Risk Factor Issues/Useful BRAWN analysis (Joseph Miller). Thank you! and a further question or two.

Since the thread I posted on this subject was getting unruly, I wanted to Narrow it down to BRAWM's response to my question and my response in its own thread.

The original thread is here:

http://www.nuc.berkeley.edu/node/2701

I am using this chart for my comparison:

http://www.informationisbeautiful.net/visualizations/radiation-dosage-ch...

The exchange I wanted to highlight is here:

Submitted by jmiller on Mon, 2011-04-11 16:57.
Sorry it took so long to respond. I'm not sure what model they're using to calculate this risk. The LNT model predicts an increased CHANCE of death from cancer during the lifetime of someone exposed to an additional 1 Rem to their whole body (lets not split hairs here with tissue specificity so we can have a discussion) during a short time (acute = days or less) of 0.08% and about half this 0.04% per Rem for chronic exposure like what we're dealing with. So, if there's 800,000 people that live in San Francisco being exposed to a Rem (or 10mSv), then we expect, over the course of their lifetime to increase their chances of dying from cancer by 0.04%*800,000*1Rem= 320 people. BUT, and this is important, the normal non-Japan crisis number of expected deaths from cancer is: 20%*800,000=160,000 people. So at 1Rem, we go from 160,000 people to 160,320 people...a 2 thousandth (0.002) percent increase.

We are not getting a Rem of chronic radiation. Lets say you only drank rain water at the highest level we measured everyday for a year, 20 Bq/L. The I-131 conversion factor is 1.85E-02 uSv/Bq multiplied by 20 Bq/L multiplied by say 1000 liters of water a year (average recommendation from the Mayo clinic) this give you 370.2 uSv which is 0.037 Rem. So if San Francisco did this, we're expect 0.04%*800,000*0.037 = 12 people to have an additional risk of cancer in their lifetimes, or a 1.000075 increase...that's small and dwarfed by smoking a pack of cigarettes at some point in your entire life or driving a total of 160 miles at any point in your entire life.

So while we acknowledge the LNT model assumes no radiation comes without some risk, the risk is very very small compared to things we do every day of our lives. It just seemed much more terrifying because the dangers are not as intuitive as a drive up the coast. But intuition doesn't change the math. I hope that helps!

Joseph [BRAWM Team Member]

»
Reply:Submitted by Bill

Thank you so much. I know it was the weekend! Here's a ...
chart I am using to understand all this and to correlate it to the Physicians for Social Responsibility position (which also uses the LNT - linear no threshold model)

Highly recommended source/chart from the Mayo Clinic:

http://www.informationisbeautiful.net/visualizations/radiation-dosage-ch...

One issue which arises from your response is that accumulation in milk and vegetables such as spinach and mushrooms ADDED together may begin to reach the levels of drinking rainwater at a high level of exposure for a year. IF radiocesium (or, God forbid, Strontium 90) and other radionuclides are uptaken into the food chain through rain and soil then we MIGHT see an overall increase in our entire diets to levels of concern and bioaccumulation in our bodies up to the level of 1 mSv per year or more.

The Physicians for Social Responsibility estimate, using the LNT model of risk, one cancer per 10,000 people for every 1 mSv of exposure.

IF the amount from drinking rainwater alone is .37 mSv (370 microSeiverts) then this would mean, using LNT) 1 cancer per 30,000 people or 3.7 cancers per 100,000 (or nearly 30 per 800,000, the population of S.F.)

SO

I WANT TO THANK YOU FOR YOUR RESPONSE

This makes it much easier to calculate the risks.

My primary concern now is the cumulative exposure from all sources which MIGHT be relatively equal to drinking the tainted rainwater for a year will result in additional risks, especially to infants and fetuses. If we get dosed in produce, water, air, milk etc it all adds up.

370 microSeiverts (your sort of worst case rainwater annual dose) is equivalent (for adults, and I assume the risks to children and infants and fetuses in utero would be much more serious, especially if ingested), according to the chart I linked (again, based on the Mayo clinic numbers), to the following:

3.7 chest xrays

74 dental xrays

120 microSeiverts MORE than release limit permitted for one nuclear power plant per year (limit is 250 microSeiverts) (Remember we now have more than 100 nuclear power plants in the US)

37 times the dose an average person recieves on an average day

More than 1/3 the EPA yearly limit the EPA allows to the general public.

That said:

LET US ALL HOPE AND PRAY THAT THE DOSES GO DOWN

and

that the cesium etc is NOT accumulating in the soil and veggies.

IF the Physicians for Social Responsibility is accurate and we DO accumulate ingested radiation to levels which reach even 1/3 of a mSv over the course of a year, we can expect on average, in adults, more than 11,000 cancers across the US.

IF the levels stay high and bioaccumulate in us, in food, in plants, in animals, etc. The rates may be higher for children by many factors, I would expect. Niot to mention birth defects, hypothyroid disease and other health problems, metabolic disorders and illnesses caused by radiation exposure.

Finally, there is one bone of contention, Joseph, although I do not expect a response from BRAWM on this really because it is a standard analysis you are following: a substantial part of the current cancer epidemic globally is, according to some sources such as the Physicians for Social responsibility, the European Commission on Radiation Risk, the Radiation and Public Health Project, a direct consequence of radionuclides in the environment since the beginning of the Nuclear age and results not only from nuclear testing but from nuclear power plant emissions (after all each one is permitted to release 250 microSeiverts per year and we have over 100 such plants in the United States alone, and they also have accidental releases on top of this limit all the time). That is an additional 25 milliSeiverts per year (from OUR OWN NUKE plants).

So comparing the risk of cancer due to excess radiation from Fukushima in your anlysis to the already existing cancer epidemic is, in my opinion, one way of obfuscating the issue and minimizing the risk, thereby enabling the industry to keep polluting ("because the risk is so minimal"). Not to be critical,as I am grateful for the response, but I noticed this also in EPA documents where they say "the increased risk COMPARED to the already existing rates of cancer is small".

I just think THAT analysis hides the true story: that the cancer epidemic is due in large part to more and more man made radioisotopes in the environment since the dawn of the nuclear age nightmare.

THANKS again, Joseph, your post was very useful in at least giving me some way of comparing the risks for adults and for my kids. I STILL Plan to do ALL I can to get my kids and my loved ones to minimize ingestion of bioaccumulative irradiated milk and produce etc. I see no end in sight for the releases and ther potential always exists for further major releases into the air (not to mention the seafood chain).

THANKS and bravo for ALL you are doing (even though we may differ on the seriousness of the risk - I could not begin to assess that risk without all your hard work and responses).

Let's hope these levels drop and drop for good in the rain and air and milk and spinach and mushrooms SOON!

And is anybody testing EGGS???

Cheers!

Bill

(SEE ORIGINAL THREAD FOR LINK AND MORE ON THE ISSUES I RAISED DUE TO THE PHYSICIANS FOR SOCIAL RESPONSIBILITY STATEMENT ON RISK)