The World - Herve Morin - paper edition dated 13/10/2007
mobile phone use is harmful to health, not just driving. An analysis of eighteen studies concluded that beyond ten years of using a cellphone, the risk of developing a malignant brain tumor - glioma - the side where the device is worn in the ear would multiplied by two. This condition occurs annually about 6 100 people 000. For violations of the acoustic nerve - neuroma - the risk would be two and half times higher in these same conditions.
Published online by the journal Occupational and Environmental Medicine (OEM), this analysis led by Lennart Hardell Sweden (Orebro University) and Kjell Hansson (Umea University), contradicts a study published in September in Great Britain, that "there has not been shown that the motives were associated with adverse biological or deleterious.
But Lawrie Challis, who led the British study, concedes, reports The Independent, that the low number of patients who used a mobile phone for over ten years, "it is not possible at this stage rule out the possibility that cancer could appear in the coming years" . Uncertainty about the lag time between exposure to electromagnetic fields and the possible development of a tumor remains a major obstacle in conducting epidemiological studies' conclusions. "
In France, where mobile telephony has gained momentum from 1992 and where there are now over 52 million subscribers, the study most recently published in September in the Journal of Epidemiology and Public Health, suffers the same limitations. It focuses on patients with brain tumors between 2001 and 2003.
"Regular use of mobile phones is not associated with an increased risk of acoustic neuromas, meningiomas and gliomas, she says. Although these results are not significant, it seems to exist a general trend an increased risk of glioma among the more "heavy users" of mobile telephony: users of long duration, high airtime users, users with more phones. "
The statistical power of the French study is insufficient to resolve the authors refer to the international Interphone Study, launched in 1999. Elisabeth Cardis, who coordinates Intercom International Centre for Research on Cancer (IARC) in Lyon, is not surprised by the results of the study Lennart Hardell and Kjell Hansson. "They are based on several studies included in Intercom, which effectively increases noted, significant or not, gliomas among mobile users," she admits. The difficulty lies in interpreting the results, she adds.
A possible bias concerns memorization by patients from their own phone use. "They seek an explanation for their illness and tend to exaggerate their exposure," said Elisabeth Cardis. This recall bias is statistically detectable: it leads to an apparent reduction in the risk of tumor in the opposite hemisphere to the phone, as if exposing a side protected the other ...
The Interphone study will also seek to clarify the location of tumors. If 20 to 30% of the dose emitted by the electromagnetic phone is absorbed by the brain, "this exhibition is very localized," says Elizabeth Cardis. It is so unlikely that a tumor in the frontal or occipital can be attributed to radio frequencies, "she notes.
lax
These methodological problems could explain, according to the researcher, the delay of several years in publishing the Interphone study, expected "within months". Meanwhile, Elisabeth Cardis refuses to rule on whether or not to revise the standards for radio emissions.
These are considered too lenient by a group of international experts, including Lennart Hardell. These experts made public Aug. 31, a report in which they demanded a tougher international regulations on electromagnetic waves, they are emitted by power lines, ovens, microwaves, antennas and telecommunications relay or mobile phones.
microwave, DECT, Wi-Fi and mobile measured in situ
The French Agency for Health Safety Environment and Labour (Afsset), which recommends the use of mobile "wisely" funded a study on the impact of radio frequencies in Besançon and Lyon. For a week, 400 volunteers wore a dosimeter. The three million measurements collected show that the vast majority of exposures are due to mobile phone, home wireless (DECT) and in microwave ovens. Study coordinator, epidemiologist Jean-Francois Viel note that these are preliminary results, to refine, particularly regarding the Wi-Fi, "which emits in the same frequency range as microwave wave.
