Coffee, Tea or
Cancer? Almost Half of Americans Oppose X-ray Body Scanners
by Michael Grabell | ProPublica
Even if X-ray body scanners would prevent terrorists from
smuggling explosives onto planes, nearly half of Americans still oppose using
them because they could cause a few people to eventually develop cancer,
according to a new Harris Interactive poll conducted online for ProPublica.
Slightly more than third of Americans supported using the
scanners, while almost a fifth were unsure.
The Transportation Security Administration plans to install
body scanners, which can detect explosives and other objects hidden under
clothing, at nearly every airport security lane in the country by the end of
2014. It's the biggest change to airport security since metal detectors were
introduced more than 35 years ago.
The scanners have long faced vocal opposition. Privacy
advocates have decried them as a "virtual strip search" because the
raw images show genitalia, breasts and buttocks — a concern the TSA addressed
by requiring software that makes the images less
graphic. But in addition to privacy objections, scientists and some
lawmakers oppose one type of scanner because it uses X-rays, which damage DNA
and could potentially lead to a few additional cancer cases among the 100
million travelers who fly every year. They say an alternative technology, which
uses radio frequency waves, is safer.
Some travelers like Kathy Blomker, a breast cancer survivor
from Madison, Wis., have decided to forgo the machines altogether and opt for a
physical pat-down instead. "I've had so much radiation that I don't want
to subject myself to radiation that I can avoid," she said. "I
decided I'm just not ever going to go through one of those machines again. It's
just too risky."
After ProPublica published an investigation,
reported in conjunction with PBS
NewsHour, showing that the X-ray scanners had evaded rigorous safety
evaluations, the head of the TSA told Senator Susan Collins that his agency
would conduct a new
independent safety study. He subsequently backed
off that promise, prompting the senator to write the TSA pressing the agency to go ahead with the study and asking it to post
larger signs alerting pregnant women that they have the option to have a
physical pat-down instead of going through the X-ray scanners.
The TSA has repeatedly touted a series of polls showing strong public support for the scanners. But those polls and surveys —
conducted by Gallup, The
Wall Street Journal and various travel sites — largely dealt with the
Only one of those polls — by CBS
News — asked specifically about X-ray body scanners, finding that 81
percent of Americans thought that such X-ray scanners should be used in
airports. But that poll — like all the others — did not mention the risk of
When confronted with the cancer-terrorism trade-off,
however, Americans took a much more negative view of the scanners.
Harris Interactive surveyed 2,198 Americans between Dec. 2
and Dec. 6. (Full
survey methodology can be found here.) The international polling firm
asked, "If a security scanner existed which would significantly help in
preventing terrorists from boarding a plane with powder, plastic, or liquid
explosives, do you think the TSA should still use it even if it could cause
perhaps six of the 100 million passengers who fly each year to eventually
Forty-six percent said the TSA shouldn't use it, 36 percent
said it should, and 18 percent weren't sure.
Asked to comment, TSA spokesman Michael McCarthy said in a
statement that the X-Ray scanners are "well within national
"TSA’s top priority is the safety of the traveling
public and the use of advanced imaging technology is critical to the detection
of both metallic and non-metallic threats," he said. "All results
from independent evaluations confirm that these machines are safe for all
The number of potential cancer cases used in the poll comes
from a peer-reviewed research
paper written by a radiology and epidemiology professor at the University
of California, San Francisco, and posted on the TSA's website.
The professor, Rebecca Smith-Bindman, concluded that 'there
is no significant threat of radiation from the scans.' But she estimated that
among the 750 million security checks of 100 million airline passengers per
year, six cancers could result from the X-ray scans. She cautioned that the
increase was small considering that the same 100 million people would develop
40 million cancers over the course of their lifetimes.
Another study by David Brenner, director of Columbia University's Center for Radiological
Research, estimated that as airlines approach a billion boardings per year in
the United States, 100 additional cancers per year could result from the
The TSA uses two types of body
scanners to screen travelers for nonmetallic explosives. In the X-ray
machine, known as a backscatter, a passenger stands between two large blue
boxes and is scanned with an extremely low level of ionizing radiation, a form
of energy, which strips electrons from atoms and can damage DNA, leading to
cancer. In the millimeter-wave machine, a passenger stands inside a round glass
booth and is scanned with low-energy electromagnetic waves, which don't strip
electrons from atoms and have not been linked to cancer.
There is a great deal of uncertainty when performing cancer
risk assessments from the very low levels of radiation that the backscatters
emit. The U.S. Food and Drug Administration put the risk of a fatal cancer from
the machines at one
in 400 million. The U.K. Health Protection Agency has put it at one
in 166 million.
Some experts say such estimates of population risk create a
distorted picture of the danger because humans are constantly exposed to
background radiation and already accept risks that increase exposure, such as
flying on a plane at cruising altitude.
In the authoritative study on the health risks of low levels
of radiation, the National Academy of Sciences concluded that the risk of
cancer increases with radiation exposure and that there is no level of
radiation at which the risk is zero.
Given that risk, Brenner and some in Congress have argued
that the TSA should forgo in the X-ray scanners in favor of the millimeter-wave
European officials have gone so far as to prohibit
the X-ray body scanners, leaving the millimeter-wave scanner as the only
option. But some countries, including Germany, have reported a high rate of
false alarms with the millimeter-wave machines.
The TSA has said that keeping two technologies in play
creates competition, encouraging the manufacturers of both technologies to
improve the detection capabilities, efficiency and cost of the scanners.