Magnetic fields expose to mutations

UEF Bulletin 2017

Research into the cellular effects of extremely low-frequency magnetic fields is currently ongoing in the Department of Environmental and Biological Sciences. Magnetic fields are suspected to play a role in the pathogenesis of various diseases such as cancer, and that’s why they have caught the attention of researchers.

Text Marianne Mustonen Photo Raija Törrönen

Researchers have long been drawn to magnetic fields, perhaps due to population-based studies that have linked power lines to increased risk of leukaemia in children. More recent research also indicates that long-term exposure to magnetic fields may increase the risk of Alzheimer’s disease, says Professor Jukka Juutilainen.

In addition to power lines, alternating current appliances and power leads also create low-frequency magnetic fields. In households, a typical magnetic field is 0.05 microteslas or less. In industrial workplaces, levels up to 100 microteslas are possible, yet still within accepted limits.

According to studies on childhood leukaemia, the risk starts to increase under exposure to magnetic fields as low as 0.4 microteslas. However, whether this is due to an actual causal relation between magnetic fields and childhood leukaemia remains unclear. Researchers are yet to discover a mechanism that could explain the biological effects of magnetic fields as weak as these.

The effects of magnetic fields on biological mechanisms have been studied at the University of Eastern Finland in cell experiments, and the findings may help shed light on the health effects of extremely low-frequency magnetic fields. Juutilainen’s research group has published several scientific articles on the topic, most recently in the Journal of the Royal Society Interface.  

The research group was the first in the world to describe genomic instability caused by an extremely low-frequency magnetic field, and this can be regarded as their most significant achievement so far. Genomic instability is a phenomenon that was first observed under ionising radiation, changing our understanding of the basic concepts of radiation biology. According to traditional radiation biology, possible mutations in a cell exposed to radiation are inherited by future generations of cells as such.

“However, more recent observations in radiation biology show that offspring cells inherit an increased tendency for mutations, meaning that there will be genetic variation in future generations of cells. This phenomenon is known as genomic instability, and recent findings now show that it can also be caused by extremely low-frequency magnetic fields.”

“Genomic instability is also likely to play a crucial role in cancers caused by environmental factors. The pathogenesis of cancer requires mutations in certain genes. The increased frequency of mutations associated with genomic instability translates into a higher probability of these mutations taking place in genes that are relevant for the development of cancer,” says Senior Lecturer Jonne Naarala.

“Genomic instability caused by extremely low-frequency magnetic fields was observed several cell generations later. In experiments with human neuroblastoma cells, genomic instability was still visible 30 days after exposure, which in these cells equals to approximately 30 generations of cells. Micronuclei were used in the experiments to observe genomic instability. The presence of micronuclei is associated with chromosome-level damage, and micronuclei are commonly used as an indicator for genotoxicity.” 

Another important observation was that biological effects could be observed in fields of 10 microteslas. Usually, magnetic fields of at least 100 microteslas are used in biological experiments to see the outcomes more effectively.

“We are now starting to experiment with even lower magnetic fields. They are challenging, as a greater degree of repetition is required in order for the findings to be statistically significant. Furthermore, the heating and regulation systems of our cell cultivation incubator are electric, and the device itself generates low magnetic fields. This means that our control sample is not in zero field,” Juutilainen explains.

“Other researchers have suggested that genomic instability is always associated with oxidative stress, an imbalance in the oxidation-reduction state of cells. However, we have carried out plenty of research into oxidative stress here, but in our experiments, genomic instability caused by magnetic fields did not require oxidative stress to occur. Antioxidant treatment did not have an effect on genomic instability,” Naarala adds.

The field of research is constantly advancing. In the near future, new devices will enable video recording of live cells and direct changes taking place in them when exposed to magnetic fields.

“When it comes to understanding these mechanisms, the magnetic sense found in animals is an important phenomenon. The magnetic sense can be explained, at least in part, by the magnetic field's quantum-mechanical effects on the life cycle of radical pairs. In humans, the existence of the magnetic sense hasn’t been verified: perhaps we’ve lost it in evolution. However, we have the same magnetosensitive proteins that enable the magnetic sense for animals, and the same basic mechanisms may also explain the biological effects of weak, low-frequency magnetic fields,” Juutilainen says.