[ RadSafe ] [EXTERNAL] Bq/kg soil

[Dennis Quinn]

A quick run of Resrad shows the following:
Keep in mind that there are many assumptions, and this can be considered a
gross estimate:

5,000 Bq/kg Cs-137, with the following pathways: Ground shine, inhalation,
soil (consumption through cross contamination) and water ingestion: 
2.7 mSv per year at start (year 0), 2.1 mSv per year at year 10, and 0.8 mSv
per year at year 50.

Using the same concentration with the same pathways PLUS vegetable
consumption, meat ingestion, milk ingestion (assuming the vegetables, meat
and milk are  from the land with 5000 Bq/kg Cs-137), then the results are
slightly higher:
3.0 mSv/year at year 0, 2.4 mSv/yr at year 10, and 0.9 mSv/yr at year 50.
The ground shine is 90% of the dose; and the vegetation consumption is about
8% and meat consumption about 2% of the totals.

Regards,
Dennis Quinn

Dennis Quinn, CHP
DAQ, Inc.
dqdx at aol.com

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Karen Street
Sent: Monday, December 05, 2011 6:33 PM
To: The International Radiation Protection (Health Physics) Mailing List
Subject: Re: [ RadSafe ] [EXTERNAL] Bq/kg soil

Pretend I'm a lay person who blogs on climate change and energy issues and
wants to put the 5,000 Bq/kg limit in Japan in context. Be kind.

I used to teach high school physics so I understand the really easy stuff.

> RESRAD is OK, but you NEED to understand your scenario, and make sure 
> the assumptions that go into it are reasonable.  RESRAD will happily 
> allow scenarios that have little connection with reality.
> 
> If you are plugging in a bunch of isotopes quantified through gamma 
> spec, make sure you leave out K40.  In many soils (and water, for that
> matter) K40 may be the isotope with the highest activity, but it 
> actually does not contribute any actual dose through ingestion 
> pathways (because the body regulates potassium so well) and if there 
> is enough
> K40 in the soil for significant external dose, you aren't farming it.
> 
> -----Original Message-----
> From: radsafe-bounces at health.phys.iit.edu
> [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Wasiolek, 
> Maryla
> Sent: Monday, December 05, 2011 1:47 PM
> To: The International Radiation Protection (Health Physics) Mailing 
> List
> Subject: Re: [ RadSafe ] [EXTERNAL] Bq/kg soil
> 
> Activity concentration in the soil gets converted to doses by using 
> the environmental transport and exposure models.  ResRad
> (http://web.ead.anl.gov/resrad/home2/) is a good example of software 
> that uses such model.
> 
> -----Original Message-----
> From: radsafe-bounces at health.phys.iit.edu
> [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Karen Street
> Sent: Monday, December 05, 2011 2:31 PM
> To: The International Radiation Protection (Health Physics) Mailing 
> List
> Subject: [EXTERNAL] [ RadSafe ] Bq/kg soil
> 
> I see Japan has a standard of 5,000 Bq/kg soil, and that a sizable 
> amount of acreage is affected.
> 
> What are the standards of other countries, and how the heck does this 
> get converted into mmSv, assuming this is agricultural land?
> 
> I assume there is variation by crop.
> 
> What do I not know? 
> 

--
Best wishes,
Karen Street
Friends Energy Project
blog http://pathsoflight.us/musing/index.php

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