Monday, December 06, 2010

Worth the risks?

I'm headed to the airport in a few hours and, if I'm unable to go through one of the standard "old-style" scanners, I intend to let the TSA grope me.

The negative medical implications of the new scanners, I believe, are too great.

Please see a letter from four staff members of the University of California, San Francisco, Department of Biochemistry and Biophysics that explains their scientific and medical concerns over the scanners--concerns that the federal government, so far, has refused to address.

Notice that the letter was written in April.

Key section of the letter (from the second page--the first page of the attached "Letter of Concern"):
The X-ray dose from these devices has often been compared in the media to the cosmic ray exposure inherent to airplane travel or that of a chest X-ray. However, this comparison is very misleading: both the air travel cosmic ray exposure and chest X-rays have much higher X-ray energies and the health consequences are appropriately understood in terms of the whole body volume dose. In contrast, these new airport scanners [due to their low beam energies] are largely depositing their energy into the skin and immediately adjacent tissue, and since this is such a small fraction of body weight/vol, possibly by one to two orders of magnitude, the real dose to the skin is now high.
Read the full letter for more details of the professors' concerns, especially about
  • Older travelers (greater than 65 years of age).
  • Females who have defects in DNA repair mechanisms and who are, therefore, particularly prone to cancer (and who, therefore, do not receive X-ray mammograms).
  • Immunocompromised people (HIV and cancer patients in particular).
  • Children and adolescents.
  • Pregnant women and their babies.
  • The impact of these machines on
    • White blood cells which perfuse the skin.
    • Testicles and the risk of mutagenesis in sperm.
    • Corneas and thymuses.
Thanks, anyway.

As the professors conclude their letter:
We would like to put our current concerns into perspective. As longstanding UCSF scientists and physicians, we have witnessed critical errors in decisions that have seriously affected the health of thousands of people in the United States. These unfortunate errors were made because of the failure to recognize potential adverse outcomes of decisions made at the federal level.

Crises create a sense of urgency that frequently leads to hasty decisions where unintended consequences are not recognized. Examples include the failure of the CDC to recognize the risk of blood transfusions in the early stages of the AIDS epidemic, approval of drugs and devices by the FDA without sufficient review, and improper standards set by the EPA, to name a few. Similarly, there has not been sufficient review of the intermediate and long-term effects of radiation exposure associated with airport scanners.

There is good reason to believe that these scanners will increase the risk of cancer to children and other vulnerable populations. We are unanimous in believing that the potential health consequences need to be rigorously studied before these scanners are adopted. Modifications that reduce radiation exposure need to be explored as soon as possible.
blog comments powered by Disqus