Examination of the effects of low static magnetic fields and rf-exposure on biochemical reactions by the radical pair mechanism.

project team:
J. Boiden Pedersen¹, Martin Jermer Hansen¹, Alexander B. Doktorov^1,2, Nikita N. Lukzen^1,2

¹Institute of Physics and Chemistry, University of Southern Denmark, Denmark.

² Russian Academy of Sciences, Novosibirsk, Russia.

research institution:
Institute for Physics, University of Southern Denmark

The project investigates whether harmful effects on biological systems could result from the magnetic component of the electromagnetic field radiated from cellular phones. The radical pair mechanism is a documented mechanism by which a magnetic field can influence the yield of a chemical reaction. The mechanism requires that the reaction has an intermediate radical pair stage, e.g. a molecule that dissociates into two radicals (molecular fragments with unpaired electron spins). Since radicals are very reactive species, an increased production could be harmful; the actual effect will depend on the local biological system. It has not been possible to directly observe the intermediate stage of biological reactions and thus experimental investigations of the effect in vivo or in vitro is not possible at present. It is, however, possible to perform accurate calculations of the effect for reactions under biological conditions and thus conclude whether such effects are at all possible. The magnitude of the effect depends on a combination of the lifetime of the radical pair, i.e. the time it takes before the radicals separate from each other or are scavenged, and the hyperfine constants of the radicals. Since the magnetic interaction is very small, it is a non-thermal and quantum mechanical effect.

We have performed numerical and analytical calculations that cover all conceivable situations and it is found that: (1) there is no effect for reactions in liquid media, (2) there is a potential effect for reactions going on in a membrane, but it requires a hyperfine constant of 32 mT for a 900 MHz rf-field; no such reactions are known, (3) enzyme mediated reactions are the only possible candidates, due to the presence of metal-ions that have large hyperfine constants. However, the resonance condition, i.e. the relation between the hyperfine constant A and the frequency of the rf-field f, is very restrictive and implies that only reactions involving radicals with very large hyperfine constants can be affected by the rf-field frequencies used for mobile communication systems. A higher frequency requires a larger hyperfine constant and consequently an effect becomes less likely. An interesting effect of a low static magnetic field has recently been predicted for enzymatic phosporylation^* due to the large hyperfine constant (21 mT) of ²⁵Mg in the enzyme which is in resonance with an rf-field of 1800 MHz. We are presently investigating whether an 1800 MHz rf-field could influence this fundamental reaction.

^* A.L. Buchachenko, N.N. Lukzen and J.B. Pedersen, Chem Phys Lett, 434 (2007) 139-143.

Read abstract from stis study here ...


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Danish Front page Det Strategiske Forskningsråd varetager forskningsprogrammet for ikke-ioniserende stråling. DSF’s bestyrelse udmønter ikke selv programmidler, og bestyrelsen har derfor nedsat en programkomite for ikke-ioniserende stråling bestående af fire anerkendte forskere. Der er afsat en samlet ramme på 30 mio. kr. til programmet. 15 mio. kr. blev uddelt i 2004, og 15 mio. kr. i 2005. Oplysninger om denne forskningsindsats – bl.a. omtale af de bevilgede projekter og forskernes oplæg på de afholdte åbne møder kan ses på DSF’s website på adressen: www.mobil.forsk.dk	Examination of the effects of low static magnetic fields and rf-exposure on biochemical reactions by the radical pair mechanism. project team: J. Boiden Pedersen¹, Martin Jermer Hansen¹, Alexander B. Doktorov^1,2, Nikita N. Lukzen^1,2 ¹Institute of Physics and Chemistry, University of Southern Denmark, Denmark. ² Russian Academy of Sciences, Novosibirsk, Russia. research institution: Institute for Physics, University of Southern Denmark The project investigates whether harmful effects on biological systems could result from the magnetic component of the electromagnetic field radiated from cellular phones. The radical pair mechanism is a documented mechanism by which a magnetic field can influence the yield of a chemical reaction. The mechanism requires that the reaction has an intermediate radical pair stage, e.g. a molecule that dissociates into two radicals (molecular fragments with unpaired electron spins). Since radicals are very reactive species, an increased production could be harmful; the actual effect will depend on the local biological system. It has not been possible to directly observe the intermediate stage of biological reactions and thus experimental investigations of the effect in vivo or in vitro is not possible at present. It is, however, possible to perform accurate calculations of the effect for reactions under biological conditions and thus conclude whether such effects are at all possible. The magnitude of the effect depends on a combination of the lifetime of the radical pair, i.e. the time it takes before the radicals separate from each other or are scavenged, and the hyperfine constants of the radicals. Since the magnetic interaction is very small, it is a non-thermal and quantum mechanical effect. We have performed numerical and analytical calculations that cover all conceivable situations and it is found that: (1) there is no effect for reactions in liquid media, (2) there is a potential effect for reactions going on in a membrane, but it requires a hyperfine constant of 32 mT for a 900 MHz rf-field; no such reactions are known, (3) enzyme mediated reactions are the only possible candidates, due to the presence of metal-ions that have large hyperfine constants. However, the resonance condition, i.e. the relation between the hyperfine constant A and the frequency of the rf-field f, is very restrictive and implies that only reactions involving radicals with very large hyperfine constants can be affected by the rf-field frequencies used for mobile communication systems. A higher frequency requires a larger hyperfine constant and consequently an effect becomes less likely. An interesting effect of a low static magnetic field has recently been predicted for enzymatic phosporylation^* due to the large hyperfine constant (21 mT) of ²⁵Mg in the enzyme which is in resonance with an rf-field of 1800 MHz. We are presently investigating whether an 1800 MHz rf-field could influence this fundamental reaction. ^* A.L. Buchachenko, N.N. Lukzen and J.B. Pedersen, Chem Phys Lett, 434 (2007) 139-143. Read abstract from stis study here ...