Mobile phone-cancer link study inconclusive

Mobile phone-cancer link study inconclusive
                from ABC News

The study tracked almost 13,000 mobile phone users over 10 years. (ABC News)

Experts who studied almost 13,000 mobile phone users over 10 years hoping to find out whether the devices cause brain tumours say their research gave no clear answer.

A study by the World Health Organisation's International Agency for Research on Cancer (IARC), the largest ever to look at possible links between mobile phones and brain cancer, threw up inconclusive results but researchers said suggestions of a link demanded deeper examination.

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

The results have been keenly awaited by mobile phone companies and by campaign groups who have raised concerns about whether mobile phones cause brain tumours.

Years of research have failed to establish a connection.

The British-based GSM Association, which represents international mobile phone firms, said IARC's findings echoed "the large body of existing research and many expert reviews that consistently conclude there is no established health risk".

The Australian-based Mobile Manufacturers Forum also welcomed the study and backed "the need for ongoing research".

Professor Wild said part of the problem with this study, which was launched in 2000, was that rates of mobile phone usage in the period it covered were relatively low compared with today.

It was also based on people searching their memories to estimate how much time they spent on their phones, a method that can throw up inaccuracies.

European scientists last month launched what will now become the biggest ever study into the effects of mobile phone use on long-term health.

It aims to track at least 250,000 people in five European countries for up to 30 years.

This kind of study, called a prospective study, is considered more accurate because it does not require people to remember their mobile phone use later but tracks it in real time.

'More research needed'

Data from the IARC study showed that overall, mobile phone users in fact had a lower risk of brain cancer than people who had never used one.

But the 21 scientists who conducted the study said this finding suggested problems with the method or inaccurate information from those who took part.

Other results showed high cumulative call time may slightly raise the risk, but again the finding was not reliable.

"We can't just conclude there is no effect," said Elisabeth Cardis of the Centre for Research in Environmental Epidemiology in Barcelona, Spain, who led the study.

"There are indications of a possible increase. We're not sure that it is correct. It could be due to bias, but the indications are sufficiently strong... to be concerned."

Because of this and because mobile phone use is rising all the time, more research was needed, the scientists said.

The 21 scientists were part of a group known as the Interphone International Study Group which was funded in part by money from mobile phone companies. The study was published in the International Journal of Epidemiology.

Mobile phone use has increased dramatically since its introduction in the early-to-mid 1980s. About 5 billion mobile phones are in use worldwide.

The researchers said the majority of people covered in their study "were not heavy mobile phone users by today's standards".

The average lifetime cumulative call time for those who took part was about 100 hours, with an average of two to two-and-a-half hours of reported use a month.

The heaviest 10 per cent of users had clocked up an average of 1,640 hours of phone use spread over 10 years, which corresponds to about half-an-hour a day.

"Today, mobile phone use has become much more prevalent and it is not unusual for young people to use mobile phones for an hour or more a day," the researchers wrote.

But increasing use is tempered by generally lower radiation emissions from modern phones and greater use of texting and hands-free sets that keep the phone away from the head, they said.

The study received 19.2 million euros ($27.3 million) in funding, around 5.5 million euros ($7.8 million) of which came from industry sources.

It analysed data from interviews with 2,708 people with a type of brain cancer called glioma and 2,409 with another type called meningioma, plus about 7,500 people with no cancer.

The same problem. You must always acknowledge sources!
npca 发表于 2010-5-17 09:37

The source can be seen from the picture

I added it unto the title either way