If your head’s hurting right now trying to keep track of official evaluations of the scale of the Fukushima nuclear disaster, well, get in line for the aspirin. If not yet the iodine pills.

For weeks we’ve been told that the still out-of-control nuclear mess at the Fukushima-Daiichi plant would ultimately come nowhere near the scale of the 1986 Chernobyl disaster. (I wrote about this comparison—and its shortcomings—last week.)
(Fukushima nuclear power plant following the March 11 earthquake & tsunami. Photo: daveeza/Flickr)

The Japanese government, for instance, had rated the accident at level 5 on the IAES’s International Nuclear and Radiological Event Scale—an “accident with wider consequences,” roughly on par with the scary but ultimately fairly limited Three Mile Island event in 1979.

Then on Tuesday, we here in the US awoke to news that Japan has re-evaluated the amount of radiation released so far, and has recalibrated the disaster as a 7—top of the IAEA’s scale, a “major accident,” and a level previously reached only by… Chernobyl.

The announcement was widely reported in leads and top graphs in ways that strongly suggested Fukushima is, in fact, comparable to Chernobyl. (See NYTimes, NPR, Kyodo News, NHK.)

Yikes.

But hold on, they told those of us who weren’t too stunned to listen or read further, Fukushima still has released only about a tenth of the total radiation released at Chernobyl. So even if it’s on the same level as Chernobyl it’s still “totally different from Chernobyl,” according to an official of Japan’s nuclear agency.

OK, so it’s the same, but actually not at all the same.

Turns out the confusion partly results from an imprecise measurement system that doesn’t distinguish between events on the top end of the scale. And there IS a very important distinction here—between a Chernobyl reactor without a containment vessel that exploded and burned for two days, spewing high levels of radiation over thousands of square miles, and the four reactors at Fukushima that have so far suffered much less damage and the impact of which has been much more localized.

Except… on the heels of the government’s announcement that Fukushima is not on par with Chernobyl came this, from an executive of the Plant’s owner, Tokyo Electric Power:

“Our concern is that it could eventually exceed Chernobyl.”

Huh?

Aside from that single quote from TEPCO’s Junichi Matsumoto, I haven’t been able to unearth any more details about this statement, certainly nothing about the level of probability behind it. And the same Japanese nuclear official who said Fukushima is totally different from Chernobyl, despite the top-level crisis rating, told the New York Times, “I cannot understand their position.”

So for the time being we’re again left in the dark. Which has been one of the biggest problems of this whole crisis—a dearth of detailed and reliable information, or context for the information we do have.

Some of this may be impossible to get for years, if ever—many instruments are broken or unreliable after the quake and tsunami, and the reactor cores are still too hot to for anyone to be able to assess them directly. It’s also impossible to measure radiation in every possible place it could have ended up. But some information may also have been withheld or massaged by TEPCO or the Japanese government, which has been wrestling with the challenge of how to manage the situation without causing panic among its people.

As I said, we do know that the dynamics of the Chernobyl incident were very different from those at Fukushima. We also know that Fukushima has been managed far better than the Soviets handled Chernobyl (not well, perhaps, but still far better). That means many fewer people have so far received acute doses of radiation this time, and that the fallout from the airborne releases seem to be much less and far more localized. And the Japanese government says that a month now into the crisis, the chances of another large burst of radiation are “significantly smaller.”

But we also know that along with the airborne releases, large amounts of radioactivity have seeped into the ground and been released into the sea, much of which, it seems, is as yet uncounted. And of course the disaster is still far from over. Radiation may continue to escape for weeks or months to come.

And amid the mixed signals, here’s one more: even as the risk of significant new releases seems to be diminishing, the Japanese government this week expanded the evacuation zone around the plant to include new areas where residents are likely to receive long-term elevated radiation exposure. It’s also becoming increasingly clear that some of these areas will be uninhabitable for at least several decades to come.

So—Fukushima like Chernobyl? Fukushima NOT like Chernobyl? I still believe the comparison is inappropriate no matter how the numbers do or don’t stack up (Are we comparing the nature of the accident? Total radiation released? Area affected? Total impact on human health?) But it’s clearer than ever this week that that’s a losing rhetorical battle, even as it’s also clear that the comparisons are more meaningless than ever.

But I sure do hope that at the very least, the IAEA will change its scale before the next nuclear disaster—this is becoming harder than ever to characterize for a general audience.

If they don’t, we’ll know that they really are in cahoots—not with the nuclear industry, as many allege, but with the aspirin manufacturers.

Peter Thomson is the environment editor at The World.

This week: Fifty years ago, the Soviets sent the first human being into space. The first man to orbit the Earth was Soviet cosmonaut Yuri Gagarin. We learn about Gagarin’s legacy in Russia and elsewhere, and about Soviet space memorabilia. A new Dutch study suggests disorderliness can breed discrimination. Study author Siegwart Lindenberg is also the guest in our latest Science Forum. Join the conversation here.

Disorder Breeds Discrimination: A new study by Dutch researchers suggests that people are more likely to discriminate against minorities and act on negative stereotypes when they are in littered and disorderly surroundings. Anchor Marco Werman speaks with study author Siegwart Lindenberg. He’s also the guest in our latest Science Forum discussion. Stop by with your questions.
Guest: Siegwart Lindenberg.
Join our Forum discussion on how physical environments influence our psyche.
The study.
The Broken Window Theory.
Lindenberg’s scientific evidence for the Broken Window Theory.

Yuri Gagarin’s Legacy: Fifty years ago today, Soviet cosmonaut Yuri Gagarin became the first the first human being to orbit the earth. We reflect on Gagarin’s legacy in Russia and beyond.
Report byThe World’s Clark Boyd.

Soviet Space Memorabilia: Fifty years after the Soviets sent the first man into space, space memorabilia is everywhere. It’s in museums, it’s on sale in auction houses. And you can even buy stuff left behind on the surface of the moon.
Report by: The World’s Alex Gallafent.
If you’d rather read the story than listen to it on the podcast, click here.

Revisiting Past Nuclear Accidents: Understanding the past can be key to current events. So check out the latest episode of The World Technology podcast for an in-depth look at the history of nuclear accidents around the world. Host Clark Boyd helps us understand the nuclear accidents at Chernobyl in Ukraine, Three Mile Island in the U.S., and in the Tokaimura plant in Japan.

Noisy Oceans Could Harm Squids: A study published this week in the Frontiers of Ecology and the Environment shows how human-made noises in the oceans could be harming squids and their cousins. I wrote a blog post about it earlier this week. Check it out here.

This week: Scientists are debating the legacy of a doomed expedition to the South Pole, which took place a century ago. Today, the Antarctic is a laboratory for all sorts of science. In fact, a small group of researchers is spending the entire winter at the South Pole. We hear from one of those researchers, an astrophysicist from Belgium. She’s also taking your questions in our latest Science Forum. Click here to join the discussion.  Also, looking back at the Chernobyl nuclear disaster after 25 years. (Photo: Credit Freija Descamps)

Debating the Legacy of a Doomed Antarctic Expedition: Reporter Eric Niiler examines the doomed South Pole expedition of British explorer Robert Scott, which took place nearly one hundred years ago.
Read more here.
‘One man won the battle, the other won hearts,’ by The New York Times.
‘Race to the End of the Earth,’ an excellent exhibition about the Norwegian and British expeditions to the South Pole by the American Museum of Natural History. The exhibition is currently traveling and will be at the National Geographic Museum starting in May 2011..
See pictures of McMurdo research station and relics from Scott’s expedition.

Life and Science at the South Pole Today: Working conditions in the Antarctic have changed a lot since Robert Scott’s expedition nearly one hundred years ago. Anchor Lisa Mullins speaks to Freija Descamps, a Belgian astrophysicist who is spending the winter at the South Pole. Descamps is working at a new observatory called IceCube, which detects ghostly subatomic particles called neutrinos. She is also our guest in the latest Science Forum discussion, so you can send your questions all the way to the bottom of the planet. Click here to join the conversation.
Read about life at the South Pole in Descamps’s blog.
See Freija Descamps’s pictures of the South Pole in this slide show.

Remembering Chernobyl After 25 Years: The nuclear crisis unfolding in Japan is taking place exactly 25 years after the world’s worst nuclear accident in Chernobyl. Brigid McCarthy reminds us of the scale of that disaster.
Read Brigid McCarthy’s story here.
More on Japan’s nuclear crisis on The World.
See pictures of Chernobyl in this slide show.

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Download MP3

This week: A new report says the Arctic permafrost is rapidly thawing due to climate change. We hear about a study of dengue fever in a modern Malaysian city, which shows that mosquito-borne diseases can occur in clean, well-planned environments — not just in poverty-stricken areas. We talk to a researcher who has been studying the secrets behind long-distance navigation by tiger sharks in the Pacific.

Melting Permafrost: We have heard a lot about the problem of melting ice as climate change warms the Arctic. But scientists are also worried about something else that is melting up there – permafrost. Permafrost is the permanently frozen soil underneath much of the northern part of the planet. Now, a report says over half of it may thaw out within the next 200 years, with big consequences for the global climate.
The projected changes in permafrost.
National Snow and Ice Data Center.
All about frozen ground.

Dengue Fever in Malaysia: We think of mosquito-borne infectious diseases like dengue as ailments that plague poor parts of the world. But modern urban development does not necessarily lead to controlling such diseases, according to new findings recently presented at the annual meeting of the American Association for the Advancement of Science. Kate Mulligan is a graduate student at Canada’s McMaster University, and her research shows that well-planned, modern cities can also cause the spread of infectious diseases like dengue fever.

How Sharks Find Their Way: The Pacific Ocean is home to countless species of fish that have a natural ability to navigate around their underwater environment. Anchor Marco Werman speaks with marine biologist Yannis Papastamatiou of the Florida Museum of Natural History in Gainesville about his research on how fish of one species — the tiger shark — seem to  how exactly where they’re going.

This week: You’ll hear all about the history and biology of kissing, from science writer Sheril Kirshenbaum. She’s the author of the new book, The Science of Kissing: What Our Lips are Telling Us. And just in time for Valentine’s day, Kirshenbaum also has some kissing tips for you. She’s also the guest in our latest online discussion. So share your kissing stories and bring all your questions to the discussion. Click here to join the conversation. Also, a new report gives a global view of obesity.

The Science of Kissing: Author Sheril Kirshenbaum talks about her new book, The Science of Kissing: What Our Lips are Telling Us. Click here to read more about her book, and to join an online conversation with her. She’s the guest in our latest online Science Forum discussion.
Guest: Sheril Kirshenbaum
Join our online conversation with Sheril Kirshenbaum.

Global Obesity Epidemic: orldwide, the percentage of adults who are obese has nearly doubled in the past 30 years. That’s according to a new report in The Lancet. Marco Werman speaks with Professor Majid Ezzati of Imperial College London. He led an international team of researchers who examined health data from 199 countries and territories.
Guest: Majid Ezzati
The Study.
Read a transcript of the interview.
The World’s Patrick Cox’s series on Obesity.

Russian Scientists Fail to Reach Lake Vostok: In Podcast no. 102, you heard that Russian scientists were close to drilling a sub-surface freshwater lake in Antarctica. But, Lake Vostok will remain untouched this year. Winter has approached in the Antarctic, forcing the scientists to put a break to their drilling for now. Find out more here and here.
A recent NPR story on Lake Vostok.

No Road in Serengeti: In Podcasts 81 and 84, we told you about a proposed highway to be built through Tanzania’s Serengeti National Park. Conservationists and scientists were opposed to the plan because of the potential impact on the conservation of Serengeti’s ecosystem. Now, the Tanzanian government has decided against building the road. Instead it’s proposing to improve the infrastructure outside the park in order to connect places on opposite sides of it. Read more here.

We also have a story on the Pentagon’s quest for a flying Humvee (nope, not a joke). We’ll talk with Bill Hennigen, who wrote a great article on the story for the LA Times. And then the BBC’s Steve Rosenberg fills us in on Russia’s plans to use inflatable tanks (also not a joke).

And we end with a nice remembrance of Benoit Mandelbrot, the genius mathematician who figured out fractals. Listen to NOVA’s Peter Tyson explain the everyday tech that is only possible through the fractal geometry that Mandelbrot pioneered.

Remember, you can follow us on Twitter and Facebook.

Also, feel free to share your own set-up for listening to the Tech Podcast. Tim Chambers did…via YouTube:

How do YOU listen?

This week: You’ll hear the true story of a Siberian tiger that hunted a poacher. We’re also talking about tigers in our latest Science Forum discussion. Our guest is renowned tiger expert, John Seidensticker. He’s taking questions about efforts to save wild tigers. Check out what he has to say in the podcast then join the conversation.   Also in today’s show, U.K scientists release first drafts of the wheat genome sequence. And please tell us what you think in this online survey!

‘The Tiger’: That’s the name of a new book that tells the true story of a Siberian tiger that killed a poacher, for revenge. The drama takes place in the late 1990s, in far-eastern Russia, just across the border from China. We spoke with the author, John Vaillant.
Guest: John Vaillant
Read the first chapter of ‘The Tiger’.

More about the Siberian tiger on National Geographic.
John Vaillant’s previous book, The Golden Spruce.

Saving Wild Tigers: The tiger is facing extinction. There are some 3500 of the beasts left in the wild today. That’s barely half their number just a decade ago. Poaching and habitat loss are among the many threats facing tiger populations around the world. Several countries are gearing up to enforce stricter measures to protect the species as part of the new Global Tiger Recovery Program. But can we save the species? Or is it doomed to become extinct? Listen to our interview with tiger expert John Seidensticker. Then bring your questions for Seidensticker to the latest Science Forum discussion. He’ll be taking your thoughts and questions until September 13th.
Guest: John Seidensticker.
Join our online conversation about tigers.
Tiger facts from the World Wildlife Fund.

Wheat Genome Sequences: Scientists in the U.K have released draft sequences of the wheat genome. The discovery comes at a time when wheat crops around the world are threatened by disease and climate change. The findings provides scientists and crop breeders with genetic tools to help select for hardier varieties of wheat in the coming years.
Guest: Neil Hall
International Wheat Genome Sequencing Consortium.
FAO cuts outlook for global wheat harvests
More work needed to get the entire genome sequenced.
Stem rust and global wheat production on Podcast 62.

We Need Your Help! We want your feedback. Please take a minute to fill out this online survey.

Listen to our interview with journalist and author, John Vaillant about his new book, The Tiger, followed by our conversation with conservation biologist John Seidensticker.

Seidensticker then joins us as our guest in this Science Forum discussion. He is a conservation biologist at the Smithsonian Washington National Zoological Park in Washington D.C. He also advises countries that are part of the Global Tiger Initiative, a tiger conservation program supported by the World Bank.

The future for tigers looks dismal.  Today, there are some 3500 wild tigers in 13 countries. That’s barely half their number just a decade ago.
Poaching and habitat loss are the two biggest threats to wild tigers today. Tiger-human conflict, where tigers sometimes attack people and livestock and are in turn killed by people also threatens survival of the species. “If there isn’t an incentive to make live tigers worth more than dead tigers, we’ll lose tigers,” says Seidensticker.

China and Russia have just announced a plan to set up the first cross-border protection zone for the Siberian tiger. There are less than 500 Siberian tigers in the wild today, only about 20 of them in China.  This international tiger conservation effort will attempt to protect the remaining tigers from poaching and habitat loss.

Nepal runs a program that pays local communities to protect tigers and tiger habitats. Other countries that are still home to the wild tiger are also drafting plans to protect the species as part of a new Global Tiger Recovery Program.

Can such efforts save the tiger? Or is it facing inevitable extinction? Bring your thoughts and questions to our conversation with John Seidensticker. It’s just to the right. He is taking your comments till September 13th.

• Tiger poaching is driven by a global demand for tiger parts and products. Can we stop this illegal trade?
• How can ordinary citizens help protect wild tigers?
• Have you ever encountered a wild tiger? Tell us about your experience.

Additional Resources:

• Read Chapter 1 of John Vaillant’s book, The Tiger on The World’s website.
• Tiger facts from the World Wildlife Fund.
• Siberian tigers: photos, videos and facts from the National Geographic.

This week: South African vineyards have a new species of visitors – baboons.  Guatemala was recently hit by tropical storm Agatha. Now Guatemala City is trying to cope with a sinkhole that’s 60 feet wide, 100 feet deep, and could get larger. Russia’s simulated manned mission to Mars. An anthropologist explains how Bruce Springsteen’s music fits into her work.

Baboons in the Vineyard: The soccer world cup starts in South Africa this week and some of the tourists heading there will probably be sipping South African wines.  The wine industry there has been booming since the end of apartheid.  But now there’s a new threat to South Africa’s vineyards: wild baboons, it seems, have developed a taste for Pinot Noir, Chardonnay and Sauvignon Blanc – the grapes, that is.
Report by: The World’s Laura Lynch
Laura’s photos from the vineyard.
We’ve covered other human-wildlife conflicts on previous podcasts–including clashes with lions, tigers, bears, and elephants.

Beneath the Guatemalan Sinkhole: Guatemala is still struggling to recover from Tropical Storm Agatha.  The storm hit last week and caused flooding and landslides all over the country.  At least 180 deaths have been blamed on it.  The storm also seems to have played a role in creating a giant sinkhole in Guatemala City.  The hole is more than 60 feet wide, and about 100 feet deep.  It opened up during the storm, swallowing up a clothing factory and an intersection.  It’s not the first sinkhole to appear in Central America after a major storm, but it’s bigger than most and almost perfectly round. And according to a geologist at the University of Pennsylvania, it could get bigger.
Guest: Timothy Bechtel
See a video of the sinkhole on the BBC website.
Sinkhole pictures from National Geographic News.

Volunteers Begin Mars500 Isolation: Last week six men began an unusual experiment in Moscow.  They stepped into a windowless warehouse that will serve as a simulated space capsule and they embarked on an imaginary trip to Mars.  It will take a year and a half round trip.  It’s a daunting prospect, 18 months with five other human beings, no sunlight and only recycled air.
Report by: The World’s Jeb Sharp.
More about the Mars500 Mission, including the crew members’ diary.
Our coverage of the shorter Mars100 mission.
Follow volunteer Diego Urbina on Twitter.

More on Locust Brains: Remember last week’s news about swarming locusts and their big brains? Well, last week I was attending a session on animal intelligence at The World Science Festival and one of the panelists was neuroethologist, Jeremy Niven of Cambridge University. He studies the behavior and brains of insects. And it turns out that the folks who did that study about the big locust brains are his colleagues. So, I asked him to give me his thoughts about why social locusts have bigger brains than solitary locusts.
Listen to last week’s locust story in podcast #69.
Jeremy Niven’s website.

Learn more about animal brains and behaviors from last week’s World Science Festival. Niven was part of this panel.
Also check out Radio Lab’s Animal Minds.

Beware the Bite of a Soldier Termite! The soldier termite bites faster than any other animals in the world. With its mandibles moving at 1/60,000th of a second, these soldier termites can kill an invader in their nests with just one bite! Jeremy Niven has been documenting these fast biting soldiers in several species of termites.
The study on a Panamanian termite.

Music in Science: Anthropologist Barbara King studies and writes about the evolution of human behavior, including communication, religion, and relating to animals. She has listened to Bruce Springsteen and the E Street Band for decades–indeed, she grew up near Asbury Park, NJ, where the band originated. The group’s music has become important to King in her work as a scientist and author.
Song: “Land of Hope and Dreams,” by Bruce Springsteen and the E Street Band
Barbara King’s website.
The Washington Post review of King’s latest book, Being With Animals.

This week:  We have a new discussion going on in our World Science Forum. Our guest is Ethan Watters, author of Crazy Like Us: The Globalization of the American Psyche. He contends that Americans are “homogenizing the way the world goes mad.” Come join the conversation with Watters after you hear our interview with him in this podcast. Also in today’s show, polio reemerges in Russia and Tajikistan, a  mystery about a 16th century astronomer’s earthly remains, and a marine biologist’s musical soundtrack to a science cruise.

Polio Reappears in Russia: The battle to eradicate polio is suffering some setbacks, including new cases in Russia and Tajikistan. The recent reemergence of the disease is making some experts rethink the war on polio.
Report by: The World’s Katy Clark
The BBC’s polio resource page.

Responding to Mental Illness: In New York’s West African immigrant communities, friends and families take it upon themselves to deal with an individual who shows signs of mental illness. Rather than encouraging the patient to see a doctor or therapist, the community sometimes pools its money to buy plane fare and pressures the person to return to Africa. Some say this is a compassionate response, but others say it is driven by shame and does not serve the best interest of the sick individual.
Report by: Laura Starecheski

Exporting Concepts of Mental Illness: Author Ethan Watters argues that America has exported its ideas of mental health, and mental illness, sometimes to the detriment of other countries. In his book Crazy Like Us, he contends that mental disorders have a strong cultural component that is often ignored by Western psychiatrists. He’s the guest in our World Science Forum.
Guest: Ethan Watters
Join the conversation with Ethan Watters in The World Science Forum.
Read an essay by Watters in the New York Times Magazine.

Where Copernicus Rests: Sixteenth-century Polish astronomer Nicolaus Copernicus figured out that the earth revolves around the sun and not the other way round. Copernicus died in 1543, but the location of his earthly remains remained a mystery — until now. Find out where his grave is located.
Guest: Owen Gingerich, Professor Emeritus, Harvard University
Watch the documentary “Copernicus Tomb Mystery.”

Music in Science: Miriam Goldstein is a PhD student at the Scripps Institution of Oceanography at the University of California San Diego. Goldstein is trying to understand how plastic in our oceans affects the health of marine microrganisms. Last summer she led a three-week expedition on an oceanographic research vessel, sampling plastic and animals from the Great Pacific Garbage Patch. She’s still working through the samples.
Song: “I’m on a Boat,” by The Lonely Island
Album: Incredibad
Miriam Goldstein’s website.
More about the expedition to the Garbage Patch.
Watch the music video of I’m on a Boat.