Electrohypersensitivity: perception thresholds of electric fields in affected individuals

What is the issue?

The operation of high-voltage power lines generates electric fields that, if they are strong enough, can be perceived as a tingling sensation on the surface of the skin, for example. This research project is investigating where the perception threshold for such fields lies. The perception threshold is the point above which people can consciously perceive a specific stimulus – in this case, the electric field.

At the same time, the project is investigating a possible connection with “electrohypersensitivity” (EHS). Some people describe themselves as electrohypersensitive. Other names for this include:

• electromagnetic hypersensitivity
• electrosensitivity
• in technical terms, “idiopathic environmental intolerance to electromagnetic fields” (IEI-EMFs).

These terms refer to a subjectively perceived special sensitivity to low-frequency and high-frequency electromagnetic fields.

Examples of applications that generate electromagnetic fields.

Those affected are referred to as EHS sufferers and attribute various symptoms – such as headaches, aching limbs and insomnia – to electromagnetic fields. However, there is no evidence of a causal relationship between the nonspecific symptoms and the electromagnetic fields.

Against this backdrop, this research project will determine and compare the perception thresholds of electric fields for two groups:

• people who describe themselves as EHS sufferers
• people who do not describe themselves as such (control group).

EHS sufferers will also undergo comprehensive environmental medical diagnostics, in which they will be asked about any previous illnesses and stressful experiences, among other things.

What is the current situation?

Powerline Source: Michael Rosskothen/stock.adobe.com

The electricity grid in Germany is currently being expanded. In the process, overhead lines are also being erected:

• for high-voltage direct current (HVDC) transmission
• for high-voltage alternating current (HVAC) transmission
• as hybrid lines that combine both transmission technologies in one route (e.g. Ultranet).

These types of cables generate static and low-frequency electric fields, and expansion is expected to result in changes in people’s exposure to fields of this kind.

• Low-frequency electric fields, such as those emitted by high-voltage alternating current power lines, are subject to limit values. Compliance with the limit values ensures that there are no health effects.
• There are no limit values for static electric fields, as there is no evidence of relevant adverse effects on health.
• Nevertheless, static and low-frequency electric fields are perceptible – for example, as a tingling sensation on the surface of the skin.

According to the 26th Ordinance Implementing the Federal Immission Control Act (26th BImSchV), significant nuisance from such fields must be avoided. To achieve this goal, it is important that the perception thresholds be known. Studies carried out on behalf of the BfS by RWTH Aachen University have shown that the perception of these fields varies greatly from person to person. People who could perceive very weak fields did not identify themselves as electrohypersensitive and did not experience any health burdens as a result of these perceptions.

Electrohypersensitivity is not recognised as a medical diagnosis by the World Health Organization (WHO). Nevertheless, the symptoms attributed to electromagnetic fields can cause considerable psychological stress. Little is known about those affected, their possible comorbidities, and their personal and social circumstances.

What are the objectives of the BfS research project?

The study aims to gain relevant insights into the perception threshold for static, low-frequency and hybrid electric fields. The research will be extended to the group of people affected by electrohypersensitivity, which has not yet been considered. It is also about developing a better understanding of these people’s characteristics. This should allow those affected to be identified more reliably and addressed in a scientifically sound manner. The research project involves:

• determining the perception thresholds of EHS sufferers,
• comparing these thresholds with those of an unaffected control group and
• correlating the results with environmental medical data such as medical history, comorbidities and socioeconomic factors of those affected.