9. Oxidative stress

In the context of possible health-relevant effects of electromagnetic fields, the concept of oxidative stress is often discussed. Oxidative stress is an imbalance in cells or tissues in which more reactive molecules or atoms are present than can be broken down by cellular processes, thereby resulting in the chemical modification of biomolecules that are essential for cell function. Oxidative stress can result from a reduction in the formation of reducing compounds and enzymes in the cell and/or increased formation of reactive chemical species, mostly reactive oxygen species (ROS) or reactive nitrogen species (RNS).

In principle, it is important to distinguish between the concepts of oxidative stress, oxidative damage, and oxidative challenge. Oxidative challenge also leads to an increase in reactive chemical species. However, this can be compensated for by cellular processes so that no chemical changes occur in important biomolecules. Oxidative challenges can even be useful for the cell because it can then better adapt to further and future stress factors. When cells are subjected to oxidative stress, essential biomolecules are chemically modified by reactive species. However, the cell has repair mechanisms that can reverse these modifications.

Oxidative damage occurs when there is an irreversible modification of biomolecules (e.g. genetic material in the form of DNA, proteins, and carbohydrates). This can lead to the change, impairment, or loss of function of the cell or tissue. Mutations initiated by oxidation processes (alteration of DNA) also belong to this category insofar as these mutations are not reversed. Permanently altered metabolism and permanently increased formation of reactive species triggered by previous oxidative processes also count as oxidative damage.

Reactive oxygen or nitrogen species or other reactive chemical species naturally occur as part of signalling processes and immune reactions. It is only the uncontrolled, non-regulable, and increased occurrence of such compounds that leads to oxidative stress or oxidative damage.

In connection with electric, magnetic, and electromagnetic fields, it has been reported that these compounds lead to an increased formation of oxidising chemical species in the cell. In addition, the triggering of oxidative stress is postulated as a possible mechanism of action of electromagnetic fields. Oxidative stress can, in turn, lead to the development of cancer and neurodegenerative diseases or promote the formation and progression of these diseases. The negative effects of electromagnetic fields on human fertility have also been connected with the triggering of oxidative stress.

However, the existing studies are quite heterogeneous, both in terms of the presence or absence of the aforementioned effects and in their overall quality.

As part of a systematic review, the study situation and the quality of research on oxidative stress and electric, magnetic, and electromagnetic fields are summarised and assessed. If further research is needed as a result of the systematic review, further studies will be initiated.

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