Friday, May 18, 2012

#Radioactive Tea from Chiba, This Year's First Pick: Max 14 Bq/kg of Cesium, Brewed, Exceeding the Safety Limit


This is the first case in Japan of this year's green tea exceeding the new safety limit of 10 Bq/kg of brewed tea.

14 Bq/kg of radioactive cesium in brewed tea could translate into the maximum 1,400 Bq/kg of radioactive cesium in the dried leaves, with the possible range between 800 to 1,400 Bq/kg, far exceeding even the provisional safety limit (500 Bq/kg) that was in place until April 1, 2012. For more on the old and new test methods for green tea, see my previous post. (If you read Japanese, here's a comprehensible togetter (string of tweets) on the subject compiled by @Kontan_Bigcat, titled "Standard for radioactive cesium in green tea was stricter last year, and here's why".)

Chiba Prefecture's test result (using only the new way of measuring brewed tea) of total 16 samples from 5 municipalities shows some samples close to the new safety limit of 10 Bq/kg of radioactive cesium in brewed tea. 2 samples exceeded the new safety limit.

Chiba Prefecture's page says the samples are prepared in this way, following the guideline from the Ministry of Health and Welfare dated March 15, 2012:

荒茶又は製茶10g以上を30倍量の重量の熱水(90℃)で60秒間浸出し、40メッシュ相当のふるい等でろ過した浸出液

Use "ara-cha" (bulk tea) or "sei-cha" (blend tea), more than 10 grams, add hot water (90 degrees Celsius) 30 times the weight of the tea, brew for 60 seconds, strain the liquid using a strainer (40 mesh)


(I put in the English labels)

No.
栽培地
Location
品目
Item
栽培状況
採取日

放射性セシウム

セシウム134
セシウム137
合計 注3
1
成田市
Narita
茶(一番茶飲用)Tea, First pick
露地
grown outdoors
5月14日
1.91
3.21
5.1
2
茶(一番茶飲用)
露地
5月14日
2.08
3.45
5.5
3
茶(一番茶飲用)
露地
5月14日
5.45
8.72
 14
4
茶(一番茶飲用)
露地
5月14日
5.17
7.33
 13
5
勝浦市
Katsuura
茶(一番茶飲用)
露地
5月15日
1.55
4.02
5.6
6
茶(一番茶飲用)
露地
5月15日
1.98
3.61
5.6
7
茶(一番茶飲用)
露地
5月15日
1.61
3.09
4.7
8
多古町
Tako
茶(一番茶飲用)
露地
5月14日
2.60
4.52
7.1
9
茶(一番茶飲用)
露地
5月14日
2.06
3.32
5.4
10
八街市
Yachimata
茶(一番茶飲用)
露地
5月16日
1.89
2.91
4.8
11
茶(一番茶飲用)
露地
5月16日
2.83
3.50
6.3
12
茶(一番茶飲用)
露地
5月16日
1.69
2.99
4.7
13
茶(一番茶飲用)
露地
5月16日
3.43
4.53
8.0
14
茶(一番茶飲用)
露地
5月16日
2.33
3.41
5.7
15
芝山町
Shibayama
茶(一番茶飲用)
露地
5月16日
1.99
2.49
4.5
16
茶(一番茶飲用)
露地
5月16日
1.33
2.19
3.5

Based on the above result, the shipping ban on the teas in Tako-machi and Shibayama-machi has been lifted. Other municipalities (except for Narita City) will soon follow.

Last year, green tea (dry leaves) from Chiba Prefecture was found with radioactive cesium ranging from slightly over 200 Bq/kg to 2,300 Bq/kg. Even the fresh leaves were found with 260 to 980 Bq/kg of cesium, according to the excel sheet data from the prefecture.

For those who are still wondering what "Becquerel" means, Chiba Prefecture's page has the definition for you, too:

ベクレル:放射能の強さを表す単位で、単位時間(1秒間)内に原子核が崩壊する数を表す。

Becquerel: Unit of radioactivity. It indicates the number of nuclei decaying in a unit time (1 second).

22 comments:

Alessandro said...

The crooked behaviour of the Japanese government is simply disgusting. I've just bought shincha from Wazuka, Kyoto. Hope that also this tea would not turn radioactive.

Darth3/11 said...

Would like to see more testing on green tea from Shizuoka, and especially near those incinerators.
Is this amount dangerous? Granted, any radiation is not good, inherently.

Anonymous said...

Laprimavera,

I've repeatedly posted comments on the "Black Dust" comment thread and they've been repeatedly deleted. What's happening there? Thanks, JP.

Anonymous said...

Btw, that happens a lot for me. Anybody else?

arevamirpal::laprimavera said...

JP, I fished out your comment among spams from used car dealers, haulers, health supplement companies.

Yes, it happens a lot and to a lot of people. My comments have gone to spam filters multiple times.

Anonymous said...

Why do people insist on drinking the most radiologically contaminated tea in the entire world ever?

Is it because of some dubious 'Organic' health claim or merely the packaging?

nottheonlyone said...

Pardon my ignorance regarding green tea brewing, but is the water used really only 90 degrees (i.e. not boiling)... and do you steep leaves for only one minute? this is quite different than brewing black tea. (there is a point to this question, depending on the answer)
Btw thank you for blogging prima, credible news thin on the ground for non-Japanese.

Anonymous said...

Personally I like my tea (or anything else for that matter) with as little additives as possible. Change the word 'becquerels' with 'shit'or 'poison' and you'll get my drift that I dont care WHAT the governmental daily rec. dose is. I dont want it so avoid aything from that region like the plague. Do what you like. Man is born free but everywhere he is in chains.

kuma shutsubotsu chuui said...

@nottheonlyone

It depends on the tea and individual taste, but 90C is not an unusual temperature, and one minute or less is not an unusual steeping time. Often people will transfer just-boiled water into the tea cups for several seconds before pouring onto the tea leaves, to cool it a little.

It's worth noting that it's common to do two or three infusions from Japanese tea leaves, so I assume the amount of cesium would be less the second and third time you use the leaves. ZERO Bq is obviously preferable, though!!!

Chibaguy said...

I know nothing about brewing tea but this guideline does not seem to fit how regular people brew tea. Are these numbers equivalent to how one makes tea or are they over diluting it? Any insight would be appreciate. Regardless, Chiba tea is not safe.

arevamirpal::laprimavera said...

@nottheonlyone and everyone else,

That's how a high quality green tea (like the first pick of the season) is brewed, not using the boiling hot water and brew for no longer than 1 minutes.

I use much lower-grade tea, so I use near boiling water and brew longer than one minute but not much longer than 3 minutes. That would kill the flavor.

William Milberry said...

Back in August of last year I made a video talking about contamination in green tea (as it stood back then.)

Recently a tea club found my video and started attacking me on youtube. They said I was spreading lies and cursing a whole industry. They claimed that the anti-oxidants of tea did more good than the radiation did bad and it was still better for your health to drink contaminated tea then none at all.

They then as a group started to give all of my videos thumbs down and voted down so many supportive comments on one of my videos that youtube didn't display them by default anymore and I had to disable comment voting.

I know this is OT, but I just had to complain a little bit. I figured the group here would be the most likely to understand how ridiculous that was along with this tea situation.

Every day at work my Japanese colleagues drink so much green tea and look at me strange for bringing bottles of oolong telling me that products from China are dangerous ...

-Will

arevamirpal::laprimavera said...

William, a tea club in Japan? Name?

William said...

@arevamirpal::laprimavera - No, they seem to be native English speakers, I don't know where they are. Actually, they just struck again giving my recent video 6 thumbs down. I know it's them because it always happens at once and the one youtube user who was posting comments until I blocked him told me it was his club when I accused him of using multiple accounts to harass me.

Anonymous said...

@William , was probably Japan Probe .com or some other outfit of arse licking foreigners here... green tea is suspect and confirmed radioactive in shizuoka etc ... its also interesting the way Japanese point the finger at the Chinese all the time, they are just as fucking bad here man...

Alessandro said...

@William: the tea club you're refferring to is by chanche www.teachat.com?

Chibaguy said...

@William, probably the brilliant group of people that call themselves Japanprobe. They attack anyone and probably made up a tea club.

Alessandro said...

@Chibaguy: don't take it for granted. I personally know of an american guy, who runs a online japanese green tea store (o-cha), who'd yell at whoever tells the truth about radiations in tea. It's probable that's him.

Chibaguy said...

@Alessandro, no problem. These people are a dime a dozen. If it is him, tell him denial only has a couple of years left re expiry date. Thank you for your input.

Alessandro said...

@Chibaguy: I used to post on www.teachat.com (subsection Green Tea). I was preaching in the desert, saying that radiation is dangerous. No one wanted to listen to me. Finally I was banned. Now I read that people is in love with Japanese Government because they lowered the cesium value in radiation tests. No one pointed out, though, that now the radiation is measured in brewed tea and thus is 1/10 of what actually the leaves cointain. A tea that reads 10bq/kg is withing the safety limit but in reality the leaves contain as much as 1000bq/kg, well above the previous limits. Thanks to the Japanese Government, the limits are being worsened.
Kevin (Kevangogh on that site) is the owner of www.o-cha.com the site I mentioned earlier. Don't buy from him.

Anonymous said...

It's not just executives at TEPCO or the nuke Mafia or the Japanese government---it's us too. Most people turn into asshole denialists when it touches their own wallet.

Chibaguy said...

@anon above, I believe for the most part that the critical thinking foreigners in Japan understand the risks and do not deny it but just try to avoid it. There is a minute population here that not only denies but attacks people and asks questions later. As I have learned these people should not be engage and just left to spread lies. Those that are aware should try and spread the truth to the Japanese no matter how they take the message. They are handcuffed and need a key.

@Alessandro, thank you for the hint. I will look into this after the eclipse tomorrow.

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