Brain-tumor cluster strikes university
Coincidence, or the fault of cell-phone masts?
A Melbourne university has emptied the top floors of one of its buildings after a spate of brain-tumour cases were reported during the past month. Most affected staff worked on the top floor, raising fears that cell-phone masts on top of the building are responsible. But experts say it is far more likely to be an unfortunate coincidence.
Since mid-April, five staff from the business school of the Royal Melbourne Institute of Technology (RMIT) University have reported developing brain tumours. Two other cases have been reported since 1999. Of the seven, two are malignant and five benign.
"We suspect there might be other cases, but these haven't been confirmed," says National Tertiary Education Union representative Matthew McGowan, who adds that the union and the university have received phone calls and e-mails from additional staff reporting health concerns.
Five of the seven staff worked on the top floor, and all except one have worked in the building for a decade, mostly on the top level. Some staff are concerned that mobile-phone-transmitter towers on top of the building are to blame.
"It is too much of a coincidence to simply be chance," says McGowan. The university has offered staff on the two top floors alternative office space while it carries out a two-week investigation.
No clear link
But international studies have been unable to provide a convincing link between cancer and the use of mobile phones or the proximity of mobile-phone towers.
"There is no consistent evidence at present that radiation frequency causes brain tumours. That's not to say it's impossible, but it is not convincing," says Anthony Swerdlow, an epidemiologist at the Institute of Cancer Research in London, and member of a radiation advisory group with the United Kingdom's National Radiological Protection Board.
Preliminary results from the university's investigation indicate that radiofrequency levels are extremely low, according to an RMIT spokesperson. "Our initial tests show no cause for alarm," he says.
Although little is known of what causes brain tumours, a bacterial or viral agent could be responsible. "That is one of many possibilities," says Richard McNally, a statistical epidemiologist at the University of Newcastle upon Tyne, UK. McNally previously reported that brain-tumour occurrence in a region of the Netherlands showed a pattern typical of diseases caused by infection1. RMIT is also testing air- and water-quality to investigate this possibility.
Many experts say it is most likely to be a coincidental clustering of cases. "My strong hunch is that it may well be a chance occurrence," says David Hill, the Director of the Cancer Council of Victoria in Australia.
McNally, who also think that this "may well be a chance occurrence that has sprung to attention," says the university should determine whether those affected had other known risk factors, such as a genetic predisposition or previous exposure to ionizing radiation. Some of the affected staff did have personal histories that may be linked to a higher risk, according to the RMIT spokesperson.
The fact that the tumours are different from each other may also make a common cause unlikely. "The tumours detected have varying origins and only three of the seven types have known associations with radiation," says John Gall, of private-health company Southern Medical Services, who has been appointed by RMIT to investigate the epidemiology of the cluster.
The university is expected to release its report next week.
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- Houben M. P., et al. Eur J Cancer., 41. 2917 - 2923 (2005).