Are Mammograms Dangerous?

Are Mammograms Dangerous?

Because the Becky Baker Foundation is giving tens of thousands of dollars to breast cancer clinics for free mammograms, I thought it wise to ask this question. There are some who claim that mammograms are dangerous and can actually “cause” breast cancer. I reached out to our Radiation Safety Officer and Diagnostic Medical Physicist from one of our area hospitals and asked this question. Actually, I sent her an Internet article that was authored by Dr. Mercola, a well-known online doctor who espouses medical advice, that had criticized mammograms and actually stated they cause breast cancer. Here is the Medical Physicist’s response:

Unfortunately, much garbage is available on the internet – and this is a prime example.  This Dr. Mercola truly does a disservice to women as he uses select references to support – and sensationalize -- his point of view.

Early detection of breast cancer is the key to battling this disease.  And the best means to detect breast cancer early is mammography.  This benefit alone outweighs any possible speculative harm from the low dose of radiation required for the exam.  (And I say speculative because the risks of health effects are either too small to be observed or non-existent.)

The typical effective dose from a mammogram (two views) is about 0.4 mSv (40 mrem).  To put this into perspective, the average person in the US is exposed to about 3 mSv of natural background radiation (that includes cosmic radiation, naturally occurring radioactivity, radon, etc.)

That means the typical radiation dose from mammography is about the same amount of radiation a woman receives from living in the US for about 7 weeks.

Sadly, mammography is not perfect. Women come in all shapes and sizes – and breast size and composition varies significantly from woman to woman.  As a result, not all breast cancers are detectable – even with mammography.  But we’ve made significant technological advances with regard to image quality (thus increasing the likelihood of detection) AND lower radiation dose.

I would remind any patient to “consider the source” when doing internet searches or surfing the net.  Not everyone who contributes to the internet is credible or scrupulous – so I’d rely on organizations such as the American Cancer Society or breast that are dedicated to providing good information to the public.

American Cancer Society

Hope this helps! 


Out of curiosity, I did a search on Dr. Mercola.  And look what came up:

Wikipedia ( says this about him:

Mercola has been criticized by business, regulatory, medical, and scientific communities.  A 2006 BusinessWeek editorial stated his marketing practices relied on "slick promotion, clever use of information, and scare tactics."  In 2005, 2006, and 2011, the U.S. Food and Drug Administration warned Mercola and his company to stop making illegal claims regarding his products' ability to detect, prevent, and treat disease.  The medical watchdog site Quackwatch has criticized Mercola for making "unsubstantiated claims [that] clash with those of leading medical and public health organizations and many unsubstantiated recommendations for dietary supplements."

And here’s his overview from “Quackwatch” (

So, while mammography is not perfect, I just don’t know of another pre-screen test for breast cancer that works as well. Hope this answers the questions that many have posed to me of late.  RB