At the airport recently, security scanners buzzed at my sandals as they had a metal buckle. I removed them and had to go into a glass booth and raise my arms above my head for a scan. Would the detector there have emitted any X-rays or other potentially harmful ionising radiation?
A. Wills, London.
Going through airport security scanners, including this glass booth, essentially means undergoing a form of X-ray, known as a backscatter X-ray. This emits ionising radiation — electromagnetic waves that can react with and damage human cells.
Ionising radiation is found naturally in the environment in the form of the gas radon, which granite can emit, and cosmic rays.
The worry is that its reaction with living cells produces free radicals, which can damage DNA; it is a known carcinogen — i.e. something that can cause cancer.
Safe flight: Airport scanners emit far less radiation than medical X-ray machines
However, the dose produced by an airport scanner is tiny: it doesn’t penetrate tissue much so cannot physically damage cells to the same extent.
A statistic that’s often quoted is that if one million people each had ten airport scans per week for a year, four additional cases of cancer would be caused.
This is a fraction of the number that travelling on aircraft are thought to cause — flying at 30,000 ft inevitably exposes us to much higher levels of cosmic radiation than living at ground level.
In fact, the radiation from airport scanners is also far lower than that emitted by medical X-ray machines — though during a diagnostic X-ray the beam is adjusted to expose only the area that is being examined, whereas in an airport security scanner the entire body is subject to the radiation.
CT (computed tomography) scanners expose patients to levels of radiation 200,000 times that of an airport security scanner. A study published in 2009 estimated that the use of CT scans in the U.S. in one year alone could result in roughly 29,000 cancer cases in the future.
One in 500 women and one in 660 men will develop cancer from an abdominal CT scan if the examination is performed at age 20. And the number of CT scans is increasing year on year.
Do be reassured, though, that there is no significant health risk to ionising radiation from the security scanner when you are travelling.
Could I have an intolerance to turmeric? I was taking a 450 mg supplement when, in one month, I had five attacks of vomiting with diarrhoea (containing blood). I had tests, but these came back clear. I started the supplement again, but had another attack. Then a month later, I was ill after a meal out that might have contained tiny amounts of turmeric. Is there any test to confirm this is the problem? Why should such an intolerance develop in later life?
J. Bennett, Matlock, Derbys.
Turmeric is a spice made from the roots of a plant from the ginger family that grows in Asia. Its active ingredient is curcumin, which is thought to be anti-inflammatory and has been shown to help relieve pain in people with arthritis.
Side-effects of curcumin supplements include bloating, acid reflux and diarrhoea. Headache, nausea and skin rashes have also been reported.
Although high doses (more than 1,000 mg per day) may cause side-effects, curcumin is generally regarded as a safe supplement.
Be careful: Side-effects of curcumin supplements include bloating, acid reflux and diarrhoea
The difficulty with your case lies in establishing whether it is curcumin that’s causing your symptoms. Your medical history suggests it may be.
One option to try is a deliberate challenge, where the body is exposed to very small traces of curcumin to see if it reacts — this is most safely done under the care of an allergy clinic, assuming your GP can refer you. An alternative is to take a dose of the supplement on an empty stomach with a small quantity of water — if this is causing your symptoms you would expect the response to occur rapidly, within minutes or an hour at most.
My sense is that the intolerance — if that is what it is — might worsen with further exposure, given that the most recent episode occurred when you had a meal which may have involved only a small quantity of curcumin.
Why some people develop an intolerance later in life remains one of the mysteries of the immune system.
For a year, I’ve had a problem with my right leg, which stiffens and is painful with pulling in my groin and tenderness in the thigh, catching in my knee. I now have muscle-wasting due to not being able to use it properly. I have had two MRI scans, acupuncture, physiotherapy, neurological tests and I’ve seen an orthopaedic surgeon, but no one knows what it could be. I’m 70.
Vivien Kavanagh, Sawbridgeworth, Herts.
While I can’t give you a definite answer, muscle-wasting with chronic pain suggests there is a problem that must have a name, it just hasn’t been identified yet.
Your symptoms point to what we call an L4 lesion; essentially something is affecting the area around the fourth vertebra (towards the bottom of the spine). This could be damage due to injury or a disease, affecting or trapping a nerve.
Typically, the problem is wear-and-tear arthritis, a prolapsed disc, collapse of a vertebra due to osteoporosis, or, much less commonly, a tumour — but your MRIs have excluded these.
What’s not clear is why these scans haven’t found evidence that the nerve has become entrapped, which would explain the symptoms. The answer might lie in the way the scans have been conducted.
Imaging scans, whether by MRI or CT, are usually carried out with the patient in a horizontal position.
But I’ve also seen spinal scans taken with the patient upright, seated or standing — the latter shows the spine when it’s load-bearing, with the vertebrae moving closer together and, in some cases, crushing a nerve root, something that may not have been revealed by the scan taken horizontally. This would cause specific, intermittent symptoms.
Do you get any relief from the symptoms when lying flat? If so, a further discussion with your GP is called for — and possibly a consultation with a neurosurgeon who has access to upright imaging.