I had a couple MRI’s in a short period of time which involve being placed in a giant magnet the size of a dump truck and laying there for a hour. After that I began to experience health problems and hormone problems, as well as night sweats and feeling cold all the time. I am wondering do strong magnetic fields have any negative health effects, especially on hormones? Also can it have any effect on the Hypothalamic–pituitary–adrenal axis. And is it possible that it has health effects we do not know of yet? For example 50 years ago we were told DDT was so safe we can eat it as seen here DDT so safe you can eat it 1947 - YouTube
Well, a few years ago magnet therapy became ‘a thing’ in Spain. People seemed to think that seeing a doctor who would subject them to strong magnetic fields would be good for their health.
A - very reliable - TV programme devoted an entire episode to alternative medicine, and they consulted a - very reliable once again - doctor. The doctor’s response was clear: there is absolutely no evidence in medical literature that magnetic fields can affect our health.
That’s a very limited cite though, I’ll wait for actual physicists and doctors to give you a proper answer
Almost certainly no. Millions of people have been having MRI scans for decades now, and so far there has been no indication of any issues. Acute problems like yours would have been flagged very early on had they been correlated with MRI scans.
Whilst this sounds a bit harsh, there had to be a reason you needed an MRI - I would start here with any subsequent health issues. At worst, you could have caught something from someone who had been in the scanner prior to you, although I would hope this is unlikely.
There is a big difference between DDT and an MRI in terms of causation. One is a poison that we thought was only poisonous to insects. The other is a very strong but static field that has no known physical mechanism to couple to any chemical process, in anything - living or dead. If you could come up with a causative mechanism for a static magnetic field to couple to your body’s processes you would be in line for a free trip to Stockholm.
This question pops up on a regular basis on the SDMB, and the majority opinion is that only varying magnetic fields can be harmful and static magnetic fields are intrinsically safe. This is dangerous misinformation, and there are regulations all over the world that limit a person’s exposure to static magnetic fields because STRONG STATIC MAGNETIC FIELDS ARE DANGEROUS! Just like radiation, UV and X-ray exposure these limits are based upon strength and duration of exposure. MRI scans will fall within these limits, but it’s entirely possible that some people will be more sensitive to exposure than others.
A while ago I worked for a company that made big turbogenerators. These used incredibly strong static magnets, and there were very strict health and safety policies in place regarding the handling of these things, even if you didn’t have a pacemaker or a metal plate in your skull.
Take your pick of cites: https://www.google.co.uk/#q=static+magnetic+field+maximum+exposure
Reading the guidelines, rather than just citing the existence is a good idea.
From The INTERNATIONAL COMMISSION ON NON‐IONIZING RADIATION PROTECTION, GUIDELINES ON LIMITS OF EXPOSURE TO STATIC MAGNETIC FIELDS.
In other words, they have set the guidelines at a point where they know it is safe, and have not gone higher, not because there is evidence it becomes unsafe, but simply because there has been no experimentation at all at these levels. Given the levels are already higher than found in MRI scanners anyway, the idea that there are known dangers in MRI scanners is actually not supported.
OH&S guidelines for large permanent magnets are going to be very much about not letting the thing kill you by getting too close to anything ferromagnetic. The field strength of these magnets is actually much less than an MRI scanner.
When challenged, the alt med crowd will mumble something about the iron in your blood, but the iron in human blood isn’t concentrated enough to respond to a magnetic field, especially the weak “therapeutic” magnets sold by the quacks
Which is it? There’s plenty of documented evidence of strong static magnetic fields causing disorientation, nausea and hallucination, although thankfully there’s nothing on Earth that would cause instant death (but don’t get too close to a magnetar).
I’d agree that there’s no evidence that MRI scans have adverse long-term effects, but it’s just not true that static magnetic fields have no effect on the body. Even if the effects are transient, you don’t want to be driving or operating heavy machinery while disoriented, nauseous or experiencing sensory distortion. I’d class that as dangerous.
I’m not getting into a pissing contest; over and out.
An article from WHO on magnetic fields and health.
So, immediate bad effects can happen, but at levels higher than you find in an MRI. And no one really knows about low level fields.
The issue with sensory effects is that moving in the field can and will induce an electric current in you. The linked to standard covers this in detail. This electric current can disturb your sense of balance leading to dizzyness, and eventually possibly nausea. It is about as dangerous as (and has a lot in common with) spinning around to make yourself dizzy. (Don’t drive a forklift after doing either.) What it isn’t, is a static magnetic field to chemical interaction with your biology.
There is a serious bottom line here about perception of effects risk, and causation.
DDT still IS safe enough to eat. It wasn’t banned for being dangerous to humans.
I will presume you got these because you weren’t experiencing optimal health?
How fast are the magnetic fields changing in an MRI, compared to transcranial magnetic stimulation? Why don’t MRIs have the same effect?
The main field of an MRI scanner is static. When operating there are gradient coils that cause slight variations in the field across the volume being scanned (hence the term gradient.) These are very low power in comparison to the static field - and are created by ordinary electro magnets - not superconductors. They do however account for the noise - they act a lot like the voice coils of a speaker inside, and rattle. Some of the early research MRI scanner actually used HiFI amplifiers to drive the gradient coils. Something that gives you an idea of the relative field strength. (The Q of a proton in the static field is very very high, which means only very slight changes in the field result in relatively high changes in frequency of precession, so the gradient could really don’t need to produce much power.
TMS creates a very high power and fast moving field. You need to discharge a bank of capacitors into a carefully crafted very focussed coil. The instantaneous field generated is very high. Orders of magnitudes higher than that generated by the gradient coils in an MRI scanner. You would no more get a TMS like effect from an MRI scanner than from waving a small magnet next to your head.
I seem to recall that Dr. mercola said that magnetic fields had negative health effects and to avoid them but don’t remember why, does anyone have the scoop on what he said?
Doesn’t matter, the man is a fraud.
Note that one side says that magnetic fields are harmful while the other side peddles magnet based therapies of one form or another.
Just throwing this out there: TMS therapy is FDA approved and is similar in some ways to an MRI. It is thought to be able to cause seizures as a rare side effect, but is well tolerated and can be of help to people with treatment-resistant depression.
This study indicates that various antiepileptic drugs can influence a person’s motor/neuronal excitability when exposed to the magnetic pulses of TMS.
While I can’t address the OP’s questions specifically, I’d have to say that there is at least some reason to explore long term effects of MRI exposure. TMS therapy is not considered “woo” by many psychiatrists, at any rate.
Anecdotally, I’ve found MRI imaging to be soothing. It may be just the environment.
:smack:
I don’t know how I missed the posts above mine discussing TMS…
I enjoyed the explanation, Francis Vaughan. I wasn’t sure of the technical differences between the two–I’ve only seen that the mechanisms are “comparable.”
Just wanted to add some new info I discovered about MRI’s from wikipedia
"Genotoxic effects
There is no proven risk of biological harm from even very powerful static magnetic fields.[56][57] However, genotoxic (i.e., potentially carcinogenic) effects of MRI scanning have been demonstrated in vivo and in vitro,[58][59][60][61] leading a recent review to recommend “a need for further studies and prudent use in order to avoid unnecessary examinations, according to the precautionary principle”.[57] In a comparison of genotoxic effects of MRI compared with those of CT scans, Knuuti et al. reported that even though the DNA damage detected after MRI was at a level comparable to that produced by scans using ionizing radiation (low-dose coronary CT angiography, nuclear imaging, and X-ray angiography), differences in the mechanism by which this damage takes place suggests that the cancer risk of MRI, if any, is unknown.[62]"
Genotoxic means it apparently causes DNA damage
If MRI’s cause DNA damage would that explain some of the health problems I received from having multiple MRI’s within a short period?
No.
This is what the NHS website has to say about it:
http://www.nhs.uk/conditions/mri-scan/pages/introduction.aspx