Mobile Phone Use and Brain Tumors in Children and Adolescents
Mobile Phone Use and Brain Tumors in Children and Adolescents
Background It has been hypothesized that children and adolescents might be more vulnerable to possible health effects from mobile phone exposure than adults. We investigated whether mobile phone use is associated with brain tumor risk among children and adolescents.
Methods CEFALO is a multicenter case–control study conducted in Denmark, Sweden, Norway, and Switzerland that includes all children and adolescents aged 7–19 years who were diagnosed with a brain tumor between 2004 and 2008. We conducted interviews, in person, with 352 case patients (participation rate: 83%) and 646 control subjects (participation rate: 71%) and their parents. Control subjects were randomly selected from population registries and matched by age, sex, and geographical region. We asked about mobile phone use and included mobile phone operator records when available. Odds ratios (ORs) for brain tumor risk and 95% confidence intervals (CIs) were calculated using conditional logistic regression models.
Results Regular users of mobile phones were not statistically significantly more likely to have been diagnosed with brain tumors compared with nonusers (OR = 1.36; 95% CI = 0.92 to 2.02). Children who started to use mobile phones at least 5 years ago were not at increased risk compared with those who had never regularly used mobile phones (OR = 1.26, 95% CI = 0.70 to 2.28). In a subset of study participants for whom operator recorded data were available, brain tumor risk was related to the time elapsed since the mobile phone subscription was started but not to amount of use. No increased risk of brain tumors was observed for brain areas receiving the highest amount of exposure.
Conclusion The absence of an exposure–response relationship either in terms of the amount of mobile phone use or by localization of the brain tumor argues against a causal association.
A steep rise in the popularity of mobile phones among children and adolescents in recent years has been reflected in both increased ownership and increased usage. One study has indicated that most children start to use mobile phones when they are around 9–10 years old, but usage before school age is not uncommon. The increase in mobile phone use has raised concerns about possible adverse health effects. Brain tumors have been a main concern because when the handset is held to the head, the brain absorbs most of the radio frequency energy emitted by mobile phones. Moreover, it has been hypothesized that children may be more vulnerable to radio frequency electromagnetic fields (RF EMFs) because they have a developing nervous system, their brain tissue is more conductive than that of adults (because of its higher water content and ion concentration), and RF EMFs penetrate into regions that are deeper in their brains [because the head circumference is smaller in children compared with adults]. Recent modeling studies have indicated that about twice as much mobile phone energy is absorbed in the peripheral brain tissues of children aged 5–8 years as in adults.
The radio frequency radiation emitted by mobile phone handsets has insufficient energy to directly damage DNA: It is nonionizing and its only known effect is heating. Hence, genotoxic effects such as DNA mutations or strand breaks cannot be directly linked to exposure to mobile phone radiation. The lack of genotoxicity of mobile phone radiation has been confirmed by experimental animal and laboratory studies. Overall, in vitro studies and experiments in mice [reviewed in ] have provided little evidence that mobile phone radiation is carcinogenic.
To date, no study has addressed the association between mobile phone use and the risk of brain tumors among children and adolescents. Studies in adults have shown no increase in risk among regular users but have been inconclusive regarding longer-term heavy use of mobile phones. The recently published INTERPHONE study found an increased risk for glioma among heavy users (cumulative call duration ≥ 1640 hours), but it is uncertain whether this reflects a true risk associated with the use of mobile phones or a spurious relationship due to recall bias or other methodological limitations. A study by Hardell et al. reported that astrocytoma was much more common among adults who first used mobile phones before age 20 (odds ratio [OR] = 5.2) or who first used cordless phones before age 20 (OR = 4.4).
In 2006, we set up CEFALO, an international case–control study of the relationship between mobile phone use and risk of developing brain tumors in children and adolescents. Participants were children aged 7–19 years in Denmark, Sweden, Norway, and Switzerland. We collected data by means of face-to-face interviews with the subjects and their parents.
Abstract and Introduction
Abstract
Background It has been hypothesized that children and adolescents might be more vulnerable to possible health effects from mobile phone exposure than adults. We investigated whether mobile phone use is associated with brain tumor risk among children and adolescents.
Methods CEFALO is a multicenter case–control study conducted in Denmark, Sweden, Norway, and Switzerland that includes all children and adolescents aged 7–19 years who were diagnosed with a brain tumor between 2004 and 2008. We conducted interviews, in person, with 352 case patients (participation rate: 83%) and 646 control subjects (participation rate: 71%) and their parents. Control subjects were randomly selected from population registries and matched by age, sex, and geographical region. We asked about mobile phone use and included mobile phone operator records when available. Odds ratios (ORs) for brain tumor risk and 95% confidence intervals (CIs) were calculated using conditional logistic regression models.
Results Regular users of mobile phones were not statistically significantly more likely to have been diagnosed with brain tumors compared with nonusers (OR = 1.36; 95% CI = 0.92 to 2.02). Children who started to use mobile phones at least 5 years ago were not at increased risk compared with those who had never regularly used mobile phones (OR = 1.26, 95% CI = 0.70 to 2.28). In a subset of study participants for whom operator recorded data were available, brain tumor risk was related to the time elapsed since the mobile phone subscription was started but not to amount of use. No increased risk of brain tumors was observed for brain areas receiving the highest amount of exposure.
Conclusion The absence of an exposure–response relationship either in terms of the amount of mobile phone use or by localization of the brain tumor argues against a causal association.
Introduction
A steep rise in the popularity of mobile phones among children and adolescents in recent years has been reflected in both increased ownership and increased usage. One study has indicated that most children start to use mobile phones when they are around 9–10 years old, but usage before school age is not uncommon. The increase in mobile phone use has raised concerns about possible adverse health effects. Brain tumors have been a main concern because when the handset is held to the head, the brain absorbs most of the radio frequency energy emitted by mobile phones. Moreover, it has been hypothesized that children may be more vulnerable to radio frequency electromagnetic fields (RF EMFs) because they have a developing nervous system, their brain tissue is more conductive than that of adults (because of its higher water content and ion concentration), and RF EMFs penetrate into regions that are deeper in their brains [because the head circumference is smaller in children compared with adults]. Recent modeling studies have indicated that about twice as much mobile phone energy is absorbed in the peripheral brain tissues of children aged 5–8 years as in adults.
The radio frequency radiation emitted by mobile phone handsets has insufficient energy to directly damage DNA: It is nonionizing and its only known effect is heating. Hence, genotoxic effects such as DNA mutations or strand breaks cannot be directly linked to exposure to mobile phone radiation. The lack of genotoxicity of mobile phone radiation has been confirmed by experimental animal and laboratory studies. Overall, in vitro studies and experiments in mice [reviewed in ] have provided little evidence that mobile phone radiation is carcinogenic.
To date, no study has addressed the association between mobile phone use and the risk of brain tumors among children and adolescents. Studies in adults have shown no increase in risk among regular users but have been inconclusive regarding longer-term heavy use of mobile phones. The recently published INTERPHONE study found an increased risk for glioma among heavy users (cumulative call duration ≥ 1640 hours), but it is uncertain whether this reflects a true risk associated with the use of mobile phones or a spurious relationship due to recall bias or other methodological limitations. A study by Hardell et al. reported that astrocytoma was much more common among adults who first used mobile phones before age 20 (odds ratio [OR] = 5.2) or who first used cordless phones before age 20 (OR = 4.4).
In 2006, we set up CEFALO, an international case–control study of the relationship between mobile phone use and risk of developing brain tumors in children and adolescents. Participants were children aged 7–19 years in Denmark, Sweden, Norway, and Switzerland. We collected data by means of face-to-face interviews with the subjects and their parents.
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