Radiation and Tea in Japan


Made from leaves that have not been oxidized.

Re: Radiation and Tea in Japan

Postby edkrueger » Mar 9th, '13, 16:15

n = 4985
xbar = .83
SD = .94
t-stat = .88

I fail to reject the hypothesis that radiation is 0. (even at the 80% confidence level.)

edit: This is the regular test. He also has the foil test and the wood test. I'm no scientist, but it doesn't really matter why he does these tests. In every case the SD is higher than the mean.
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Re: Radiation and Tea in Japan

Postby Seeker » Mar 11th, '13, 14:28

Just watched the youtube video - and I'm very concerned. I drink Yuuki-cha tea every day - both matcha and sencha. Tho not the matcha tested.
Some thoughts - I wonder who that is doing the testing in the video. Is the testing legit (where were the baselines for the container he was using, the foil, the wood, the immediate environment (there was strong wind in the mic - so outside?! seems hardly a well controlled environment).
Truth is I am prone to a bias because I love green tea so much, so there is a danger of my wanting so badly for the tea to be safe.
I wish I understood the testing process and data and the graphs so that I could be more discerning.
edkrueger - could you explain your comments? I don't understand what you're saying? (who's hypothesis that radiation is zero? what is an 80% confidence level? what is the significance of the SD being higher than the mean? and what do those numbers mean, what do we compare them to regarding "safe" levels?
Now I'm stressed, and I'm going to go drink my matcha Tenkei-Tori now, probably staring into it with some concern.
:shock:
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Re: Radiation and Tea in Japan

Postby Seeker » Mar 11th, '13, 15:37

Since I was a little nervous, I went with baochong instead of Sencha after my tenkei tori. :?
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Re: Radiation and Tea in Japan

Postby Seeker » Mar 11th, '13, 15:39

Ed - I read your post again and looked at the data you share, and see what you mean by sd > mean in each case (xbar & t-stat). It's been an awfully long time since I was steeped in statistics, but it does seem strange that the standard deviation is larger than the mean in each case - shouldn't the sd be only a fraction of either? If I'm correct about this, then those results would seem to be completely bogus.
BTW - on the test report page over at Yuuki, they post a comment on what I'm guessing is this video - but very unspecifically.
Also - in the comments section on that YouTube page, most of the comments are by that veritas person - is that the person who did the testing?
I find myself concerned about how to discern safety here where so much personal gain is be in the mix.
Starting to wonder about having my tea tested - but the expense.
Sigh.
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Re: Radiation and Tea in Japan

Postby edkrueger » Mar 11th, '13, 16:34

Well its certainly possible that the SD is greater than mean, but that means that the estimate is very imprecise. Remember your 95% confidence interval is [mean-1.96SD, mean+1.96SD]. Which basically means that there is a 95% chance that the true mean is in the interval. (This interpretation isn't quite right, but the reason why is essentially a philosophical issue.) Since, in this case, 0 is in the interval, we can't conclude that the radiation is non-zero. If mean<SD then interval certainly includes 0. If mean/SD were around 1.6, I might start worrying if I were worried about radiation.
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Re: Radiation and Tea in Japan

Postby NPE » Mar 11th, '13, 17:33

To be quite honest, I would not be too worried. From what I gather, one person would have to drink a LOT of tea to get any significant increase in the overall exposure to radiation, let alone any actual bodily damage. As someone who has been in Western Europe when Chernobyl happened, I am quite sure that I got exposed to more radiation then than I will ever manage by drinking yummy Japanese tea.
And, in order to put things into perspective (and I am no statistician here), I am totally convinced that 'normal' modern living, including the daily commute to work, eating the occasional bit of processed food, a mainly sedentary lifestyle, not as much fresh air as I would like etc. will work its magic in reducing my lifespan much more than my beloved tea ever could - regardless of any (presumed) radiation levels.
Life is dangerous and will invariably end with death. Our genetic makeup (and the driving skills of our fellow commuters :wink: ) will be the most decisive factors in how long we live. All we can do really is decide on how much we enjoy the road from A to B.
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Re: Radiation and Tea in Japan

Postby Maneki Neko » Mar 12th, '13, 03:38

Ok, I'm watching this video too and I'm absolutely allergic to that "Yuuku Chi" of him :evil: C'mon, how hard is it to pronounce "Yuuki Cha" correctly!
This makes the guy less credible for me, to be honest.

Although I'm a total layperson when it comes to the numbers, I won't eat the Uji Gyokuro leaves anymore, just to be on the safe side. My UG is from the 2011 harvest and doesn't taste like it used to anyway. Pity...

Besides, the Yame Sencha leaves are much softer and tastier :mrgreen:

Here on the forum 2 bq/kg is 'virtually zero' and safe, while our friend Veritas Caute has thrown his tea out... :roll:

It's a confusing thing, this RadioactiviTea... :?
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Re: Radiation and Tea in Japan

Postby Maneki Neko » Mar 12th, '13, 03:47

"Yakka Chi"........

...what an idiot :roll:
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Re: Radiation and Tea in Japan

Postby edkrueger » Mar 12th, '13, 09:28

To put this really bluntly. It means that the rigged up radiation meter does not produce enough evidence to suggest that there was any radiation in the leaves.

The so called lab reports might be more concerning (If you are into being scared about radiation), but there again there are no reports of the number of tests or standard deviations. I also don't know if this lab is anymore of a lab than the one in the video.
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Re: Radiation and Tea in Japan

Postby beforewisdom » Mar 12th, '13, 13:30

I know this is veering off topic, so admins, I will no offense if you remove it.

This incident has made me even more anti-nuclear power than I was. I read some technical forums and have a lot of engineers telling me how fantastically safe modern designs are.

However, I read that the design used for the Japanese nuclear power plant flooded by the tsunami was already deemed "risky" by Rand McNaly back in the 70s when it was built.

Right or wrong, I've always had the image of the Japanese as being an extremely conscientious and civic minded people. If they could choose to use a bad reactor design and knowingly put it in a hazardous area I shudder at what American power companies would due with nuclear plants if they were so allowed.
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Re: Radiation and Tea in Japan

Postby Seeker » Mar 12th, '13, 13:39

Maneki Neko wrote:"Yakka Chi"........

...what an idiot :roll:


OMG - I totally agree!!! :lol:
I was gagging, rolling my eyes, and just getting an overall stomach clinch every time the guy mispronounced it. And he couldn't seem to decide which mispronounciation to go with.
Sheesh.
:roll:
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Re: Radiation and Tea in Japan

Postby NPE » Mar 12th, '13, 14:13

Seeker wrote:
Maneki Neko wrote:"Yakka Chi"........

...what an idiot :roll:


OMG - I totally agree!!! :lol:
I was gagging, rolling my eyes, and just getting an overall stomach clinch every time the guy mispronounced it. And he couldn't seem to decide which mispronounciation to go with.
Sheesh.
:roll:


To be honest it did strike me as a bit suspect that this guy managed to mispronounce a not too complicated name with such a variety of versions - it actually struck me as an intentional thing. Normally when someone misreads something, it is this one version until corrected. Could it be that someone has taken to trolling and is willing to put a bit of effort into it???
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Re: Radiation and Tea in Japan

Postby Chip » Mar 12th, '13, 18:29

EDIT: the link was removed, so here it is again.

http://www.youtube.com/watch?v=5H34KucE6GQ

Taking anything seriously from this guy is contrary to conventional wisdom. The guy is running a rube test at best and trashing the credibility of a vendor in the process based upon an extremely crude test. If this was posted on TeaChat, it would be removed immediately. Call this censorship if you want ... I call it being responsible and holding posters accountable. I do defend the credibility of vendors whenever I feel there is a potential or probable injustice.

This is NOT factual information as was the announced parameters in my OP for this second effort on the same topic on Radiation relating to Tea.

If results of testing for radiation or any contamination for that matter are to be "aired" for public consumption (or indigestion as the case may be) they should be conducted by a certified lab. Period.

While youtube is often entertaining and educational, it is a double edged sword in that it gives irresponsible knuckle heads the ability to seem ... credible and even erroneously damage the financial stability of a vendor sans any accountability. Such is the internet.

I do agree, if the guy cannot even pronounce their name ... not even the simple word "cha," why waste your time. I feel like he robbed me of 10 minutes of my life.
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Re: Radiation and Tea in Japan

Postby AdamMY » Mar 12th, '13, 18:51

Chip wrote:I do agree, if the guy cannot even pronounce their name ... not even the simple word "cha," why waste your time. I feel like he robbed me of 10 minutes of my life.


You made it through 10 Minutes! :shock: :shock:

I couldn't stand it because like you said my bullsh*t meter was going off non-stop throughout the entire video. Not to mention Ed's humorous realization on the guys data.

Lets just call this an extension of the "It's on the Internet it must be true" rule. There are a lot of so called experts all over the Internet, and really in the end anyone reading anything should grant the same skepticism to anything they read on the Internet as they would to things they hear in discussions in a bar or coffee shop, or any other place where discussions are common with no real authority figure on the topic.
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Re: Radiation and Tea in Japan

Postby Chip » Mar 12th, '13, 18:54

... well truth be told, I could not handle watching the entire video ... a lot of skipping occurred. :lol:

But how long do you really need to look at a pile of bull plop to realize ... "hey, that is bull sh*t!"
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