Sorry, I think I went off track with that last posting on this topic.
I'm not an expert, but I don't think the Micro-wave concept would be possible. Due to the variency of materials that exist in the mail, that could prove to be a big problem. I also read that the ozone produced during the irradiation is causing a problem and concern for workers.
I was thinking on the units you wrote..GRAY! I believe that is associated with Rad's, not Rems. It would be interesting to see if there is any type of correction factor associated with determining Rem equivelent?
I'm always cynical when it come to the publications in the Radiation Sector. Manufacturers will always define the least hazardous statistic associated with their product. It makes it sound safe and even your three year old should own one.
It would also be interesting to see the time frame associated with the Absorbed dose. Is it 5.6 Rad in a hour, minute, second, or micro second? The area measurement unit would also be interesting.
Many years ago I did a couple of TDL shots on a dentist xray machine. The total shot time was 1/10th of a second. The shallow dose came out to be 480 Mr. The deep dose came out to be 28 Mr. When you calculate it out, it come to 17280 Rem/hr shallow, 1008 Rem/hr Deep dose.
I would just be guessing, but with the production of ozone in the mail irradiators, I would have to say they are producing far above the xray machine. With that in mind, I believe they are more than capable of producing the effects you described, either via the radiation directly, or through the bi-products produced from the radiation.