Featured Research

from universities, journals, and other organizations

Are whole-body image scanners used for U.S. airport security safe?

Date:
March 20, 2011
Source:
Radiological Society of North America
Summary:
The Transportation Security Administration has begun to use whole-body imaging scanners as a primary screening measure on travelers passing through airport security checkpoints. One type of scanner currently deployed at airports uses backscatter X-rays that expose the individual being screened to very low levels of ionizing radiation. Two new articles address the question of what potential long-term public health threats backscatter X-ray systems pose.

The U.S. Transportation Security Administration (TSA) has begun to use whole-body imaging scanners as a primary screening measure on travelers passing through airport security checkpoints. One type of scanner employs millimeter wave technology, which delivers no ionizing radiation. However, the second type of scanner currently deployed at airports uses backscatter X-rays that expose the individual being screened to very low levels of ionizing radiation. In the April issue of Radiology, two articles address the question of what potential long-term public health threats, if any, these backscatter X-ray systems pose.

Related Articles


In the first article, David J. Brenner, Ph.D., D.Sc., director of the Center for Radiological Research at Columbia University Medical Center in New York, N.Y., proposes that from a public health policy perspective, given that up to one billion such scans per year are now possible in the U.S, we should have concerns about the long-term consequences of an extremely large number of people being exposed to a potential radiation-induced cancer risk, no matter how slight.

"The risks for any individual going through the X-ray backscatter scanners are exceedingly small," Dr. Brenner said. "However, if all air travelers are going to be screened this way, then we need to be concerned that some of these billion people may eventually develop cancer as a result of the radiation exposure from the X-ray scanners."

In the second article, David A. Schauer, Sc.D., C.H.P., executive director of the National Council on Radiation Protection and Measurements (NCRP), argues that the summation of negligible average risks over large populations or time periods into a single value produces a distorted image of risk that is out of perspective with risks accepted every day, both voluntarily and involuntarily.

"There is no scientific basis to support the notion that a small risk to an individual changes in any way for that individual as others around him are also exposed to the same source of radiation," he said. "Critics of security screening acknowledge that doses from backscatter X-ray systems are very low and safe for an individual."

Dr. Schauer advocates strict regulatory control of the backscatter scanners in order to ensure that their use is consistent with the goals and objectives of radiation protection, which include justification (benefits exceed cost or harm), optimization (exposures are kept as low as reasonably achievable) and limitation (individual doses are limited).

"Any decision that alters the radiation exposure situation should do more good than harm," Dr. Schauer said. "In other words, people should only be exposed to ionizing radiation for security screening purposes when a threat exists that can be detected and for which appropriate actions can be taken. In addition, exposures must be justified and optimized."

Both Dr. Brenner and Dr. Schauer agree that the scanners using millimeter wave technology should be considered as a first option, since they are similar in cost and functionality to the backscatter machines, but do not expose the passenger to ionizing radiation. However, they also say that the average traveler should not be overly concerned about being screened with the backscatter scanners.

"As someone who travels just occasionally, I would have no hesitation in going through the X-ray backscatter scanner," Dr. Brenner said. "Super frequent fliers or airline personnel, who might go through the machine several hundred times each year, might wish to opt for pat-downs. The more scans you have, the more your risks may go up -- but the individual risks are always going to be very, very small."

NCRP has recommended that backscatter X-ray systems adhere to an effective dose of 0.1 microsieverts (΅Sv) or less of ionizing radiation per scan, which roughly equates to the radiation exposure each passenger receives in under two minutes on the plane while flying at 30,000 feet. The average person in the U.S. receives an effective dose of about 3 millisieverts (3,000 ΅Sv) per year from naturally occurring radioactive materials and cosmic radiation from outer space.


Story Source:

The above story is based on materials provided by Radiological Society of North America. Note: Materials may be edited for content and length.


Journal References:

  1. David J. Brenner. Are X-ray Backscatter Scanners Safe for Airport Passenger Screening? For Most Individuals, Probably Yes, but a Billion Scans per Year Raises Long-Term Public Health Concerns. Radiology, (in press)
  2. David A. Schauer. Does Security Screening with Backscatter X-rays Do More Good than Harm? Radiology, (in press)

Cite This Page:

Radiological Society of North America. "Are whole-body image scanners used for U.S. airport security safe?." ScienceDaily. ScienceDaily, 20 March 2011. <www.sciencedaily.com/releases/2011/03/110316084409.htm>.
Radiological Society of North America. (2011, March 20). Are whole-body image scanners used for U.S. airport security safe?. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2011/03/110316084409.htm
Radiological Society of North America. "Are whole-body image scanners used for U.S. airport security safe?." ScienceDaily. www.sciencedaily.com/releases/2011/03/110316084409.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Leaves Orphans Alone in Sierra Leone

Ebola Leaves Orphans Alone in Sierra Leone

AFP (Nov. 27, 2014) — The Ebola epidemic sweeping Sierra Leone is having a profound effect on the country's children, many of whom have been left without any family members to support them. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com
Experimental Ebola Vaccine Shows Promise In Human Trial

Experimental Ebola Vaccine Shows Promise In Human Trial

Newsy (Nov. 27, 2014) — A recent test of a prototype Ebola vaccine generated an immune response to the disease in subjects. Video provided by Newsy
Powered by NewsLook.com
Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) — Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
Today's Prostheses Are More Capable Than Ever

Today's Prostheses Are More Capable Than Ever

Newsy (Nov. 26, 2014) — Advances in prosthetics are making replacement body parts stronger and more lifelike than they’ve ever been. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins