to remove cesium, test by University of Nebraska at Lincoln

Removing i-131 from drinking water

EPA water details on reverse osmosis to remove radionuclides

Aeon Grocery Stores

OK Food – citizens crowdsourced safe food information system in Japan

Japan pre-accident background levels of radiation

Radiation readings around Japan by citizen networks

Safecast public sourced radiation readings and maps for Japan


MEXT radiation data*

MEXT interactive radiation maps Japan*

*MEXT radiation data was transferred to Japan’s Nuclear Regulator (NRA)
In March of 2022, NRA will hand this over to JAEA, Japan’s nuclear research agency.
The JAEA site is live but has technical issues and loads extremely slow. This site does
have a wide variety of available radiation data types.

NRA Fukushima Fallout Deposition Map

JAEA Radiation Monitoring Page

Food contamination search tool

Food contamination spreadsheet for 2012 up to April

*check our pages for updates on food contamination as we receive them.  

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