Originally Posted by RadioGirl

I understand completely you not wanting your daughter in any imaging machine and you should have that right.

The MMW scanner uses radio energy. Like WiFi, like Bluetooth, like cell phones, like any number of other systems that are around you every day.

Where is it written that "long-term exposure studies" must be done to support the safety of such devices? Do you think that such studies were done on WiFi, Bluetooth, vehicle keyless entry? (Answer: no.)

The studies that were done for MMW were about as follows: "The MMW scanner produce xx watts per square centimeter of radio energy on the surface of the person being scanned. Long-established safety standards for radio energy say that the limit is yy watts per square centimeter. xx is much lower than the limit of yy; therefore these devices can be used."

This is the same type of analysis that has been done for cell phones, WiFi, Bluetooth and all those other radio devices. I'm a radiocommunications engineer and I do these sort of calculations for a living. I've seen the numbers on MMW scanners (they were supplied to the FCC to assess interference to other radio systems and are on the FCC website) and done the calculations. The levels come out as being several orders of magnitude less than exposure to cell phones (which are in turn several orders of magnitude lower than the maximum exposure allowed.)

X-ray ("backscatter") is different. The long-held safety standard is that there is no "safe" limit and that any exposure should be kept to the minimum necessary for the medical purpose. Since backscatter body scanners serve no medical purpose, there is no excuse for using these on the public.

The fact that the same agency said both devices are safe doesn't make them both unsafe; it is possible for them to be right (quite possibly by accident) about one and wrong (deceitful, whatever) about the other.