Thorium lens and TMI

[FIELDRW@aol.com]

Laura,

Thorium is often used in lenses to reduce the dispersion of light.

It reminds me of a time long past when I was sampling around TMI after the
accident.  I received a call from a women who was convinced her home was
contaminated from TMI radiation.  I was quite surprised by her fears since she
lived 20 miles from TMI.  Nonetheless, I agreed to survey her house and car.
I found no contamination.  I could not understand the source of her fear.

She then said, "but look at my camera".  She had dropped her camera in the
soil across the river from TMI.  She took it home and monitored it with a
newly purchased survey meter.  Sure enough the camera was radioactive.  Logic
told her the camera must be radioactive, because it fell in the soil near TMI.
She was sure she had then contaminated her car and home with soil that had
dropped off her camera.  I showed her there was no removable contamination
from her camera.  I pointed out that she had bought a camera with a lens that
contains radioactive materials.  Within the month, she had sold her car.
Within in a year, she moved from her beautiful home to another state.   She
sent the camera to a researcher at a university somewhere in Philadelphia
(perhaps a radsafer).

Eventhough I managed to convince her that TMI was not the source of the
radiation on her camera, she never got over her fear that her home and car may
be contaminated.  Risk perception is indeed an intersting area of study..

Regards, Bill Field
University of Iowa
bill-field@uiowa.edu   
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