# Magnetic Fields Trump Oxygen in Controlling the Death of Erythro-Leukemia Cells
## 1 Introduction  
Exposure to man-made electromagnetic radiation (EMR) consists of two main parts. First and oldest are extra-low-frequency magnetic fields (ELF MFs, 50/60 Hz) from power systems. Humans are commonly exposed to MFs reaching 1 \(\upmu\)T or more in proximity to electrical power [1], but exposure is much smaller when far away from electrical devices and networks.  
The second part involves radio-frequency carriers (RF, 3 kHz to 300 GHz) for transmission of analog or digital signals. RF signals carrying digital signals contain substantial ELF MFs, because of their use of data bursts. In the case of the global system for mobiles (GSM), with carriers near 900 and 1750 MHz, ELF components at 8.3, 217, and 1750 Hz [2] are present. A cellular phone user is therefore exposed to ELF MFs emitted by the cell phone antenna, plus the pulsed MFs from the phone's battery, such peak fields rating as high as 95 \(\upmu\)T at the head during actual GSM handset use [3]. The range of 0 to 1 \(\upmu\)T for ELF MFs chosen for investigation in our work is therefore relevant to both power system and cellular phone exposures [4].  
In the results to follow, we compare effects of variations in MFs (0 to 1 \(\upmu\)T) to those of variations in oxygen levels. Incubator levels are as high as 18.6%, and, in the human body, 13% in large systemic arteries, falling rapidly along the arterial tree to tissue values of 5 to 0.6%. As much as 82% of oxygen readings in solid tumors are less than 0.33% [5]. Many cells in the body are subjected to oxygen levelvariations corresponding to changes in perfusion (as a result of exercise or vasodilation), or because white blood cells can lodge in different tissues. We have therefore chosen the widest practical range of oxygen variations in our experiments: from the 18.6% present in incubator air (\"High O\({}_{2}\)\") to the 0.4 to 0.7% (\"Low O\({}_{2}\)\") maintained over cultures initially flushed with anoxic medical gas.  
Our interest in MF changes stems from our previous observations on oxygen [6] and on MFs where, even using a variable as blunt as karyotype, cancer cells needed more than a month to recover from a 0 to 1 uT transition, and changes as small as 0.01 uT triggered cell adaptations [7].  
Within the MF range of 0 to 1 uT, various environmental sources of EMR combine to create human exposures that are highly variable over multiple time scales, best described by the term \"fractal instability\". The slowest layer of exposure complexity is provided by the user's transient use of a cellular phone or powered device, while the protocols of cellular phone data transmissions contribute faster layers. Digital techniques use sudden transitions to carry signals (bits) because these provide a high signal to noise ratio. Carriers are further manipulated with frame and burst structures, and time and frequency-domain-multiple-access, to increase data carrying capacity. Beam-forming using dipole arrays, proposed for 5G, adds further space segmentation to the previously used time and frequency segmentations. Under the assumption that human physiology needs to adapt to this fractal instability of EMR, it becomes important to evaluate changes in EMR exposures for potential impacts on human health.  
In environmental toxicology, the efficacy of an agent in eliciting toxic responses (here, necrosis and apoptosis) is often obtained from the measurement of outcomes within the range of exposures present in the environment. Oxygen is one of the most scrutinized agents in biology, while environmental EMR is a subject of much controversy. Comparing the two agents over their intensity ranges is instructive of their relative physiological influence. We therefore attempted the simulation of the range of MFs (0 to 1 uT) and oxygen levels (High and Low O\({}_{2}\)) present in the human body to investigate this question.