How electric and magnetic fields influence biological cells - The physical mechanisms behind EMF effects

Introduction: Invisible forces, real effects

Electricity and magnetism are fundamental forces of nature - invisible but omnipresent. From the human nervous system to technical devices, many processes are based on electromagnetic fields (EMF).

For decades, scientists have been investigating how EMFs affect living organisms. Two key questions are driving research at:
1️⃣ Can electric and magnetic fields influence biological processes?
2️⃣ And if so, through which physical mechanisms?

The studies by Frank S. Barnes (2005) and A.H. Hashish et al. (2008) provide remarkable answers: While Barnes describes the underlying physical forces, Hashish and colleagues show their biological consequences in animal experiments.

Basics: What are electric and magnetic fields?

Electric fields: Movement of charged particles

An electric field is created when there is a voltage potential between two points. It exerts a force on charged particles (ions) and can thus influence ion currents, molecular orientations and reaction rates.

The basic formula is:

F=qE
(force=charge × electric field)

In biological systems, this primarily affects cell membranes - where electrical potentials and ion flows form the basis for nerve conduction, muscle contraction and signal transmission.

Magnetic fields: Forces, torques and resonance

Magnetic fields are created by moving charges (e.g. electric currents). They can align dipoles (e.g. electron spins) or even change energy states in molecules.

A static magnetic field acts through:

• Forces on charged particles (Lorentz force)

• Torques on magnetic dipoles

• Changes in energy states (Zeeman effect)

How cells react to electric fields

Ion transport and membrane currents

When electric fields act on cells, ion currents are set in motion. This changes local concentrations and electrical potentials - an effect that can influence biochemical reactions and signalling pathways.

In his work, Barnes describes detailed microelectrode measurements that were used to detect these current flows in cell cultures.

Orientation of dipoles and molecules

Many molecules have electric dipole moments - i.e. positive and negative poles. Electric fields can orientate these molecules and thus change the probability of reaction between them. This influences enzyme activity and binding to membrane receptors in particular.

The influence of field gradients

Not only the strength, but also gradients (changes in direction) in the field can be decisive. Inhomogeneous fields cause polarisable molecules to collect in certain zones - an effect known as dielectrophoresis (Pohl, 1978).

Magnetic fields and their effect on biological systems

Induced currents and magnetic forces

An alternating magnetic field generates electric fields (Faraday's law of induction). These induce currents in biological tissue, which in turn can influence cell membranes - similar to low-frequency electric fields.

Zeeman effect and energy shifts

Static magnetic fields can change the energy states of electrons and molecules - known as Zeeman splitting. Even small shifts can alter biochemical reactions if free radicals are involved.

Free radicals, spin resonance and oxidative reactions

A central mechanism: magnetic fields change the spin states of electrons in free radicals. This influences their lifetime and reactivity - which can ultimately promote or mitigate oxidative stress.

Barnes describes that particularly strong effects can occur at certain frequencies - the so-called cyclotron or spin resonance frequency.

From theory to practice: evidence from animal experiments

Hashish et al (2008): Long-term exposure in mice

In this study, mice were exposed to static (2.9 mT) and low-frequency (1.4 mT, 50 Hz) magnetic fields for 30 days.

Changes in the liver, blood and immune system

The researchers found:

• Weight loss and low blood sugar,

• altered liver enzymes (LDH, GGT, GST),

• decreasing lymphocyte counts,

• increased lipid peroxidation (signs of cell stress).

Oxidative stress as a central mechanism

These effects indicate a shift in the redox balance: More free radicals, less antioxidants (GSH). This confirms Barnes' theoretical predictions that magnetic fields influence biochemical reactions via spin mechanisms.

Combined view: physics meets biology

How electrical forces control chemical reactions

Electric fields influence how often and how efficiently molecules collide. Chemical reaction rates vary due to changes in dipole orientation and ion concentrations - even with weak fields.

Relationship between field strength, frequency and biological reaction

Barnes emphasises that biological systems react non-linearly: Small changes in frequency or amplitude can trigger large effects via resonance phenomena.

Threshold values and resonance phenomena

Effects occur particularly when field frequencies correspond to natural biological processes (e.g. ion resonances). At other frequencies, there is no effect - one reason why many EMF studies produce contradictory results.

High-frequency fields: Heat, energy and molecular dynamics

Thermal effects dominate at radio and microwave frequencies.

The decisive factor is the specific absorption rate (SAR) - it describes how much energy tissue absorbs. Even slight changes in temperature can influence reaction rates and cell processes.

However, Barnes also points to non-thermal mechanisms: radiofrequency fields can theoretically change the lifespan of free radicals or stimulate molecular transitions if frequencies are exactly right.

Health significance and unanswered questions

What risks are real?

Most of the known effects occur at field strengths that are significantly higher than everyday exposures. Nevertheless, studies show that even weak EMF can modulate subtle biological processes - especially via oxidative stress.

Research gaps and future approaches

It remains to be seen how strongly these mechanisms work in humans and whether long-term exposures (e.g. from 5G or power lines) have cumulative effects.
Future research should specifically investigate resonance and redox processes.

FAQ - Frequently asked questions about EMF

1.Can weak magnetic fields really have biological effects?
Yes, if they interact with the natural resonance frequencies of biological processes.

2.What is the cyclotron resonance effect?
A resonance phenomenon in which charged particles react strongly in magnetic fields at specific frequencies.

3.What is oxidative stress?
An imbalance between free radicals and antioxidants - often the cause of cell damage.

4.Are mobile phone or WLAN fields dangerous?
In everyday life, field strengths are far below the limit values, but research into long-term effects is still ongoing.

5.How can you protect yourself?
Keep your distance, switch off WLAN at night, use devices with cables where possible.

Conclusion: Between science and precaution

The studies by Barnes (2005) and Hashish et al. (2008) show:
Electromagnetic fields can influence biological systems in a physically comprehensible way - via electrical forces, molecular resonances and oxidative stress.

Whether these effects are relevant to health in everyday life depends on the field strength, frequency and duration of exposure. One thing is certain, however: EMF research remains a key topic in which physics, biology and medicine must work closely together.