With news reports of radiation from Japan being found from California to Massachusetts — and now even in milk — math teachers need to help our students put it all in perspective.
xkcd to the rescue!
Pajamas Media offers a brief history of radiation, plus an analysis of our exposure in Banana Equivalent Doses:
And the EPA offers a FAQ:
[T]he levels being seen now are 25 times below the level that would be of concern even for infants, pregnant women or breastfeeding women, who are the most sensitive to radiation… At this time, there is no need to take extra precautions… Iodine-131 disappears relatively quickly in the environment.
— Centers for Disease Control and Prevention (CDC)
pages 4-5 of EPA FAQ
[Hat tip: Why Homeschool.]
Denise Gaskins' Let's Play Math 
It’s on my office door. Only a handful of kids have stopped to read it, but that’s a handful more than otherwise would have.
Jonathan
Brilliant!!
I am so happy to see this quantified comparison of the radiation levels experienced in the recent Japanese disaster to other exposures.
This is the way to deal with emotive reports of dangers to the public: real dangers do exist, but let’s have some facts about how much radiation is actually being experienced by people in different situations.
This is putting math to practical, everyday informative use – thanks so much for sharing!
Love the inclusion of the banana 🙂
I’m glad you find it useful. I thought the chart was very well done, and the difference between a day near Fukushima (top left) and 10 minutes near Chernobyl (lower left) is impressive.
I do think the author left out one important item: the equivalent of all the brown items (lower right) in yellow boxes (lower left). I think they add up to about 15 yellows, if I counted correctly, which would be less than half of the Chernobyl amount shown. But the chart makes it look as if they equal the Chernobyl amount.
It would also have been interesting to me if the chart showed an average radiation dose for cancer patients undergoing radiation therapy. That’s something I have experience with, since my husband suffered through it last year. It would obviously be much more than a CT scan, but surely it’s less than “severe radiation poisoning” — though it felt pretty severe to him! I’m curious where in the range it lies.