In modern times, it seems a little strange to read claims in Europe and in U.S. cities like San Francisco that cell phone radiation is harmful to humans - but their reasoning is based on work in the 1970s which found an epidemiological association between increased risk of childhood leukemia and living near overhead power lines.

Like most epidemiology claims that find two curves going the same way and garner media attention, some skepticism is warranted, and later studies were unable to find the same connection, but the perception has held. Regardless,  groups like the International Agency for Research on Cancer have categorized low frequency magnetic fields as "possibly carcinogenic" even though a mechanism for this association has never been found.

A team from the Manchester Institute of Biotechnology has ruled out one of the prime candidates in a new Journal of the Royal Society Interface paper. They studied the effects of weak magnetic fields (WMFs) on key human proteins, including those crucial for health, and found that they have no detectable impact. The team looked at how WMFs affected a protein class called flavoproteins, which are key to processes vital for healthy human function, such as the nervous system, DNA repair and the biological clock.

If these proteins go wrong then there are serious knock-on effects for human health. But after subjecting them to WMFs in the lab it became clear that they have no detectable impact.

Dr Alex Jones, research fellow at the School of Chemistry at The University of Manchester, and co-lead author of the paper, said, "There is still some concern among the public about this potential link, which has been found in some studies into cases of childhood leukaemia, but without any clear mechanism for why. 

"Flavoproteins transfer electrons from one place to another. Along the path the electrons take, very short lived chemical species known as radical pairs are often created. Biochemical reactions involving radical pairs are considered the most plausible candidates for sensitivity to WMFs, but for them to be so the reaction conditions have to be right. This research suggests that the correct conditions for biochemical effects of WMFs are likely to be rare in human biology."

Professor Nigel Scrutton, co-lead author of the paper, from the Faculty of Life Sciences, said, "More work on other possible links will need to be done but this study definitely takes us nearer to the point where we can say that power-lines, mobile phones and other similar devices are likely to be safe for humans."