Re: Cs-137 in wood ash

[RADPROJECT@aol.com]

In a message dated 98-07-08 10:32:23 EDT, you write:

<< I know that at some point this was posted on radsafe and the copy that I
 saved, well...I guess I hit delete instead of save.  How much Cs-137 is
 in wood ash and what is the average annual dose from burning wood for
 heat in a typical home?
 
 Emelie Lamothe
 lamothee@aecl.ca >>

My earlier post on this subject did not address an estimate regarding the dose
from  burning wood in a home, but a simple calculation from the use of ash as
a fertilizer to grow vegetables and gras, raise cows, feed livestock, etc.

Cs-137 concentration in woodash from domestic burning ranges from about 300
pCi/kg of ash from CA to about 33,000 pCi/kg of ash in Northern Florida. One
could calculate exposure to wooddust in cleaning out a fireplace or exposure
to a certain mass of woodash containg Cs-137 at any level due to direct
radiation.

There was a lengthy article on the Cs-137 issue in the Eganville Leader
(Canada) on Jan. 8, 1992, written by Ray Stamplecoski. The articles title:
"Radioactive trees, wood ash traced to nuclear bomb test --U.S researcher
finds ash thats 100 times more radioactive than levels of radiation releases
prohibited at nuclear power stations." Another artilce in this collection was
titled: "Survey Implications for the Ottawa Valley --"Is it time to kiss your
ash goodbye?" --U.S. physicist.

The issue of wood ash from northern Florida having the highest Cs-137 levels
of any samples I've analyzed raises a potentially important issue of current
note. The current forest fires raging in Florida have  reduced hundres of
thousands of acres of  trees and vegetation to ash. A wildfile can release
more than 5 percent of the ash generated into the air. Given a certain areal
density of vegetation, and assuming that there will be an ash fraction of
about 1% vs total wood weight, and that about 5% or more of the ash generated
will become airborne you can derive a Cs-137 airborne areal source term that
will be dispersed from a wildfire. The dose from this pathway in the FL case
is likely to be small, but it could easily  lead to elevated levels of Cs-137
being picked up in environmental air monitoring programs near nuclear plants
unrelated to plant operations or detected in samples collected from any other
air monitoring network.

This pathway was clearly documented at much  higher levels 5 or 6 years ago in
wildfires in the environment around Chernobyl when Cs-137 fixed in trees from
the original accident was re-dispersed over a very wide area.

In 1991 when I presented my first paper on this subject: "Cs-137 in Woodash
-Results of  Nationwide Survey" at the HPS Annual meeting in Washington, DC
and dozens of news articles resulted, I got some interesting phone calls about
this matter. One caller said he read of the Cs-137 issue in  "Garbage"
magazine ["Fallout from the Fireplace", Nov/Dec 1991] and was a "Compose
Officer" from Toronto, Canada. He said he was concerned what might happen if
woodash was used in compost since the article in Garbage said to keep wood ash
out of the compost pile [I never spoke to Garbage and never said this].  At
first I thought this call from a "Compost Office" was some kind of prank call
by a friend since I didn't believe there was really a magazine called
"Garbage" or that there were jobs titled "Compost Officers". I was wrong on
both counts and Compost Officers do exist in Canada.

Another caller from Canada was concerned because he was a chimney sweep and
was worried that Cs-137 in the creosote buildup in chimneys might present a
risk to him in his occupational exposure to it. I was able to give him some
perspective that his major concern by far was his exposure to polycyclic
aromatic hydrocarbons (PAH) and other organic carcinogens in the creosote not
Cs-137. I told him a bit about the history of epidemiology and the initial
documentation of a high rate of scrotal cancer in English chimney sweeps in a
study by Dr. Percival Potts hundrends of years ago. I also have some data on
Cs-137/K-40 levels  in creosote  vs. woodash on the same home which shows some
interesting fractionation, but that is another story.

The issue of NORM, and NARM, and TENR [Technologically enhanced natural
radioactivity] have all received attention. However, Cs-137 in wood ash
whether from a home fireplace or stove or commercial woodburning boilers like
in power production or the pulp and paper industry produce millions of tons of
technologically enhanced fission product radioactivity [TEFPR  as an
acronym??] in the ash generated

Overall, I found my interactions with interested news and environmental
publications and private individuals on the Cs-137 in woodash issue to have
been very productive, in that it gave me a chance to make certain points in
numerous popular press news articles about relative risks of radiation vs.
other agents and the inconsistency in regulating radioactivity in nuclear and
hospital waste streams vs. other waste streams that contain elevated levels of
weapons test fallout. The greatest antipathy to discussing the  Cs-137 in
woodash issue came surprisingly from nuclear utilities  which felt it best not
to discuss anthing about radioactivity in the environment with any members of
the public because it would do nothing but scare or confuse them. It seems the
root problem is that nuclear utilities and their public spokesperson tend to
think the public is too simple to really understand radiation issues, and that
rather that deal with the deep public interest about radiation matters on a
meaningful basis, it is best to just avoid interactions, keep a low profile,
and just do the job of generating power. I believe this policy is
fundamentally flawed and has proven to be nothing more than suicide on the
installment plan.

Almost every publication of the dozens I dealt with on the Cs-137 in woodash
issue, including Organic Gardening Magazine [New Ground Feature on the latest
research: "Is Wood Ash A Nuclear Worry?, p. 18-19, Jan 1992] by Rodale Press
gave me a chance to critique the final articles and correct technical errors
or sometimes inflamatory statements without my having to have demanded upfront
that they give me this priviledge [which would have killed any coverage].
Organic Gardening's first draft said my claims about minimal risk due to
Cs-137 in woodash might be considered an attempt to focus attention on
radioactivity in the natural environment because of pressure vessel
embrittlement problems at a nuclear plant in Western Mass!!!

At the time of Organic Gardening drafting its feature article, I was
Operations Support Manager for a central environmental lab run by a New
England utility nuclear service division, which also operated a nuclear plant
in Western Massachusetts. The parent nuclear utility company was having to
deal with neutron embrittlement of the pressure vessel at the Rowe Nuclear
plant. Initially Organic Gardening wrote my statements about Cs-137 dose and
risk being minimal  might be a whitewash of the potential that the pressure
vessel of this older generation plant "might fracture in an accident
contaminating an area the size of Pennsylvania".  I was able to convince the
editor that this comment was a "cheap shot". I told Organic Gardening  I was
an environmental radiation and public health scientist and that I had nothing
to do with the engineering side of the utility. Further, my first raising the
issue of  woodash radioactivity went back to the mid-1980s as did my initial
measurements of Cs-137 in woodash-- at a time I was not employed by the
utility in question or any utility.  Fortunately, the final article in Organic
Gardening changed their comments about a China Syndrome like scenario to read
on this point:

     "Farber acknowledges that some have questioned his good intentions here.
He notes, with a laugh, that he has been accused of using his report to focus
attention on radioactivity in the natural environment in order to "whitewash"
concerns about radioactive waste disposal.
      Farber stresses that although he does work for a nuclear power company,
his wood ash study is neither endorsed by nor fundded by Yankee Atomic, and
that several independent radiation specialists are not investigating this
issue as well.
     Stay tunes. We'll make it our business to bring you any further good
science on this, uh "burning" issue."

Organic Gardening in answering its own question  "Is Wood Ash A Nuclear Worry?
by stating that wood ash :
     "....is likely to contribute no more that [sic] about 1 millirem per year
[from Cs-137] of additional radiation to an individual eating vegetables,
milk,  and meat raised on wood-ash contaminated fields."
     "To put that number in perspective, the average dose of 'background'
radiation that we each receive 'from environmental sources' is 360 millirems
per year. So woodash fertlilizer does not seem to pose a large radioactive
risk."

If a societal consensus could be reached among enviromental interests that an
increment of 1 millirem per year from fission products "does not seem to pose
a large radioactive risk." we would be well on our way to defining de minimus
and nuclear interests being able to license nuclear waste disposal sites.
Perhaps by taking  Organic Gardening's statements at face value on the CS-137
dose/risk issue as a precedent we can begin to discuss the issue more
rationally with the public.

What this one case makes clear is that the only way to get any interest to
think about what constitutes an "acceptable" level of risk, is to connect the
risk factor to something the individual can relate to. With woodash Cs-137 we
are dealing with a fission product in a waste stream the individual often
generates and uses as a fertilizer. We are not dealing with natural isotopes
vs. fission products or radiation risks vs. other types of risks. 

When I posed the tongue-in-cheek question: "Woodburners and organic farmers
--Is it time to kiss your ash goodbye?" I was not trying to convince anyone of
anything, but simply posing a legitimate question. Would an individual
homeower, because Cs-137 is present in woodash from domestic woodburning at
levels of 20,000 pCi/kg [the typical levels in northern New England and
Canada] be willing to spend  $200 per cu.ft. to dispose of the woodash. What
would this disposal cost do to the economics of domestic woodburning.
Industrial woodburning generated 905,000 tons of ash (63%) and residential
woodburning about 543,000 tons of the total of 1,446,000 tons of total woodash
produced in the US in 1989. As Science News reported ["Wood ash: The
unregulated radwaste"]: 

     "if ash were subject to the same regulations, he says [ as low-level
nuclear waste streams] its disposal would cost U.S. wood burners more than $30
billion [at 1991 prices] annually."

These kinds of comparisons get peoples attention and make both homeowners and
industrial woodburners stop and suddently think about what is sensible when it
comes to regulating low-level nuclear waste streams. 

The Cs-137 in wood ash issue and the potential pathways of exposure to the
public was raised by critics in 1991 concerning the licensing of a 50 MW(e)
wood burning power plant in Killingly, CT. I was retained as an expert witness
by the host city of Killingly on the licensing of this plant and testified at
a DEM hearing on environmental impacts. I developed a basic sampling protocol
to characterize the radiological impacts of this plant which the developer
vehemently opposed conducting. Before the issue was settled, the State of
Connecticut voted to approved an $18 million buyout deal by Northeast Utlities
to payoff the private developer for sunk costs to cancel the project at that
moment rather than complete the $70 million dollar project.   

I was later told by the Attorney for the developer who cross-examined me very
harshly about my report as to characterizing the radiological impacts of this
wood fired power plant [which I testified were likely to be small but never
adequately measured to date] that the radioactivity issue was the "nail in the
coffin" for the project. Killing the Killingly project was certainly not my
intention, but perhaps resulted in some corporate non-nuclear interests
appreciating the impact which undue concern about low-level radioactivity can
have on industrial operations, perhaps even their own.


Stewart Farber, MS Public Health
Consulting Scientist
Public Health Sciences
19 Stuart St.
Pawtucket, RI 02860

Phone: (401) 727-4947   Fax: (401) 727-2032   E-mail: radproject@usa.net