The million dollar question

Abstract

Mobile phone (“cell phone”) use has dramatically increased over the last decade, but doubts remain over its safety. Gro Harlem Brundtland, director general of the World Health Organisation, is clearly concerned about the effects of mobile phone use, particularly in children. Speaking at the 18th UICC International Cancer Congress in Oslo on July 1, she expressed concern about children using mobile phones for hours every day, simply because we don't yet know enough about the damage they might cause. Just as patients with lung cancer have locked horns with tobacco companies in the law courts, mobile phone companies face litigation from patients who claim that phone use is responsible for their brain tumours. In June, Vodafone admitted to its shareholders that it is facing litigation from four of its users in the USA. If just one of these claims reaches the courts, the company could incur costs of up to $1 billion. Another case that has caught media attention is that of a US neurologist who has regularly used a mobile phone over a 9-year period to keep in touch with his patients. He was diagnosed with a brain tumour behind his right ear in 1998 and is now suing Motorola, Verizon Communications, and the Telecommunication Industry Association, among others, for $800 million. In deciding whether cases like these should be put to a jury, judges have to draw on the currently available evidence to make up their own minds about the health effects of mobile phone use. This is no easy task. Although numerous studies have been carried out over the last decade, definitive answers are still lacking. A report published in the UK by the Independent Expert Group on Mobile Phones (2000) concluded that, based on currently available evidence, there is no health risk from mobile phone use. However, it does support Brundtland's concerns stating, “if there are currently unrecognised adverse effects from the use of mobile phones, children may be more vulnerable because of their developing nervous system, the greater absorption of energy in the tissue of the head, and a longer lifetime of exposures…we believe that the widespread use of mobile phones by children for non-essential calls should be discouraged”. The proposed health effects of mobile phone use range from headache, sleep disturbance, and increased blood pressure, to cancer of the brain—the area of the body most exposed to low levels of radiofrequency radiation emitted by handsets. It is now widely accepted that mobile phones cause a “heating effect” in tissues of the head. As a result, guidelines have been established by the International Commission on Non-ionising Radiation Protection to ensure that non-ionising radiation from mobile phones does not exceed a given specific absorption rate (SAR). However, it is now feared that non-thermal effects—which could occur below the SAR safety threshold—may cause damage at a cellular level. A study published in the June issue of the journal Differentiation by researchers at the Finnish Radiation and Nuclear Safety Authority showed that a I-h exposure to non-thermal levels of radiofrequency radiation caused increased expression and activity of stress-response proteins in cultured human endothelial cells. These cells, which line blood vessels and have an important role in maintaining the blood-brain barrier, are known to be “leaky” in tumours. Although the authors stress that their study was designed purely to determine non-thermal effects at a cellular level, the results have raised concerns in the media over whether these effects also occur in human beings. More studies that directly investigate the effects of mobile phone use in the human population are urgently needed. Studies by the World Health Organisation, the International Agency for Research on Cancer, and the UK government are all underway. But when the results of these studies are published 3–4 years down the line will we still be none the wiser? Huge case-control studies of tens of thousands of mobile phone users will be necessary to tease out what could be small risks associated with mobile phone use. Surely the mobile phone industry is in the unique position of having access to the necessary data (millions of mobile phone billing records) and the funding to carry out such studies? With an estimated 1-6 billion mobile phone users worldwide by the end of 2005, even a small association of mobile phone use with brain cancer could have massive implications, for mobile phone users and the industry alike.