Radiation doesn't seem to be anywhere near negligible
I spent a significant amount of time today to understand the math. To me, it seems like the radiation is not negligible with "no" health risk!!
And, this is just from the air contamination - not including water.
Here are the assumptions:
1. To be conservative, I have taken that we breathe 40Liters of air per minute (here's the source: http://www.arb.ca.gov/research/resnotes/notes/94-11.htm)
2. I have used Effluent concentrations for air (col 1 from http://www.nrc.gov/reading-rm/doc-collections/cfr/part020/appb/) similar to our UCB friends
3. I have taken the air contamination numbers provided by UCB on their website with rounding up of the contamination for ease of calculation (again little more conservative, but not off!)
4. Instead of calculating amount of radiation in terms of number of cross-country round trip flights, I converted to milliSieverts/yr so that we can compare against the radiation exposures (http://www.nuc.berkeley.edu/UCBAirSampling)
For I-131, Cs-137, and Te-132 together, I am getting 13.15 milliSievert/yr which is more radiation than getting a full body CT-scan every year!!
All right, one will argue that I-131 will decay in just a few weeks and so this conclusion is not correct. UCB results I believe have already accounted for this. Nevertheless, even if I completely discount I-131 and Te-132 radiation impact (9.73 mSv/yr and 0.7 mSv/yr), I get 2.72 mSv/yr for Cesium alone!!
Assuming an average exposure of 6.2mSv/yr that Americans are exposed to, this is 44% more radiation!!!
Sounds serious to me!! You can put whatever spin you want, but reality sucks :-( For eg; 2 cents a minute of talk time is equivalent to 300-400 USD per year!! They are the same, but numbers can be used to divert attention!
FINALLY, I HOPE I'M WRONG, BUT I BELIEVE I AM NOT!! SOMEONE PLEASE CONVINCE ME I'M WRONG!!
Calculations from Low Level Radiation Campaign
http://www.llrc.org/
No new monitors sent to CA and none here read Iodide 131
Japan
It took only a few minutes for Hirsch to state that all his PAGs work has been put on hold by the unfolding events in Japan. He has been consumed with trying to get the American government to deploy appropriate radiation monitors – which they do have, somewhere – into California to detect radioactive iodide from radioactive plumes possibly coming from Japan. No such deployment has occurred.
Hirsch said there were 12 monitors deployed in California and that only 5 of them are operational. None of them are capable of detecting radioactive iodide. Under standard operating procedures the samples would be sent to Georgia for processing and the results should be available 5 days later. But by that time the radioactive plume would no longer be in California so the data would be completely useless in helping to protect humans from being exposed to radiation.
The government does have monitors that can detect radioactive iodide instantly, but they have not been deployed in California as of this writing. CollapseNet told Hirsch that, based on what he was saying, it seemed like the federal government had no intent to detect radioactive iodide in time to prevent exposure.
“It certainly gives that impression,” responded Hirsch.
Worst Fears
It seems that the Strangelove-wing of the EPA is working so hard to change the PAGs it is as if the powerful are anticipating radiological disasters in America as inevitable. Anything is possible, and everything is conceivable in the continuing collapse of human industrial civilization.
----------------------------
ENDNOTES
i Interview with Jeff Ruch, Executive Director of PEER (www.peer.org), on March 17, 2011 at 4:45pm EST
See also http://www.tennessean.com/article/20110316/NEWS08/110316027/1969/NEWS/Group-warns-EPA-ready-increase-radioactive-release-guidelines-?odyssey=nav|head
ii Ibid
iii Ibid
iv The email originating with Sara DeCair was sent to me via pdf attachment from Jeff Ruch on March 17, 2011, and has been published along with this report. (see below)
v http://www.gpoaccess.gov/fr/
I know its not your fault,
I know its not your fault, and I do thank you for helping us. But it should not be that we have to come to you for answers, peace of mind. I am 42 and I have never felt so betrayed by my govt as I do at this time.
I mean what are you going to say if we are being compromised? Honestly, I am not sure if most people in that position would feel safe blowing the whistle. But I would hope you would if it were the case.
My daughter consumed some stream water in sonoma county sunday
She got strangely sick 12 hours later. Nausea, cold chills, extreme exhaustion. She went to school (she is 14, weighs 130, is 5' 6") and felt sick to her stomach, fell asleep for 4 hours at school, came home at 1 pm, went to watch her lacrosse practice @ 4, fell asleep again, at the practice!, ate dinner @ 7:30, asleep again@ 9. Radiation poisoning a possibility?? Sunday was march 27 I think. Strangest sickness I have ever seen. I am mom of four, 3 lived in japan till 2000, so aim watching j news carefully. I lived there 1985-2000. Appreciate any thoughts. Oh, and my oldest daughter is a freshman
@ cal.
Your daughter might have
Your daughter might have been exposed to bacteria from feces. The symtoms sound similar. If she isn't better maybe she should get checked out by a physician.
Radiation is the least of
Radiation is the least of your worries in stream water. Rain water and runoff to the streams contain chemical hazards that are known toxins and carcinogens, e.g. from car exhaust, oil and stuff on the roads, or I don't know what else.
The symptoms are not those of acute radiation sickness, besides the levels we've observed some millions of times (at least) too low to cause any short-term effect. So I think it is not related to radiation.
Still, I hope she feels better soon.
Seems high: Using your
Seems high:
Using your number: 40L/min = 21024000 liters/yr
Highest Activity we have measured = 5e-6 Bq/L (air)
Total Activity Inhaled: 105 Bq (per year)
Dose Conversion Factor: 1.86e-8 Sv/Bq
Effective Biological Dose: 1.95 uSv
Total Environmental Radiation Dose: 2-6 mSv
% Environmental = 0.05% (assuming 4mSv env.)
This is of course assuming we will have I131 for a full year at the highest activities we currently see.
Please check these numbers.
absorbed dose from air
This calculation is a pure nonsense. Yes, you breath 40 L/min, but you are assuming that all radioactivity contained at each inspiration is retained into the body, whereas most of it is likely to be sent back out. We would need to know how much is retained. I haven't this data, and it is likely to be different for each substance, depending of such things as homeostasis. All food is radioactive since the world exists, in absence of nuclear accidents, mainly due to 14-C and 40-K, and as a results we become ourselves radioactive, but not more than the food we eat. An average person counts for about 7000 Bq. Hum ... should we all be considered radioactive waste? Please, stop all that nonsense, these kind of calculations is absolutely non-sense. To the date, the only useful source of information are epidemiological studies from previous accidents, or with people living areas with high rates of naturally-occurring radioactivity, and the main outcome is that the greatest public health threat remains tobacco (mostly a self-imposed thread, except for passive smokers), followed by car-exhaust air pollution (not self-imposed at all), and a long list of other factors. Fukushima, Chernobyl and then like come far far far below all these. Human emotional factors come high too, but this is difficult to quantify, and so far, over-reaction is probably being more harmful than the radioactivity itself (social distress, alcoholism, drug-abuse and the like have become a major problem among the so-called Chernobyl liquidators). I believe that the measures taken by authorities are largely enough with respect to radioactivity, and that we should not push for more. A fraction of this with respect to the other threats would be welcome, because I believe we are really too soft over almost all remaining threats. An opinion, though.
you compare us to the chernobyl liquidators?
so by the end of these we will have a dosage like the chernobyl liquidators????
liquidators
Who said anything even approaching such statement? Tweaking opponent's words is one classic manipulative method. Don't playing this game.
you cover up - these are all valid questions
you call the calculations nonsense? how much are they giving you to cover it up?
giving me a lot
Well, yes, that much, enough to build a house, sorry, a mean a huge palace, in Bahamas. come on! Is that all you and the like have to say?
My point is that crucial information is missing to give any meaning to the above calculations. The food you eat contains 100 Bq/kg of 14-C and 40-K, but this does not mean we incorporate it, in fact most of it will go out again, and after the year we will stay with the same 7000 Bq we had at the beginning. Iodine per os is different, and can be a concern, because it can be fixated to the thyroid gland unless saturated with ordinary iodine. But when inhaled, how much is incorporated to the body and how much exhaled? This is the relevant question, and the above calculations missed that point. The whole question is very complex and many many guesses I have seen take the same simplistic approach. So far, the best approach I know to take all into account is epidemiological studies. Simplistic guesses deserve rationality under a false appearance of technicality, and may be used either way. For example they have been used very successfully by industry to convince public that smoking is not harmful, whereas epidemiology, without saying a word about mechanisms, had demonstrated long before the central point: what is the final outcome. My view (medically biased) is that concerns should be addressed under this light, unless you already have The Truth, and experimental knowledge bothers your certitudes.
you are downplaying again uc berkeley
there seems to be a pattern of downplaying of valid concerns ---very interesting---is the government giving you research money?
Appreciate your response a
Appreciate your response a lot. Where did you find the Dose Conversion Factor from? Can you please post the same for Cs and Te isotopes too?
dose conversion factor
Keep in mind the dose conversion factor they are using, is just an estimate. These does conversion factors are pulled from the probability distribution that is calculated to model biological effect. In this case the value they are using is 1.85E-08 Sv/Bq is just something that the NRC apparently releases for I-131. I could not find any literature to support this value. EPA uses a dose conversion factor of 4.76E-08 Sv/Bq for ingestion of I-131.
When I really looked into this, I found that there is a great deal of uncertainty in doing this conversion. Here are some factors and their contribution to variance (specific to I-131). My understanding is that this represents an N-dimensional probability distribution.
http://web.engr.oregonstate.edu/~hambydm/papers/benke.pdf
Raj, I thank you for your
Raj, I thank you for your continued vigilance on the DCF. The ALI values we are using are derived from the International Committee on Radiation Protection (ICRP). There continues to be much research on these numbers but this has been confined to a standard scientific debate held in technical conferences all over the world and within peer-review in respected journals. The job of the ICRP is to consider all evidence that has been peer reviewed and come up with a standard dose and dose response model for all types of exposure to radiation. I applaud anyone who tries to review the voluminous literature on this subject and come to a conclusion, but for us we would rather leave that to the ICRP and trust their findings.
But you have come to a conclusion...
You've repeatedly assured folks here about the insignificant health risks at the levels you've reported, but the scientific literature on this subject seems to indicate quite a bit more uncertainty than your strong seem to suggest regarding the lack of risk (i.e. Prof. Chivers comment to "relax, breath, and enjoy the weather" - http://www.nuc.berkeley.edu/node/1951).
Have you reviewed the ICRP Draft report of Committee I/Task Group entitled "Low dose extrapolation of radiation related cancer risk" (Dec. 10, 2004 available at: http://www.icrp.org/docs/Low-dose_TG_rept_for_web.pdf)?
According the ICRP report:
"Epidemiological data from studies of human populations exposed to ionizing radiation provide direct evidence that such exposure is associated with increased risk of cancer, and reason to believe that excess risk is not confined to persons exposed to very high radiation doses . . . It is highly likely that there will always be uncertainty about low-dose risk, and that we will have to come to terms with that uncertainty."
Clearly everyone will have different risk tolerances, but perhaps statements like those made by Professor Chivers ("relax, breath, and enjoy the weather") should be presented more accurately? It's odd, but hearing "we don't know" the true risk or "it's somewhere between 1 additional cancer per 100,000 to million" is more reassuring than just "don't worry about it" particularly when the crisis isn't over, radiation is still being emitted and we don't know how much Ce-137 has been deposited here in California for the long term.
There is uncertainty at
There is uncertainty at these low dose levels and I have never suggested that there is zero risk here. However, even if one chooses the most conservative study on dose conversion, the risk is still insignificant. One should not pull out a single statement without context from the ICRP report. The low-dose that the ICRP speaks of is normally at the levels of the 50-100mSv rather than the .01 mSv level we are estimating in this case. Numbers matter and I have tried to give people reassurance in both numerical and non-numerical ways depending on who I am responding to. We have put just about all of our data in the most transparent way on the this site. We have provided the maximum amount of context that we know and have tried to provide it in the most understandable way to a wide audience. Sometimes we fail, but I hope the majority of the time we succeed.
The Petkau effect is an
The Petkau effect is an early counterexample to linear-effect assumptions usually made about radiation exposure. It was found by Dr. Abram Petkau at the Atomic Energy of Canada Whiteshell Nuclear Research Establishment, Manitoba and published in Health Physics March 1972.
Petkau had been measuring, in the usual way, the dose that would rupture a particular cell membrane. He found that 3500 rads delivered in 2¼ hours (26 rad/min) would do it. Then, almost by chance, he tried again with much weaker radiation and found that 0.7 rads delivered in 11½ hours (1 millirad/min) would also destroy the membrane. This was counter to the prevailing assumption of a linear relationship between total dose or dose rate and the consequences.[1]
The radiation was of ionising nature, and produced negative oxygen ions. Those ions were more damaging to the membrane in lower concentrations than higher (a somewhat counterintuitive result in itself) because in the latter, they more readily recombine with each other instead of interfering with the membrane. The ion concentration directly correlated with the radiation dose rate and the composition had nonmonotonic consequences.
ICRP revised their I-131 DCF values
ICRP released a series of documents where these figures have been revised. Are you sure you are using the latest? It doesn't look that way.
publication 72, 88, 95 were released in 1996, 2001, and 2004
These are the latest age specific Dose Conversion factors:
(in Sv/Bq)
adult: 2.2e10-8
10 year: 5.2e10-8
1 year: 1.8e10-7
3 month: 1.8e10-7
fetus: 2.3e10-8
I wasn't able to download the ICRP publications. They cost about $100 each.
http://www.elsevier.com/wps/find/bookdescription.cws_home/600265/descrip...
Do you have them, specifically publication 72? I found this document which has a table of the DCF values and cites the latest ICRP publications.
http://www.hpa.org.uk/web/HPAwebFile/HPAweb_C/1207121671036
--
Raj
We may be dealing with
We may be dealing with roundoff error in the ALI numbers. I will have someone check this out. I have seen the 2.2e-8 DCF a few times internally here in the department so I suspect you are right here. We will revise if this is the case. Thanks again for your vigilance.
I recently added tables of
I recently added tables of the dose conversion factors we are using on the dose conversion page. We are using 1.8e-8 Sv/Bq for I-131 in water. I calculated these in a spreadsheet so there shouldn't be roundoff error. Could it be a difference between which version of the ICRP numbers the NRC ALI's are using?
factor of 2
I think you are missing the factor of 2
see these excerpts from here:
http://www.nrc.gov/reading-rm/doc-collections/cfr/part020/part020-appb.html
...and a factor of 2 to adjust the occupational values (derived for adults) so that they are applicable to other age groups.
The water concentrations were derived by taking the most restrictive occupational stochastic oral ingestion ALI and dividing by 7.3 x 107. The factor of 7.3 x 107 (ml) includes the following components: the factors of 50 and 2 described above and a factor of 7.3 x 105 (ml) which is the annual water intake of "Reference Man."
The way I am reading this is that you should multiple your result by 2 to to adjust the occupational values (derived for adults) so that they are applicable to other age groups and arrive at 3.7E-08 Bq/S
--
Raj
Factor of 2 already included
Hi Raj, thanks for looking into this. My reading of that document is that the factor of 2 is already included in the air and water concentrations in Table 2. For example, in the paragraph you quoted about water concentrations, I read that as saying that they took the 5 rem occupational ALI for water and divided by 50 and 2 for two reasons: to make the dose limit 0.1 rem instead of 5 rem, and a factor of 2 to account for different age groups.
So my reading would place the dose conversion factor situation like this: if this factor of 2 were not included in the ALI limit for water for I-131, the number in Table 2 Column 2 would be 2E-6 uCi/mL instead of 1E-6 uCi/mL. This would be the occupational dose limit scaled to the limit for an adult in the public but not to all age groups (the factor of 2). Then the dose conversion factor would be 0.925E-2 instead of 1.85E-2
Cheers,
Mark
degree rithmetic precision
Hi Mark,
Ok thanks again for responding to this. Yeah I double and triple checked your calculations on a spreadsheet, and you are correct. The factor of 2 must have been used to obtain the limit of 1E-6 uCi/ml.
This seems really strange to me that the DCF for adults would be 9.26E-09 Sv/Bq. It is just way off from everything that I have read.
I checked the NRC tables, and they all contain values with only 1 significant digit. 1E-6 is not as precise as 1.00E-6 correct? Therefore, doesn't this limit the degree of precision of your calculations.
In your table you list I-131 with a DCF of 1.851E-03 millirem/Bq shouldn't you state this as "2e-03 millirem/Bq" given the fact that the value 1e-6 was used to arrive at this value?
--
Raj
See our Dose Calculation
See our Dose Calculation page.
The dose conversion is stated as 68.49 millirem/microcurie which you need to do some unit conversions to get to Sv/Bq:
1 Sv = 100e3 mrem
1 uCi = 3.7e4 Bq
We calculate this from ICRP backed allowable level on intake (ALI) numbers put out by the NRC. I will also say there are other dose conversion factors for I-131 that could be 20 times higher than this (for infants), so this one number is not hard and fast.
Appreciate your help. Isn't
Appreciate your help. Isn't there a difference between ingestion and inhalation. Do you use different dose conversion for the two cases?
Derived air concentration(DAC) vs. annual limit on intake(ALI)
The short answer is yes. The derived air concentration is based on uptake of breathing the air 24/7 365 for one year. The ingestion limit is based on ingesting it so the uptake factors(the amount that enters the body in versus the amount that stays) are different.
Good point Cameron. I
Good point Cameron. I recalculated for the Air Inhalation ALI and come up with a dose conversion of 2.8e-8 Sv/Bq (check me on this). This is 50% higher than the water ingestion. This must reflect uptake efficiency and possibly an increase of exposure to the lungs. Either way, this is still very low cumulative dose.
Low cumulative for an adult
Low cumulative for an adult or a child?
both are quite low.
both are quite low.
Thank you. I am kind of
Thank you. I am kind of laughing here. I don't even know you and you are the only one I can even begin to trust to be honest on such a serious subject.
Honestly, in my heart though, I feel like we have been exposed to enough that we will be your lab rats for years to come. I almost forgot! I was wondering, do you know of any universities down in So Cal that might be willing to do thyroid testing for active radiation for free?
Ty <3
Hi Ty, I am not aware of any
Hi Ty,
I am not aware of any studies being done in So Cal. There may be some, I just don't know of any. I would check UCSD and UCLA medical centers.
To summarize are these the
To summarize are these the dose conversion factors you guys are using?
1. Air (inhalation): 2.8e-8 Sv/Bq
2. Water (ingestion): 1.86e-8 Sv/Bq
Are these same for all isotopes you have detected or can this be different for Cs due to a drastically different half life?
It is different for
It is different for different isotopes. Follow our table 2 link in the Dose Conversion Page and you should be able link to any isotope you wish.
Also, to use the weighting
Also, to use the weighting factor for Thyroid, should I just multiply the uSv/yr number with 0.05?