From Health magazineYES: The radiation dose is too small to be dangerous.
Kimberly Applegate, MDVice Chair For Quality and Safety in the Department of Radiology at Emory University School of Medicine

  • You get more radiation from the flight itself.
    In March, some airports began installing a new security device called a backscatter machine. It uses low-level X-rays to create an image that reveals if anything is hidden under your clothing. The U.S. Department of Homeland Security says that one scan is equivalent to the radiation you get flying two minutes at cruising altitude—and if that were harmful, wed have been warned to not fly at all.
  • Theres no harm to the body.
    Unlike X-rays at the doctors office, these scanners use a frequency thats high enough to see whats under clothes but low enough to avoid skin penetration. The rays just bounce off the skin.
  • Even frequent fliers are safe.
    It would take 1,000 trips through the backscatter to reach the equivalent radiation of one chest X-ray—and thats still a very low dose.

NO: Though the radiation levels are low, there are risks.
John Sedat, PhD Professor Emeritus of Biophysics at the University of California, San Francisco

  • The radiation may be higher than claimed.
    The backscatter X-ray dose was calculated by averaging its exposure through the entire body. But in reality, the exposure is limited to the bodys surface and thus may yield 10 to 20 times higher a dose. Its possible that this could put some populations in danger of a skin cancer, such as melanoma. We just dont know the true intensity.
  • The dose is set for adults.
    This means children could be exposed to more radiation than necessary, potentially causing changes in the DNA that could be damaging. The rays may be especially harmful to pregnant women and their developing babies.
  • What if the machine broke?
    If the X-ray beam got stuck on one body part—even for a few seconds—the resulting dose could lead to a radiation burn, or worse.

The Takeaway:
If youre a frequent flier, pregnant, or traveling with children—or if youre simply wary about the radiation—choose a pat-down instead of going through the backscatter body scanner. There are expected to be about 1,000 of these machines in airports by the end of 2011.