Reply #11: Honestly I don't know why I believe that

[salvorhardin]

Probably a half-remembered factoid from some long ago lecture. I just googled to find something that would corroborate that statement but this was all I could find:

Dr. Devra Davis, professor at the University of Pittsburgh Cancer Institute, said women should refrain from mammograms until after menopause to limit their exposure to cancer-causing radiation.

Davis said that women who are at least 40-years-old are the only women who should undergo mammography. However, younger women who have blatant breast cancer symptoms or family histories of breast cancer should receive mammograms earlier. In an interview with breastcancer.org, Davis said younger women are more susceptible to the harmful effects of radiation than older women because their bodies are still developing.

"The vulnerability to the cancer-causing effects of radiation is dependent on the rapid cell growth of a young girl," Davis said. "The younger the age at first exposure, and particularly when exposure takes place at a time of great development, the greater the risk."

According to studies of women in Hiroshima after the atomic bomb, Davis said women under 20-years-old were at higher risks for developing breast cancer by middle age because of radiation exposure. Middle-aged women did not show such increased risks.
http://media.www.mucdynamo.com/media/storage/paper1287/news/2008/02/27/PreventingCancer/Mammogram.Radiation.Risks-3237986.shtml

Sorry if I gave out bad info.