Milk tests
What does "locally bought" milk mean? That means nothing. I'm interested in locally produced milk, i.e., milk from dairies in Northern California. Milk "bought" in supermarkets can be sourced from dairies anywhere, usually in the Western US, not just in CA. Of particular interest to me is organic milk, which would be sourced in Northern California from free range herds grazing on grass exposed to the recent irradiated rains. Mega, non-organic dairies use feed that can be from anywhere, and certainly could be using old feed, i.e., NOT exposed to recent radiation, and to me, on a short term basis might be more healthy than organic milk with possible higher radiation levels.
dose estimation
This is an excellent web site. Thank you for posting your results. May I recommend however that you modify your methods of dose calculation? For example, for the ingestion of I-131, I would recommend that the absorbed dosed to the thyroid gland of infants and younger children be estimated rather than the effective dose to the entire body for an adult. Infants and children are the critical group among all who would be potentially exposed. The dose conversion factor for the thyroid gland of a 1 year old infant is approximately 4 microGy per Bq ingested. The dose conversion factor for a ten-year old child, by contrast is about 1.4 microGy per Bq ingested.
The effective dose is not an appropriate quantity when estimating potential health impacts from inhalation or ingestion of I-131 as the main health impact of concern is the chance of thyroid cancer in later life. When calculating an effective dose, the ICRP assigns a weight of 0.05 to the thyroid gland. This organ weighting factor is used by ICRP because thyroid cancer is highly "treatable" and thus is seldom fatal.
For public health protection we are more interested in the potential for the incidence of harm, not just the chance of a fatality. The risk of thyroid cancer in later life is dependent on the absorbed dose to the thyroid gland, and the age and gender of the individual who is exposed, as well as the appropriate age and gender baseline rate for the incidence of thyroid cancer.
When estimating the absorbed dose to the thyroid gland from milk consumption, assumptions will need to be made about the amount of milk consumed and the duration of time over which milk remains contaminated.
Nobody answered my original
Nobody answered my original question about the significance of "locally bought" milk. The thread got hijacked. Does this mean locally produced, local (NorCal) dairies? What, where, what brands, a mix of brands in one measured batch? What? This thread hasn't helped me to decide whether to serve my children milk or not until further notice...
Great post
and well said Owen. Many thanks.
Now you found "it" in the
Now you found "it" in the milk! It was clear you will, but it was not clear how much it will be. Now we know - good job, guys, keep doing it!!!
One comment I have is that the comparison to the SF-DC flight does not sound quite right. Isn't there another way to explain what you mean? For example, the EPA prescribes a max of 4 Beqs/per liter for drinking water, and you found 0.43-0.97 Beqs/per liter in the milk. In other words, can you try to use an "apples-to-apples" comparison instead of using "apples-to-bananas" explanation.
Thanks,
Very Concerned.
P.S. Where are the drinking water results?
See http://oaspub.epa.gov/env
See
http://oaspub.epa.gov/enviro/erams_query_v2.simple_output?Llocation=Stat...
for CA milk monitoring done by the EPA. Clearly levels of the same 0.7 Bq/L seen here have been detected before.
They estimate 0.148 Bq/L as giving a possible cancer incidence of 1 in 1 million. Utilizing the Linear No Threshold Model, we would estimate about 1 in 200,000 possible cancer incidence for the 0.7 Bq/L measured in this milk sample.
Compare this to a 1 in 256 chance of getting cancer just from being a Californian.
http://www.ccrcal.org/
Your numbers are sound.
Your numbers are sound. This is very close to what I have calculated using the LNT model. I also come up with a 1 in 250 number for risk of incidence in CA.
So 1 in 200,000 risk means out of 10 million Californians
Fifty will get cancer or die from cancer?
fifty MORE than there would be just for being a Californian (or are the rates in California higher in part due to nuclear emissions from the nuke plants there?)?
And I assume that this is for adults.
So if the risk is, say, an order five times higher for infants and fetuses exposed in utero then out of ten million children in California there may be 250 childhood cancer deaths?
And what about birth defects in developing fetuses and infant mortality in those exposed. And what about metabolic disorders and hypothroidism? If we all get dosed and some of us die but many of us will get sick is that an acceptable result of nuke power.
Can TELCO be charged with intentional manslaughter or crimes against humanity for killing 50 or 250 or a thousand people?
And what if your numbers are off by a factor of ten or a hundred because you relied on a bad model or relative risk?
So if my little girl gets leukemia from this because she ingested a "miniscule" amount of radio-cesium in the tap water or milk or on veggies, or my grandchild is born with a cleft palate or a heart-valve defect or worse is spontaneously aborted, this level of exposure and risk is acceptably low? Or below the threshold of risk to be concered about?
Damn it is a sad and strange world. and it is raining/snowing radioactive stuff here. And I have kids who are now victims of exposure and I have no way of knowing if they will "win" or "Lose" in the Fukushima cancer lottery.
It is a dangerous world.
It is a dangerous world. People die, get cancer, and lots of bad things happen.
The risk from the fallout we've seen is relatively small compared to risks we take every day and consider acceptable.
If you want to continue worrying about it, take action, or whatever you like, that is your prerogative.
My comlaint here is that the risk models are inaccurate
and thus saying there is little risk is wrong when we KNOW that prevailing scientific opinion says there is no low threshold for damage to dna.
I am not concerned about the "relative" risks --- I am seeking a more definitive answer to the question "what are the risks fromn THIS exposure" (and not, its the same as a cross country flight if you drink x amount of water or milk).
The .7 picocuries per liter resulting in an increased risk for adults of 1 cancer in 200,000 is useful but it does not address the dangers to infants, fetuses, nursing children whose mother drink c0ontaminated milk ro water or eat contaminated produce.
It is pretty clear that the Berkeley team on this project are not really qualified to answer these questions BUT if that is the case it is, imho, disingenuous of the project leaders to say there is really nothing to be concerned about.
As I said above, if fifty or 250 or 500 Californians more will die from this or in viewing the whole nation of 300,000,000 plus at a 1 in 200,000 rate (adults) or multiples of that rate of cancer for children - we are talking THOUSANDS of additional cancers nationwide from this event.
My point too is that the known harm from nuclear power far outweighs the risks and IF the models used are off by multiple factors as many experts assert, we may be talking tens or hundreds of thousands or more getting sick eventually or suffering mutations and birth defects.
The estimates from Chernobyl in toto are about 1 million cancer deaths and total 2 million cancers. If the rates of radiation releases into the environment at Fukushima are from 25-50% of these rates then we can expect, especially due to high density populations in Japan and on the US West Coast, to see similar comparative numbers (i.e. 250,000 to 500,000 deaths and 500,000 to 1 million cancers).
As the project moves forward and as we get more data (which I am honestly truly grateful to Chivers and the Berekely team for), especially as it appears the numbers are dropping as long as there are not new events putting huge amounts of radioactive material into the upper atmosphere, the risks can be better quantified.
But IF there are new releases and new pathways for the radionuclides (food chain, milk, produce, etc) increasing exposure say in California spinach, fruit, produce, seafood, etc) which add to the total exposures we need to be cognizant of what these risks are in a quantifiable way.
Comparing the risks to cross country flights and xrays id NOT comparable to ingestion over a sustained period (which is what will happen with the cesium in the soil, water and produce). Yes the iodine should decay in several months from the time it is released in Japan, but in reality the radio-cesium will remain in soil, water, produce, etc for hundreds of years --- which is the main complaint I have with respect to the risk models used.
To be honest, this is more a way of assessing the risks to us all of nuclear power so that we can make intelligent decisions for the future. But it ALSO is essential to respond when assertions are made that the risk is below a nonexistent threshold of harm when this is not demonstrable scientifically or accepted by the vast majority of experts and agencies which have studied this.
The reassurances we get that it is not dangerous at all is belied by the potential for thousands of new cancers, mutations and disease globally from this one series of releases at Fukushima which appears now to be nearly equivalent to Chernobyl which killed, according to the New York Academy of Sciences study, nearly one million people since it happened.
If we only get 1/4 to 1/2 that number of cancer deaths is that a "relatively small risk". Not to mention birth defects, mutations, miscarriages, infant mortality etc all of which happened to those downwind of Chernobyl (pretty much the whole northern hemisphere)