Yet another weird SF fan
 I'm a mathematician, a libertarian, and a science-fiction fan. Common sense? What's that?Go to first entry

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 Yet another weird SF fan

### Personal Incredulity Is Not an Argument

Alexander Higgins is incredulous about a possible explanation of why I-131 was detected at a water treatment plant in Philadelphia:

This article on the Philadelphia Inquirer just made me sick to my stomach.

………

Kathryn Higley, a health physicist at Oregon State University, said the most likely source is a nearby or upstream medical facility that treats cancer patients with Iodine-131, which can enter the water supply when patients go to the bathroom.

That is an awful lot of iodine for Cancer patients to be urinating into the drinking water. The article goes on to say they will begin treating the water with “carbon as a precautionary measure”. It also noted that radioactive iodine was detected in the water last year but this makes me question whether that statement is really true or not.

Let's start calculating how much I-131 you might expect to find in groundwater as a result of urination by nuclear medicine patients. In a typical year, patients in the United States use 1.7 × 105 GBq of I-131. The RDA for iodine is 150 μg and the average amount in a human body has been estimated at 50 mg. That means the half life of iodine in human bodies due to urination is 230 days (50,000 × ln 2/150), which is almost 30 times longer than the half-life of I-131 due to decay. In other words, 1/30 of the I-131 used by nuclear medicine patients will be excreted. The United States has an area of around 107 km2. The average annual rainfall is (at a wild guess) around 50 cm. Put this all together and we find U.S. nuclear medical patients excrete 5.9 × 103 GBq per year, which is diluted by 5 × 1015 kg of water. This amounts to slightly over 0.0012 Bq/kg, which around 1/30 the EPA drinking water standard.

At first this looks like it demolishes the patient-urination theory, until we recall that the United States isn't homogeneous and the Philadelphia measurement appears to be an outlier. I live in Nassau County, NY which is 50 times more densely-populated than the U.S. average and Philadelphia is 130 times more densely-populated than the U.S. average. A water-treatment plant that's near a hospital will be even more exposed to nuclear patients.

On the other hand, it takes time for the iodine to get from the sewer to the water-treatment plant via groundwater and I-131 has a rapid decay rate. I'd call the urination theory dubious but not preposterous. If the I-131 is still there in a month, we'll know it's not from Fukushima.

Meanwhile, it looks like the “Greens” are finally starting to realize what we've been trying to tell them for years: Everything is radioactive. Of course, now that they have an excuse, they think it's all Our Fault.

#### I know you are but what am I moment

People who regard anthropogenic global warming as a crisis frequently accuse my fellow wingnuts of believing that the world's climate scientists are engaged in a conspiracy to Hide the Truth. (Actually, we believe that the world's reporters aren't covering climate research right. We think it's possible that the reporters are overemphasizing research that indicates there is a crisis and underemphasizing research that indicates there isn't.) The accusation might not be true about us but it's definitely true of the anti-nuclear people.

For some reason, I'm reminded of the following from The Vicar of Dibley:

Alice Horton: [walks out of the kitchen carrying two cups and gives one to Geraldine] I've been reading that fantastic new book from the Bible.
Geraldine Granger: [confused] *What* fantastic new book from the Bible?
Alice Horton: The Da Vinci Code. You know it's *so* much better than Genesis and that boring old stuff.
Geraldine Granger: I hate to tell you Alice but The Da Vinci Code is *not* a new book in the Bible. It's just a story.
Alice Horton: [downcast] Oh, that is so disappointing.
Geraldine Granger: [broken voice] I know.
Alice Horton: To think that Catholic Church has fooled you as well Mrs Gullible... Gussit. That's what they want you to believe. And I've been thinking...
Geraldine Granger: Ooh. Always a worry.

#### Addendum

If the I-131 is from the recent meltdown, it must have been time traveling:

The U.S. Environmental Protection Agency told the Daily News yesterday that Philadelphia water samples from last August contained nearly twice as much radioactive iodine as the recent samples collected after the Fukushima disaster.

Phphphphttttt!!!!

#### 0 Comments:

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