Radiation contamination found on tea grown in Kanagawa prefecture (Ashigara tea)

Note: This was written in May 2011

Before I post Part II of the Keeping Japan Going series, I thought I should address this 'breaking news' item. I got some questions about the 'contaminated tea leaves' in the news (this has been in the Japanese news for the past few days actually).

It is now tea gathering season in this part of Japan, and it seems that the tea leaves are just now getting tested (I have no idea why they didn't do it earlier by the way.) The tea in question is Ashigara tea, from Kanagawa prefecture...local to me since I'm in Yokohama, the largest city in Kanagawa, as I type this (my mom lives here). Tea here in Kanagawa is grown in a small scale way in several towns and villages. It's not considered to be top-class tea per se, and is often just branded as Ashigara tea even if it's not actually grown in the town of Ashigara. Anyway, levels of radioactive cesium (caesium for Brits and Aussies) above the 500 becquerel limit set by the Japanese central government were found from tea leaves harvested in a total of 5 villages, and tea growers in the entire region have been requested to stop shipments, and the tea growers association has already decided to destroy the contaminated crop. Needless to say they are not happy at all, especially since tea, unlike green leafy vegetables, takes a very long time to grow. (NHK World news report in English.)

Now, why was just cesium detected and not the most often detected radioactive substance, iodide 131? My somewhat educated guess is that the iodide has already deteriorated and dissapated to an undetectable level because of its short lifespan of 8 days. Cesium has a much longer lifespan, up to 37 years I believe. So anyway, that is the situation: if you happen to encounter Ashigara tea from this year (unlikely, because of the shipment stoppage) then it's safer not to use it.

If you're from elsewhere you may wonder if your Japanese tea is affected. If you already have it or it's at your stores, it's not - because remember this is THIS year's harvest we are talking about, which is just starting now. I am sure all tea growing areas are measuring their harvests. In Japan, the major tea growing areas - that grow enough to export - are Shizuoka, the Kyoto area (Uji and so on), and southern Kyushu such as Kagoshima. So far there have been no reports of any problems with tea or any produce grown in these areas, which are further away from Fukushima. (There were earlier reports of some iodide found on green leafy vegetables grown in Kanagawa, though not above safety limits.) So if you are looking forward to new-harvest tea (shincha), as long as you are getting your Japanese tea from reputable sources that clearly state their origin you should be fine. As far as Shizuoka and the Kyoto area are concerned, the recent news that the Hamaoka power plant in Hamamatasu, Shizuoka is in the process of being shut down for precautionary reasons may give a sigh of relief to farmers in the area.

I have also been accused in some quarters of trying to downplay the seriousness of the situation regarding the Fukushima plants. I don't think I am, but I'm not trying to spread panic either. The tea leaf contamination as far as I can tell, based on looking at ongoing measurements of atmospheric radiation (not just on what's reported in the news media) is not from a new radiation leak from the Fukushima nuclear power plants, but from the earlier ones soon after the earthquake, especially around March 15th. (See my previous report about vegetables, and the links at the bottom to various sources of information.) No new incidents per se have occured at the Fukushima No.1 plant as far as anyone can tell from the numbers. Let's hope it stays that way, and that the reactors and spent fuel chambers can be cooled down safely.

I know it's all very scary and disconcerting, but so is stuff like food being contaminated by e.colli or growth hormones or (even worse) purposefully contaminated with melamine or mercury and so on. I firmly believe that we all have to keep constant vigilance and make informed decisions about the things we consume.

On a personal level, my tea-snob mom never bought Kanagawa grown tea anyway, and I guess she's not going to start now. ^_^; (She favors an organically grown tea from Kagoshima at the moment for what it's worth.) (ETA: The tea is from Shimodozono, and not only is it organic, it is grown with no fertilizers of any kind added to the soil - 'tea as it grows in nature'. They also sell conventionally grown tea, so if you want to try the 'natural' tea it's this one (Japanese only page I'm afraid, and I'm not sure if they ship overseas. They ship all over Japan though.)

[Update:] Above-limit amounts of cesium have also been found on some tea grown in Ibaraki, Chiba and Gunma prefectures in the past few days, and these tea leaves have been withheld from the market. These are the same prefectures that had the problems with green vegetables a few weeks ago. So far I have not heard any news of contamination further south or west than Kanagawa. (Please pull out your maps of Japan if you're not sure which prefecture is where.)