RODALE NEWS, EMMAUS, PA—In response to a failed Christmas-day attempt to blow up a plane over Detroit, the U.S. Transportation Security Administration (TSA) is moving forward with plans to place 150 more full-body scanning machines in U.S. airports in the coming months. The machines will allow security workers to virtually undress passengers, checking to make sure they aren't hiding any metallic or nonmetallic weapons, drugs, or explosives. The announcement is getting mixed responses, including criticism from privacy-rights activists, support from security experts, and questions from passengers concerned about their health. The words "body scan" are causing some worry among health-conscious air travelers, partly because last month the journal Archives of Internal Medicine published studies estimating that the radiation levels from medical CT scans cause more than 20,000 new cancers a year. (Currently, about 70 million scans a year are performed in the U.S., compared to just 3 million in 1980.) However, before you worry yourself sick over exposure, it's important to understand the radiation dose of these machines, and also your rights as a U.S. citizen in line at a security checkpoint.
THE DETAILS: There are two types of body scanners being put into place. Millimeter-wave imaging-technology units do not produce ionizing radiation, the kind we're exposed to when we get X-rays, or, in much higher doses, when we have CT scans. Currently, there are 40 millimeter-wave scanning machines already in use in 19 U.S. airports. They are used as either the primary screening machines that passengers walk through, or more commonly, for secondary or random screenings. The other type of body scanning that has been tested by TSA uses backscatter technology, which does produce small amounts of ionizing radiation by using extremely weak X-rays. After testing them in a pilot program, the administration has 150 of these machines on order, and they will be deployed to U.S. airports in the coming months.
WHAT IT MEANS: The first step is to put the radiation exposure in perspective. According to TSA, the amount of radiation you're exposed to during a two-second millimeter-wave scan exposes you to radio-wave radiation that is 10,000 times less powerful than radiation levels that pulse from a cellphone. A backscatter scan exposes you to the same amount of radiation you would experience during two minutes of a cross-country or ocean plane flight, thanks to cosmic radiation in the atmosphere. According to the National Council on Radiation Protection and Measurement (NCRP), a traveler subjected to at least 2,500 backscatter scans a year would barely reach the Negligible Individual Dose. In same report, NCRP found that a traveler subjected to at least 2,500 backscatter scans per year would barely reach the Negligible Individual Dose. However, the report does stress that records need to be kept to ensure that radiation levels of backscatter machines remain stable and below the limit. In an American College of Radiology release, Mayo Clinic neuroradiologist Peter Kalina, MD, voices concerns over machine maintenance and record keeping, particularly if developing countries adopt the security practice. "As a traveler, I don't know who's checked that machine or equipment. Can I be sure there won't be a larger dose of radiation coming from it?" Dr. Kalina asks.
If you're concerned about airport body-scan radiation, remember these tips:
• Take steps to reduce bigger sources of radiation. Research is mixed when it comes to the safety of cellphones and nonionizing radiation risk. But if you want to practice the precautionary principle, choose texting over putting a phone to your ear to talk, because radiation exposure significantly drops off when the phone is three feet from your head. If you want to chat, opt for an air-tube headset and keep the phone several feel from your body. To lower the amount of radiation you're exposed to through medical tests, check out these two Rodale.com stories: Is That Scan Really Necessary and Are We Scanning Ourselves Sick?
• Know your rights. If you feel uncomfortable going through advanced-imaging airport body-scan machines, know that you do have the right to an alternative search, although it may be in the form of a more invasive pat-down-type search by a security worker. In addition, some people may want to avoid the scans for medical reasons—about 5 percent of the general public is radiosensitive, including women who carry the BRCA1 and BRCA2 breast cancer genes. TSA says that fliers with pacemakers should notify airport security of the condition because other forms of screening may be necessary, such as a pat down or hand-wanding.