Saturday, April 7, 2012

#Radioactive Japan: Commercial-Use Skim Milk Powder Found with 23 Bq/kg of Radioactive Cesium

The data, photos and the graph are from Security Tokyo, with express permission to reprint.

Item: skim milk power in 1kg bag, commercial use
Manufacturer: Zenrakuren (all-Japan federation of dairy industry)
Manufactured in: Kita Fukuoka Factory in Iwate Prefecture

Iodine-131: ND
Cesium-134: 10 Bq/kg
Cesium-137: 13 Bq/kg
Total cesium: 23 Bq/kg
17,500 seconds precise measurement
Measurement error ±0.3Bq/kg (Cs-137)
Measurement using germanium semiconductor detector with proper calibration

Radioactive cesium has been constantly detected since the nuclear accident last year, albeit in small amounts (usually less than 20 becquerels/kg), from milk and milk products produced in Tohoku and northern Kanto. The cause may be the feed that milk cows eat. Until April 1, 2012, the safety limit for animal feed was 400 becquerels/kg (lower than for humans, which was 500 becquerels/kg). With the new safety limit of 100 becquerels/kg of cesium for humans, the safety limit for animal feed has also been revised down to 100 becquerels/kg.

Skim milk powder is used commercially for baked goods (bread, cookies, etc). It is also used for health supplements.

9 comments:

Chibaguy said...

If people still question whether or not the food chain has been impacted, guess what, this goes right to the top of the chain directly from the top. Sad state of affairs to say the least. I wonder how many bread makers actually test their raw materials?

Chibaguy said...

Just one more thing to add; Japan has always operator under a false sense of security. For example, if the cosmetic appearance of a product box was in question (nothing a consumer could buy on their own), doctors would file a compliant (i.e., a dimple or dent or a slight tear in the shrink wrap). Non of these reason impacts quality but this is the definition of quality in Japan. The Japanese definition of quality is superficial and cosmetic. They care more about how the outer box appears rather than the actual quality of the product. This is an oxymoron to say the least and why I continue to think this is the absolute worse country to have a nuclear disaster.

Anonymous said...

No bakery is testing their starting materials in Japan as in most places of the world. Rest assured that it is not only bread, milk powder is in chocolate, ice cream, most cookies, ...

If you want to be positive, smile while eating and hope it got quite diluted during the process.

This document details the production process of skimmed milk powder. I guess in Japan it will be the same. http://nzic.org.nz/ChemProcesses/dairy/3C.pdf

So 100L (= 100kg) whole milk result in 9kg of skimmed milk powder (about 1 to 10 ratio). This means, the starting milk had ~ 2.07 Bq/kg total Cs.
This is not such a big worry. If you check this publication http://www.irpa.net/irpa10/cdrom/00733.pdf (from Austrian Nuclear Research Facility) you will read in the first line: 'Among the many radionuclides possibly released in a severe reactor accident or a nuclear weapon's detonation 137Cs and 90Sr are of particular importance for the long-term exposure. Due to their long physical halflife
of 30 and 28.5 years, respectively,...' and the second paragraph states: '90Sr contributed to more than 80 % of the exposure after the atmospheric nuclear weapons' tests and also
to a significant extent in past accidents.'
Why? Because in contrast to Cs, once ingested Sr will never leave you again.

So on page 2 you will find a nice table, milk analysis in Austria 1997 (11 years after Chernobyl). Usually one can estimate that the amount of Sr released during a reactor accident is about 0.5-1% of the Cs content released. Also MEXT measurements showed this picture (with some local fluctuations). The table shows that Sr is especially accumulated in Milk on the long run.

From the table (in Bq/kg milk)
Alpine foothills, high fallout (this is probably comparable with some parts of Chiba or Saitama)
0.1218 ± 0.0429 Sr90 and 0.596 ± 0.381 Cs137

Alpine foothills, low fallout region
0.0616 ± 0.0349 Sr90 and 0.104 ± 0.053 Cs137

This means, the milk in Austria contained about 20-50% of Sr90 compared to its Cs137 content! Figure 3 shows that directly after Chernobyl, more Cs was present in milk than Sr (~1%), but after 1 year the ratio already changed to closer to 10% of Sr compared to Cs.

Lets get back to this skimmed milk powder in Japan, there are about 23 Bq/kg Cs total and 13 Bq/kg Cs137. This means it contains a bit less than 1.3 Bq/kg Sr90 , converted to the whole milk that was used to make this powder it contained around 0.12 Bq/kg Sr90.

Another interesting fact about Sr90 is that in rennin cheese the ratio of Cs to Sr is 1:30, since the Cs stays with the whey, while the Sr90 gets complexed by the protein and goes to the cheese. In butter it is opposite, we can find a Cs to Sr ration of 10:1, since the Cs is very well soluble in fat, while Sr90 does not really like to stay close to the fat if there is little protein.

By they way, another fact about Cs to Sr ration can be found in this publication http://www.springerlink.com/content/j442470x27k65ux3/ - they were feeding pregnant reindeer with Sr85 and Cs134 (biological behaviour of Sr85 and Sr90 is identical same is for Cs134 and Cs137). From the abstract: 'Although the gastrointestinal absorption of 85Sr was low, an apparently higher transfer of the absorbed fraction of 85Sr than 134Cs from the mother to the foetus led to similar accumulation of 85Sr and 134Cs in foetuses. At birth 1.4–1.6 and 1.5–2.5% of the total administered activities of 85Sr and 134Cs, respectively, were present in the calves‘ bodies. ' Not nice to be pregnant currently in Tohoku.

By the way, Austria is far away (more than 1000km) from Chernobyl and Austrians did not eat food produced in Ukraine or Bella Russia. In contrast Tokyo is about 250km away from Fukushima and people are eagerly eating food from Fukushima and the neighbouring provinces....

Atomfritz said...

What a pity that Fukushima milk powder hasn't been tested.

Back in the 1986+'s, German milk powder with its 8000+ Bq/kg wasn't even sellable to countries like Somalia.

Immense quantities of milk powder were stored for years on some railway storage, causing protests from neighboring citizens.

In 1990 it was decontaminated with some process similiar to the Areva process that Tepco discarded because of the wrong (=foreign) origin.

(Please excuse me for omitting sources, as a simple search on any search engine will yield more hits than you'll like)

So the questions remain:
How much was Fukushima milk powder contaminated?
What happened with the Fukushima milk?
Has the Fukushima milk (powder) been fed to children (no matter whether Japanese, Somalian or whatever)?

arevamirpal::laprimavera said...

@Atomfritz, there is no single-origin milk in Japan as long as it goes through the dairy association. Fukushima's milk is mixed. So is Miyagi's milk. Or Iwate.

I have a sinking feeling that the milk products like this are going to places where the canned fish will go on ODA.

Anonymous said...

send some samples to Obama for his testing.....surely he has a major concern regarding most of everything.

Anonymous said...

Obama is too busy watching ESPN sports.

Vitamin D said...

Ya Skim milk powder is used in all kinds of dairy products. Also this milk has Vitamin D which is good for health.

Anonymous said...

Since the XX amount of Cesium is in milk, and its SAVED in the human tissues (or animial), then that amount must be added to the TOTAL radiation exposure for the person. So if the max lifetime is X, each time you take a drink of milk, add it to your lifetime max. Or in another way, each amount of Cesium is then taken from each years total radiation allowed. For example, year 1 person has had 23 Bq/Kg for all the milk used, in sooner than two years..you will not be allowed to have more radiation--internal or external. Think of a baby drinking milk.....
Good thing we have 5 years of milk products(for four people) already in storage..pre-Fukushima. Or twenty years for one person...however it not enough with Cesium's half-life. Think about that..

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