Re: Los Alamos -Aiirborne activity from wildfires due to weapons' test fallout

[RadiumProj@cs.com]

In a message dated 5/12/00 6:51:42 AM Eastern Daylight Time, 
jstraka@doeal.gov writes:

> > 
>  > Radsters,
>  > First, my condolences to all those who have already lost their homes 
from 
>  > the fire.  My questions are:
>  > 
>  > Is there distributed surface contamination from historic activities at
>  > LANL 
>  > that could be remobilized from the fire, and if so, what kind of
>  > additional 
>  > monitoring is being done there and in the surrounding communities?
>  > 
>  > What can be learned from this?
>  > 
>  > Phil Egidi
>  > ORNL/GJ
>  > 7pe@ornl.gov
>  > ******************************************

Radsafers:
It should be noted that it is not merely "distributed surface contamination 
from historic activities at LANL that could be remobilized from the fire" as 
questioned above, but residual nuclear weapon's test fallout in biomass that 
could be mobilized by wildfires. I've noted in several earlier posts that a 
nationwide survey of Cs-137 in domestic fireplace woodash which I conducted 
in 1990-91 showed Cs-137 levels as high as 20,000 pCi/kg ash. Subsequent 
measurements showed Cs-137 in woodash from FL in excess of 30,000 pCi/kg 
woodash. Although I had only a few measurements of Sr-90 in woodash, the 
levels can range as high or higher than the Cs-137 levels due to the transfer 
factors for Sr vs. Cs from soil to plant being much higher for any unit 
deposition.

A wildfire can kick up incredible amounts of ash.  I recollect the airborne 
ash fraction can range from 2 to 5% of the total mass of  biomass being 
burned]. Depending on the level of Cs-137 and Sr-90 in biomass in the area 
[which was found to vary widely across the US by a factor of 100 fold from CA 
to FL in the survey I reported upon at the 1991 HPS Annual Meeting in 
Washington, DC titled:  "Cs-137 in Woodash -Results of Nationwide Survey -- 
or Woodburners and Organic Farmers, Is it Time to Kiss Your Ash Goodbye?] , 
most of which would certainly be due to generalized weapon's test fallout, 
not LANL releases, I would imagine [although I have no direct information on 
LANL historic radioactivity airborne releases],  the inventory of fallout in 
trees/biomass in the area could be a quite significant and unexpected 
non-LANL related contributor to any airborne levels of residual Cs-137 and 
Sr-90  measured in the area which might result from these tragic wildfires 
devastating the area.

Stewart Farber, MS Public Health
Public Health Sciences
172 Old Orchard Way
Warren, VT 05674
[802] 496-3356
email: radiumproj@cs.com
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