Re: Breast cancer, Hinkley nuclear power plant...--ConfoundingVariables

[RadiumProj@cs.com]

In a message dated 4/14/00 1:50:41 AM Pacific Daylight Time, 
bcradsafers@hotmail.com writes:

>  Low lying areas and river valleys where such 
>  contamination might be brought in on the tide also showed an excess, the 
>  report says.
>  
>  The theory is that the discharges from the power station lodge in 50 
square 
>  kilometres of the mudflats and dry out at low tide. They can be blow in on 
>  the prevailing wind or during storms in sea spray that penetrates well 
>  inland. Women living further inland and on the coast above 200 metres and 
>  away from the source of the particles had a below average chance of 
>  suffering breast cancer.
=====================
Radsafers:

Does anyone have any info as to whether the "theory" that the mudflats at 
Hinkley dry out at low tide and become a source of airborne particulates 
inlands has any basis in fact?  As an environmental radiation monitoring 
specialist in the 1970s, I had the opportunity to perform numerous radiation 
surveys looking at the buildup of plant discharges in the mudflats around 
Maine Yankee at a time when plant effluents were discharged directly into 
Bailey Cove. There was a buildup of activity in the rich organic sediments 
but the mudflats never to my experience dried out at low tide. The pathway of 
interest there was direct radiation to worm diggers who harvested worms at 
low tide due to the buildup of plant activity. My experience was that the mud 
was quite wet at all times and it was quite difficult to avoid being sucked 
into the muck. Keeping your waders on was a challenge.

Of note, the incremental dose rate from plant related activity in the 
mudflats [while clearly present] was such that the total dose rate over the 
flats was less than measured over undisturbed soil inland from the shoreline. 
Also for several other nuclear plants I surveyed, the exposure rate near the 
shoreline was almost always far less than at points inland, since the sandy 
soil near beaches and near shore terrestrial environment, will have less U 
and Th compared to soil inland which will be, on average, higher in natural 
radioactivity.

As noted in the Hinkley nuclear plant news report about the study at hand:
Women living further inland and on the coast above 200 metres and 
>  away from the source of the particles had a below average chance of 
>  suffering breast cancer.

If the total  WBDE radiation exposure rates inland are indeed higher than 
that typically seen at the shoreline [even with some theoretical incremental 
dose from "airborne" particulates from mudflats] might this not be another 
example of hormesis in action?? ie: higher natural radiation exposure "inland 
and on the coast above 200 metres" yields lower rates of breast cancer. This 
highlights the importance of looking at the total radiation exposure being 
received by some population group about whom claims of health impact are 
being made, and not just look at the theoretical exposure received from some 
potential plant related pathway.

Stewart Farber, MS Public Health
Consulting Scientist
Public Health Sciences
172 Old Orchard Way
Warren, VT 05674

email: radiumproj@cs.com
[802] 496-3356
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