There has been no substantial change in the number of adult brain tumours since mobile phone usage sharply increased in the mid-1990s, Danish scientists say.
The Danish Cancer Society looked at the rates of brain tumours among 20 to 79 year olds from Denmark, Finland, Norway and Sweden. They found that trends in cancer rates had not altered from the period before mobiles were introduced. But they say longer follow-up studies are needed.
The research, published in the Journal of the National Cancer Institute, says radio frequency electromagnetic fields emitted from mobile phones have been proposed as a risk factor for brain tumours, but a biological mechanism that could explain the potential effects has not been identified.
The study was based on 59,684 brain tumour cases diagnosed over 30 years from 1974 to 2003 among 16 million adults.