scholarly journals Upper bound on the biological effects of 50/60 Hz magnetic fields mediated by radical pairs

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
PJ Hore
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Upper Bound ◽  
Prolonged Exposure ◽  
Radical Pair ◽  
Biological Effects ◽  
Radical Pair Mechanism ◽  
Childhood Leukaemia ◽  
Radical Pairs ◽  
Increased Risk

Prolonged exposure to weak (~1 μT) extremely-low-frequency (ELF, 50/60 Hz) magnetic fields has been associated with an increased risk of childhood leukaemia. One of the few biophysical mechanisms that might account for this link involves short-lived chemical reaction intermediates known as radical pairs. In this report, we use spin dynamics simulations to derive an upper bound of 10 parts per million on the effect of a 1 μT ELF magnetic field on the yield of a radical pair reaction. By comparing this figure with the corresponding effects of changes in the strength of the Earth’s magnetic field, we conclude that if exposure to such weak 50/60 Hz magnetic fields has any effect on human biology, and results from a radical pair mechanism, then the risk should be no greater than travelling a few kilometres towards or away from the geomagnetic north or south pole.

scholarly journals Upper bound on the biological effects of 50/60 Hz magnetic fields mediated by radical pairs

2018 ◽  
Author(s):  
P. J. Hore
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Upper Bound ◽  
Prolonged Exposure ◽  
Radical Pair ◽  
Biological Effects ◽  
Radical Pair Mechanism ◽  
Childhood Leukaemia ◽  
Radical Pairs ◽  
Increased Risk

AbstractProlonged exposure to weak (~1 μT) extremely-low-frequency (ELF, 50/60 Hz) magnetic fields has been associated with an increased risk of childhood leukaemia. One of the few biophysical mechanisms that might account for this link involves short-lived chemical reaction intermediates known as radical pairs. In this report, we use spin dynamics simulations to derive an upper bound of 10 parts per million on the effect of a 1 μT ELF magnetic field on the yield of a radical pair reaction. By comparing this figure with the corresponding effects of changes in the strength of the Earth’s magnetic field, we conclude that if exposure to such weak 50/60 Hz magnetic fields has any effect on human biology, and results from a radical pair mechanism, then the risk should be no greater than travelling a few kilometres towards or away from the geomagnetic north or south pole.

Time-resolved studies of radical pairs

2009 ◽  
Vol 37 (2) ◽  
pp. 358-362 ◽  
Author(s):  
Jonathan R. Woodward ◽  
Timothy J. Foster ◽  
Alex R. Jones ◽  
Adrian T. Salaoru ◽  
Nigel S. Scrutton
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Chemical Reactions ◽  
Radical Pair ◽  
Radical Pair Mechanism ◽  
Magnetic Field Effects ◽  
Radical Pairs ◽  
Time Resolved ◽  
Field Effects ◽  
Field Sensitivity

The effect of magnetic fields on chemical reactions through the RP (radical pair) mechanism is well established, but there are few examples, in the literature, of biological reactions that proceed through RP intermediates and show magnetic field-sensitivity. The present and future relevance of magnetic field effects in biological reactions is discussed.

scholarly journals Radical pairs may play a role in microtubule reorganization

2021 ◽  
Author(s):  
Hadi ZADEH-HAGHIGHI ◽  
Christoph Simon
Keyword(s):  
Magnetic Field ◽  
Radical Pair ◽  
Spin Dynamics ◽  
Radical Pair Mechanism ◽  
Magnetic Field Effects ◽  
Radical Pairs ◽  
Quantum Theories ◽  
Mechanism Model ◽  
Field Effects ◽  
Isotopic Dependence

The exact mechanism behind general anesthesia remains an open question in neuroscience. It has been proposed that anesthetics selectively prevent consciousness and memory via acting on microtubules (MTs). It is known that the magnetic field modulates MT organization. A recent study shows that a radical pair model can explain the isotope effect in xenon-induced anesthesia and predicts magnetic field effects on anesthetic potency. Further, reactive oxygen species are also implicated in MT stability and anesthesia. Based on a simple radical pair mechanism model and a simple mathematical model of MT organization, we show that magnetic fields can modulate spin dynamics of naturally occurring radical pairs in MT. We show that the spin dynamics influence a rate in the reaction cycle, which translates into a change in the MT density. We can reproduce magnetic field effects on the MT concentration that have been observed. Our model also predicts additional effects at slightly higher fields. Our model further predicts that the effect of zinc on the MT density exhibits isotopic dependence. The findings of this work make a connection between microtubule-based and radical pair-based quantum theories of consciousness.

scholarly journals Magnetic field effects as a result of the radical pair mechanism are unlikely in redox enzymes

2015 ◽  
Vol 12 (103) ◽  
pp. 20141155 ◽  
Author(s):  
Hanan L. Messiha ◽  
Thanyaporn Wongnate ◽  
Pimchai Chaiyen ◽  
Alex R. Jones ◽  
Nigel S. Scrutton
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Radical Pair ◽  
Radical Pair Mechanism ◽  
Magnetic Field Effects ◽  
Experimental Conditions ◽  
Flow Measurements ◽  
Field Sensitivity ◽  
Biochemical Systems ◽  
The Magnetic Field

Environmental exposure to electromagnetic fields is potentially carcinogenic. The radical pair mechanism is considered the most feasible mechanism of interaction between weak magnetic fields encountered in our environment and biochemical systems. Radicals are abundant in biology, both as free radicals and reaction intermediates in enzyme mechanisms. The catalytic cycles of some flavin-dependent enzymes are either known or potentially involve radical pairs. Here, we have investigated the magnetic field sensitivity of a number of flavoenzymes with important cellular roles. We also investigated the magnetic field sensitivity of a model system involving stepwise reduction of a flavin analogue by a nicotinamide analogue—a reaction known to proceed via a radical pair. Under the experimental conditions used, magnetic field sensitivity was not observed in the reaction kinetics from stopped-flow measurements in any of the systems studied. Although widely implicated in radical pair chemistry, we conclude that thermally driven, flavoenzyme-catalysed reactions are unlikely to be influenced by exposure to external magnetic fields.

scholarly journals Radical pairs can explain magnetic field and lithium effects on the circadian clock

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Hadi Zadeh-Haghighi ◽  
Christoph Simon
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Circadian Clock ◽  
Spin Dynamics ◽  
Hyperfine Interactions ◽  
Oscillator Model ◽  
Radical Pair Mechanism ◽  
Dependent Manner ◽  
Radical Pairs ◽  
Chemical Oscillator

AbstractDrosophila’s circadian clock can be perturbed by magnetic fields, as well as by lithium administration. Cryptochromes are critical for the circadian clock. Further, the radical pairs in cryptochrome also can explain magnetoreception in animals. Based on a simple radical pair mechanism model of the animal magnetic compass, we show that both magnetic fields and lithium can influence the spin dynamics of the naturally occurring radical pairs and hence modulate the circadian clock’s rhythms. Using a simple chemical oscillator model for the circadian clock, we show that the spin dynamics influence a rate in the chemical oscillator model, which translates into a change in the circadian period. Our model can reproduce the results of two independent experiments, magnetic field and lithium effects on the circadian clock. Our model predicts that stronger magnetic fields would shorten the clock’s period. We also predict that lithium influences the clock in an isotope-dependent manner. Furthermore, our model also predicts that magnetic fields and hyperfine interactions modulate oxidative stress. The findings of this work suggest that the quantum nature of radical pairs might play roles in the brain, as another piece of evidence in addition to recent results on xenon anesthesia and lithium effects on hyperactivity.

scholarly journals Magnetic field effects in flavoproteins and related systems

2013 ◽  
Vol 3 (5) ◽  
pp. 20130037 ◽  
Author(s):  
Emrys W. Evans ◽  
Charlotte A. Dodson ◽  
Kiminori Maeda ◽  
Till Biskup ◽  
C. J. Wedge ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Blue Light ◽  
Radical Pair ◽  
Model Systems ◽  
Radical Pair Mechanism ◽  
Magnetic Field Effects ◽  
Radical Pairs ◽  
Chemical Systems ◽  
Field Effects ◽  
Blue Light Photoreceptor

Within the framework of the radical pair mechanism, magnetic fields may alter the rate and yields of chemical reactions involving spin-correlated radical pairs as intermediates. Such effects have been studied in detail in a variety of chemical systems both experimentally and theoretically. In recent years, there has been growing interest in whether such magnetic field effects (MFEs) also occur in biological systems, a question driven most notably by the increasing body of evidence for the involvement of such effects in the magnetic compass sense of animals. The blue-light photoreceptor cryptochrome is placed at the centre of this debate and photoexcitation of its bound flavin cofactor has indeed been shown to result in the formation of radical pairs. Here, we review studies of MFEs on free flavins in model systems as well as in blue-light photoreceptor proteins and discuss the properties that are crucial in determining the magnetosensitivity of these systems.

scholarly journals HEK293 cell response to static magnetic fields via the radical pair mechanism may explain therapeutic effects of pulsed electromagnetic fields

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243038
Author(s):  
Marootpong Pooam ◽  
Nathalie Jourdan ◽  
Mohamed El Esawi ◽  
Rachel M. Sherrard ◽  
Margaret Ahmad
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Cell Cultures ◽  
Radical Pair ◽  
Memory Loss ◽  
Radical Pair Mechanism ◽  
Therapeutic Effects ◽  
Cellular Mechanisms ◽  
Pulsed Electromagnetic ◽  
Regulated Gene Expression

PEMF (Pulsed Electromagnetic Field) stimulation has been used for therapeutic purposes for over 50 years including in the treatment of memory loss, depression, alleviation of pain, bone and wound healing, and treatment of certain cancers. However, the underlying cellular mechanisms mediating these effects have remained poorly understood. In particular, because magnetic field pulses will induce electric currents in the stimulated tissue, it is unclear whether the observed effects are due to the magnetic or electric component of the stimulation. Recently, it has been shown that PEMFs stimulate the formation of ROS (reactive oxygen species) in human cell cultures by a mechanism that requires cryptochrome, a putative magnetosensor. Here we show by qPCR analysis of ROS-regulated gene expression that simply removing cell cultures from the Earth’s geomagnetic field by placing them in a Low-Level Field condition induces similar effects on ROS signaling as does exposure of cells to PEMF. This effect can be explained by the so-called Radical Pair mechanism, which provides a quantum physical means by which the rates and product yields (e.g. ROS) of biochemical redox reactions may be modulated by magnetic fields. Since transient cancelling of the Earth’s magnetic field can in principle be achieved by PEMF exposure, we propose that the therapeutic effects of PEMFs may be explained by the ensuing modulation of ROS synthesis. Our results could lead to significant improvements in the design and therapeutic applications of PEMF devices.

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