The most comprehensive study to date on whether mobile devices can cause brain tumours has not provided a clear answer.

by Sigrun Landro Thomassen

Over the past decade, the mobile phone habits of more than 13 000 people in 13 countries have been investigated in order to assess whether mobile phones can cause cancer. The study was conducted by the World Health Organization's International Agency for Research on Cancer (IARC).

The study found no solid evidence that radio-frequency energy emitted by mobile phones does increase the risk of certain brain tumours.

However, the study did find a slightly greater risk of cancer among heavy users.

According to the study, the 10% who used their phones the most – 30 minutes a day or more on average for at least 10 years – had a substantially higher risk of developing some form of brain tumour.

"The results really don't allow us to conclude that there is any risk associated with mobile phone use, but... it is also premature to say that there is no risk associated with it," Christopher Wild, director of the IARC, said to Reuters.

Flaws in the study design
The 21 scientists who conducted the study admitted that the findings suggested problems with the method, or inaccurate information from those who participated.

"This was a very complex study, and results were very difficult to interpret because of a number of methodological issues," said Elisabeth Cardis at the Centre for Research in Environmental Epidemiology in Barcelona, who led the group of scientists.

According to Wild, one of the sources of error is that mobile phones are being used far more today than in 2000, when the study began. In addition, new mobile phones generate less radiation than earlier. Another problem is that the participants estimated how much they used their mobile phones, and it is highly unlikely that all these estimates are accurate.

Effects on children not included
Importantly, the study does not take into account the impact of mobile phone use in children, whose skulls are thinner than adults, and who may be more sensitive to mobile phone radiation.

More research
A total of 5,117 people with two different types of brain cancer and 7,500 people without cancer participated in the study. The participants are from Australia, Canada, Denmark, Finland, France, Israel, Italy, New Zealand, Norway, Britain, Sweden and Germany.

Last month, scientists launched another large study to examine the long term effects of mobile phone use. The Cosmos study will follow 250,000 people for as long as 30 years to look at cancer and other illnesses.

Kids and Media’s advice to reduce exposure to radiation:

• Limit the number of calls and their duration.

• Send text messages rather than making calls.
  

• Use hands-free kits.

• Keep the phone away from your body while talking.

• Do not keep the phone under the pillow or near your body at night. Ideally, turn it off.

• Choose a phone with a low level of radiation.

• Make sure you have good coverage while making calls.

Related articles:

BBC News
No proof of mobile cancer risk, major study concludes

Guardian
Mobile phone study finds no solid link to brain tumours

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