A Summary of Recent Literature (2007-2017) on Neurobiological Effects of Radio Frequency Radiation

Abstract

A Summary of Recent Literature (2007-2017) on Neurobiological Effects of Radio Frequency Radiation By Henry Lai. Chapter 8: 187-222. Abstract Neurological effects are caused by changes in the nervous system. Factors that act directly or indirectly on the nervous system causing morphological, chemical or electrical changes in the nervous system can lead to neurological effects. The final manifestation of these effects can be seen as psychological/behavioral changes, for example, memory, learning, and perception. The nervous system is an electrical organ. Thus, it should not be surprising that exposure to electromagnetic fields could lead to neurological changes. Morphological, chemical, electrical, and behavioral changes have been reported in animals and cells after exposure to nonionizing electromagnetic fields (EMF) across a range of frequencies. The consequences of physiological changes in the nervous system are very difficult to assess. We do not quite understand how the nervous system functions and reacts to external perturbations. The highly flexible nervous system could easily compensate for external disturbances. On the other hand, the consequence of neural perturbation is also situation-dependent. For example, an EMF-induced change in brain electrical activity could lead to different consequences depending on whether a person is watching TV or driving a car. Conclusions 1. A major concern is that in some of the studies, details of the exposure setup and dosimetry are not provided. This is important since details of the independent variables are very important in interpreting the validity of the experimental results, that is, dependent variables. In many of these studies, a cell phone was used in the exposure of animals and humans. But information on how the cell phone was activated, in many instances, was not provided. Thus, the amount of energy deposited in the body was not known.... 2. Most of the studies were carried out with relatively high levels of RFR compared to environmental levels. However, if you look through the narratives, there are studies that reported effects at very low level, for example, Bak et al., (2010). Indeed, biological/health effects of RFR at levels much lower than most international RFR-exposure guidelines, for example, International Commission on Non-ionizing Radiation Protection (ICNIRP), have been reported (see table 1 in Levitt and Lai, 2010). This raises the question on whether the guidelines used in most countries nowadays are actually obsolete and new exposure guidelines have to be set. 3. Thus, there is ample evidence that RFR exposure affects the nervous system from both acute and long-term exposure experiments. Brain electric activities, nerve cell functions and chemistry, and behavior can be affected. Some explanatory mechanisms for these effects have emerged. One consistent finding is that animals exposed to RFR suffered from memory and learning deficits. These effects can be explained by the results of numerous reports that showed RFR affected the hippocampus, a brain region involved in memory and learning. However, the location and configuration of the human hippocampus are quite different from those of a rodent. There have not been many studies on the effect of RFR on the human hippocampus. Several studies did report deficits in memory in human subjects exposed to RFR, particularly on short-term memory, a function specifically related to the hippocampus.... 4. Another very consistent finding is that RFR affects free radical metabolism in the brain. This may explain some of the cellular and physiological effects of RFR on the nervous system. As a matter of fact, oxidative changes in cells and tissues after exposure to RFR is a very common phenomenon (cf. Yakymenko et al., 2016). This happens in many organs of the body and can provide explanation of many reported biological effects of RFR. 5. Many of the effects of RFR on the nervous system, for example, on the hippocampus, oxidative effects, and behavioral effects are also observed with exposure to extremely low frequency electromagnetic field (cf. my section on the neurological effects of ELF EMF in the Bioinitiative Report, bioinitiative.info). There has been speculation whether biological effects observed with low frequency modulated RFR were actually caused by the modulation. There are two reports published in the last decade that seemed to refute this hypothesis Another question is whether one type of modulation is different from another in causing biological effects. Cell phone technology advances from one generation to another. Do the research data of a 3G phone apply to 4G or 5G phone radiation? RFR is a complex entity. Its biological effects depend on many of its physical properties, for example, frequency, direction of the incident waves relative to the object exposed, dielectric properties, size and shape of the exposed object, polarization of the waves, and so on. Thus, it is unlikely that one can easily extrapolate the effects from one form of RFR to another. An assumption that 3G radiation is safe does not necessary imply that 5G radiation is safe. Each one of them has to be investigated separately. 6. An important area of research is on how RFR in the environment affects humans and wildlife. Environmental RFR level has become higher and higher over the past decades due to the employment of RFR wireless devices. Take the example of Bak et al. (2010) mentioned above, an effect on human event-related brain potential was reported after 20 min of exposure to a GSM signal at a power density of 0.0052 mW/cm2. This is very close to the levels found in some cities. The highest power density of ambient RFR measured near schools and hospitals in Chandigarh, India, was reported to be 0.001148 mW/cm2 in 2012 (Dhami, 2012). The maximum total RFR power density emitted by FM and TV broadcasting stations and mobile phone base stations in centers of the major cities in the West Bank-Palestine was 0.00386 mW/cm2 (Lahham and Hammash, 2012). One also has to take into consideration that exposure in the Bak et al. (2010) study was acute (20 min), whereas environmental exposure is chronic. Related to the neurological effect is the magnetic sense possessed by many species of animals. It is essential for their survival. Interference by RFR of magnetic compass orientation in animals has been reported (e.g., Landler et al., 2015; Malkemper et al., 2015; Pakhomov et al., 2017; Schwarze et al., 2016; Vácha et al., 2009). Understanding the effects could help in preserving the ecosystem and ensure survival of the species on this earth.

AI evidence extraction

Main findings

The review summarizes evidence that radio frequency radiation (RFR) exposure affects the nervous system in animals, cells, and humans, including changes in brain electrical activity, nerve cell function, chemistry, and behavior such as memory and learning deficits. Effects have been reported at both high and low exposure levels, sometimes below current international guidelines. Oxidative stress and free radical metabolism alterations are consistent findings. Effects depend on multiple physical properties of RFR and may differ across technologies (e.g., 3G vs 5G). Environmental RFR exposure levels have increased and may affect humans and wildlife, including interference with animal magnetic orientation.

Outcomes measured

• neurological effects
• morphological changes
• chemical changes
• electrical changes
• behavioral changes
• memory deficits
• learning deficits
• oxidative effects
• free radical metabolism changes
• brain electric activity changes
• nerve cell function changes

Limitations

• Many studies lack detailed exposure setup and dosimetry information.
• Most studies use exposure levels higher than typical environmental levels.
• Differences in species anatomy (e.g., human vs rodent hippocampus) limit direct extrapolation.
• Biological effects depend on multiple complex physical properties of RFR, complicating generalization.
• Limited studies on effects of newer technologies (4G, 5G).

Suggested hubs

• 5g-policy (0.7)
  Discusses differences between 3G, 4G, and 5G radiation effects and need for separate investigation.
• occupational-exposure (0.5)
  Includes studies of cell phone exposure and experimental exposures relevant to occupational settings.

{
    "study_type": "review",
    "exposure": {
        "band": "RF",
        "source": "cell phone, environmental RFR, GSM signal",
        "frequency_mhz": null,
        "sar_wkg": null,
        "duration": "acute and long-term exposures, including chronic environmental exposure"
    },
    "population": "animals, cells, humans",
    "sample_size": null,
    "outcomes": [
        "neurological effects",
        "morphological changes",
        "chemical changes",
        "electrical changes",
        "behavioral changes",
        "memory deficits",
        "learning deficits",
        "oxidative effects",
        "free radical metabolism changes",
        "brain electric activity changes",
        "nerve cell function changes"
    ],
    "main_findings": "The review summarizes evidence that radio frequency radiation (RFR) exposure affects the nervous system in animals, cells, and humans, including changes in brain electrical activity, nerve cell function, chemistry, and behavior such as memory and learning deficits. Effects have been reported at both high and low exposure levels, sometimes below current international guidelines. Oxidative stress and free radical metabolism alterations are consistent findings. Effects depend on multiple physical properties of RFR and may differ across technologies (e.g., 3G vs 5G). Environmental RFR exposure levels have increased and may affect humans and wildlife, including interference with animal magnetic orientation.",
    "effect_direction": "mixed",
    "limitations": [
        "Many studies lack detailed exposure setup and dosimetry information.",
        "Most studies use exposure levels higher than typical environmental levels.",
        "Differences in species anatomy (e.g., human vs rodent hippocampus) limit direct extrapolation.",
        "Biological effects depend on multiple complex physical properties of RFR, complicating generalization.",
        "Limited studies on effects of newer technologies (4G, 5G)."
    ],
    "evidence_strength": "moderate",
    "confidence": 0.59999999999999997779553950749686919152736663818359375,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "radio frequency radiation",
        "neurological effects",
        "memory",
        "learning",
        "oxidative stress",
        "free radicals",
        "cell phone radiation",
        "environmental exposure",
        "hippocampus",
        "animal studies",
        "human studies"
    ],
    "suggested_hubs": [
        {
            "slug": "5g-policy",
            "weight": 0.6999999999999999555910790149937383830547332763671875,
            "reason": "Discusses differences between 3G, 4G, and 5G radiation effects and need for separate investigation."
        },
        {
            "slug": "occupational-exposure",
            "weight": 0.5,
            "reason": "Includes studies of cell phone exposure and experimental exposures relevant to occupational settings."
        }
    ]
}

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