SECOND ANNIVERSARY OF THE FUKUSHIMA DISASTER IN JAPAN

March 11, 2013 is the second anniversary of the Fukushima Daichii disaster in Japan. This was the largest nuclear disaster since the Chernobyl disaster in 1986. On that date, a 9.0 magnitude earthquake and tsunami killed nearly 19,000 people and crippled the Fukushima Daiichi nuclear plant. It triggered meltdowns and spewed radiation over a wide area. The damage, leakage of radiation and challenges involved in control, repair and disposal of contaminated materials (such as soil, water) were much worse than initially expected.

Some 160,000 people were forced to flee their homes and farms. Farmers and fishermen lost their livelihoods. Thousands of lives were changed forever.

This blog gave intensive coverage to the effects of the disaster on radiation in food, starting with regular blog posts just days after the event. It made predictions about which foods and radionuclides would be involved. These were largely based on research at Chernobyl, but taking into account agriculture land use, waterways, and dietary patterns in Japan. These predictions have generally proven correct.

Yes, the main disaster at the nuclear plant has now passed. Radiation levels in the communities near Fukushima Daichii have fallen. The volatile iodine-131 that was released into the air and water only has a half-life of 8 days.Caesium-134 was also produced and dispersed, but has a 2-year half-life. However, Caesium-137, the other main radionuclide, has a 30-year half-life, is easily carried in a plume, and can contaminate land for some time. Caesium is soluble and can be taken into the body, but does not concentrate in any particular organs. It has a biological half-life of about 70 days.

Work inside the wrecked facility has made major progress, although some remains to be done and reports suggest that some, though much less, leakage is still occurring.

As for long-term effects on people's health, much still remains uncertain. Experts seem to agree that long-term, those who are likely to suffer most are the emergency workers, and people living closest to the crippled power plant , particularly northwest of it, who, for whatever reason, refused to leave for months after the incident. Among the latter, children are at greatest risk. The World Health Organization (WHO) has predicted that children near the plant who were exposed to high levels of radiation have a significantly higher risk of developing certain kinds of cancers over their lifetime.

So what about the radiation-contaminated food - greens, rice, fish, dairy, meat and even tea? Yes, it happened and reports are still turning up, for instance in fish. Overall, radiation in food has been part of the general risk situation and has extended far beyond the evacuation area. There are many posts on this blog that cover these issues. In spite of controls, contaminated food has, on occasions, even reached countries outside Japan.

But overall, there is no reason to believe that this incident has created major food-related health risks outside Japan, or will do so in the future. Food-related risks in Japan are also decreasing, although some people remain concerned. If they can afford it, they have turned to imported food, or, to diversifying what they eat, so as to limit their risk. The government continues to monitor radiation levels in food, which may not always catch all incidents, but does help.

To your good health,

TSF

IS THERE TOO MUCH RADIATION IN RICE?

This blog warned about nuclear contamination of food in Japan very soon after the Fukushima nuclear plant crisis in northeast Japan on March 11. At that point, there was, as yet, no evidence or discussion of it. (Read the 20 earlier posts on this issue, beginning March 15). These fears have been confirmed. Excessive levels of radiation have been found in milk, vegetables, fruit, seaweed, fish, drinking water, animal feed - and, most recently, in beef.

It was only a matter of time before attention would turn to rice. Back on April 10, I (see "Can Rice be Contaminated?") I mentioned that the Government of Japan had advised farmers not to plant rice in certain areas because of this risk. We'll know soon whether such warnings were enough. The rice planted back in the spring is about to be harvested. Government-required testing of the rice is beginning in at least 14 prefectures in north and east Japan. About 40 percent of the annually harvested over 8 million tons of rice is grown in this area.

The testing will check levels of cesium in rice to make sure that they are not above the maximum government-imposed cap of 500 becquerels per kilogram. If any are, then shipments of rice from the area will be stopped.

Obviously farmers are anxious. But so are consumers. Rice is something that most people in Japan eat every day - including young children and pregnant women, who are at special risk. Cesium can build up in the body, resulting in higher risk for certain cancers as well as other health problems.

To your good health,
TSF

RADIATION-CONTAMINATED BEEF IN STORES

On July 7, I reported about high levels of radiation found in some beef cattle from Fukushima prefecture in Japan ("Why Radiation-Contaminated Cattle are Bad News"). These cattle were raised about 20-30km away from the radiation-spewing nuclear power plant. I also noted that testing had caught the problem before the beef reached the market. Not so. The initial reports were wrong. Some of this beef, with 3-6 times allowed levels of the radionuclide, cesium, has been sold - and eaten. At least 2,650 pounds of it. Consumers in Japan are not happy. With reason.

In fact, it turns out that the contaminated meat has not just been sold in Tokyo, but in at least 13 prefectures of Japan (maybe more). Japan's second-biggest retailer, Aeon Co. admitted today to selling the beef. It's not the only one. The cattle had been fed rice straw tainted with radiation, in spite of the farmer's claims that he was very careful about cattle feed.

New bans and better testing are in the works. Consumers are suffering, and so are farmers, distributors, retailers. As far as we know at present, the suspect beef has not been exported to other countries. Japanese food exports are already down as a result of bans on many products in a number of countries. This will make the situation worse.

Unfortunately, with food contamination events, the news invariably gets worse than in the initial reports: more products are found to be contaminated, hazardous food is found to have been distributed more widely than initially thought, more people become ill. And, on occasions, dangerous food has been sold and eaten when we believed that testing had caught it in time. As in this case.

Is more bad news to come? My guess: as testing is expanded, high levels of cesium will soon be found in more cattle and in other food animals and poultry (read the four questions I raise in the July 7th post).

To your good health,
TSF

HOW DANGEROUS IS RADIATION IN GREEN TEA?

We tend to think of green tea as a healthy drink. Initially, I found the taste a little difficult to become used to, but am now drinking a couple of cups a day. I have friends who drink ten cups or more. All those wonderful antioxidants that our bodies need! Not only has green tea been drunk for thousands of years in countries such as China, India, Thailand and Japan, but it has been used as a medicine to treat anything and everything, ranging from flatulence to heart conditions. Besides, it is supposed to be good for your complexion.

Now we are reading reports that some of the tea grown in Japan may be accumulating high levels of radionuclides from the crippled Fukushima Dachii nuclear power plant (see yesterday's post). The tea growers from Shizuoka Prefecture, where much of Japan's tea is grown, say this kind of concern is ridiculous. So do some members of the opposition party.

After all, dry tea is a concentrated product. When tea leaves are fresh, and therefore heavier, testing would show lower levels of unhealthy radionuclides such as cesium-137 and 134. And besides, when you add water to dry tea leaves, it becomes even more diluted, thus lowering levels of radionuclides to acceptable levels.

Yes, all this is probably true, but still, I can't say I like the idea of drinking my "healthy" green tea with a touch of nuclear contaminants.

And you had better not chew on the green tea leaves, just in case! Some people do. Not even in your chewing gum, or those delicious Trader Joe's green tea candies.

To your good health,

TSF

HIGH LEVELS OF RADIATION FOUND IN GREEN TEA

Efforts continue to contain the situation at the crippled Fukushima Daichii nuclear power plant in Japan. I just looked at Ministry of Health's latest published results on testing of food for iodine, cesium-134 and cesium-137. I found the levels of radionuclides to be surpisingly low for the most part, although clearly some rivers (and fish) are becoming quite contaminated.

But the news hitting the wires is the discovery of high levels of radiation in a green tea shipment at the Charles de Gaulle Airport in Paris yesterday. The tea had come from Japan's Shizuoka Prefecture. Apparently the detected level of the radionuclide cesium were 1,038 becquerels per kg of tea. This is about double the European Union's maximum allowed radioactive load in foods (cesium 134 and cesium 137). (But note - I have found no official statement.)

This Shizuoka Prefecture produces some 40% of Japan's green tea. Some ten days ago, the Prefecture announced that it had found levels of 679 becquerels of radioactive cesium per kilogram of tea from a producer 355 Km from the nuclear plant. The tea farmers in the area are very upset since their livelihoods are at stake. Shipment of tea from this producer was stopped, and testing expanded. But apparently some got through from somewhere. Or so it seems - if these reports are true.

But relax - customs officials detained the tea and it did not enter the marketplace. At least this shipment didn't. Who knows what other countries received some from the same or neighboring producers. I certainly know that here in the U.S. we import green tea from Japan. I just finished drinking some...

To your good health,

TSF

WILL RADIATION-CONTAMINATED SEAWATER REACH THE UNITED STATES?

Looking at the statistics for this blog, I notice that quite a few people in the United States have been searching about radiation in food, including in fish. I don't think they are just worried about imported fish from Japan (although some people are certainly avoiding that). They are also wondering whether radiation in the sea near the crippled Fukushima power plant will reach U.S. waters and contaminate the fish here.

Japanese officials have now raised the severity of the Fukushima disaster to that of Chernobyl - a level 7. But, in terms of its impact on oceans, the effect is actually greater. Certain radionuclides have been found at higher levels in the Pacific than they were after Chernobyl in the Black Sea and the Baltic Sea. They got into the Pacific not only from the hundreds of thousands of tons of very radioactive water discharged into the ocean, but also from the air. So where does all this water go? To answer that question, I did a bit of searching to see what the oceanographers are predicting.

Yes, it does seem that the main currents from the Fukushima area of Japan move across the Pacific towards the west coast of the United States. I think they are the Kuroshio and the Oyashio, which converge (see NASA photo taken 100 miles north of the Fukushima plant). The contaminated seawater is expected to reach Hawaii in about a year and get as far as California in two to three years. It takes a while.

In the meantime, it will get more and more diluted. So it seems that Americans - including people here in California - shouldn't be too worried.

Let's just stick to focusing more on our home-grown toxins in seafood , such as those found the the San Francisco Bay and Santa Monica Bay of California - PCBs, DDT, dieldrin, chlordane and dioxins. And, any that our own nuclear plants discharge into the environment.

To your good health!

TSF

UPDATES ON RADIATION IN SEAWEED AND FISH NEAR FUKUSHIMA

No one seems to really know how much radiation has entered the sea near the crippled Fukushima power plant, just how far this water will drift, or how badly radiation will contaminate ocean fish and sea vegetables such as seaweed. What we do know is that hundreds of thousands of tons of highly radioactive water has been dumped in the sea, or flown from the land to the sea. And, we haven't reached the end of it yet.

But, as I predicted in my post on April 15, seaweed has indeed been found to be contaminated. On May 13, the environmental activists group, Greenpeace announced that it had found much higher than normal levels of radiation contamination in seaweed off the coast of Japan, as much as 65Km from the crippled Fukushima power plant (their vessel was reportedly not allowed into territorial waters to do its sampling). It has called on Japan's government to undertake a comprehensive testing of the seaweed along the coast, just as seaweed harvesting is beginning.

And, as I also predicted - March 27th post "Radiation in Fish?" which is now 40 posts ago, abnormally high levels of radiation have turned up in seafood in the Pacific waters near the Fukushima plant. But but so far they have only been detected in only one species of fish. But I can promise you that more will be found - especially in fish that are predators, eating contaminated smaller fish (as I blogged earlier) and in fish from lakes and probably rivers as well. Longer term, radiocaesium rather than iodine will be of more concern.

The trouble is that people who eat fish and seaweed from those waters have no way of knowing which fish is contaminated, and which seaweed is contaminated. On the positive side, a few meals are unlikely to hurt you.

To your good health,
TSF

ARE FUKUSHIMA CUCUMBERS SAFE?

I just checked my blog statistics for search keywords, and found this exact phrase: "Are Fukushima cucumbers safe?" I have been thinking about cucumbers lately anyway, so this prompted me to address the issue.

A few days ago, while involved in my daily reading of The New York Times, and as always, checking on the situation in Japan, I came across an interview with a Fukushima Prefecture farmer. He was not farming inside the evacuation zone, but nearby. (In the Nakadori area which is the agricultural center of the prefecture). He was saying that he had to throw out his entire crop of cucumbers because no one would buy them. How sad. Having worked with small farmers much of my professional career, I know how devastating the loss of an entire crop can be. And growing some vegetables myself, I know what hard work it is, with so many climatic and wildlife risks involved. And on top of all this, who needs radiation?

But could his cucumbers have been contaminated with radiation, even tens of kilometers from the evacuation area? Yes, they could have been. The radiation waste is spreading much further than the evacutation area, though at lower levels, and any growing vegetables absorb and concentrate such toxic substances.

Back on April 28, I blogged "The Biggest Threat in the U.S. Food Supply." Wait - you are asking what this has to do with Fukushima cucumbers. Well, it does. Radiation in Fukushima cucumbers would be one of those longer term type of hazards in Japan's supply, especially relevant to people who are younger - and particularly children, who will have several decades of life ahead of them. But even then, someone would have to eat radiation-contaminated cucumbers regularly for a while before they were affected. How long it would take, would depend on how badly contaminated they were, and the eater's own age and health.

But take Salmonella bacteria in cucumbers (as occurred in the U.S. food supply - see Post of May 3). If cucumbers in Japan were carrying Salmonella, eating just half a contaminated cucumber could be enough to cause a case of food poisoning.

So particularly if you are older, I would not worry about eating a few Fukushima cucumbers. But wash it well and peel it, and don't eat a cucumber a day for several months.

To your good health,
TSF

CHILDREN ARE MORE AT RISK FROM RADIATION

I have a new hero. His name is Toshiso Kosako. Until recently, he held the very prestigious position of Senior Nuclear Adviser to the Government of Japan. But I don’t admire him because of his importance. I admire him because he gave it up, and for the reason he gave it up. That took a lot of guts and showed tremendous integrity.

Among the reasons he reportedly gave up the adviser post was that he could not go along with allowing children living near the crippled Fukushima Daiichi nuclear plant to receive doses of radiation that are equivalent to levels established for adult nuclear power plant workers. He understands that they are more vulnerable. This greater vulnerability also applies to any nuclear (or other toxic) contaminants they receive from food.

When this crisis began, I blogged the special dangers pregnant women needed to be aware of. Maybe I should have given more attention to infants and young children. Their bodies are much smaller, and therefore a small quantity of a toxic substance can affect them as much as a larger quantity would affect an adult.

Their brains and bodies are also still developing and can be easily damaged. In addition, infants are sometimes more vulnerable to toxic substances in the environment because they crawl and put things in their mouth. In fact, they could be exposed from several sources - the atmosphere, direct contact with contaminated surfaces, and contaminated food and water.

But a final thought on the food issue: infants and young children can also be more exposed to toxic iodine and cesium from radiation-contaminated food, because they rely on a limited range of food and drink, day after day. This concentrates their risk. If one of these is contaminated - such as milk, apple juice, certain vegetables, it can be very bad news indeed.

Thank you Mr. Kosako, for speaking out for children.

TSF

IS FUKUSHIMA FOOD CONTAMINATION OVER?

The Fukushima power plant disaster hasn't been as much in the news during the last few days, at least not in the U.S. Nor have we heard much about the dangers of nuclear waste in the food supply. Does that mean an "all clear" signal. Is it over? No more need to worry?

Unfortunately not. I have just finished listening to a video recording of a speech by the well-known Australian anti-nuclear activist, Dr. Helen Caldicott. Frankly, it was very frightening. She views Fukushima as being worse than Chernobyl. I hope that isn't true.

The good news is that Tokyo Electric Power Company has finally outlined an ambitious plan for bringing the damaged and leaking reactors to what is called " cold shutdown" (the repairs haven't worked). The bad news is that in the meantime, radioactive emissions from the plant will continue for at least three or more months while this is taking place (and hopefully, will work, but nothing is for sure). They will continue to enter the air, the ocean, lakes and rivers, and seep into the soil.

This is not good news for any food grown in areas where such radiation is spreading (and the experience of Chernobyl shows that it can spread over a very wide area as time goes by). This applies to leafy greens, root vegetables, rice, other grains, milk, meat, fish, shellfish - just about anything. Unfortunately, contaminants can become increasingly concentrated in water and soil - and in food. We will hear much more, as testing is done and results are released to the public.

TSF

UNHAPPY 25TH ANNIVERSARY, CHERNOBYL

Today is the 25th anniversary of the Chernobyl incident. On April 26, 1986, one of the reactors at the Chernobyl nuclear power facility (in what is now Ukraine) exploded. To remember, look at the photos on: http://www.boston.com/bigpicture/2011/04/chernobyl_disaster_25th_annive.html. They are very, very, moving - beautiful as well as tragic.

The World Health Organization (WHO) estimates that some 4,000 people have died from this accident (but others say this is a huge underestimation). The cost in terms of human suffering has been much higher.

In the wake of the more recent Fukushima disaster, a number of countries such as Germany, China and Switzerland, have re-assessed their nuclear power plans. Other nations are considering such moves. In the meantime, the leaks at Fukushima, continue to threaten the health of the population of Japan, not just through direct exposure, but through food and water.

TSF

IS EATING SEAWEED GOOD OR BAD?

Seaweed has been flying off the store shelves in recent weeks in China, Russia and many other countries - metaphorically speaking, of course. Why? Because people believe it can protect them against nuclear radiation - what everyone seems to be afraid of these days.

Yes, it is true - most types of seaweed such as nori, wakame, dulse, kombu, arame and other sea vegetables, contain large (though variable) quantities of iodine 127 - a trace element that our bodies need. This is the "good iodine" used in potassium iodine pills and in iodized salt, which have also sold out in many places. This good iodine helps protect our thyroid gland by giving it what it needs so that it won't take up the radioactive kind if we happen to be exposed. It's a bit like giving your puppy a tough rubber toy to chew on, so it won't eat your carpets (as mine did recently).

But then there is the other point of view. Can seaweed - especially seaweed harvested in the Pacific ocean near Japan, itself be absorbing the radiation that is being released into the sea from the Fukushima power plant? Such fears are making some people wary about eating seaweed. I have a friend who used to order seaweed salad every time we ate out, who has even started taking the nori wrap off her sushi. Several countries such as Australia and Indonesia, have halted or restricted seaweed imports from Japan in case it is contaminated with radioactive iodine.

True, seaweed can in theory absorb the dangerous iodine-131 from nuclear waste as well as all those good minerals and other substances that give it such a healthy reputation. Unfortunately, the seaweed can't tell the difference between the safe kind of iodine and the unsafe kind. But don't get too nervous. Remember, the ocean is a big place, not all seaweed comes from the ocean near Fukushima (even Japan imports seaweed from other countries as well), and many seaweed farms in the disaster area have (sadly) been wiped out by the tsunami. On top of all this, much of the iodine-131 in seaweed would usually have degraded before it reaches our plate.

What I am saying is that the risk of dangerous doses of radioactive iodine from your seaweed salad or miso soup or sushi are pretty small. But also, you shouldn't eat huge amounts of those wonderful sea vegetables thinking that they will protect you if nuclear radiation does come your way in air currents, water or food. This is not a case of "more is better." Too much "good" iodine can be toxic to your body.

TSF

RADIATION IN FOOD: THE FACTS ABOUT CESIUM-137

Since the Japan disaster, we have been hearing a lot about radiation exposure in the news, including about the isotope cesium-137 . Several recent posts on this blog have also mentioned it. But what is it? And, how does it affect us? I am not an expert on cesium-137, so I did some research using reliable websites, including those of the U.S. Environmental Protection Agency (EPA) and the National Institutes of Health (NIH). This is what I came up with.

Cesium 137 is a common radioactive form of the metal cesium (cesium 134 can be present in food, but is less common). It can be in a lot of other places as well. Cesium 137 is used in some industrial processes and in certain treatments for cancer. It can be found in hospital and research laboratory waste, which is usually safely disposed of. But, as we know, it is also released into the environment by nuclear reactor accidents. This happened at the Chernobyl disaster, and has also been occurring over the past month at the Fukushima power plant.

From the environment, cesium-137 can enter growing food. Leafy vegetables and grass tend to pick it up first from the air, helped by wind currents and rain. Cattle and other animals eat grass, and from there it gets into our milk and meat. Some is also absorbed by soil and water and enters root vegetables and fish. Unlike iodine-131, which can last as little as 8 days, cesium-137 has a half-life of about 30 years. Cleanup of soil or lakes or rivers is very difficult and costly. It also creates a high level of risk for the workers doing it.

The problem is that you cannot feel, smell or taste cesium in your food or water. Unless you use special equipment to check for it, you don't know if you are being exposed. If you do ingest it, this metal is apparently easily absorbed by the GI system. Some would be excreted through urine, but a portion would build up in your body, especially in the muscles. The cells lining the intestine and stomach are particularly vulnerable.

Exposure to enough cesium 137 can raise your lifetime risk of cancer fractionally, for example, from 20% to 24%. It can also cause genetic and developmental problems or result in other damage to organs. In the short term, sizeable exposure (unlikely with food or water) may give you headache, diarrhea, bleeding gums, nausea, vomiting and even fever. The size of the dose, and how regularly and how long you keep eating the contaminated food will determine how much you are affected overall.

As with almost all contaminants in food, health effects of radiation will partly depend on who you are: your age and general health, although case studies have documented mysterious exceptions to the rule. Again, as with many contaminants, if the doses are few and small, the cesium-137 will not affect your health. But if your consumption of cesium-contaminated food is "acute" or regular over a long enough period of time, especially if you are also getting radiation from other sources (such as the environment, X-rays, your occupation, international flights, or whatever), it can add to these other sources of cesium and damage your health.

Yes, there are several tests for cesium-137, that can measure levels of it in your urine, blood, bones, feces, hair or skin. But don't expect such tests to be widely available. Most medical laboratories don't do them. If diagnosed with dangerous levels of cesium-137 in your body, treatments are available.

TSF

WHICH IS WORSE - RADIATION OR SALMONELLA IN YOUR FOOD?:

(photo by Micael Elins for TIME).
A lot of people around the world seem to be nervous about radiation in their food. Radiation detectors are the latest hot item. They are not just being bought in Japan. There is also an active market in the U.S. - and, elsewhere. I read an article in the Business section of the New York Times today (my favorite daily read) that was talking about high-end restaurants in Manhattan, New York, using geiger counters to check the fish they buy- and every other item that enters the restaurant (I wonder if they advertises "radiation-free food?).

Frankly, I think people are exaggerating the risks. Yes, as I predicted, both radioactive iodine and cesium have been found in higher than normal levels in fish caught between the Fukushima power plant site and Tokyo. And yes, these unhealthy substances have also turned up in fairly high levels in some leafy greens, and in milk. This is just as I predicted. And yes, I bet we'll soon get reports about radiation-contamination of root vegetables in Japan (as the rains drive the radiation down into the soil), and then, of eggs and of meat.

But let's look at this in context. You have to regularly eat these food items for your health to be affected (although pregnant women and children have to be extra careful). One meal or a few meals are not going to hurt you. And if you are nervous, there are ways of detecting the presence of such radioisotopes, although it may cost you over a thousand dollars to buy a reliable radiation detector. Besides, governments all over the world are busily testing for radiation in foods imported from Japan, so maybe you can just leave it to them and save your money.

Let's compare this to some of the bacteria contaminating our food supply these days. OK - take a look at my earlier post about food contaminants in California. One meal with a hefty dose of Clostridium botulinum, Salmonella, or Listeria monocytogenes can be enough to make you seriously ill - and, can even be deadly. Yes certainly, in countries food such as the U.S. and Canada (and many others) testing for such bacteria is done by both the company and government to make sure that they won't turn up in your lunch or dinner. But believe me, it's not that simple. They'll only catch some of them (see the book for details on this).

So, what I am saying, is " Don't stress out about radiation in your food." Life - and food - is full of risks, and all said and done, radiation may not be the worst of them.

TSF

MORE ON RADIATION IN FISH AND SHELLFISH

I blogged on March 27 about the likely risk of radiation contamination of fish and shellfish near the Fukushima power plant. That was over a week ago. It was also before we heard about the tons of radiation-contaminated water flowing into the sea near the Fukushima power plant. In fact, the latest numbers say about 7 tons of radiated water an hour is flowing into the sea from that crack in the pit at the damaged Reactor No. 2 (where ongoing efforts are now resorting to newspaper and sawdust to plug it). It was also before concerns about radiation in fish affected fresh fish sales in Tokyo, and before the media began to discuss it all over the world, including in the U.S.

And, it was before there were any reported findings of radiation in seafood near the Fukushima plant. The International Atomic Energy Agency has now reported that at the port of Choshi, in Chiba prefecture south of Fukushima, about 20% of the fish caught have been found to have elevated levels of caesium-137 (not high enough to be considered unsafe - yet).

Caesium-137? Isn't everyone talking about iodine-131? Well, yes. But most radioisotopes, including Iodine-131, have pretty short half lives (the time it takes for half the amount that initially enters the water to decay), measured in days or weeks. Testing may show elevated levels in surface seawater now (and I bet it's in lakes and rivers too) but it will get diluted, and soon just decay. In fact, the International Atomic Energy Agency said iodine-131 in seawater would “soon be of no concern.”

But other radioisotopes such as caseium-137 and stronium-90 can stick around for a long time - years, and even decades. I gather from the research on Chernobyl, that if it's in water bodies it's likely to sink down into the sediment and bioaccumulate (that is, build up) in the fish and shellfish in the area.

I wonder when we'll hear about the levels of caesium-137 found in seafood in rivers and lakes near Fukushima? I would guess, pretty soon.

By the way, I notice that my local store has stopped selling scallops imported from Japan.

TSF

RADIATION IN FISH?

Radiation in food is becoming a big issue. People everywhere are becoming nervous - not just in Japan. Even in America. Radiation fears are slowing sales of fish from Japan, and sushi restaurants are finding their customers disappearing. But is the situation at the Fukushima nuclear power plant really likely to result in radiation-contamination of fish as well as of vegetables and milk?

The experience of Chernobyl, as well as of smaller incidents at power plants (including in the U.S.) would argue that it is. And it is not just a question of contaminated marine fish. The Chernobyl disaster of 1986 showed that radiation can also enter rivers and lakes and show up in the fish living there. Fish is very important in the Japanese diet. Fish is also a major export commodity. It comes from a variety of sources: wild-caught ocean fish, marine aquaculture, inland fishing and inland water aquaculture.

After plowing through a number of research studies and scientific papers, I concluded that the levels of radionuclides entering a particular water body will not be the only factor in determining which fish are most likely to become contaminated. A number of other factors are also likely to be involved. One is whether the water is flowing rapidly or not. Another is the type of fish: whether it is predatory, and whether it is a bottom feeder or a surface feeder. The experience of Chernobyl suggests that fish in lakes and ponds will have higher build-up of radionuclides than the same type of fish from fast-moving rivers and streams. Predatory fish will have higher levels than fish which were not predatory. Benthic fish (those that like to lie on the bottom, such as carp - Japan's most popular fish) are more likely to pick up contamination than those fish which tend to live near the surface.

As far as I know, no contamination of seafood from Japan has been reported so far. But the chances are, that it will be soon. If so, don't panic. As I keep saying, in most countries, any radiation-contaminated fish is likely to be caught before it reaches the market. Even if it does get there, a few meals are unlikely to harm you. But if you are pregnant, and for young children, it is still better to stick to the safer fish.

TSF

RADIATION RISKS FOR PREGNANT WOMEN IN TOKYO AND NEARBY

The good news today is that radiation levels in Tokyo are slightly down from yesterday. But they are still many times what they should be. We can't really be sure just how high radiation is in Japan's food and water. But we do know that soil, irrigation canals, drinking water systems and growing crops, grass and food animals as much as 100km away from the affected Fukushima power plant are picking up radioactive iodine and other contaminants such as caesium 134 and 137. And, we also know that at least some radiation-contaminated food and water is even reaching Tokyo.

Japan's Ministry of Health has warned about risks for infants, but has not issued warnings for pregnant and nursing women. They should have. Pregnant women also take up more iodine-131 and this dangerous substance does cross the placenta to the fetus. Animal testing and studies of human atomic bombing victims and those exposed by incidents like Chernobyl have shown that such iodine may have disasterous effects on the fetus. It can not only cause childhood cancers, but also miscarriages, malformations (such as neurological and motor problems), growth retardation, reduction in IQ and even mental retardation.

Two main risk factors are: the radiation dose, including whether it is acute ( a single dose) or chronic (small doses over time) and the stage of pregnancy when exposed. Exposure during the first trimester is the most serious. Pregnant women need to take extra precautions to avoid exposure to radiation from any source. That includes food and water.

If there is a shortage of bottled water in the home, priority needs to be given to the pregnant woman. She should also be careful what fresh milk she drinks and what vegetables and fruits she eats. This might be a good time to resort to tinned and powdered milk and to tinned and frozen produce, on the assumption that these were produced before the recent tragic earthquake, tsunami and associated nuclear power incident.

TSF

MORE RADIATION CONTAMINATION IN FOOD IN JAPAN

So the latest news is that above-safety radiation levels have been found in 11 types of vegetables (as well as in milk, water) in Japan. Some of these veggies are growing 60km or more away from the Fukushima power plant. I am not surprised. As testing continues, it will find more - also in fruit, and eventually in meat, fish. As in the case of Chernobyl, rain is speeding up such food contamination.

The World Health Organization says that there is no evidence of radiation-contaminated food reaching other countries. Let's hope. Japan does export certain fruit, vegetables, dairy products and seafood to Hong Kong, China and the United States, as well as to other places.

China has now announced that it is monitoring food imports from Japan and South Korea has also said that it is expanding inspection of Japanese food. So far, Australia and the U.S. seem to feel there's no need for extra precautions. This may change.

In the meantime, remember that although the levels of radioiodine are above those considered safe, you still won't get much from just a few meals to hurt you.

TSF

CONTAMINATED SPINACH AND MILK NEAR JAPAN'S NUCLEAR PLANT

It was simply a matter of time. As I have been arguing for the past few days, the spread of fairly high levels of radiation in Japan will contaminate growing food. And, I said that the experience of Chernobyl suggested that vegetables like leafy greens and milk would be first to be affected. I was right.

Today Associated Press, Reuters and other news sources reported that the levels of radiation contamination found in spinach and milk on farms near the affected nuclear plant (some as far as 60 miles away) now exceed government safety levels. Further tests are being done and shipments of food from the area may be stopped and people advised not to eat them.

If that does happen, the same thing could occur as did after the Chernobyl: the food will be sold informally and eaten locally anyway, in spite of government warnings. Why? Because there is food scarcity in many disaster-affected places. People who are faced with a choice between hunger and the risk of a little toxic food, will often opt for the latter.

The good news is that a few meals will be unlikely to affect them. But eating it over a period of time - say a year - could do so, especially in the case of children, and with people also exposed to radiation directly.

TSF

HOW RADIATION COULD CONTAMINATE JAPAN'S FOOD: LESSONS FROM CHERNOBYL

With the ongoing disaster in Japan on my mind, I spent some time today trying to find out about how radioactivity could affect Japan's agriculture and how long contamination could last. I looked to UN and other research done on the Chernobyl incident for answers, although hopefully, the amounts of radioactive materials released will not be as bad in the case of Japan. At present we simply don't know. Here are some potential lessons from Chernobyl for Japan's food production and consumption that emerge from these studies.

In the early months after the Chernobyl disaster in the Ukraine, food contaminated in areas with high radiation exposure was mainly due to radioiodine. It turned up in high levels in plants and grass and plant eating animals and their products (such as milk, including goat and sheep milk) and in fish in certain waters, with special risks for children and pregnant women. But iodine-131 is short lived. After a couple of months, most of it decayed. After that the main hazard for food crops was the uptake by root vegetables of radioisotopes from the soil (where rain had deposited it), especially the dangerous caesium.

What I found interesting in the Chernobyl case was that apparently the levels of radiocaesium in food crops and in animal feed were not just affected by how much of it floated around in an area and landed on the soil, but by factors such as the type of soil and type of agriculture and livestock management practices that area people used.

Problems persisted longer in the extensive type of agriculture system (think "traditional" or "subsistence") where the soil is not ploughed much, there is a lot of organic content, and where animals graze in open "natural" pastures. The Chernobyl case suggests that forest foods and animals grazing in forest and mountainous areas can retain high levels of radiocaesium for decades.

In sum, as I understand the findings (and I hope I have got it right) in the short term (about two months) the main food hazard in agriculture areas after radioactivity is radioiodine in fresh fruits and vegetables (e.g. leafy greens) growing above ground, and in milk and dairy products from area cattle. For the next couple of years or so after that, caesium contamination of root vegetables would be the main risk to avoid, particularly on organic farms and where traditional farming practices are still used. Over the still longer term , caesium contamination in milk, meat and forest products (wild mushrooms, berries and game) could continue to be risks.

TSF