An interesting way to explain radiation exposure and risk

By Maggie Koerth-Baker at 7:40 am Monday, May 7 • Comments • Share

Science blogger Lee Falin has a potentially useful analogy for putting radiation dose and risk into perspective—treat it like currency. Part of the problem with explaining radiation is that there are multiple units of measurement in play and they're all unfamiliar to the average Joe and Jane. The numbers get confusing quickly and when numbers get confusing, most people just tune them out. "Blah blah blah blah radiation blah blah" is both an unhelpful message, and an often terrifying one.

Falin tries to get around that problem by putting radiation doses into a number system that everybody knows and uses every day—money. He starts by deciding arbitrarily that 1 sievert of exposure is worth $1000. Once you've got that established, it's easier to understand relative doses. In this system, getting $4000 all at once is a deadly dose. Most of us get $2.00-$3.00 a year in background radiation exposure. A mammogram is worth .40.

This is not a perfect method. In particular, it seems to work best for acute exposure. Falin still hasn't totally solved the problem of explaining the accumulation of radiation over time. But I think that this idea—thinking of radiation doses in terms of money—could go a long way to helping some people understand this stuff a little better. I really liked how he explained cancer risks, for instance:

What about the long term risk of cancer caused by radiation exposure? According to the EPA, an average of 2,000 out of every 10,000 adults will die from some form of cancer. If you expose everyone in that group to an extra $10.00 of radiation in one year, the number will jump to about 2,005 people.

Read the rest at Everyday Einstein

Image: International Money Pile in Cash and Coins, a Creative Commons Attribution (2.0) image from epsos's photostream

Bunnie Huang's open Geiger counter: design notes and reference

By Cory Doctorow at 8:00 am Thursday, Mar 15 • Comments • Share

Bunnie Huang, cracker of the Xbox and creator of the Chumby, wanted to do something to help people in Japan following the Fukushima Daiichi disaster. He created a reference design for a cheap, reliable, stylish Geiger counter for everyday carry, under the auspices of Safecast, a group that works on ongoing disaster relief in Japan. Being a consummate hardware hacker, bunnie has documented the steps he took along the way to create his free/open Geiger counter.

After much discussion and review with the Safecast team, we decided that a key component of the user experience should be a graphic display, instead of a 7-segment LED readout. Therefore, a 128×128 pixel OLED panel was incorporated into the design. The OLED panel would be mounted behind a continuous outer shell, so there would be no seams or outward design features resulting from the introduction of the OLED. However, as the OLED is not bright enough to shine through an opaque white plastic exterior shell, a clear window had to be provided for the OLED. As a result, the naturally black color of the OLED caused the preferred color scheme of the exterior case to go from light colors to dark colors. User interaction would occur through a captouch button array hidden behind the same shell, with perhaps silkscreen outlines to provide hints as to where the buttons were underneath the shell. I had originally resisted the idea of using the OLED because it’s very expensive, but once I saw how much an LND7317 tube would cost in volume, I realized that it would be silly to not add a premium feature like an OLED. Due to the sensor alone, the retail price of the device would be in the hundreds of dollars; so adding an OLED display would help make the device “feel” a lot more valuable than a 7-segment LED display, even though the OLED’s presence is largely irrelevant to the core function of the apparatus.

Safecast Geiger Counter Reference Design

Hacking geigers: Safecast crowdsources radiation data in Japan after Fukushima disaster

By Xeni Jardin at 6:21 pm Thursday, Nov 10 • Comments • Share

Watch Online "Hacker" Group Crowdsources Radiation Data for Japanese Public on PBS. See more from PBS NEWSHOUR.

On PBS NewsHour tonight, a report I helped the program's science correspondent Miles O'Brien produce about the challenge people in Japan face of finding and sharing reliable data about radiation contamination, after the disaster at the Fukushima Daiichi nuclear plant.

Embedded above, a conversation between Miles and NewsHour host Hari Sreenivasan about our report, which focuses on a grassroots group called Safecast that measures, maps, and publishes data on radiation contamination levels throughout the country.

While in Tokyo, Miles spoke to Hari Sreenivasan about his trip with Safecast workers into the voluntary exclusion zone around the Fukushima Daiichi nuclear plant, where they detected levels reaching the equivalent of six X-rays per day.

He also filled us in on his conversations with Japanese officials working in evacuated areas and Japanese residents eager for more information about the consequences of the nuclear accident.

I'll post the video for the full feature when it's available online.

How much radiation are you exposed to on a plane?

By Maggie Koerth-Baker at 6:45 am Thursday, Oct 20 • Comments • Share

Since the Fukushima nuclear disaster, you've probably heard me and other people talk about the radiation exposure we experience in everyday life. All humans, throughout history, have been exposed to background radiation produced constantly by the natural environment. Then there's added exposures from modern sources: X-rays and medical scans, living near power plants (both coal and nuclear, and the coal is actually worse), and flying in airplanes.

That last source of exposure works because the higher you get, the less you can rely upon Earth's atmosphere to shield you from radiation in space. It's the same reason why there's an increase in radiation exposure associated with climbing a mountain. All of these exposures are small. Small enough that most people don't need to worry about them. (For instance, a pregnant woman can safely take an airplane trip. You'd have to be a pregnant flight attendant, regularly working long-haul flights, before the exposures would start adding up to a quantifiable risk.)

But because we use these small-dose numbers to talk about relative risk and when radiation should and shouldn't scare us, it's interesting to know where they're coming from ... and how accurate they are. That's why I was interested in something weird noticed by Ellen McManis. She operates a research nuclear reactor at Reed College in Portland, Oregon, and like many of us, she's curious about how much radiation people are actually being exposed to as a part of everyday life. Unlike us, however, McManis actually has access to things like dosimeters. With the help of her colleague, Reuven Lazarus, she recently took one on a cross-country plane flight—from Portland to DC, with a layover in Chicago. To her surprise, she found that the dose her dosimeter registered was actually a lot lower than the dose she'd been expecting.

Read the rest

At a Tokyo radiation hotspot, weirdness abounds

By Maggie Koerth-Baker at 6:48 am Friday, Oct 14 • Comments • Share

Officials were worried this week, when they discovered a radiation hotspot in Tokyo, kicking off readings as high as 3.35 microsieverts per hour. (For context, a dental x-ray is about 5 microsieverts. This wasn't a massive amount of radiation, but it was concerning. The AP reports that readings of that level have been found in the Fukushima evacuation zone.)

The good news: This has nothing to do with Fukushima. It turned out to be an extremely localized hotspot, and officials found the real source nearby.

The bad news: The real source turned out to be something the AP is describing as "mystery bottles" stored under someone's house. No. Really.

So, I guess the takeaway to this story should be something like: Japanese officials find source of radiation hotspot, and are no longer worried that it's being caused by Fukushima. Instead, they are now worried about why somebody in Tokyo is storing bottles of a radioactive substance under a house.

(Via Steve Silberman)

Another radioactive Boy Scout

By Maggie Koerth-Baker at 9:51 am Tuesday, Sep 13 • Comments • Share

My old employers, mental_floss magazine, have a new editor and some cool new stories out in their September/October issue. One is about a kid who built a nuclear reactor at age 14. No, not that kid. Meet Taylor Wilson, a kid who shares some hobbies with the more-famous "Radioactive Boy Scout" David Hahn, but with, apparently so far, less tragic results. (It helps that Wilson, unlike Hahn, discussed his plans with adults who helped set him up with the right safety environment to build his reactor in.) Another difference: Wilson's interests lie with fusion, not fission.

By the time Wilson stumbled across Fusor.net, 30 hobbyists worldwide had managed to produce the reaction; Wilson was determined to become the thirty-first. He started amassing the necessary components, such as a high-voltage power supply (used to run neon signs), a reaction chamber where fusion takes place (typically a hollow stainless steel sphere, like a flagpole ornament), and a vacuum pump to remove air particles from the chamber (often necessary for testing space equipment).

Wilson also funneled money collected from Christmases and birthdays toward buying radioactive items, many of which, to his surprise, were available around town. Smoke detectors, he learned, contain small amounts of a radio-active element called americium, while camping lanterns contain thorium. In antique stores, he found pottery called Fiestaware that was painted with an orange uranium glaze. Wilson trolled websites such as eBay for an array of nuclear paraphernalia, from radon sniffers to nuclear fuel pellets, and came to own more than 30 Geiger counters of varying strengths and abilities. Most of Wilson’s radioactive acquisitions weren’t dangerous, given their small quantities. But a few—vials of powdered radium, for example—could be fatal if mishandled, which is why he’s never opened them. (Although he’s been tempted.)

There's a longer preview of the story online. The rest is in the new print issue.

Image: Radiation Suit Minifigure, a Creative Commons Attribution Share-Alike (2.0) image from n8kowald's photostream

What sulfur particles in California can tell us about Fukushima

By Maggie Koerth-Baker at 1:30 pm Monday, Aug 15 • Comments • Share

During the early weeks of the Japan 3/11 crisis, after a tsunami critically damaged the Fukushima Daiichi nuclear power plant, we talked on Boing Boing about why Americans on the West Coast didn't need to worry about exposure to radioactive fallout. Shorter version: The levels of radiation that made it across the Pacific were far too low to cause a serious health concern.

Now here's something really interesting: The levels of fallout that made it across, while too low to pose a risk to humans, were detectable by extremely sensitive scientific equipment. And those measurements are now being used to document what happened at the site of the disaster.

In the process of trying to cool down the overheating reactors, officials in Japan dumped sea water and reaction-slowing boric acid into the reactor cores. The resulting chemical reaction—chloride ions in salt water combining with fast-moving neutrons from the reactor—produced a form of radioactive sulfur. Meanwhile, scientists at the University of California, San Diego, were already measuring sulfur particles in the air as part of climate research. Days after the crisis began, their instruments picked up the radioactive sulfur that had crossed the ocean.

Now, using modeling and some basic knowledge about how particles behave, they've been able to use the information they gathered in California to estimate how high radiation levels were in Fukushima in the early days of the crisis. A couple of things they've found: Further evidence that at least one of the reactor cores suffered a meltdown, and evidence suggesting that the damaged reactors didn't re-start after the emergency began—a possibility that has been pointed out by other scientists. I'll have a more in-depth look at this study later this week. For now, check out the write ups at Nature News and USA Today.

The full research paper is at The Proceedings of the National Academy of Sciences.

(Thanks, Miles O'Brien + Jenny Marder of PBS NewsHour)

Read the rest

Fukushima: Very high radiation levels still being found in some parts of power plant

By Maggie Koerth-Baker at 3:15 pm Tuesday, Aug 2 • Comments • Share

This image shows two spots at the Fukushima nuclear power plant in Japan, at the bottom of a ventilation stack between the No.1 and No.2 reactors, where radiation levels are still high enough to kill a human being. I'm talking about the quick-death-by-radiation-poisoning sort of "kill," not the possible-death-by-cancer-at-some-point-in-the-future sort. At the colored spots, radiation levels were measured at 10 sieverts (10,000 millisieverts) per hour.

The image was captured using a gamma ray camera, the same sort of equipment that researchers use to track radioactive isotopes in the human body as part of medical treatments.

Image: REUTERS/Tokyo Electric Power Co

Via David Biello and the Atlantic Wire

The pros and cons of irradiated food

By Maggie Koerth-Baker at 9:56 am Friday, Jul 29 • Comments • Share

Irradiating food doesn't make it radioactive, and it does kill dangerous bacteria, like the E.coli that killed many Europeans this summer. But it's also not a panacea against food poisoning and it's definitely not the most popular idea ever thought up. In a column in the New York Times, Mark Bittman examines the evidence behind irradiation, and how that evidence does and doesn't get considered in the choices we make about food.

When it comes to irradiation, you might need a primer. (I did.) Simply put, irradiation — first approved by the FDA in 1963 to control insects in wheat and flour — kills pathogens in food by passing radiation through it. It doesn’t make the food radioactive any more than passing X-rays through your body makes you radioactive; it just causes changes in the food. Proponents say those changes are beneficial: like killing E. coli or salmonella bacteria. Opponents say they’re harmful: like destroying nutrients or creating damaging free radicals.

Many people are virulently for or against. Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, says that irradiation “could do for food what pasteurization has done for milk.” (The main difference between irradiation and pasteurization is the source of the energy used to kill microbes.) Wenonah Hauter, the executive director of Food & Water Watch — which calls irradiation “a gross failure” — told me it was “expensive and impractical, a band-aid on the real problems with our food system.”

There are a few people in the middle. Former assistant secretary of the Department of Agriculture (USDA) Carol Tucker-Foreman is mostly anti-, but said that if she ran a nursing home or a children’s hospital — a place where people with weaker-than-average immune systems were cared for — it “might be something I wanted to do.” Marion Nestle, a New York University nutrition professor and the author of “Safe Food: The Politics of Food Safety” (and a food-movement icon), allows that “the bottom line is that it works pretty well if done right, and I’m not aware of any credible evidence that it does any worse harm to foods than cooking. But it isn’t always done right, and foods can become re-contaminated after irradiation.”

Via Andy Revkin

Image: NAM - Nabob Irradiated Coffee, a Creative Commons Attribution Share-Alike (2.0) image from lifeontheedge's photostream

Japan: angry Fukushima citizens confront government (video)

By Xeni Jardin at 11:36 am Monday, Jul 25 • Comments • Share

The video above documents what I am told is a meeting between Fukushima residents and government officials from Tokyo, said to have taken place on 19 July 2011. The citizens are demanding their government evacuate people from a broader area around the Fukushima nuclear plant, because of ever-increasing fears about the still-spreading radiation. They are demanding that their government provide financial and logistical support to get out. In the video above, you can see that some participants actually brought samples of their children's urine to the meeting, and they demanded that the government test it for radioactivity. When asked by one person at the meeting about citizens' right to live a healthy and radioactive-free life, Local Nuclear Emergency Response Team Director Akira Satoh replies "I don't know if they have that right." Boing Boing reader Rob Pongi spotted this online and sent this in to us. I asked him for more info.

The current evacuation zone in Fukushima is only 20-30 kilometers. The Japanese government has compensated the evacuees from inside that zone and has financially supported them in moving out of it. However, as more and more high levels of radiation are being discovered outside of the evacuation zone, many more Fukushima residents (and many others located nearby Fukushima) want the government to also help them logistically and financially so that they can move out further away from the nuclear plants. Especially since many children are now being exposed. But the government does not want to do this at all and many people are getting very upset. This video was filmed in Fukushima at the Corasse Fukushima Building on July 19, 2011. The meeting was entitled "Japanese Government Discussion - Demands for Evacuation Authority". This meeting was attended by residents of Fukushima and some Representatives for the Nuclear Safety Commission Of Japan. It was filmed by some anonymous members of the "Save Child" website. This site includes Japanese news about the Fukushima Nuclear disaster, advice on how to avoid contamination, and many, many related videos. This site is much like enenews.com on steroids! I checked domaintools.com and the name of the registration is private. You can see the original Japanese videos of this meeting on the Save Child website here (English), and on Youtube here. This video was translated by pejorativeglut. And, for sure, the English subtitles are correct. I was not involved in the production of this video.