Fallout effects from Fukushima on the US west coast...

I would be interested in your reaction to:



Are they wrong? If you could give a scientific explanation why it might make me feel a little better about this situation...

Here is an excerpt:

[slightly technical] A nuclear engineering academic
department scientist at a university in California has recently made
public the concentrations of radioactive material found in rain water collected
on the roof of a hall on a Berkeley campus.  The values reported for March 19 were
measurements of 5.61 Becquerels per Liter for Iodine-131 and 0.26
Becquerels per Liter for Cesium-137 (a sampling run ending on 3/20
found slightly lower levels of Cesium-137 and 7.1 Becquerels per Liter for Iodine-131.) 

If our calculations are correct, and
the units convert to 151 picocuries per Liter of water for Iodine-131 for the March 19th values, then each liter of tap
water consumed at these levels will give affected Americans a thyroid dose of
about 1 millirem (or 1,000 microRems).   [NRC NUREG 1.109 rev. 1
Oct. '77 gives 0.0139 milliRems thryoid dose per pCi of I-131 for infants; and
0.00195 mRem for adults). We use average of 0.008 milliRems thryoid dose per pCi. ]  

If our estimates are correct, each
liter of tap water (March 19th values) with Cesium-137 is 25% of the levels that scared the pants
off Taiwanese officials on March 20 when imports of Japanese beans were measured at '1
becquerel of cesium ...detected in 1 kilogram (about 2 pounds) of fava bean.'  

The Berkeley lab's levels are equal
to 7 picoCuries per liter/or kilogram of Cesium-137 in rainwater, which, if
manifested at those levels in grown foods, this would be similar to lower levels
in the U.S. food supply in the 1960s. More maps on that here.  

How do foods become contaminated
by rainwater?  It is well established that cow milk tends to
reflect a concentration about 1,000 times the levels of radioiodines in the air over a pasture. 
This effect, called bioaccumulation, also applies (although to a lesser extent) to cesium-137 and
strontium-90 in milk. 
The radioactive
'distilling' effect in the air-grass-cow-milk-human chain is enhanced when it rains because
precipitation is more effective at depositing airborne radioactive debris to the ground
than with 'dry deposition.'  Even on dry feed lots, cows drink from puddles of rain
water and are exposed in other ways to their rain-soaked environment.
So, the slightly
radioactive levels in California air - according to recently
released EPA data - that included a high reading of 0.068 picoCuries per cubic meter (March 18, San Francisco, CA) for
iodine-131 means that pasture-fed dairy cow milk measuring 68 picoCuries per
*liter* may have recently been on Bay Area store shelves. Iodine-131 levels in milk could have been even higher than this because the EPA failed to correct for the fact that iodine-131 captured on the San Francisco RADNET filter
decayed during transit to the EPA's lab in the Southeast.  Although
public health officials might consider these levels to be of zero concern,
prolonged intakes of contaminated milk might pose a health danger to toddlers, infants or young children.  State and federal public
health officials need to determine the impact of sustained and uncertain radioiodine inputs to the thyroid glands
of the young. The daily rate of
exposure is not the issue - it is the cumulative exposure that could lead to
dire problems down the road. 

Thanks so much for posting

Thanks so much for posting this data! As a scientist, I am seeking quantification to make my own decisions. It's great that you are testing the various pathways too, e.g. seeing how much accumulates in cows based on the levels in the grass they eat.

I'm waiting to see how this pans out in our surface water and groundwater supplies. Personally, I'd like to minimize my risk, but without being overcautious. So again, thank you.

Picocuries/need help

Me too! Same problem with the method the EPA is measuring the levels. And I am mathematically challenged to begin with so this is way beyond me. And something I find very odd, correct me if I am wrong.On the 20th they reported to the press they had found Xe 133 in Sac. Is that possible given the first explosion was the 12th? Sorry for writing a book and thanks in advance whether you can help or not.

I did find this Dose and Risk Calc software on the CDC site if may be of any help. No restrictions on the public using it or anything.


From EPA

All units are in per meter cubed.

- Filter results for Anaheim, Calif. found:
Cesium-137: 0.0017
Tellurium-132: 0.012
Iodine-132: 0.0095
Iodine-131: 0.046

- Filter results for Riverside, Calif. found:
Cesium-137: 0.00024
Tellurium-132: 0.0014
Iodine-132: 0.0015
Iodine-131: 0.011

- Filter results for Seattle, Wash. found:
Cesium-137: 0.00045
Tellurium-132: 0.0034
Iodine-132: 0.0029
Iodine-131: 0.013

- Filter results for San Francisco, Calif. found:
Cesium-137: 0.0013
Tellurium-132: 0.0075
Iodine-132: 0.0066
Iodine-131: 0.068

But in looking closer I see that there are more steps that are needed to really know what a persons radiation dose is. Because of disintegration and then body weight is a factor. That may be of a concern for our children. And because Cesium is a longer life, what 30yrs half life that is also not a great thing.I don't know because I don't know what these dumb readings actually are saying. Also there are other factors I believe such as the type of radiation, half life. Beta, alpha, gamma types. And it looks as if the rad is going to keep coming fairly steady as it has been being continually emitting. Then the neutron beam thing now could be a bad sign. I am praying not. Those poor people. So so very sad.

Here is the info I found on the measured dose calculating.

Please forgive me if I am sending you info you already would know, just trying to be thorough and also give you their method of calculating.

Measuring Emitted Radiation

When the amount of radiation being emitted or given off is discussed, the unit of measure used is the conventional unit Ci or the SI unit Bq.

A radioactive atom gives off or emits radioactivity because the nucleus has too many particles, too much energy, or too much mass to be stable. The nucleus breaks down, or disintegrates, in an attempt to reach a nonradioactive (stable) state. As the nucleus disintegrates, energy is released in the form of radiation.

The Ci or Bq is used to express the number of disintegrations of radioactive atoms in a radioactive material over a period of time. For example, one Ci is equal to 37 billion (37 X 109) disintegrations per second. The Ci is being replaced by the Bq. Since one Bq is equal to one disintegration per second, one Ci is equal to 37 billion (37 X 109) Bq.

Ci or Bq may be used to refer to the amount of radioactive materials released into the environment. For example, during the Chernobyl power plant accident that took place in the former Soviet Union, an estimated total of 81 million Ci of radioactive cesium (a type of radioactive material) was released.
Measuring Radiation Dose

When a person is exposed to radiation, energy is deposited in the tissues of the body. The amount of energy deposited per unit of weight of human tissue is called the absorbed dose. Absorbed dose is measured using the conventional rad or the SI Gy.

The rad, which stands for radiation absorbed dose, was the conventional unit of measurement, but it has been replaced by the Gy. One Gy is equal to 100 rad.

From CDC

Japan measures radiation dose in the metric system unit of Sieverts (Sv). The press in Japan has reported doses in milliSieverts (mSv). A milliSievert is one thousandth of a Sievert (1000 mSv = 1 Sv). The United States’ unit of a measurement for radiation dose is the rem (Roentgen Equivalent Man). In the U.S., doses are most commonly reported in millirem (mrem). A millirem is one thousandth of a rem (1000 mrem = 1 rem).

Converting Sieverts to rems is easy. One sievert equals 100 rem. (1 Sv = 100 rem). One milliSievert equals one hundred millrems (1 mSv = 100 millrems).

Your missing one final step

Your missing one final step and that is going from Gy (grays) to Sv (Sieverts). Sieverts and rem are a measure of biological effects. This requires an evaluation of the various effects on specific organs given a type of radiation (gamma, alpha, beta, etc). For whole body dose (i.e. external gamma-ray dose) a weighted average of all organs are used. For I-131, the primary weighting that is used is the dose absorbed by the thyroid. If you multiply the absorbed dose (Gy) by these weighting factors, you get Sieverts (Sv). In general, weighting factors for gamma-rays are 1, for alpha is 20, neutrons 10, etc. One can convert Gy to Sv to using these factors. See the Wikipedia on Sievert


Thank you very much

There is a lot here, so I

There is a lot here, so I will do my best. Indeed, we have conservatively estimated the cumulative thyroid dose at ~1mrem (actually 0.0088 mSv). This assumes 1L per day consumption of the highest readings we have registered for two months. The half life of I-131 is 8 days and after around 3 or 4 more weeks it will have decayed away. For context, this amount is 1/400th of the natural dose we get every year. This is a fifth of the dose we get for a trans-continental plane flight. There are other contextual comparisons, but in short, this amount of dose is insignificantly low.

>> It is well established that cow milk tends to reflect a concentration about 1,000 times the levels of radioiodines in the air over a pasture.

Read this carefully,...,this says the concentration of the radionuclides in the air, not water.
I am not sure of this number as there is no source, but the concentration of the levels in air for I-131 is at least 100,000 times less than in the water we are measuring.

>> The daily rate of exposure is not the issue - it is the cumulative exposure that could lead to
dire problems down the road.

The 1 mrem estimate we come up with (again very conservative) is indeed cumulative as it includes biological half life, organ-based dose factors, and the half-life of I-131.

if you add the natural dose

if you add the natural dose we get every year, hasn't our yearly dose approximately doubled ?

Thank you very much for your

Thank you very much for your information and efforts. A couple of questions.

First, what is your conservative estimate for the absorbed doses (both internal and external) of Cesium-137, and over what time period?

Second, what source are you relying on for the statement that "the concentration of the levels in air for I-131 is at least 100,000 times less than in the water we are measuring"?

Third, in comparing levels of radioisotopes in air and water, are they both in measured units per L? What time unit are you using for the air measurement?

Thanks again for your time and answers.

Please don't lose track of

Please don't lose track of my questions! I would really appreciate your information. Thank you, Erin

Studys showing 1000:1 realation between forage and milk levels

Here's a study documenting the 1000:1 transfer multiplier of radionucleotides between water, forage crops and milk "Deposition of Fallout Cesium 137 on Forage and Transfer to Milk" - GERALD M. WARD, Ph.D., JAMES E. JOHNSON, Ph.D., and DANIEL W. WILSON, M.S.:


And another related article: "Influence of Grazing Intensity on Cesium-137 Levels in Milk'" FRANZ J. BURMANN ~ U. S. Department of Health, Education and Welfare, Cincinnati, Ohio:


and: http://www.idealist.ws/DSCN3428a.JPG

The gist I took from these papers is that radioactive elements are rapidly removed from soils via leaching and bio-uptake. The initial forage levels are relatively high; +/- within an order of magnitude of the rainwater levels, and milk levels are about two orders of magnitude higher than that. But levels rapidly decrease over time as material is leached and moved through the food chain. Strontium 90 levels in US milk returned to near baseline after nuclear testing ceased in only three years.

Regarding forage types, pasture feed is highest, first cut alfalfa is second highest, and subsequent cuts are lower still. Cows fed alfalfa had 1.5 orders of magnitude LOWER radioactive concentrations in their milk than pasture fed cows.

It's worth noting that right now, since it's winter, most dairies have their herds on alfalfa, which is probably why little or no radiation is being detected in CA milk.


Fallout effects from Fukushima on the US west coast...

Thanks for the links G, However, Winter on CA farms is not hay feeding time-
California's rainy season/forage growing season began in September and ends in May. Right now the pastures are at their peak of productivity.
Beef cattle are on pasture right now, organic dairy cattle should be on pasture. My dairy goats are on pasture as are my pastured poultry. My fava beans are flowering, my chard and kale are ready to harvest, it's peak outdoor grow season in CA -right now.


what will be the radiation effect on eggs from pastured hens?

We are quantifying these

We are quantifying these pathways currently. The nice thing about hard data is we can calibrate these models to what actually is occurring.

Half life of iodine-131

The half life of I-131 is only 8.02 days and it is a direct fission product. This means that all production of it stopped when the control rods were inserted in the reactors on March 11th. So concerns about it being in our food supply for long periods of time are negligible because it is no being produced by the reactor in Japan in significant quantities and the half life is relatively short.

In terms of cesium I think the factor of a 1000 that is arbitrarily introduced is suspect. In general the rainwater is diluted after being mixed in with groundwater. While the cow might concentrate compared to the level in the groundwater this level will most likely be much less than the level observed in the rainwater.

Finally no strontium-90 has been observed by any monitoring stations and it isn't expected to be.

are you sure about

are you sure about strontium? it may take days to get results for that.

.26 Bq/l

Thank you for your time, please address this question:
0.26 Becquerels per Liter for Cesium-137 (a sampling run ending on 3/20)
If our estimates are correct, each liter of tap water (March 19th values) with Cesium-137 is 25% of the levels that scared the pants off Taiwanese officials on March 20 when imports of Japanese beans were measured at '1
becquerel of cesium ...detected in 1 kilogram (about 2 pounds) of fava bean.'

and please convert the .26 Bq/l to cph & picocuries.

Thank you

.26 Bq/l

Thank you for your time, please address this question:
0.26 Becquerels per Liter for Cesium-137 (a sampling run ending on 3/20)
If our estimates are correct, each liter of tap water (March 19th values) with Cesium-137 is 25% of the levels that scared the pants off Taiwanese officials on March 20 when imports of Japanese beans were measured at '1
becquerel of cesium ...detected in 1 kilogram (about 2 pounds) of fava bean.'

and please convert the .26 Bq/l to cph & picocuries.

Thank you

I do not have a source for

I do not have a source for the "25% that scared the pants off Taiwanese officials", and just because they were scared does not mean there was a health risk. There are 27 pCi per Bq. Thus, 0.26 Bq/l is 7 pCi/l .

Thank you for your response.

Thank you for your response. Do you have any idea as to why strontium has not been detected? Is it because of the fuel they use at the plant doesn't contain high amounts of it or is about strontium that doesn't let it travel the full distance to the US.

Also, the same question regarding plutonium. Is there anything about its make up that would lead you to believe it won't be distributed as far as iodine 131 or cesium?

beta particles

My understanding is that strontium is not expected to be transported as far as cesium because it is not as soluble in water as cesium. In addition it also has a slightly lower fission yield than cesium.

Iodine is a completely different story altogether because it is a gas it will escape into the atmosphere and be distributed more readily.

Finally plutonium is not transported very far due to its chemistry. Again my understanding is that it is not particularly water soluble, it tends to form oxides, so very little of it is in the steam which is being released.

Thank you again for the

Thank you again for the quick response. This makes me feel a little better about the US West coast. I feel terrible about the people still trapped in Japan though.

I asked the CDC the

I asked the CDC the following and with post their reply under that.
My question to the CDC:
Why do you mention Iodine 131 on your website but you say nothing about Cs 137? According to UC Berkeley's Nuclear engineering Dept there is .55 bq/L Cs 137 in our rain water here in the Bay Area. In the last couple of weeks, all during the horrific nuclear crisis in Japan, we have had torrential rains. Now the sun is coming out and the Cesium dust is rising. What are we to do? You make no mention of this on your site and the EPA doesn't either. Our risk here in the Bay Area seems far greater than anywhere else in the country since we were the first land mass to be dumped on as the rain "scrubbed" the air of radioactive particles. Please check out UCB's website and tell me we have nothing to worry about.

From the CDC:
The primary isotope that we have detected is I-131. On our website under the first FAQ is a link to the data summaries for our monitoring stations. If you click over to these summaries you will note I-131 and little else being reported. Down in the notes you will see reference to Cs-137 and Cs-134 as being below the MDA (Minimum Detectable Amount) for our sensors. If we increased the sampling interval for our stations we would successfully be able to detect lower levels of the radioactive isotopes but then our results for the things that we can detect would not be as timely. Cesium-137 levels of 0.55 becquerel/liter are very low levels although they are above background. The miniscule quantities of cesium-137 that may be present will largely bind to solid surfaces so the risk of resuspension cesium-137 as dust is minimal.

I hope this helps. Also - I had a sore throat and emailed my doctor. She assured me that radiation levels are far too low to cause any health issues. She also said there's a lot of pollen in the air and my symptoms point ot allergies. She's seen a lot of allergy sufferers and people with colds but no one has shown up at Kaiser with anything approaching radiation sickness. When I asked about increased cancer risk she said these levels won't cause an increased risk. She also said our DNA has mechanisms to deal with small levels of readiation.

I empathize with you. Hopefully sharing my info will help. Remember - anxiety creates stress hormones which bombard your heart and is not good for your health.

While I do not want to

While I do not want to dismiss your reassuring comment, I would like to point out that we are not concerned about radiation sickness as a result of this fallout. What we are concerned about is the increased risk for cancer, which we won't know until about several years down the road.

Here's a PDF someone from the CDC forwarded to me.

This is an official
CDC HAN Info Service Message
Distributed via Health Alert Network
March 27, 2011, 12:20 EDT (12:20 PM EDT)
Monitoring for Increased Levels of Radioactive Material in the US as a
Result of the Incident with the Fukushima Nuclear Incident in Japan

As a result of the incident with the Fukushima nuclear plant in Japan, highly sensitive
radiation monitors operated by EPA and others are detecting very low levels of radioactive material in
the air in the United States. These levels were expected and consistent with estimated releases from the
damaged nuclear reactors and are far below levels of public health concern.
Elevated levels of radioactive material in rainwater have also been expected as a result of the nuclear
incident after the events in Japan, since radiation is known to travel in the atmosphere. There have been
reports received that several states including Pennsylvania and Massachusetts have detected elevated
levels of radiation in rainwater following recent precipitation events.

The numbers of the elevated levels of radioactive material being reported in Massachusetts are 79
picocuries (pCi) per liter (one picocurie is a trillionth of a curie). The numbers reported in Pennsylvania
range from 40-100 picocuries per liter. Although these are levels above the background levels historically
reported in these areas, they are still about 25 times below the level that would be of concern for use as a
sole source of water over a short period of time, even for infants and pregnant or breastfeeding women,
who are the most sensitive to radiation.

While short-term elevations such as these do not raise public health concerns – and the levels seen in
rainwater are expected to be relatively short in duration – the U.S. EPA has taken steps to increase the
level of monitoring of precipitation, drinking water, and other potential exposure routes to continue to
verify that.

Given the release of radiation in Japan, it was expected that radiation monitors in this country and
elsewhere will detect minute quantities of radiation. These monitors are highly sensitive and can detect
amounts of radiation in trillionths of a Curie. We expect environmental monitors will continue to detect
low levels of radiation in surface waters due to radioactive material in the air. When it rains or snows, the
radioactive material is washed to the ground and onto surface waters.

What the US Federal Government is Doing:
EPA’s Radiation air monitoring network continues to conduct near-real-timeair monitoring in networks
across the nation. With these recent reports, the US EPA has increased monitoring across the country to
ensure that the American people have the most up to date information.
What information is available to the public:
The EPA has posted information on its website at http://www.epa.gov/japan2011/
CDC has posted FAQs on our website at
USA.gov continues to consolidate federal guidance related to this situation at

The federal government’s only recommendation to state and local governments at this time is to continue
to share their testing results with the appropriate federal authorities. EPA will continue to communicate
nationwide sampling results as they come in.
At this time, there continues to be no indication for anyone in the United States to take potassium iodine
or switch to bottled water on the basis of the events in Japan.

This says anything above

This says anything above short term use is unsafe. It doesn't say how long short term is.

Massachusetts is different than California!

you cannot trust EPA.

Yes, how smart of them to

Yes, how smart of them to focus on the East Coast which had obviously much lower fallout and forget to mention the readings in California. Reality shaping.