Sunday, December 06, 2009

No tumour link to mobile phones, says study

Not that this will slow down the elitists who think that everything popular must be bad

A very large, 30-year study of just about everyone in Scandinavia shows no link between mobile phone use and brain tumours, researchers reported on Thursday. Even though mobile telephone use soared in the 1990s and afterward, brain tumours did not become any more common during this time, the researchers reported in the Journal of the National Cancer Institute.

Some activist groups and a few researchers have raised concerns about a link between mobile phones and several kinds of cancer, including brain tumours, although years of research have failed to establish a connection.

"We did not detect any clear change in the long-term time trends in the incidence of brain tumours from 1998 to 2003 in any subgroup," Isabelle Deltour of the Danish Cancer Society and colleagues wrote. Deltour's team analysed annual incidence rates of two types of brain tumour -- glioma and meningioma -- among adults aged 20 to 79 from Denmark, Finland, Norway, and Sweden from 1974 to 2003. These countries all have good cancer registries that keep a tally of known cancer cases. This represented virtually the entire adult population of 16 million people, they said.

Over the 30 years, nearly 60,000 patients were diagnosed with brain tumours. "In Denmark, Finland, Norway, and Sweden, the use of mobile phones increased sharply in the mid-1990s; thus, time trends in brain tumour incidence after 1998 may provide information about possible tumour risks associated with mobile phone use," the researchers wrote. They did see a small, steady increase in brain tumours, but it started in 1974, long before mobile phones existed.


"From 1974 to 2003, the incidence rate of glioma increased by 0.5 per cent per year among men and by 0.2 per cent per year among women," they wrote. Incidence of meningioma tumours rose by 0.8 per cent a year among men, and rose by 3.8 per cent a year among women starting in the mid-1990s. But this was mostly among women over the age of 60, who were already among those most likely to have brain tumours, they noted. In addition, it became easier to diagnose these tumours because of better types of brain scans.

Overall, there was no significant pattern, they said. "No change in incidence trends were observed from 1998 to 2003," they added. That would have been when tumours would start showing up, assuming it took five to 10 years for one to develop, they said.

It is possible, Deltour's team wrote, that it takes longer than 10 years for tumours caused by mobile phones to turn up, that the tumours are too rare in this group to show a useful trend, or that there are trends but in subgroups too small to be measured in the study. It is just as possible that mobile phones do not cause brain tumours, they added.

Most scientific studies show no association between mobile phone use and brain tumours and researchers trying to find a connection have failed to find any biological explanation for how a mobile phone might cause cancer. "Because of the high prevalence of mobile phone exposure in this population and worldwide, longer follow-up of time trends in brain tumour incidence rates are warranted," Deltour's team advised.


Surgery gives gift of 'HD' sight

PATIENTS are having their eyes fitted with an artificial lens that allows them to see in "high definition". Surgeons begin the process by implanting the lens into the eye using the standard procedure for cataracts. Then, for the first time in Britain, they can fine-tune the focus of the lens several days later. The technique gives patients vision so sharp that it is even better than 20/20 - the best an adult can usually hope for.

Bobby Qureshi, the first ophthalmic surgeon in the UK to use the lens, described it as "a hugely significant development". It can correct both cataracts and the long-sightedness that usually comes with age. The lens is made from a special light-sensitive silicone. By shining ultraviolet light on specific parts of the lens, surgeons can change its shape and curvature, sharpening the image seen by the patient.

Mr Qureshi told Sky News: "We have the potential here to change patients' vision to how it was when they were young. "The change is so accurate that we can even make the lens bifocal or varifocal, so as well as giving them good vision at distance we can give them good vision for reading. "They won't need their glasses at all."

The technique can overcome tiny defects in the eye that cause visual distortions. The lens can be adjusted several times over a period of days until patients have perfect vision. A final blast of light then permanently fixes the lenses' shape.


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