MedWire News: Regular mobile phone use does not increase the risk for brain tumors among children and adolescents, report researchers.
Increased mobile phone use among children and adolescents has raised concerns about possible adverse health effects, and brain tumors in particular, note Martin Röösli (Swiss Tropical and Public Health Institute, Basel, Switzerland) and colleagues.
Furthermore, it has been hypothesized that children may be more vulnerable to the radio frequency electromagnetic fields (RF EMFs) emitted by mobile phones because they have a developing nervous system, their brain tissue is more conductive than that of adults, and the RF EMFs penetrate into deeper into children's brains as their head circumference is smaller than that of adults.
To investigate whether mobile phone use is indeed associated with brain tumor risk among children and adolescents, Röösli and team set up the CEFALO study, a multicenter case-control study conducted in Denmark, Sweden, Norway, and Switzerland that included 352 individuals aged 7-19 years who were diagnosed with a brain tumor between 2004 and 2008.
The researchers estimated each participant's mobile phone use through face-to-face interviews, and from cell phone subscriber records where available. They compared their findings with those from 646 controls who were randomly selected from population registries and matched by age, gender, and geographical region.
As reported in the Journal of the National Cancer Institute, patients with brain tumors were not significantly more likely to have been regular mobile phone users than controls.
More specifically, 194 (55.1%) patients reported regular mobile phone usage (at least one call per week) compared with 329 (50.9%) controls.
In addition, 265 (75.3%) patients with brain tumors and 466 (72.1%) controls reported having spoken on a mobile phone more than 20 times before the case patient was diagnosed.
The team also found that there was no increased risk for brain tumors in the brain areas receiving the highest amount of exposure.
However, they note that, in a subset of study participants for whom operator recorded data were available (n=163), brain tumor risk was related to the time elapsed since the mobile phone subscription was started (odds ratio=2.2 for >2.8 years regular use vs never regular use), but not to amount of use.
"Because we did not find a clear exposure-response relationship in most of these analyses, the available evidence does not support a causal association between the use of mobile phones and brain tumors," write Röösli and co-authors.
Nevertheless, since mobile phone usage among children and adolescents has increased over the years, the researchers suggest that incidence rates of brain cancer in the general population should continue to be monitored.
In an accompanying editorial, John Boice and Robert Tarone, from the International Epidemiology Institute in Rockville, Maryland, USA, said that Röösli et al "have filled an important gap in knowledge by showing no increased risk of brain tumors among children and adolescents who are regular cell phone users."
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2011
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