Are x-rays completely safe?
Doctors do a lot of x-rays on children. Is there a risk to that, or are x-rays completely safe? The answer, for chest, bone, and abdominal x-rays, is that they are very, very, very safe, but not totally risk-free. All of us are constantly exposed to radiation similar to x-rays. It comes primarily from naturally-occurring radioactive things around us, such as radon gas seeping up through the ground, or from outer space in the form of cosmic rays. People living at higher altitudes receive higher doses of such background radiation, amounting to about half again as much for someone living on the Colorado plateau compared with someone at sea level. To put things in perspective, the radiation dose in a single chest x-ray, on average, is similar to the background radiation most of us receive during a ten day time span living our normal lives.
There are several important things to remember about radiation risks. High radiation doses definitely cause death and disease (primarily cancer); the atomic bomb and the disaster at Chernobyl clearly showed this. A second key point is that radiation risk is cumulative over a lifetime. This is an important consideration for children, since they have most of their life ahead of them. Children are also more sensitive to the effects of x-rays than are adults. Still, it is logical to think of routine chest, arm and leg, and abdominal x-rays as being virtually without risk unless the child has already gotten for some reason a large radiation dose in the past.
Computed tomographic scans, CT scans, are another form of x-rays. We most commonly use CT scans to look at a child’s head, chest, or abdomen. The technology produces good images of the organs inside those body regions, and CT scanning has revolutionized how medicine and surgery are practiced. But CT must be used judiciously, particularly in children, because it subjects the child to much more radiation than does a simple chest or abdomen x-ray–200 to 300 times more, depending upon the particular technique used. So if a chest x-ray is the equivalent of ten days of background radiation exposure, a child getting a CT scan receives the same radiation dose as anywhere from five to ten years of normal living. I’ve written more about CT scan risk here.
The future cancer risk to a child from a single CT scan is still vanishingly small, and the benefits of getting the information the CT provides nearly always outweigh this tiny risk. However, this may not be the case for children who get many CT scans or have been exposed to other radiation in the past. Fortunately, this represents a relatively small number of children. There are ways of using reduced radiation doses in children, compared to the doses adults receive for CT. If you are concerned about this issue, ask your child’s doctor about it, or you can read more about it here.
I’ve also posted here about what medical risk means.
My son is tree years old.Two weeks ago he had 7 pictures x_ray to both arm.I am worried that what kind of risk he has now.The radyolojist said there is no harmful effect to my child.is it right?
Thanks for your question.
I think what the radiologist told you is correct. Seven simple x-rays would carry essentially no risk to your child. That amount of radiation is in the ballpark of the amount of background radiation that your child would get in a month of two of normal living. (This background radiation comes from both naturally occurring materials in the earth and from the cosmic rays that strike everywhere on the earth from outer space.)
My son, 5 years old, has had 2 abdominal x-rays in the past 3 months – the first about 3 months ago and the second one about a month ago. Is it safe to have another one in the near future? He is diagnosed with psychogenic constipation and we want another abdominal x-ray soon to see how much his colon has cleared since the last abdominal x-ray. Thank you.
Yes, I think that would be safe. As with any test, we weigh the risk of the test, which in your son’s case is very, very tiny, against the usefulness of the information the test will give us, which for your son is quite useful.
My own son was in a similar situation–we needed a series of abdominal x-rays to see what was happening when a steel ball he ate got stuck for a while in his intestines.
This winter my 17 month old son has had pnemonia, a chest infection, hospitalised for viral wheeze and more recently another chest infection. During this period he had three sets of x ray’s (total of six pictures) in May and June 2008. And has had two more sets (four pictures) in the last 8 days. The doctor has requested another set be taken at the end of November. He is on seretide to try to prevent any more lung or chest infections. I am worried that he is being over exposed with the xrays.
Please can you advise me if I should be worried. Thank you.
I don’t think you should be worried. I think this is a good example of where the benefit of the information the x-ray will give for your son’s care far outweighs the infinitesimal risk of the chest x-rays.
I am curious to know about the effects on kids regarding abdominal xrays and steriliy? Could you comment?
We do have data about the dose of radiation that can cause sterility. In men, this is at least 350 rads, in woman about 250 rads. A good estimate for the dose to the gonads of an abdominal x-ray is less than 0.01 rad — 35,000 times or more less than that. These figures are for adults. Because of how the biology of reproduction works, I’d expect the risk to children to be much, much less, especially boys.
As I wrote in the post, most information is about future cancer risk of x-rays and the potential effect on developing embryoes in the early stages of pregnancy. It is standard practice to shield the gonads — testicles in boys and ovaries in girls — when doing x-rays if possible. For abdominal x-rays in girls, of course, this isn’t possible because you would be covering up the area you are trying to see on the x-ray.
To me, the most useful data about radiation risk relate to altitude and background radiation. The Colorado Plateau region (where I live), has a much higher dose of cosmic radiation and ground radiation (since it is relatively rich in uranium and radon). Yet there is no difference in fertility or cancer rates there.
Thanks for your question. Here’s a useful link to the site of the highly respected Hospital for Sick Children in Toronto with more information and references.
i m very very tense today coz my 6 mnt old had skull xray today and the person there took seven times skull xray.what effects might me there after this?i m just worried about if my daughter might get head cancer in later life coz she has been exposed to rays 7 times.could you please answer me honestly…or what do u reckon?Thanks a lot.
A tensed mum.
The normal way we x-ray the skull does involve several separate views, called a “skull series.” What she got sounds like the standard routine. She’ll be fine. As I wrote above, she’s just gotten the equivalent of the normal background radiation we all receive while living a month or so of normal life.
thnx a lot for your answer.
Hello…I was needing to ask you a question. I am so terribly worrying about this, to the point that I cannot think about anything else. My son went for a head ct in January. He is 5 years old and weighs about 42 pds. He would not hold still, so the technician ended up scanning him 4 times. The last time (the 4th) he eventually had to hold him still with his hands while another tech came in and ran the machine in back. He said that this was the last time, that he had enough. SO when I came home I began to worry. I got on the internet and what I read was horrifying! Everything it told me was awful, that a child should never have any more than one scan, and about cancer risks and everything. So I got on the phone and called the hospital and talked to the tech that did the scans, I told him where my son was scanned so many times that i was worried about the radiation, and he said to not worry, that there was nothing to worry about, that there are people that come in there and have ct scanned every day for up to five days. And I asked him was the machine turned down to child size.And he said that they have to use a pediatric protocol every time they scan and it sends into the computer. I dont really know what he meant by protocol. I asked around and found out that the guy who did the cts was over the entire radiation department of the hospital, so I thought that maybe being the head of the dept. he prob knew what he was doing.
I asked my sons pediatrician also about all the scans and the radiation, and I dont know if she knew what she was talking about, she said that the amount of radiation he received during each scan was very small. That a chest x ray was more. I know that it says on here that a ct scan equals so many hundred chest x rays, so maybe she was talking about a adult chest x ray. I just worry about the fact he was scanned 4 times. Please help me……
I think the best way to answer your question is to think a little bit about risk — what it means in practical terms. Consider an event that has a one-in-a-million chance of happening. What if I told you now that thing was, instead of having a one-in-a-million chance, now had a two-in-a-million chance of happening. That’s a 100% increase, a doubling in risk!! But what is its real-life meaning? The real meaning is that something with an infinitesimally tiny chance of happening has changed into . . . something that still has an infinitesimally tiny chance of happening. In practical terms, there is no difference — it hasn’t changed at all.
Let’s think about a practical example — the chances of being hit by lightning. That also is a low risk event. But we know there are some things we can do to make it even lower — for example, don’t climb mountains in the afternoon, don’t play golf in a thunderstorm, and don’t be out in a metal boat during a thunderstorm.
The risks of x-rays are like that. The risks are very low, but there are still things we can do to make them even lower, like using a different technique with CT scans for children. But the very most important thing we can do to reduce risk is to make sure, when we do the CT scan, that the benefit of the information we get from the scan outweighs the tiny risk of doing it. For example, if a child hits his head after a fall from a high place we often really, really need to know if the accident caused any bleeding in his head — the benefit to the child of getting this information far outweighs the tiny risk caused by the radiation itself.
Bottom line — if your doctor wants to do a CT scan on your child, ask what the risks would be of NOT doing the scan, of not having the information the scan will give. Then you can decide. Also understand that very likely your child will have a greater risk of harm driving with you to the CT scanner (from an auto accident) than he will experience from the radiation of the scan.
I hope this is helpful to you. In some ways it’s a really complicated question, but in another way it’s very simple — compare the risk of doing the scan with the risk of not doing it. In your case, assuming there was a good reason for doing them, I wouldn’t worry about the CT scans. Life has many risks, but radiation from CT scans, by comparison, is one of the very tiny ones. Not zero, but very tiny.
My daughter is ten years old. Today she had 2 x_ray [one chest and PNS xray]. I am worried that what kind of risk she has now for future. She suffer from Cough and cold problem.
That amount of x-rays should give her no increased risk of future problems from them.
When I was around 19-20 weeks of pregnancy, I had severe kidney stones. Both my OB/GYN and the urinologist said that I needed an IVP of the abdomen. So, I ended up getting 5 x-rays. I am just worried sick that my baby will develop cancer over their lifetime. Please help.
Megan — I’m sure your child will be fine. X-rays beyond the first 3 months of pregnancy are quite safe. And the five x-rays for your IVP carry virtually no risk of later cancer for your child.
My little boy had a routine cbc and it came back with a blast on it. The doctor and the hematologist looked at it and said it was “not” cancer. I don’t know what to think. I am so worried about it. I had some x-rays when i was pregnant with him and I don’t know if that has something to do with it. What else could the blast mean? Are they for sure that it is not cancer and that I should not worry?
The key thing here is that a hematologist, a blood expert, looked at the blood cells and said it was OK. Some times the blood smear (the slide the hematologist looked at) can contain what we call “immature” cells that can resemble cancerous blast cells but really are not cancer. If you are still concerned, though, I would just take your son to see the hematologist and recheck the blood test — have another blood smear made. It’s quite easy to do and the simplest way to answer the question for sure.
Hi Dr. Johnson,
I’m about 3 weeks pregnant, and on Friday, 04/10 had a chest x ray. My last period was on 03/13 and I ovulated on 03/26, therefore I was 14 days pregnant when I got the chest x ray. I wore two lead aprons during the procedure. Now, I’m very concerned about the potential effects of the x ray on the embryo. Can you advise on the matter? Thank you!
You and your child should be fine. First, the exposure to your lower abdomen from a chest x-ray is very, very low because the beam is quite directed at the chest. Second, you were shielded to catch any stray energy, however faint. Third, the radiation from a chest x-ray is itself very low in comparison to other forms of radiologic studies. So I wouldn’t worry. And congratulations!
Thank you, Dr. Johnson! I really appreciate your promt response!
baby had a ct scan at 9 months because she was not sitting up. at 11 mnths she had a one picture x ray to determine if she had pneumonia and then at 16 months she fell and had a 3 pic x ray of her face.
I am afraid that she develops cancer
are the three x rays a safe level of exposure? i am so anxious i can not sleep and i am very worried that i should have said no to at least the last one
I think you’re child will be fine. That amount of radiation doesn’t increase her risk of future cancer significantly.
The important thing to remember is to get x-rays, and especially CT scans, only when they are really needed. For your child, it sounds as if the x-rays were needed. The CT scan of the brain is important for a child who is behind in motor development, facial x-rays are needed if the doctor is worried about broken facial bones after a fall, and many times a chest x-ray is the only way to find out if a child has pneumonia.
My 2 year old son fell in Jan and broke his leg, the doctor had to do three sets of xrays (4-5 xrays in each set) to find the fracture, they also did 2 pelvic xrays to check his hip. A month later he had 2 chest xrays (including his stomach). That is alot of radiation and I’m so worried now that the xrays might cause something in the future….like cancer, or something. What risks does he face now? Please help me, Thank you so much.
I wanted to add also that he is do for dental xrays next week, is that going to be safe on top of all the other xray he recieved earlier this year?? Thank you so much for your help.
Thanks for your questions. The short answer is that I wouldn’t worry about it if it were my son. But it’s also important to think about the long answer — about why I think that’s a true statement. We need to think about the notion of relative risk.
I would be lying if I told you that x-rays of the kind your son had don’t have any risk at all — they do. But here’s the way to think about that risk: that risk is a very, very, very, very small number. Increasing risk from a tiny number, say one-in-a-million, to a larger, but still tiny number, say two-in-a-million, does represent a doubling of risk. But such a mathematical doubling of risk is, in real-life terms, totally meaningless, because the new risk remains very, very, very small. So, in real-life terms, the new risk is no different from the risk before the x-rays.
Now let’s consider your son’s broken leg, still thinking about risk. Quite often we need several x-rays, often taken from different angles, to identify precisely how a leg is broken. We need those films because it determines what we do about the broken bone. Then, we often need some additional x-rays, taken after the broken bone is fixed (either with a cast or, for the worse breaks, with surgery) to make sure the bone edges are where they need to be to heal properly. What would be the risk of not doing the x-rays? The risk — a high one — would be that your son’s leg would not heal properly because the doctor would have no way of knowing if the bone edges are back together correctly. We would be doing things just like the “bone-setters” of centuries ago did them, and our results would be as poor as theirs were. These days we are trading the infinitesimally small risk of the x-rays for the very real, very high risk that your son could be permanently affected if we don’t get his leg to heal right. In real life, that’s a good trade-off of risks.
The same reasoning applies to the pelvic x-rays. Broken legs in a two-year-old may involve the pelvic bones. There’s no way to tell if this is the case without an x-ray. The risk to a growing child of not finding this out at the time of injury is many, many, many times the risk of the x-ray.
Regarding the dental x-rays — properly done, these have a very low radiation exposure. And, since radiation exposure is cumulative over a lifetime, there’s no difference between your son getting them soon after his other x-rays or waiting. So timing here doesn’t matter.
Here’s the bottom line. Simple x-rays do add radiation risk. But it is infinitesimally small risk. A chest x-ray, for example, is the same as about 10 days of just living a normal life and getting hit by the natural radiation around us. What’s the best way to control even this tiny, tiny risk? Just be sensible about doing the x-rays, always weighing the risk of doing them against the risk of not doing them. So if your doctor wants to do an x-ray, ask him or her to explain the need for it to you in those terms — what’s the risk of not doing it? And never do an x-ray just because you (or your doctor) is simply curious.
Every parent naturally wants to avoid doing risky things to their child. But we easily accept the risks of driving them to school, sending them to summer camp, and buying them a bicycle, because in life we always weigh the risks of doing something against the benefits that doing the thing will bring to the child.
It’s a long and windy answer, I know, but I think it’s a good way to think about x-ray risks.
Thank you so much Dr. I have worried and worried about this time and time again. I have spent many sleepless nights worrying about the long term effects his xrays would cause. Altough I’m a natural worrier and I will probably still continue to worry, your answer has given me some peace with it, THANK YOU SO MUCH FOR YOUR TIME…:)
I’m glad you found my comments useful. Good luck!
Thank you for answering my previous question. In another response you explained that radiation exposure is cumulative. can you explain further, and given an early exposure in her CT Scan and x rays can i do thingss to reduce future radiation exposure.
What I mean by cumulative is that radiation risk is spread out over a lifetime. That means there’s no difference between a brief series of exposures and the same number of exposures separated by periods of time.
Remember, though, most of what we know about radiation risk comes from people who have had massive exposures, such as nuclear bombs, reactor accidents, and early workers with radiation, such as Madame Curie. Another source of our knowledge is what happens to people who have received radiation treatment for some disease, typically cancer. These doses are many hundreds (even thousands) of times greater than those of simple x-rays. Our assumptions about medical x-ray risks are to a large part based on what we learned from these kinds of much more severe exposures.
The best way to avoid unnecessary risk from medical x-rays and scans is to emphasize the word “unnecessary.” When a doctor wants to do an x-ray on your child, make them explain exactly what benefit will come to your child from the x-ray. Especially ask them what the risk would be of not doing the x-ray — then you can make an informed, intelligent choice about what to do.
i have been asking a lot of questions. But thanks for answering. i recently found out about MRI why in my case didnt the doctor opt for MRI. Baby has a large over bit, and i am worried thinking that she will need another xray for her braces. MRI sames so much safer especially for babies. Can MRI be used for dental imaging.
You’re right about MRI being a good way to image the brain. It also has no ionizing radiation. So in that sense it’s safer than CT scans and x-rays. For small children and especially babies, however, MRI adds a different kind of risk — the risks of sedation. MRI is also much more expensive.
MRI scans take much longer than CT scans to perform and virtually no baby will lie still long enough. The scanner is also enclosed in a way that can be scary to children (and adults), and it makes an unpleasant noise. So small children nearly always need to receive some kind of sedative medicine so they will cooperate. Sometimes they need very deep sedation — nearly general anesthesia. That has risks. However, those risks are easily dealt with by making sure that there is a trained physician present to manage the sedation medicines properly and intervene immediately if the child gets into trouble (decreased breathing is the most common potential risk). So, like everything in medicine, we weigh the risks of doing something versus the risks of doing something else, or nothing.
I’m not aware of using MRI imaging for dental purposes — you would need to ask your dentist about that.
My 17 year old daughter, who is a small girl, has had two abdominal CT exams in the last year. I was never told about the risks of the radiation and now I am sick about the exposure she has had from these tests. The first CT was actually of the abdomen and pelvis. I have read that an abdominal ct is one of the tests with the highest exposure to radiation. I feel like I will always be looking for signs of cancer if she is ever ill in the future and I feel so guilty that I was foolish enough to think a CT was just a quick x-ray.
Should I ask for her records to see exactly how much radiation she was exposed to so doctors will know what to be aware of for her cancer risk? I feel like I have ruined her future health. Please help me.
Thanks for your question. The fundamental principle of your concern boils down to relative risk — what is it and what does it mean.? I don’t know if you’ve read through any of the other questions and comments on this thread, but many, many parents have the same question you have. CT scans do carry some risk (although that risk is extremely tiny). However, the key to understanding this issue is understanding the practical implications of that risk. Here’s what I mean.
When a doctor orders a CT scan, he or she is weighing the very tiny risk of the scan against the risk of NOT doing the scan. In other words, is the risk of NOT getting the information from the scan more than the very tiny risk of doing the scan? If, for example, a doctor is worried that a child has appendicitis and needs a scan to see if this is true, the risk of NOT doing the scan, and missing the appendicitis, could be very high — far, far higher than the tiny risk the scan itself carries. And missing appendicitis is a bad thing. So it’s really all about balance.
All parents worry about their children — it’s a natural thing. But worrying about your child getting cancer from two CT scans is on the scale of worrying your child will be hit by lightning — it’s very, very unlikely. Not impossible, but very, very unlikely.
I’m not minimizing you concern. In practical terms, I would tell you not to send your child out to play in a thunderstorm with a metal golf club in her hand. That’s just common sense. Regarding a CT scan, I would tell you not to agree to one unless the doctor can explain why the information from the CT scan is important to your child’s health. That’s common sense, too. If there is a good reason for the scan, the tiny, tiny risk of the scan is outweighed by the crucial information the scan gives.
The take-home message is never to get an x-ray because you (or your doctor) is just curious — make sure there’s a good reason. If there is a good reason, then get the scan.
I hope this helps you. But really — I wouldn’t worry about it. There are so many other things to worry about with our children that are much more significant — things like their first solo drive on the interstate highway, or going off to college and going to parties on their own, or traveling across the country on their own, or having friends offering them cigarettes. These are all things for which good parenting can lesson the risk.
Thank you so much for your prompt reply! The CT scans were done because after a virus there was blood in my daughter’s urine (not red blood, but where her urine looked as if a coke had been poured into the toilet- kind of a grayish or brown color.). This continued with other virus bouts. The lateset virus that caused this bleeding was mononeucleosis. She was very ill with the mono, but still, I kept asking the doctors why she would have blood in her urine? The doctors only said that a virus could cause such an episode. (No one doctor was ever the same, as we were at different ERs and her primary doctor had been changed out of a group of doctors- interns.) Finally, I pushed for her latest primary to ask the older, more experienced doctors if a differential diagnosis was an option. I didn’t want to hurt the feelings of the intern, but I could not understand why, out of my seven children, this daughter would have blood in her urine when all my other children came through the viruses fine? Finally, we got a preiliminary diagnosis of IgA nephropothy. Please understand, my daughter did not have any abdominal pain with the bleeding. It was the look of her urine that was distressing and to me-it being not normal. This is why I took her to the ER. I wonder now if the CTs were needed and this causes my distress.
I so appreciate your help. You have helped to reassure me. I am upset enough by the diagnosis and then to think it may have been my actions that prompted the doctors to do the ct scans- this thought has caused great guilt for me. I have to say, I am somewhat angry that I was not told the risks of the CT. But since learning about the risks I have already been able to spare my daughter a third CT by letting the doctor know about the last two. The primary said it was just fine not to do a third, as long as we don’t put off coming back in if things seem to be worsening. Our next stop is the nephrologist. I feel now that I will be better able to make decisions with this doctor about further tests.
I am so grateful for your help. I’m picking up everything you have written and have told all my friends and family about your help. I wish all doctors could be as forthcoming as you!
I’m glad you found this website helpful. Certainly if your daughter has IgA nephropathy it is best for her to be seeing a nephrologist for that problem — they’re the experts on that condition.
Good luck to both of you!
Hello, my 4 month old son recently had a barium swallow to determine the degree of his acid reflux. I’m worried about the safety of radiation he received, do you think its safe at his age to have had a barium swallow performed. Thanks
The key question with any test, especially x-rays, always is: is the tiny risk of radiation worth the importance of the information we get from the test? The degree of acid reflux in small children is often key information to have because knowing it affects very much what we do about the problem, which can range all the way from medicines to surgery. So in your son’s case — yes, I’d get the test. I would if he were my son.
I hope this helps you.
What is the increased risk from having multiple barium swallow studies? My daughter (born with esophageal atresia) has had 2 and they want to do another. She has also had 2 esophagrams. I’m concerned about the cumulative amount of radiation she has been exposed to and long term cancer risk. Thanks.
It’s true that muliple barium swallows do increase radiation exposure. But I think the way to look at the situation is that the long-term risk is still very, very tiny. Two times a tiny, tiny number is still a tiny, tiny number.
As with any test, we need to balance the risk of the test against the importance of the information the test gives us. For a child who had esophageal atresia, barium swallows are often pretty important to their care because the results can significantly affect what the doctor does next.
I can’t give you specific advice because I’m not your doctor, but I think if you’re really worried about it you should should simply share your wories with your doctor. Caring for any child is a partnership between parents and medical staff. Ultimately, though, the decision is yours to make.
I had a Ct Scan head last month for the first time after a car accedent. I am 30 years old and my sex is male. Would you mind explaining me what will be the negative repercussion of this CT with regard to infertility and cancer. Thank you in advance.
There are no repercussions regarding fertility, since only your head gets the radiation exposure.
The added future cancer risk of the single head CT, that is, in addition to whatever your background risk already is, is infinitesimal. It is not zero, but it is so nearly zero that I would not be concerned about it at all.
I hope this helps
my son had upper G.I x-ray that was about 26 x-rays , is that a normal amount for a barium test?
I think that’s probably more than the average, but not an outrageous amount — sometimes the radiologist needs to take quite a few snapshots to see what is going on. It depends somewhat upon what the study was done for, what question the radiologist was trying to answer. If you’re concerned about why it took that many, I’d just ask your doctor about it. All the doctors I know would rather have their patients ask us those kinds of questions than worry about them without letting us know.
Hi … I am wondering about the long term affects of having almost a dozen xrays and ultrasounds on my daughter. She is 7 now and had several at 1 for a hip condition than again when she was 2 and 4 than 2 today -some were convering her ovaries and half were not. Will this affect her fertility? Reading some of your earlier comments – most of these I feel were necessary although I think sometimes (angrily) that the people taking the xrays just take another one if the first not completely readable or how they would like it not thinking of the patients long term welfare which infuriates me to no end. Please advise…. Thanks in anticipation for your comments as this matter regarding her later fertility options upsets me to no end – not to mention any other risks…
Ultrasounds carry no risk because they have no radiation. Regarding your question about the x-rays, I don’t think that number of plain x-rays will affect her future children. I’m not an expert on that question, but here is a link to the website of the Health Physics Society where an expert answers pretty much the same question — what the risk is to a child’s ovaries of hip x-rays taken when they are not completely shielded.
You many want to spend some time scanning their answers to other questions about radiation safety because it’s a good and reliable source.
I found your site as a result of the same worrying that has plagued so many parents here. My son received a chest x-ray after swallowing some excrement during birth. Given the length of the labor, or how commonly they perform x-rays on newborns, they did not consult us on the decision or offer for us to come along. He turned out to be fine, but I often wonder about the long-term effects of the radiation on his first day of life…and, since we were not invited to observe, what exactly the procedure involved (multiple images, safety precautions, etc.) So, if you have a moment and wouldn’t mind indulging my paranoia: how vigilant are radiographers in dealing with higher-risk patients, in general? And does modern x-ray equipment take the sensitivity of a newborn into consideration by default, or is it the responsibility of the tech or nurse?
To answer your first question, the risk to a newborn baby of a chest ray such as your son received is as near to zero as is possible. As I mentioned upthread, the radiation exposure of a film like that is the equivalent of about a week or so of the background radiation (from the earth and from cosmic rays from the universe) he gets in his normal daily life, or of a medium-distance airplane flight.
To answer your larger question, it is the routine to adjust the amount of radiation according to the size of the person. X-ray technicians are quite vigilant about that. The reason is not simply safety — it’s also to get a good quality film. The settings used for an adult will not give a good picture of a baby’s lungs.
Finally, meconium aspiration (the fancy name for the problem your son had) nearly always needs a chest x-ray to see how extensive it is. Like everything we do in medicine, we need to weigh the risk of doing a test against the risk of not doing it, that is, of not getting the information the test gives. In your son’s situation, we weigh the truly infinitesimally small risk of the x-ray against the important and useful information the x-ray gives us — the balance overwhelmingly favors doing the x-ray.
I hope these comments are useful to you, and that your son is doing fine. I really wouldn’t worry at all about the effects of the chest x-ray when he was born.