April 2011
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Day April 24, 2011

Iodine-131 in US Milk: Cause for Concern?

A good friend who trusts my judgment (silly rabbit) has asked me to comment on a recent blog report that screams, “Japan Nuclear Iodine Radiation in San Francisco Milk over 2600% Above EPA Drinking Water Limit”.

Now, I’m as concerned as the next guy (maybe more so) over contamination from the Fukushima reactor accident. But I don’t find reports like this one to be very helpful. Let me count the ways.

1. “Japan Nuclear Iodine Radiation” doesn’t make much sense to me.

2. There is no such thing as “San Francisco Milk”. In point of fact, there aren’t even any dead people in San Francisco, much less dairy farms.

3. “Over 2600%” sounds so much scarier than “over 26 times”.

4. Milk ain’t drinking water.

5. Call me a curmudgeon, but for years I’ve felt the way in which news is delivered is even more important than the content of the news. This blog is littered with ads for radiation treatments, scare headlines, lots of typos and out-and-out misstatements (e.g. I graduated from the University of California, Berkeley and not “University of Berkeley” so I’m pretty sure there is no such institution).

It was a good opportunity for me to go and take a look at the data. Here’s what I found. But first, some background on radiation and why we’re concerned about iodine-131 (also shown as 131I, a shorthand I’ll use here).

When a reactor accident or above-ground nuclear test occurs, a number of radioactive isotopes are given off. Radioactive decay occurs when the number of positively-charged protons and/or the number of non-charged neutrons in the nucleus are more than this structure can support. The picture here shows nuclear fission, but a number of other types of radioactive decay occur that don’t make for as violent a picture.

Seven Deadly Sins Sunday: Gluttony Part 2

Each Sunday, I’m excerpting a chapter of The Seven Deadly Synapses, a book on the neuroscience of sin. In this series, we’re examining the sin of Gluttony.

In part 1 of “Gluttony”, we didn’t get to the scientific part. It was mostly just a warm-up. Now it’s time to figure out how the taste system sends a signal to the brain, and how the digestive system handles food.



Part 2

For most of mankind’s history, eating has been the key to staying alive and so has been a human’s main job. Most of a person’s waking hours were devoted to getting calories, processing calories into a healthy and digestible form, and storing calories for future needs. The word “famine” appears 107 times in the King James Version of the Christian Bible (including the passage shown here, that describes a famine so severe that a mother boils and eats her son); “hunger” 60 times; “starve”, “starving”, “starvation”, 19 times. Other religious texts show a similar historical fixation with either metaphorical or real hunger: the word is used 74 times in the Qur’an, and only 18 times in the Upanishads. Gluttony is likely to be a sin mostly because it revels in the flaunting of what mankind has struggled so hard, for so many years, to achieve: nutrition.


To find food, and eat it, and to balance surfeit with famine, is the responsibility of a few thousand nerve cells in a pinky-end-sized hunk of brain called the hypothalamus. Just like the thermostat in your house keeps the household temperature close to where you want it to be, the hypothalamus is responsible for your body’s balancing acts, the processes and feedback loops that physiologists call “homeostatic mechanisms”. Like Goldilocks, we want our bodies to be “just right”. not too cold, not too hot; not too thin, not too fat; not too much breath, not too little. How the hypothalamus causes us mischief is the root of our story.