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How Dangerous Are The EMFs From CT Scan Radiation?

Posted by Lloyd Burrell on May 27, 2011 under EMFs and x-rays | 51 Comments to Read

Back in 2002 when I first became electrosensitive my doctor, in his quest to find out what was wrong with me, sent me for a whole battery of tests. One of these tests was a CT scan.

I remember laying there as my body passed through the hole of this big white donut shaped device. What I did not realize at the time was the high levels of ct scan radiation I was submitting myself to.

In 2002 I was just beginning to get a grip on the dangers of cell phone radiation, of WiFi and electromagnetic fields generally. I was learning about these things first-hand because I was suffering from their effects every day. So it never occurred to me that the CT scan I was undergoing was even more deadly in terms of radiation exposure.

How Do CT Scans Work?

CT (Computed tomography) or CAT scans use a computer and a rotating x-ray device to create detailed cross-sectional images of organs and body parts.

ct scan radiation

CT or CAT scan

These can be full body or partial scans. Multiple images are taken and then the computer compiles them into complete, cross-sectional pictures of soft tissue, bone, and blood vessels. Doctors use CT scans to identify small nodules or tumors which they cannot see on an x-ray.

How Much Radiation Do You Get From A CT Scan?

I have now had time to do my research on this topic. There are so many statistics I could quote to you, here’s one that really brings it home:

One CT scan is equivalent to about 750 chest x-rays.

A 40-year old woman who has a coronary CT scan has a 1 in 270 chance of getting cancer from that single scan. This statistic doubles for a 20 year old Woman.

That’s massive when you consider that in the US

– around 19500 CT scans are conducted daily (over 70 million scans annually)

– between 2000 and 2005 spending for imaging studies more than doubled

one in five Americans will receive a CT scan in any given year

Some estimates say that CT scans cause 29,000 excess cancers each year in the US alone, mostly in women.

Is CT Scan Radiation Worse Than Cell Phone Radiation?

This is a bit like comparing apples and pears. You use a cell phone just to have a conversation, not to perform what may be a life-saving diagnosis. But clearly a CT scan exposes you to a far higher dose of radiation at a far higher frequency (x-ray) than cell phone radiation and whats more it exposes you to ionizing radiation just like regular x-rays.

Cell phone radiation, and other wireless forms of radiation, are dangerous because of long-term constant exposure to relatively small amounts of radiation. Whereas CT scan radiation is more about undergoing a single, or perhaps only several, massive doses of radiation which has its health consequences may be 10 or 20 years later.

To put this in perspective you need to be scanned 200,000 times by an airport body scanner to accumulate the radiation that you would get from a single CT scan. A CT scan is the equivalent of about 74 mammograms.

Why are CT scans on the increase?

I hate to say it but I think it’s mainly to do with money, again. This is a multi-billion-dollar industry which encompasses the CT equipment manufacturers, radiologists and hospitals. It’s an industry which feeds off the publics health fears. If you can have a scan and know in a few hours if you have a life-threatening tumor, or not, then people do not need a lot of convincing.

As with cell phone radiation, where this is all wrong is that the public is being kept completely in the dark as to the danger of the CT scan radiation. Some studies even suggest that a majority of radiologists are unaware of the cancer risks of CT scans.

How can CT scan radiation be avoided?

Ultrasounds can be substituted for CTs in certain cases. But it is true that often there is really no substitute to a CT scan, in terms of the quality of diagnosis it will provide. But the question you need to ask yourself is do I really need a CT scan? Do I really need this level of diagnosis? Given the dangers of such a scan, do the benefits outweigh the dangers?

Is the CT scan worth the radiation risk?

Yes this is a question you really need to ask yourself, because CT scans are a truly remarkable piece of technology that they are also an overused technology, not unlike cell phones! Also like cell phones, children are particularly susceptible to the dangers.

My advice: only go for the CT scan if you have made absolutely sure you need one.

Here is a news item highlighting the dangers:

Announcer: “In Alabama, a school teacher Becky Coudert’s hair has fallen off. Her lawyers say she received a higher than normal radiation dose after having a CT brain scan in September.  Two other patients have come forward with similar stories. In Los Angeles, Cedar Sinai Medical Centre is being investigated for giving excess radiation to more than 250 patients during their CT scans. The problem of too much radiation during CT scans maybe more widespread than anyone thought and the doses administered are actually higher than generally reported.

CT Scan Radiation Dosages Vary

New research has found a wide variation in radiation dose for the most common CT scans like abdomen, pelvis and chest. A survey of 4 hospitals found some patients received 13 times more radiation than others for the same type of scan. Depending on where a particular patient was sent, be it hospital 1 or hospital 2 or if it was in the afternoon or the evening, the dose that the patient received was found to be profoundly different and this degree of variation was what really was so surprising.

Radiation is a known carcinogen even in the relatively small amounts used with most CTs. There are a number of uncertainties involved in predicting cancer risk, but a recent study estimates that about 29000 future cancers might be caused by the 72 million CT scans done in 2007. So if a CT scan is truly indicated patients are advised to proceed with that scan but they should be sure to choose an accredited facility that can be relied upon to control the radiation dose and make it as low as possible. The FDA in investigating the type of brain scan that went wrong in California and Alabama hospitals. Meanwhile experts are calling for regulations to standardize how all CT scans are performed.”

Remember, when you go for a CT scan you are exposing yourself to CT scan radiation, this is not to be taken lightly…

  • Mike King said,

    If a car was capable of killing 1 in 400 people over 10 to 20 years it would be sued off the market never to be seen again. Each radiologist agreeing to do an unnecesary CT should have the same treatment.

  • Mary said,

    I have had 5 CT scanns, 5 years ago, I am very worried, I didn’t know at the time that scanners where dangereous, doctors did not told me, of course, now I know why. What do you recomend me.
    Thank you for your information

  • Lloyd said,

    Studies show EMF exposures are cumulative, I would suggest that you try and minimize your exposures to EMFs generally, look under the category “electromagnetic protection” for some ideas, and you might want to subscribe to my newsletter.

  • Mike said,

    If you are worried about your CT scan, ask your radiology group for a physicists report on radiation dose you received and likely outcomes. Most are “almost” safe compared with not having one. A lot are not needed but performed for medico-legal reasons(who wants to be sued).
    A chest and abdo CT has the equivalent radiation dose of at least 750 chest x-rays.

  • Lloyd said,

    Getting a physicists report is a good idea but EMF mitigation is your best line of defense.

  • John said,

    What happens to the radiation after the CT Scan is done? I work in an office with several people that have had CT Scans and I am afraid of sitting in the chairs that they have sat in.

  • Lloyd said,

    I don’t know of any research on this subject, so I can only speculate. The CT scan can have a big impact on the health of the patient, particularly in the long term, but I think it fairly unlikely that your health would be put at risk by using the same furniture as them.

  • Mike said,

    CT and X-ray radiation is EMF, the same as a light bulb, turn it of and there is no effect left, unlike cobolt, radium etc which is a source radiation with ongoing effects.

  • Lloyd said,

    The studies talk of the cumulative nature of EMF exposures, if there was no effect when you “turned EMFs off” this cumulative effect would not be observed. Clearly there are ongoing effects with CT and X-ray radiation also.

  • Mike King said,

    Hi, yes you are right, there is an ongoing effect on living objects, the radiation doesn’t keep going, the damage done by the x-ray wave-length is non fixable but a chair or inanimate object doesn’t notice such effect as its cells are not dividing or multiplying as in living things.

  • John said,

    Ok. Since ionizing radiation is capable of separating electrons from their mommies, can the subatomic particles released continue to cause damage after the x-ray or ct scan is taken? From your explanation I understand that there would not be any residual energy after the x-ray/ct scan device is stopped.
    Can ionizing radiation produce radioactive material like a nuclear reactor?
    Please forgive my ignorance.

  • Lloyd said,

    Ionizing radiation from CT scans etc break down the bonds that hold molecules together, which create free radicals. Free radicals in themselves are not dangerous, but if there are too many of them they are believed to be responsible for cancer, aging, and a variety of diseases. So it’s not so much about residual energy it’s about these free radicals.
    As for your second question on radioactivity, sorry I can’t help this is not my speciality.

  • Darin said,

    Hi, i just had a CT scan today. During the scan my eyes were closed and i felt something hot on my head and yellow light on my eyes. I don’t know how much radiation they put on me.. and do you have any suggestion what should i do to prevent the causes of Radiation that will may happen in my future.. my email is [email protected]

  • Lloyd said,

    Whats gone is gone and there is no point in worrying about it. Given that radiation exposures are believed to be cumulative you need to be vigilant about your future exposures. For a list of sources of EMF exposures in the home see My EMF protection free report (download from the home page) also has valuable information.

  • Teddy J said,

    We are moving into an office one floor above a medical imaging place that has MRI’s and a CT scanner. Are we in danger? What precautions should be taken?

  • Lloyd said,

    MRI and CT scans are different animals. An MRI works with non ionizing radiation…magnetic fields and RF radiation….there’s plenty about the dangers of this technology on this website. A CT scan uses ionizing radiation….considered much more dangerous. Are you in danger? – possibly. If I were in your shoes I would be looking to get some readings. I would guess it would be possible to test an MRI with a Trifield meter. Testing emissions from a CT scanner is more specialized…you’d need a professional in to do this.

  • megan said,

    hi im meant to book myself in for a ct scan in a few days but after reading this im thinking about not doing it. i have been getting reaccouring chest pain for 10 mths. my mother died from lung cancer so im very worried about the radiation.

  • Lloyd said,

    Hi Megan
    This article is about setting the record straight on whats involved with a CT scan…I’m saying before you take one of these scans make sure you know and understand the dangers…weigh up the all the pros and cons…perhaps there is a natural treatment you can try before undergoing the scan….or perhaps you have got more to gain in doing the scan than to lose…

  • greg said,

    im not doubting your fact but where did you get the data that “A 40-year old woman who has a coronary CT scan has a 1 in 270 chance of getting cancer from that single scan. This statistic doubles for a 20 year old Woman.” also would you say that CT scans are the most dangerous x rays out there?

  • Lloyd said,

    I have included the link for the cancer statistic above. CT scans are much more dangerous than conventional x-rays…and more dangerous than MRI scans (uses non-ionizing radiation)….

  • don said,

    Do you have a list of most dangerous radiation we deal with in this world to the not as dangerous but still relevant

  • Lloyd said,

    The most dangerous form of radiation is ionizing radiation, its used in nuclear reactions, x-ray machines, airport scanners, etc. The dangers are widely accepted. I talk mainly about non-ionizing radiation….as emitted by cell phones, cordless phones, powerlines, electrical wiring etc. Most governments consider this radiation not to be dangerous…but it is. It might not be as dangerous as ionizing radiation but it still very relevant and dangerous, as the studies show.

  • Elsa said,

    Hi Lloyd,

    the low hum noise i struggle with in our home led me to have my ears checked. They found assymmetrical hearing, although myhearing is acute. So it was suggested byt hte ENT specialist that I have a brain MRI to chekc if there is a tumor ( benign even) affecting my hearing in one ear. if the hearing loss is due simply to age, then the loss is equal in both ears.
    So I went to have the MRI, then panicked about the radiation and left. The doctors says that mostly these MRI’s come back negative.
    Can you lead to me to some more info about Brain MRI’s so I can weigh up the pro’s and con’s of having the MRI?
    As I am also a bit worried that I am getting dementia ( my father has it, and at times I think I have symptoms of it have a degree in Psychology so not sadi lightly), apparently they could see that too.
    A brain MRI is one first line of testing for dementia, so many older patients are undergoing this.
    Many thanks LLoyd. have a great day

  • Lloyd said,

    Hi Elsa
    MRI scans are less harmful than CT scans….. but MRI (magnetic resonance imaging) scans use non ionizing radiation (like cell phones, smart meters, WiFi) which is also dangerous. See
    Personally if I were in your shoes I would not be seeking a solution using these kinds of scans….I would seek out a reliable alternative health practitioner… the advantage is zero side effects BUT only you can decide whats best for you….

  • JR said,

    Megan said, “…the low hum noise i struggle with in our home.” Well, there is usually a low-hum noise discernable within this completely closed house.

    The source is from industrial exhaust fans one mile away. It is easier to submit to scanning than it is to get companies to abate noise – which wouldn’t cost much – I checked. But I’d sure try.

    But our computers usually emit sound, too. Turning off as many electronic things as possible before assuming dread disease is worth a try as well, don’t you think.

    Thank you for the information on your website, Lloyd.

  • Elsa said,

    Thanks JR too,

    How did you know that the noise is from the industrial fans one mile away? Elsa

  • Elsa said,

    When I tried to watch the above video it said that the uploader had not made the video available in my country.. Australia. mmm why?

  • JR said,

    Well, Elsa, I drove around until I located it. What gets me is that other residents do not complain. There is no sound ordinance. The place employs a lot of people.

    Then again, so many people have tv’s, etc. on, and loudly – but even with sound on in the house, that hum permeates, and it is easily fixable.

  • greg said,

    mammograms, do they use ionizing or non ionizing

  • Lloyd said,

    Mammograms use ionizing radiation at a fairly high dose…one mammogram can expose you to the equivalent of 1,000 chest x-rays….so in terms of radiation, potentially worse than a CT scan.

  • JR said,

    I don’t feel up to finding the comparison charts that I trust on dosage, but a mammogram is not delivering the dose of 1,000 chest x-rays. On this one, you go too far, comparing it to a CT scan. I say this as one who has not had a mammogram in 7 years, with a history.

  • Lloyd said,

    It might sound as though I’m making this up….I’m not, see –

  • Ru said,

    Lloyd appreciate the article. However have found widely conflicting data re CT scan exposure and the equivalent number of xrays. Would like to spread the word but know (from past experience) that I need sound medical references to be believed. Couldn’t find a direct reference to 750 chest xrays being equivalent to one CT scan but maybe it was ‘hiding’ somewhere in the link included?

  • Lloyd said,

    The information is in the link – but not very easy to find I know. Scroll about one third of the way down the page, here is exactly what it says “The dose of a 64-slice cardiac Computed Tomography corresponds to about 750 chest x-rays, the dose of a coronary angiography and stenting to about 1,000 chest x-rays “

  • Ru said,

    Thanks Lloyd :-)

  • brandy said,

    compare x rays and MRIs in terms of radiation and emf exposure. Thank You

  • Lloyd Burrell said,

    An MRI scanner exposes you to non ionizing radiation….the type of radiation talked about on this website.
    An X-ray machine exposes you to ionizing radiation….considered even more dangerous.

  • brandy said,

    The cable guy that works on equipment at my office claims the only kind of radiation to be worried about is gamma rays, how would you compare gamma rays to wifi or microwave

  • Lloyd Burrell said,

    Gamma rays use ionizing radiation (meaning it has the ability to break molecular bonds)…..WiFi, cell phones etc were long considered safe because they use non-ionizing radiation (cant break bonds from molecules) but because this radiation is more insidious (and basically uncontrolled) its more dangerous….exposures are linked to cancer, cardiovascular disease, brain tumors, autism, Alzheimers etc.

  • brandy said,

    What frequency does wifi run on? and what distance from the router would you consider the most dangerous to not as harmful. (How far in feet does wifi radiation travel)

  • Lloyd Burrell said,

    WiFi typically has a carrier signal in the 2.4 GHz range and a digital pulsed signal in the 10-250Hz range. The closer you are to your modem or router the more dangerous it is….but there is no distance at which you can say you are absolutely safe except to say as far away as possible – See :

  • brandy said,

    do sonograms (ultrasounds) casue radiaition or damage the body?

  • Lloyd Burrell said,

    Ultrasound is a form of non-ionizing radiation, typically it uses frequencies in the 2 to 18 MHz range…..some studies have linked the use of ultrasound with an increased risk of childhood leukemia but nothing conclusive.

  • Anthony said,

    I also received an abdominal CT scan and didn’t know the details on how much radiation it put out. Do you know if any nutrients to take to eliminate free radicals and protect cells? Thanks

  • Lloyd Burrell said,

    Organic, balanced meals leaning towards the vegetarian diet, prefer whole foods to processed foods, is what I recommend.

  • abriel said,

    Iam a nurse from a trauma hospitL and its our routine to send our patient to ct scan whenever they1need too. but I always think about the risk iam getting every time we transfer the patient from the ctscan bed to trolley. my question is,are there any radiations present after the the procedure is finish?are these radiations have the ability to pass through walls?

  • Lloyd Burrell said,

    Cell phone radiation because of its high energy (frequency) can travel through walls and people…….CT scans use an even higher form of energy….ionizing radiation…..which most certainly can travel through walls and people……BUT the CT facility will be shielded and exposures controlled…..the question is are these exposure levels sufficiently low? Is any radiation left after the procedure has finished? I can’t give you any certainties about these exposures but from what I know about non-ionizing radiation (as from cell phones) its possible that even with the shielding you are impacted by the radiation from the CT facility…..

  • Carol said,

    MRI are actually low frequency the same as RADAR.
    When you think shortwave covers a short distance.
    Hence RADAR is long wave.
    And covers a long distance….
    The wrong polarity is being used.
    Everything is off scal in reverse polarity.
    Hence nuclear.

  • Carol said,

    Hi Lloyd

    Could you clarify the current thinking on Mammograms – the article abot is 2003 – in one of your remarks you equal them to CT Scans but in another you say that CT scan equals about 74 Mamograms – I am 49 ad have been called for sceening – I am electrically sensitive

    Many thanks


  • Lloyd Burrell said,

    Hi Carol
    The important thing to understand is that mammogram radiation exposures are not insignificant – make sure you’re aware of the risks before you take the examination.

  • Alex said,


    Since I just discovered the dangers of CT scans, after doing three of them, I will report what I found online. First, the head scans deliver about 2Msv per scan, a coronary angiography about 16 Msv, and a virtual colonscopy about 10 Msv. 1 Msv is equal to ten chest x-rays, so I think you are overestimating by a lot when you say that a CT scan is 750 chest X-rays. It is a lot less than that, depending on the scan, but still the exposure is high and concerning.

    You can go to to get a specific report of your additional risk, based on the particular scans you did, and how many. In my case, the risk from the three procedures together was increasing my cancer risk by about .17 percent. In other words, if I had a 20 percent chance of getting cancer before, I now have a 20.17 percent chance. Restated, there is a 99.8% chance that the procedures will not cause cancer in my case. The percentages can worsen for younger patients, whereas I am in my 50’s.

    I don’t take a lot of comfort from the statistic. I would not have done the exams if I had known. I have a hard time believing that 360 chest x-rays are not significant, but that is what I am reading.

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