Mammogram radiation levels aren’t comparable with nuclear bomb

31 March 2023
What was claimed

Following a 10-year mammogram protocol will expose you to as much radiation as standing one mile from the atomic bombing in Hiroshima.

Our verdict

Even in the highest mammogram exposure scenario this is not true, and the vast majority of women will have significantly lower radiation doses than this.

What was claimed

A Canadian study showed no mortality improvement with mammograms, and that breast self-examination was equally effective.

Our verdict

The study did not find a mortality benefit when compared to physical examinations, but it found that mammograms picked up many cancers that examinations did not. Other large studies have shown an improvement in death rates with mammograms.

A clip from a video recorded over six years ago containing false information about mammograms has resurfaced in an Instagram post which has received more than 7,000 likes. 

The video features Dr Veronique Desaulniers, who is a chiropractor, not a general medical doctor. 

In the video, she makes claims about levels of radiation in mammograms, their effectiveness in picking up cancer and their effect on death rates. These claims are not borne out in the data. 

False information about cancer investigations could lead to people making decisions that can harm their health. Missing early diagnosis opportunities for cancer can be fatal. 

The NHS advises that “Anyone registered with a GP as female will be invited for NHS breast screening every 3 years between the ages of 50 and 71” and that “screening saves around 1,300 lives each year in the UK”.

Dr Desaulniers told Full Fact that she would not post this information now, that she does not discourage women from having mammograms, and that the Instagram page did not have her permission to post the video. 

She told us the Hiroshima claim was based on mammograms in the past, which she said would have used higher levels of radiation. We have not verified if the claim would have been accurate with older mammograms.

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How much radiation comes from mammograms?

In the video, Dr Desaulniers claims that “if a woman follows the 10 year protocol, getting a mammogram every year or every six months, she's getting as much radiation as a woman had at Hiroshima, the atomic bomb, if she stood a mile away from the epicentre”. 

Mammograms are x-rays of breasts done as part of screening for cancer–aiming to pick up tumours early, before a lump or other symptoms have been noticed. 

There is a very small increased risk of cancer from having repeated x-rays over a long period of time, due to the radiation they use. The NHS says: “Most people feel the benefits of breast screening outweigh the possible risks.” Mammograms are sometimes used to diagnose cases of breast cancer in men.

The video appears to be from the US. Different countries have different breast screening programmes, and different providers and areas in the US may do things differently. The recommendations there are generally for screening to start earlier and be more frequent than in the UK. However, we can find no major US organisation that recommends routine six-monthly screenings.

Dr Desaulniers may be referring to recommendations to consider following up a finding of a likely non-cancerous lump with a repeat scan at six months

On this basis, we’ve calculated the maximum expected dose of radiation from the maximum schedule Dr Desaulniers describes. Women with larger breasts end up absorbing more radiation, and it is possible they require more images to be taken. For someone in this category, having 20 mammograms over 10 years, the radiation dose would be 0.2 Gray (or 20 rad or 200 mSv). Gray, rads and milliSieverts all measure how much radiation has been absorbed. 

It’s important to note that this does not reflect a typical mammogram schedule. Almost all people will receive smaller doses, and the average radiation per mammogram is less than a third of what we have used in this calculation. As we’ve noted, mammograms also tend to happen less frequently than every six months. However, we have taken the largest possible number to check if Dr Desaulniers might be right for some women.

In the video, Dr Desaulniers claims that traditional methods of mammography will expose such a patient to over five rads of radiation. As we can see, current practice provides significantly less radiation than this. Historic radiation exposure may have been higher.

And an atomic bomb?

A Japanese government agency has estimated the absorbed radiation dose at 1600m (or around one mile) from ground zero of the Hiroshima bomb at 403mSv. So it’s false to say that six monthly mammograms give a larger dose of radiation. 

It’s also not just total radiation doses that matter–so does the length of time over which the exposure is spread. A dose received in one go is generally considered more dangerous than the same dose spread over a longer period. 

What effect do mammograms have on cancer rates?

In the video, Dr Desaulniers then mentions a Canadian study, claiming it “found that mammograms did not decrease breast mortality rate at all. In fact, they were just as effective as a self breast exam that women do.”

The study she referred to did find that there was no difference in breast cancer mortality between a group of women undergoing mammograms and a group receiving physical examinations. It also found that some cancers picked up in the study may have been overdiagnosed by mammograms (meaning cancers that may not have been life-threatening or even noticeable were picked up and treated). But the researchers found that patients with tumours detected by mammogram had smaller tumours and a better 25-year survival than those who did not have mammograms. 

The study also did not show that mammograms were just as effective as self-exam. The mammograms picked up a significant number of tumours that couldn’t be felt on examination. 

Comparisons with self-exams aside, other large studies have found reduced mortality rates in patients undergoing mammogram screening.

A Public Health England (now largely the UK Health Security Agency) report from 2017 estimated that 150 deaths are averted by breast screening for every cancer death caused by screening radiation.

 

Image courtesy of the National Cancer Institute

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