Supplementary Table: Evidence for the influence of geomagnetic activity (GMA) on biological systems. Due to space constraints, all evidence could not be presented in the main journal article. However, due to the complexity, size and controversial nature of the literature, a detailed summary of the evidence is presented below.
A large number of the studies below are epidemiological or correlational, investigating associations of GMA with health, physiological or behavioural outcomes. Further publications have directly studied animal and human outcomes during the course of GMS. Such studies are unlikely to suffer from the same confounders (e.g. seasonality, latitude, etc.) that could lead to problems with the epidemiological data. Further animal studies utilised applied earth-strength (or near earth-strength) static magnetic stimuli (as opposed to power-frequency magnetic stimuli) to simulate changes to the earth’s magnetic field. Furthermore, geomagnetic storms (GMS) do not come at random intervals, but instead have a number of stochastic periodicities, the primary one of which is linked to the approximately 11.5 year solar cycle. Thus, other studies investigated associations between epidemiological data and the solar cycle. Furthermore, the peak periods of maximum GM disturbance are the spring and autumn, due to the seasonal change in the geometry of the earth’s magnetic field relative to the sun. A further set of studies therefore argue that seasonality findings implicate the role of geomagnetism. As these studies move further from direct correlations, it is appropriate to treat findings with increasing caution.
This literature presents other major obstacles to the researcher, confounding truly systematic review – it is of a highly international nature and language barriers often pose significant problems, and there are a plethora of study designs. However, attempts were made to scan the literature in a structured manner, with search results supplemented by the authors existing knowledge of the literature. Furthermore, the reference lists of key publications (e.g. reviews and recent publications) were manually examined for further relevant references. Attempts have thus been made to include all major evidence for an influence of GMS on health and behavioural outcomes in the table below.
Key: Black = significant associations or supporting evidence; Red = no association or negative evidence; Orange = contrary, equivocal or ambiguous evidence
Melatonin & Circadian BehaviourCorrelations of GMA with human physiological outcomes or sleep behaviour / Lower mean nocturnal melatonin [1–6]
Sleep paralysis and dreaming [7–9]
Correlations of GMA with animal physiological outcomes / Melatonin profile of rats [10]
Reduction in synaptic ribbons of the pinealocytes [11]
Physiological animal studies using simulated magnetic fields / Significantly influences the pineal serotonin-N-acetyltransferase (NAT) activity or reduces the melatonin expression of various rodents [12–20]; the response is eye and light-dependent [12,13,19]
No reduction of melatonin expression in specific rodent species and strains [15,16,20]
Inconsistent results with pulsed DC magnetic fields [21]
Significantly influences the melatonin expression of birds [22]
Circadian activity rhythm influenced by geomagnetic shielding in birds [23]
Influences Drosophila circadian behaviour; this response not present in cryptochrome-knockout animals [24]
Circadian behaviour influenced in mice [25] and flies [26]
Physiological human studies using simulated magnetic fields / Circadian behaviour influenced in humans [27–29]; also influenced by geomagnetic shielding [30]
No association with circadian responses [31]; authors discuss shortcomings of study in replicating changes to the natural GMF
Correlations with seasonality or solar cycle / Seasonal pattern of melatonin profile in humans has been suggested to relate to GMA [32]
Seasonal pattern of melatonin profile in rats has been suggested to relate to GMA [33]
Other Hormones
Correlations of GMA with human physiological outcomes / Associations with thyroxine expression [34]; authors suggest that suppression of melatonin by increased GMA attenuates thryroxine expression
No significant association with cortisol or prolactin [34]
Association with 17-corticosteroid and prolactin [35]
Associations with cortisone expression [4]
Correlations of GMA with animal physiological outcomes / Increased corticosterone lability [10]; the authors argued that communication between the pineal to adrenocortical network constitutes a mechanism underlying the physiological and pathological associations of the brain and heart with GMS.
Cardiovascular Outcomes
Correlations of GMA with health outcomes / Myocardial infarction (MI) [35–54]; the largest study analysed Moscow emergency ambulance callout data, including 6 million ambulance calls and over 85,000 MIs, revealing that hospitalisation for MI increased 13% during GMS [42,55]
No association with MI [56–59]
One notable positive association with MI [60] was later retracted [61]
Stroke [48,62–65]
No association with stroke [66]
Angina pectoris [67]
Inverse correlation with implantable cardioverter defibrillators (ICDs) discharges [68]; authors suggest due to possible antiarrhythmic effect of GMA
An inverse correlation sudden cardiac death (SCD) [35,38,69,70]
A positive correlation with SCD [71]
Acute coronary syndrome [72]
Correlations of GMA with human physiological outcomes / An inverse correlation with heart rate variability (HRV) [35,73–85]
Increased blood pressure [6,35,73,86–93]
Increased heart rate [74,75]
No association with heart rate [87]
Capillary blood flow [94] and microcirculation parameters [95,96]
Circadian rhythms of blood pressure [97]
Changes to a range of haematological parameters: platelets, basophils, fibrinogen, leukocytes [35]; coagulation and inflammation [98]; platelet aggregation and blood coagulation [99]; erythrocyte sedimentation rate [100]
Physiological human studies using simulated magnetic fields / No association with blood pressure, heart rate or HRV [31]; authors discuss shortcomings of study in replicating changes to the natural GMF
Correlations of GMA with animal physiological outcomes / Blood pressure of rabbits [101,102]
HRV of rabbits [101]
Intracardiac pressure [103] and ultrastructure of cardiomyocytes of rabbits [103–105]
Size of myocardial mitochondria and the degree of cardiac contractility in rabbits [106]
Successful Therapeutic Intervention / Geomagnetic shielding in CV patients [97]
Melatonin therapy in CV patients [107]
Responsive treatment regimen in CV patients [108]
Static magnetic field therapy in rabbits [102]
Verapamil therapy in rabbits in response to both GMS and simulated MF changes [109]
Correlations with seasonality or solar cycle / In years of peak GMS activity patients admitted for MI increases [77,110,111]
Number of monthly CV deaths highly correlated with solar activity [112]
Congenital heart disease correlated with solar activity during pregnancy [113]
Negative correlation with monthly GMA and pregnancy induced hypertension [114]
Negative correlation with monthly GMA and stroke [115]
Inverse correlation with CV disease and solar cycle [116]
Psychiatric Outcomes
Correlations of GMA with health outcomes / Increased hospitalisations for depression & manic depression [117]
Ambulance callouts for psychiatric disorders [42]
Admissions to a psychiatric unit [118,119]
Associations with hallucinations [120,121]
Positive associations with suicide [42,62,122]
Negative associations with suicide [36,48,123,124]
Weak or no association with suicide [125–127]
Correlations with seasonality or solar cycle / Seasonality of suicide rates peaks during spring and autumn [123,125,126,128,129]
Greatly diminished seasonal effect [130]
Inverse correlation of first psychiatric admissions with monthly GMA [131]
Associations between geomagnetic disturbance and seasonality of schizophrenic births [132]
Association of solar cycle with schizophrenia [133]
No association of solar cycle with schizophrenia [134]
Epilepsy
Correlations of GMA with health outcomes / Associations with sudden unexpected death [135]; authors argued that GMA suppresses the activity of the endogenous anticonvulsant melatonin and lowers the threshold for paroxysmal electrical seizures.
No association between sudden unexplained death in epilepsy [136–138]
Association between postnatal geomagnetic activity and development of epilepsy [139]
Correlations of GMA with animal health outcomes / Associations with epileptic seizures [140,141], seizure latency [142] or severity of limbic seizure-induced hypothermia [143] in rat epileptic model
Animal studies using simulated magnetic fields / Enhancement [144,145] or increase [146] of limbic seizures in rat epileptic model; authors relate effect to suppression of nocturnal melatonin
Association with sudden unexplained death in rat epileptic model [147]
Correlations with seasonality or solar cycle / Association of annual seizures and GMA [148]
Immune System
Correlations of GMA with human physiological outcomes / Significant changes in autoimmune markers [149]
Prolactin expression [35]
No significant association with prolactin [34]
C-reactive protein expression [150]
Correlations with seasonality or solar cycle / Associations between the solar cycle and flu pandemics [151–155]
Human papillomavirus (HPV) infection synchronised with the solar cycle [156]
Leishmaniasis infection synchronised with solar cycle [157]
Animal experimental studies / Rats shielded from the natural GMF revealed significant differences in immune system function [158]; the authors conclude that GMF shielding eliminates fluctuations in the GMF that would normally act to supress melatonin, with subsequent positive benefits to the immune system.
Suppression of experimental allergic encephalomyelitis in rats associated with specific frequency, timing and intensity of applied magnetic fields [159–161]
Other Health Outcomes
Correlations of GMA with health outcomes / Total number of deaths [47,162]
Sudden infant death syndrome [163]
Association with foetal cardiotocography [164]
Intra- and postoperative complications or prognosis with lung [165] and breast cancer patients [166]
Neural tube defects [167]
Migraine severity [35,168] and frequency [169]
Correlations with seasonality or solar cycle / Correlation of longevity with solar cycle [170–174]
No correlation of longevity with solar cycle [175]
Correlation of total monthly number of deaths with GMA [48]
No correlation of total monthly number of deaths with GMA [53]
Monthly solar activity associated with premature labour [176]
Correlation of solar cycles with the incidence of malignant melanoma [177–180]; geomagnetic-melatonin interactions being cited as one of the plausible explanation [178]
Inverse correlation of monthly oncology deaths with geomagnetic activity [181]
Animal studies using simulated magnetic fields / Reduced litter sizes in rats [182]; authors note implications for sudden infant deaths
Neuronal cell migration during in utero development in rats [183]; authors note implications for sudden infant deaths
Behavioural & Other Outcomes
Correlations of GMA with human behavioural outcomes / Anxiety and irritability, lower attention and accuracy [184]
Negative influence on emotional state [185,186]
Road accidents [48,62,123,187,188]
Pilot errors [189] & air crashes [190]
Crime [191]
Religious experience [192]
Partial epileptic-like experiences [193]
Bizarreness of dreams [9]
Trigger for suicide bombers [194,195]
Reduced EEG spatial synchronisation [196]
Speed of acoustic-motor reaction [197]
Effective and cognitive competence in preschool [198]
Stock market returns [199]
No association with stock market returns [200]
Animal studies using simulated magnetic fields / Increased aggression in rats [201]
Increased sucrose consumption in rats [202]
Correlations of GMA with animal outcomes / Increased aggression in rats [203,204]
Nociceptive behaviour in mice [205,206]; authors suggested this effect may be mediated by pineal gland [205]
Increased sucrose consumption in rats [202]
Navigational disorientation in birds [207–209], bees [210] and whales [211]
No association with behaviour in fish or cockroaches [212]
Correlation with Drosophila lifespan [213], fertility and egg survival [214]
Correlations with seasonality or solar cycle / Births with monthly GMA [215]
Riots, revolutions, battles [44]
Wars, economic cycles, social crises and intellectually creative works [216]
Moderate association with wars [217]
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