Petkau effect

The Petkau effect is an early counterexample to linear-effect assumptions usually made about radiationexposure. It was found by Dr. Abram Petkau at the Atomic Energy of CanadaWhiteshell Nuclear Research Establishment, Manitobaand published in Health Physics March 1972.

Petkau had been measuring, in the usual way, the dose that would rupture a particular cell membrane. He found that 3500 radsdelivered in 2¼ hours (26 rad/min) would do it. Then, almost by chance, he tried again with much weaker radiation and found that 0.7 rads delivered in 11½ hours (1 millirad/min) would also destroy the membrane. This was counter to the prevailing assumption of a linear relationship between total dose or dose rate and the consequences.

The radiation was of ionising nature, and produced negative oxygenions. Those ions were more damaging to the membrane in lower concentrationsthan higher (a somewhat counterintuitive result in itself) because in the latter, they more readily recombine with each other instead of interfering with the membrane. The ion concentration directly correlated with the radiation dose rate and the composition had nonmonotonic consequences.

External links

• Gulf War Syndrome, Depleted Uranium and the Dangers of Low-Level Radiation
• Fallout at Shippingport— Secret Fallout, chapter 15

This article is licensed under the GNU Free Documentation License.
It uses material from the http://en.wikipedia.org/wiki/Petkau+effect Wikipedia article Petkau effect.