[ RadSafe ] Z-backscatter technology

Bradt, Clayton (HEALTH) clayton.bradt at health.ny.gov
Wed Oct 28 12:17:39 CDT 2015

John, thanks. I am familiar with these dose estimates and assume that they are accurate.  But the information I want is two-fold: 1) How is the technology able to both penetrate the scanned vehicle and produce a backscatter image of what is inside? (And apparently what is inside of who is inside!) , and 2) What is the legal basis for allowing cops to apply ionizing radiation to humans.  Whether or not there is a health risk from this specific technology - which apparently there isn't - the law provides no way to approve the practice.

Clayton Bradt

Principal Radiophysicist

NYS Dept. of Health


Date: Wed, 28 Oct 2015 16:22:49 +0000

From: "Dixon, John E. (CDC/ONDIEH/NCEH)" <gyf7 at cdc.gov<mailto:gyf7 at cdc.gov>>

To: "The International Radiation Protection (Health Physics) Mailing

          List"   <radsafe at health.phys.iit.edu<mailto:radsafe at health.phys.iit.edu>>

Subject: Re: [ RadSafe ] Z-Backscatter technology


Here is a good link to this device:


If you pull down the safety tab you will find this:

"Dose to Cargo: Less than 0.1 microSievert (?Sv) per scan (equivalent to 10 microRem (?rem)), at an average speed of 5 km/h (3 mph) at a scan distance of 1.5 m (5 ft). Should a stowaway accidentally be scanned, the effective dose is well below the ANSI specified limit for accidental exposure and is equivalent to flying two minutes at altitude."

1 mrem maximum for a scan of a stowaway (aka- the cargo) isn't all bad. No health risk here...


John Dixon

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