The researchers discovered that rats exposed to a weak magnetic field oscillating 60 times per second for 24 hours showed DNA damage to their brain cells. Rats exposed for 48 hours showed even more damage.

They also say that the exposure resulted in an increase in brain cell “apoptosis” or “cell suicide” - a process in which the cell self-destructs because it cannot repair itself.

Additionally, UK’s National Radiological Protection Board has already noted a weak association between the incidence of childhood leukaemia and exposure to elevated magnetic fields.

The association is not observed in the UK, but has been seen in the USA and Sweden. One possible reason for this difference is because the USA uses a 110-volt electricity system, which confers a higher exposure to residual magnetic fields than the 240-volt system used in the UK and mainland Europe.