"The doses are low – extremely low," said Rebecca Smith-Bindman, MD, a professor of radiology at UCSF, who made the calculations with Pratik Mehta, an undergraduate at UC-Berkeley. "The amount of radiation in these scans is so low that you don't have to be concerned about it."
The amount of radiation absorbed in a single scan, they say, is about the same as what the average person absorbs every three to nine minutes on the ground – just from being alive. (The human body naturally absorbs radiation all the time from such sources as the sun and the earth). In their analysis, Smith-Bindman and Mehta also determined that the average person would absorb 100 times more radiation flying on an airplane than standing in a scanner.
At the same time, Smith-Bindman cautions that the analysis is based on the assumption that the backscatter devices work perfectly and are used as designed.
How certain can Americans be that there are not as-yet-unknown safety risks? For instance, is there potential for software glitches, human errors or mechanical malfunctions that could cause the scanners to exceed their design specifications and expose people to higher levels of radiation?
Questions like these are valid, said Smith-Bindman. She concludes that it would be prudent for the U.S. Transportation Security Administration (TSA) to allow further testing and monitoring of the devices in the field. Currently the TSA does not permit scientists to have access to the scanners to do independent testing.
"Given how many people are being exposed to these machines," she said, "I would just want to make sure no possible unanticipated error could happen."
The analysis appears in a special article published online on Monday, March 28, 2011 in the journal Archives of Internal Medicine.
Scanners to Double in Number this Year
Ever since a failed bombing attempt in December of 2009, when a passenger on a Detroit-bound flight successfully boarded a plane with explosives hidden in his underwear, "backscatter" radiation scanners have been deployed more and more in airports across the country.
About 500 of these scanners have appeared in 78 U.S. airports so far, and the federal government ultimately has plans to double the number of them by the end of this year, said Smith-Bindman. Backscatter scanners are different from millimeter wave scanners, also used in airport security, which image the body using a different type of energy than ionizing radiation.
Because backscatter scanners use low energy X-rays to penetrate clothing, image the human body and reveal hidden articles underneath, they have drawn public scrutiny about privacy concerns and potential health risks.
X-ray radiation can damage DNA, causing a cancer risk with exposure to X-rays from any source. Taking the available published specifications for the backscatter instruments, however, Smith-Bindman and Mehta determined that the amount of radiation absorbed from routine scanning is relatively low and the added risk of developing cancers is likewise low.
About 100 million passengers take 750 million flights in the United States each year, and Smith-Bindman and Mehta calculated that fully implementing backscatter scanners would not significantly increase the lifetime risk of cancer for travelers.
They also looked at the U.S. population that may be at greatest risk: children. Because children are expected to live longer than adults, their lifetime risk of cancer would be higher.
Smith-Bindman and Mehta focused on a subset of children, considering five-year-old girls who fly round trip once a week. Even within this frequent flying group, they estimated that backscatter scanners would not significantly increase their lifetime risk of cancer.
UCSF is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care.
Follow UCSF on Twitter at @ucsf/@ucsfscience
Jason Socrates Bardi | EurekAlert!
Antarctic Ice Sheet mass loss has increased
14.06.2018 | Technische Universität Dresden
WAKE-UP provides new treatment option for stroke patients | International study led by UKE
17.05.2018 | Universitätsklinikum Hamburg-Eppendorf
In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.
Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...
Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
21.06.2018 | Life Sciences
21.06.2018 | Earth Sciences
21.06.2018 | Life Sciences