A practical question from a resident in Tokyo

[britinjapan]

I discovered your site yesterday, and have been fortunate to find such fine quality and detailed information on the Japan situation. Forgive me if I missed this already, but I have a few questions on actually living in Tokyo - I would much appreciate any responses:

1. The radiation level seems to be around 0.20-0.30 micro sieverts per hour - although I read this is not high, what precautions should I be taking? Covering skin (bald head!); changing clothes at door (keeping outdoor clothing separate etc)?

2. Regarding the levels of drinking water, Iodine 131 and Cesium 134 and 137 are currently in drinking water (http://ftp.jaist.ac.jp/pub/emergency/monitoring.tokyo-eiken.go.jp/monitoring/w-past_data.html). What is anyones advice?

3. I just recently fould out about MOX in reactor 3 - is there anything else I should be looking out for - a few words on Plutonium for a novice would be appreciated.

4. Lastly - at what trigger does one move south or out? If the Japanese Government move the radius around the plant to 100km, this is obviously a sign that the situation is getting a lot worse? An explosion? Any other things to look out for, or levels to be monitored?

Any comments and views appreciated for a novice and resident in Tokyo.

Once again, thanks for your access to your fine site.

Regards,

[Bob S]

1. The radiation level seems to be around 0.20-0.30 micro sieverts per hour - although I read this is not high, what precautions should I be taking? Covering skin (bald head!); changing clothes at door (keeping outdoor clothing separate etc)?

4. Lastly - at what trigger does one move south or out? If the Japanese Government move the radius around the plant to 100km, this is obviously a sign that the situation is getting a lot worse? An explosion? Any other things to look out for, or levels to be monitored?

Any comments and views appreciated for a novice and resident in Tokyo.
The United States Nuclear Regulatory Commission recommended annual occupational dosage limits for adults is given in

http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1736/

Specifically see page 3-38 at

http://www.physicsforums.com/attachment.php?attachmentid=33280&d=1300574969

The recommended maximum annual occupational dose is 5 rem, or 50 milliSieverts. This is equivalent to about 6 microSieverts per hour. Dose rates less than this are tolerable.

If you spend a lot of time outdoors, cover your head, or risk getting sunburned.

Bob S

[britinjapan]

Many thanks. Could anyone comment on the implications/consequences that Plutonium has now been discovered in the top soil near the plant? Thanks

[marcusl]

You might keep track of the US government's evacuation advice to US nationals living in Japan. As the disaster unfolded they advised US citizens within a 50 mile radius to evacuate, as opposed to the Japanese government's 12 km or so (I may be remembering the numbers wrong).

There is reason to suspect that we are reporting radiation levels and risks more accurately than the Japanese government (remember when our government said the reactor fire wasn't out after the Japanese said it was, and when they looked again they did find fire?)