The adverse health effects of low-level magnetic and electric fields is not clear-cut – approximately half of published studies have proven such radiation as being harmful, the other half have proved no influence whatsoever (Lin, 2014). Recently, studies done by the Institue of Electrical and Electronics Engineers (IEEE) and the World Health Organization (WHO) have linked heavy cellphone use to increased cancer rates (Lin, 2014). As well, it is well known that magnetic fields can change chemical reaction rates – but how?
Magnetic fields can cause changes in nuclear spin rates and the angular momentum of electrons in molecules. Think about it – electrons are negatively charged, and nuclei are positively charged, so external fields can definitely influence both. In a study published by the IEEE, the influence of an external magnetic field on the production of free radicals in the body was done (Barnes and Greenenbaum, 2016), explaining this influence.
When the weak bonds holding molecules/atoms together break (in biological organisms), they break off into fragments known as radicals. The radicals are unstable, since their outer energy shells are not full. This occurs during metabolic processes, so it is completely natural (Barnes and Greenenbaum, 2016).
More than just electron spin states, atoms have nuclear spin states too. The ones relevant to radicals in this case are the S and T states (singlet or triplet radicals). Fragments in the S state have nuclear spins aligned with electron spins with opposite spins. Two fragments can only recombine if they have a combined angular momentum of zero, as is the case with S states. Fragments in the T state have nuclear spins aligned with electron spins that are parallel, so together they have angular momentum that does not sum up to zero, so it is not energetically favourable for them to recombine (figure 1). They end up diffusing elsewhere, reacting with other molecules which causes them to break into fragments too, thus beginning a chain reaction (Barnes and Greenenbaum, 2016). The issue with this is that the chain reaction could lead to them reacting with important cellular components such as cell membranes or DNA. This could affect the cell in numerous unknown ways, possibly having little to no effect or possibly killing the cell.
It must be noted that active electrons (valence) and nuclei create a coupled magnetic field, which is why this is all possible. It was postulated in the study (Barnes and Greenenbaum, 2016) that for weak external magnetic fields, the magnetic coupling between the active electrons and nuclei is stronger than this field. It was further hypothesized that differences in the observed recombination concentration of radicals would be observed depending on the applied magnetic field.
The valence electrons of each of the radical pair fragments can be thought of as rotating about their nuclei at different rates, so the net magnetic moments switch from an S state to T state in dependence upon this. The rate at which they switch is affected by an external magnetic field, because the energy levels (nuclear spin, electron orbital levels, etc.) of each fragment are shifted by the field. Consequentially, this affects recombination and the rates of recombination as well, since they shift the energy barriers for rates of recombination (it takes energy to recombine). Further, magnetic fields at frequencies corresponding to the differences in energy levels of S and T states can change the concentration of the radicals in these energy levels, changing the recombination lifetimes for these radical pairs too (Barnes and Greenenbaum, 2016).
The most noticeable differences were seen for experiments involving the static magnetic field (SMF), an example of which is the earth’s magnetic field. This may explain how animals can sense small changes in earth’s magnetic field, such as birds’ migration. While it was seen that a reduction in the growth rate of E. coli was seen when the SMF was reduced significantly, it was also seen that changes in the growth rate of cancer cells were significantly larger than the difference in the growth rate of regular cells. It was determined that the amplitude, frequency, and time duration of an applied magnetic field influences the recombination and rates of recombination of radical pairs, increasing or decreasing for different biological molecules and cells. Based on this study alone, long-term exposure to external magnetic fields leads to increased radical concentrations associated with cancers, justified theoretically and experimentally.
Since the most significant influence of magnetic fields on biological cells is only observed with long-term exposure, more studies need to take this into account, since most other studies only consider short-term exposure (Barnes and Greenenbaum, 2016; Lin, 2014). The effect of cellphones on biological cells is not definitely proven yet, but with a basic understanding of physics, biology and chemistry, it is not difficult to see a possible correlation.
References
Barnes, F. and Greenenbaum, B. (2016). Some Effects of Weak Magnetic Fields on Biological Systems: RF fields can change radical concentrations and cancer cell growth rates. IEEE Power Electronics Magazine, 3(1), pp.60-68.
Lin, J. (2014). Reassessing laboratory results of low-frequency electromagnetic field exposure of cells in culture [telecommunications health and safety]. IEEE Antennas and Propagation Magazine, 56(1), pp.227-229.
Sugimoto, T. and Fukutani, K. (2011). Electric-field-induced nuclear-spin flips mediated by enhanced spin–orbit coupling. Nature Physics, [online] 7(4), pp.307-310. Available at: http://www.nature.com/nphys/journal/v7/n4/fig_tab/nphys1883_F1.html [Accessed 11 Nov. 2016].