Is radiation from mobile phones harmful? Multiple studies globally have not conclusively reached an answer. But an analysis by AIIMS of all research on the subject has found an interesting pattern-government-funded studies show increased risk of brain tumour on long-term exposure to mobile phone radiation while industry-funded research tends to underestimate the risk.

“We found that industry funded studies are not of good quality and tend to underestimate the risk. Government funded studies show increased risk of brain tumour on long-term exposure,” said Dr Kameshwar Prasad, head of neurology at AIIMS, who is lead author of the study .

According to Prasad, based on studies on long-term mobile use (at least 10 years or over 1,640 hours), it can be said that such exposure increases brain tumour risk by 1.33 times. In other words, if 100 people suffer from brain tumour, factoring in radiation exposure increases the number to 133. The AIIMS professor and his team of neurologists recently analysed results of 22 case-controlled studies conducted globally on 48,452 participants from 1966 to 2016 that reported the results for the risk of brain tumour.

Of this, 10 were funded by government, seven had mixed funding from phone industry, government and mobile manufacturers and at least three studies were solely funded by the phone industry.

Results of this analysis, which has been published in medical journal Neurological Sciences, states that while government funded studies have a quality score of 7 or 8, all studies by phone industry and mixed sources have a score of 5 or 6. Lower quality score points to increased risk of selection or measurement bias that can affect results.

AIIMS research shows studies with higher quality score show a trend towards harm, while lower quality score studies show a trend towards protection. “It is baffling how certain studies even propound that mobile phone use can protect against brain tumour,” said a researcher.

Meta-analysis, according to sources of funding, clearly shows a consistent increase in risk of brain tumour with mobile phone use of more than 10 years.

While summary estimate of government funded studies shows a 1.64 times increase in odds, mixed funded studies shows a 1.05 times increase in the odds of risk of brain tumours, the AIIMS research states.

It clarifies that data for more than 10 years of use were not available for phone industry funded studies, a major weakness from the point of view of analysing a possible link between mobile phone radiation and the risk of brain tumour on long-term use.

Dr Prasad said the association between mobile phone use and the risk of brain tumour is beset with controversies. The AIIMS paper provides an insight into the underlying reasons for this. Source: TOI