Do strong static magnetic fields have an impact on human health?

Individuals come in contact with strong static magnetic fields, for instance, during Magnetic Resonance Imaging, i.e. an imaging procedure used in medical diagnosis. Devices currently used in clinical practice are mostly operated at a magnetic flux density of 1.5 or 3 Tesla (T). In research, 7 and 11.7 Tesla-devices are already being tested which are intended to be used in medical diagnosis as well in the future.

At the end of 2012 patients with brain tumours were for the first time examined in a 9.4 Tesla tomograph at the Max Planck Institute for Biological Cybernetics in Tübingen, Germany. In veterinary medicine devices with flux densities of up to 16.4 Tesla are used.

Three research projects

The question, if these stronger fields affect the health of patients and medical stuff, has been investigated in three research projects commissioned by the BfS.

Results:

• Exposure of mice to a magnetic field of seven Tesla per day over the total period of their embryonic development did not result in behavioural abnormalities or differences in emotional behaviour (anxiety, depression) or cognitive behaviour (working memory, long-term memory) in the young adult age.
• The indications from scientific literature as to the occurrence of dizziness were able to be confirmed, primarily within a magnetic field strength of seven Tesla and during movements within the gradient of a static magnetic field The perception of dizziness had no influence on the cognitive performance of the test persons. Most of the test persons were able to rapidly adapt to the fields and subsequently had no complaints any more.
• The fertility of male and the course of pregnancy of female mice were not affected by repeated strong magnetic field exposition. The offspring exhibited a slightly delayed development in terms of weight and opening their eyes, as compared to controls. It is possible that the developmental delay was induced by stress during exposure.