Mobile phones, brain cancer and pseudoscience, revisited
Saturday October 03rd 2009, 9:50 am

One of the top 10 most frequently read posts on mgk is Do cellular phone base stations cause brain tumors?, which I wrote back in May, 2006. The short and sweet of it is ‘no, they don’t,’ as there’s simply no medical evidence to support the idea.

However, this lack of evidence of harm doesn’t stop the urban myth machine from propagating rumours. Mainstream media frequently carry these tales, such as this recent example, “How safe is your mobile phone?” from the Sydney Morning Herald, which levers frightening and misleading phraseology:

Handsets from high profile manufacturers such as BlackBerry and Motorola might be beaming out higher levels of radiation than those of some of their peers, says a recently published report.

The SMH story cites an outfit called the ‘Environmental Working Group’ which has released a comparison of the ‘radiation’ from particular makes and models of mobile phones.

I suspect this mythology is mainly due to the use of the term ‘radiation,’ which many people automatically associate with the gamma rays emitted from radionuclear substances like uranium, plutonium, etc.

The term ‘radiation’ simply means the emission of something in all directions from a particular point. ‘Radiation’ does not necessarily refer to cancer causing gamma rays. It can be reasonably said that a candle flame emits ‘radiation’ of light energy, but to my knowledge, no one has ever tried to implicate candles in the causation of cancers.

The reason why there’s no hazard from mobile phones or their associated base stations is that the signals they emit are incapable of ionisation. Ionisation is the gain or loss of an electron from a neutral atom by exposing the atom to energy of some form. If that energy is an electromagnetic emission, the frequency of the emission must be at or higher than the frequency of ultraviolet light for ionisation to occur. Below the frequency of UV, emissions don’t have the ability to knock electrons off the atoms which comprise DNA molecules. At or above the frequency of UV, ionisation can occur, which does have the possibility to damage DNA, resulting in improper replication. This improper copying may express as cancers.

As you see from this chart from the US Environmental Protection Agency (with my added annotation of the relative frequency of mobile phone emissions to other common electromagnetic signals), mobile phone signals (1800MHz or 1.8GHz) are in the microwave region, about 650MHz below the 2.45GHz operating frequency of microwave ovens.

How the concept of mobile phones being associated with cancers entered the lexicon of urban mythology is somewhat mysterious as there’s no medical research or evidence that indicates any correlation- in fact, there’s significant medical research to the contrary, notably this conclusion from the World Health Organisation

No recent national or international reviews have concluded that exposure to the RF fields from mobile phones or their base stations causes any adverse health consequence.

…and the results of this more than 10-year-long Swedish study into the same, as published in the American Journal of Epidemiology:

Handheld mobile phones were introduced in Sweden during the late 1980s. The purpose of this population-based, case-control study was to test the hypothesis that long-term mobile phone use increases the risk of brain tumors. The authors identified all cases aged 20–69 years who were diagnosed with glioma or meningioma during 2000–2002 in certain parts of Sweden. Randomly selected controls were stratified on age, gender, and residential area. Detailed information about mobile phone use was collected from 371 (74%) glioma and 273 (85%) meningioma cases and 674 (71%) controls. For regular mobile phone use, the odds ratio was 0.8 (95% confidence interval: 0.6, 1.0) for glioma and 0.7 (95% confidence interval: 0.5, 0.9) for meningioma. Similar results were found for more than 10 years’ duration of mobile phone use. No risk increase was found for ipsilateral phone use for tumors located in the temporal and parietal lobes. Furthermore, the odds ratio did not increase, regardless of tumor histology, type of phone, and amount of use. This study includes a large number of long-term mobile phone users, and the authors conclude that the data do not support the hypothesis that mobile phone use is related to an increased risk of glioma or meningioma.

It’s worth noting that the ‘Environmental Working Group’ also oppose fluoridation of municipal water supplies, based on no evidence in particular.

Furthermore, EWG make this statement on their ‘Health/Toxics: Kid-Safe Chemicals Act’ page:

We are at a tipping point, where the pollution in people is increasingly associated with a range of serious diseases and conditions from childhood cancer, to autism, ADHD, learning deficits, infertility, and birth defects.

…also based on no evidence in particular.

If there were anything substantial at all to the suspicion that mobile phones or associated base stations cause any adverse health effects, with the explosion of numbers of the devices in service since the 1980s and most certainly since the introduction of pocket-sized phones in the mid 1990s when they became ubiquitous, you would also expect a correlating explosion in the numbers of brain cancers… and it just hasn’t happened. There simply are no legion lines of people queued for treatment of brain cancers commensurate with the numbers of mobile phones now in service.

It’s worth noting that you rarely if ever hear anyone banging on about brain cancers being caused by microwave ovens, despite the facts that the operating frequency of microwave ovens is 650MHz closer than mobile phones’ emitted signals to that of UV light and that their power output, usually around 1000-1100 watts, is 3 orders of magnitude (x10³) greater than the 600mW (0.6W or 6/10 of 1 watt) maximum emitted by handheld mobile phones. Also, the acceptable signal leakage from microwave ovens (0.2 mW/cm²) is double that of the electromagnetic emissions absorbed by human tissues from a mobile phone pressed to one’s ear (0.1 mW/cm²). I have yet to hear of a P&C group insisting that microwave ovens not be operated within 1km of a school, as was demanded by a Faulconbridge NSW P&C regarding a proposed (and thankfully now approved and soon to be completed) 3-watt output mobile phone tower.

If the net result of this urban mythology and rumourmongering was merely giving people something to talk about around the water cooler, that’d be one thing. However, there’s a real economic cost to such pseudoscience as well as real emotional disturbances to people who really don’t need any. Of note is an attempt to correlate with electromagnetic signals a ‘breast cancer cluster’ said to have occurred at the ABC’s Toowong (Brisbane) Queensland facilities as well as another claimed ‘cluster’ at the ABC’s Southbank, Victoria studios. The ABC abandoned the Toowong facilities in 2006 at a cost of millions of dollars, despite the later finding that the incidence of cancers at both facilities were not abnormal nor statistically significant. That the ABC attempted to be accommodating to their employees is laudable. However, such conciliatory actions merely give conspiracy theorists something to crow about and at the end of the day, do absolutely nothing but feed rumour mills and needlessly deplete the public purse.

People have enough real hazards in this world to worry about. Publicising invented or imaginary hazards not only diverts attention from the real ones, but also desensitises people to valid warnings about such genuine hazards.

-weez


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2006 reports of a ‘cancer cluster’ among workers in a building at RMIT prompted the university to close the top two floors of the building and conduct extensive testing in search of carcinogens. The paper discussing the results is here.

Comment by weez 11.05.09 @ 7:06 am

No tumour link to mobile phones, says study
December 4, 2009

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.

Comment by weez 12.05.09 @ 10:15 am



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